COMPARISON OF NUTRITIONAL DEFICIENCIES AND COMPLICATIONS FOLLOWING VERTICAL SLEEVE GASTRECTOMY, ROUX-EN-Y GASTRIC BYPASS,

Transcription

1 COMPARISON OF NUTRITIONAL DEFICIENCIES AND COMPLICATIONS FOLLOWING VERTICAL SLEEVE GASTRECTOMY, ROUX-EN-Y GASTRIC BYPASS, AND BILIOPANCREATIC DIVERSION WITH DUODENAL SWITCH Kinsy Miller A Thesis Submitted to the graduate college of Bowling Green State University in partial fulfillment of the requirements for the degree of MASTER OF FAMILY CONSUMER SCIENCE August 2009 Committee: Martha Sue Houston, Advisor Rebecca Pobocik Priscilla Coleman

2 ii ABSTRACT Martha Sue Houston, Advisor Background: The prevalence of morbid obesity continues to increase and bariatric surgery remains the superior way to treat morbid obesity and related disorders. Although bariatric surgery can produce significant weight loss and alleviate comorbidities, it can also impact nutritional status in ways that have not been adequately studied. Objective: The objective of the present study was to compare the incidence of nutritional deficiencies, significant complications, and amount of weight loss in patients undergoing three different bariatric surgery procedures: Vertical Sleeve Gastrectomy (VSG); Roux-en-y Gastric Bypass (RNY-GB); and Biliopancreatic Diversion with Duodenal Switch (BPD-DS). In addition, the role of the registered dietitian (RD) in the outcome of bariatric patients was explored. Design: A review of all patients undergoing bariatric surgery between April 2006 and December 2007 (n = 119) was conducted from prospectively maintained medical records of a single bariatric surgery practice. Laboratory data related to specific nutrients, hyperlipidemia, and anemia, concerns about compliance with nutrient supplement intake and dietary protein intake, and complication and post-surgery hospitalization rates were compared among patients undergoing the three surgical procedures, VSG, RNY-GB, and BPD-DS. Patients were followed for a minimum of 6 months and a maximum of 18 months after surgery. Results: Vitamin B12 and calcium deficiency were uncommon after surgery at 1.2% and 2.6%, respectively, among recipients of all surgery types (p = 0.506, and p = 0.092, respectively). The overall rate of folate deficiency was 7.2% and the rate of BPD-DS patients developing folate deficiency after surgery was 37.5% (p = 0.002). The overall rate of anemia was 33.8% and the

3 iii rate of RNY-GB patients developing anemia following surgery was 50% (p = 0.010). Vitamin D deficiency was markedly high at 66.7% of all patients. All of the BPD-DS patients developed deficiency, which was significantly higher than the other groups (p = 0.003). Protein and vitamin A deficiency were present in 38% and 34.8% of all patients, respectively, but there were no significant differences among surgery types (p = 0.216, and p = 0.141, respectively). Patients who were documented as non-compliant with multivitamin/mineral intake were more likely to develop anemia (p = 0.015) and those who were documented as non-compliant with calcium supplements were more likely to develop vitamin D deficiency (p = 0.022). Weight loss over time among all surgery types was significantly different (p < ). At 12 months after surgery average percent excess body weight loss (EBWL) was 70.9% for BPD-DS, 59.7% for RNY-GB and 40.2% for VSG. There were no significant differences across groups in the risk of developing complications after surgery relative to weight loss (p = 0.079). Lower albumin levels following surgery were correlated with more complications (r = , p = 0.008). RD visits were positively correlated with higher minimum albumin levels (r = 0.24, p=0.025) and greater %EBWL (r = 0.30, p = 0.002). Conclusions: Nutritional deficiencies and anemia occurred as a result of all bariatic surgery procedures, both restrictive (VSG) and malabsorptive procedures (RNY-GB and BPD-DS) in the 18 months post-surgery. The incidence of vitamin D deficiency (66.7%) was particularly concerning. Patient intake of recommended levels of nutrient supplements and dietary protein was poor and was related to some of the nutrient deficiencies and anemia. RD visits were beneficial as more RD visits were related to greater weight loss and higher albumin levels following surgery. Increased RD visits and monitoring of nutritional status, nutrient supplement intake and dietary intake of patients pre and post-bariatric surgery is warranted.

4 iv ACKNOWLEDGMENTS I would like to acknowledge my advisor, Dr. Sue Houston, for all of the hours and work put in to this project. In addition, I would like to acknowledge my thesis committee members Dr. Rebecca Pobocik and Dr. Priscilla Coleman for their time and efforts in putting this thesis together. Finally, a thank you to the Bowling Green State University Statistical Lab for all of their hours devoted to analyzing the data presented in this study.

5 v TABLE OF CONTENTS Page CHAPTER I. INTRODUCTION TO OBESITY... 1 CHAPTER II. LITERATURE REVIEW... 4 Introduction to Bariatric Surgeries... 4 Normal Digestion and Absorption... 7 Nutritional Deficiencies... 8 Comparison of Nutritional Deficiencies Following Bariatric Surgeries STATEMENT OF THE PROBLEM RESEARCH QUESTIONS CHAPTER III. METHODS Nutritional Counseling Indicators of Nutritional Status STATISTCAL METHODS CHAPTER IV. RESULTS CHAPTER V. DISCUSSION REFERENCES

6 vi LIST OF FIGURES/TABLES Figure/Table Page 1 Anatomy of roux-en-y Anatomy of biliopancreatic diversion with duodenal switch Anatomy of vertical sleeve gastrectomy Summary of protein, iron, vitamin B12, calcium, and vitamin D deficiency (% of subjects) following various bariatric surgeries Number of patients undergoing medically supervised weight loss for 3 or 6 months per type of surgery performed Foods included in full and clear liquid diet prior to surgery Vitamin, mineral, and protein recommendations per type of bariatric surgery at 0-1 months and 3 + months post-operatively Protein requirements following bariaric surgery per diet phase Optisource chewable vitamin and mineral supplement Nutrition parameters studied and laboratory data available during the study period a Pre-operative characteristics of subjects by surgery type a Evidence of nutritional deficiencies pre and post-surgery Evidence of iron-related nutritional deficiencies pre-and post-surgery Evidence of cholesterol related abnormalities pre-and post-surgery a,b Documented concerns regarding adequacy of patient intake of multi-vitamin mineral supplements, calcium supplements, vitamin A & D supplements, and protein dietary intake after bariatric surgery... 37

7 vii LIST OF FIGURES/TABLES, CONT. Figure/Table Page 13 Difference in nutritional deficiencies among patients categorized by documented concerns regarding multivitamin mineral supplement and protein intake following bariatric surgery Differences in nutritional deficiencies related to compliance with calcium supplementation Comparison study of weight loss Differences in pounds lost over time among the 3 different surgery types Differences in Percent Excess Body Weight Loss (%EBWL) over time among the 3 different surgery types Complications following bariatric surgery a... 46

8 1 CHAPTER I. INTRODUCTION TO OBESITY Obesity has been linked to almost 300,000 deaths yearly and $117 billion dollars in direct (preventive, diagnostic, and treatment services) and indirect (value of wages lost by people unable to work because of illness and/or disability and premature death) annual healthcare expenditure in the United States alone (1). The direct cost of obesity, defined as a body mass index (BMI) 30 kg/m 2, is estimated to be 39.3 billion dollars per year, which is over 5% of all healthcare costs (2). The prevalence of obesity has been on a steady incline and has more than doubled since 1960; from 13.3 to 32.1 percent of United States adults aged This incline has been prevalent among both genders, all ages, all racial and ethnic groups, all educational levels, and all smoking levels (3). Obesity is divided into three classes: Class I obesity corresponds to a BMI between kg/m 2, class II obesity corresponds to a BMI between kg/m 2, and class III obesity corresponds to a BMI > 40 kg/m 2 (25). The prevalence of hypertension, gallbladder disease, type 2 diabetes, sleep apnea, heart disease, and osteoarthritis, increases exponentially from class I to class III obesity (2). Morbid obesity of all classes is also associated with dyslipidemia, complications of pregnancy, menstrual irregularities, hirsutism, stress incontinence, and psychological disorders such as depression (1). Most studies show mortality rate is increased by 10-50% in obese individuals compared with individuals in a healthy weight range (BMI = kg/m 2 ). This relates to an extra 112,000 deaths per year relative to healthy weight individuals (4). The primary goals of treatment for morbid obesity are to control co-morbidities, symptoms, complaints, and to minimize psychosocial adverse effects through weight reduction (5). Unfortunately, conservative medical treatments such as dietary regimens, behavioral

9 2 modifications, and exercise have largely been unsuccessful in achieving and maintaining long term weight loss results. Even medical therapy remains greatly limited by the unfavorable side effects of the drugs and their inability to result in significant weight loss over the long term (6). Considering these limitations, bariatric surgery is the only current treatment modality that results in maintained weight-loss and control of medical co-morbidities that are related to morbid obesity (5). Morbid obesity is defined as having a BMI greater than or equal to 40 kg/m 2. Bariatric surgery is a collective term that describes operations that reduce the size of the gastric reservoir with or without a malabsorptive component. Bariatric surgery was first introduced to the United States in the 1950 s (6). There has been extensive evolution of bariatric surgery since that time, but two main principles still exist in combination or on their own. These are restriction and malabsorption. Purely restrictive surgeries include vertical banded gastroplasty (VBG), gastric banding, and vertical sleeve gastrectomy (VSG). Malabsorptive procedures include roux-en-y gastric bypass and biliopancreatic diversion with or without duodenal switch (6). Some of the more common procedures that will be discussed further are the roux-en-y gastric bypass (RNY-GB), biliopancreatic diversion with duodenal switch (BPD-DS). The VSG will also be discussed further although still considered an investigational procedure. Although successful in producing weight loss, these surgeries have been shown to result in a number of nutritional deficiencies. RNY-GB and BPD-DS have been shown to cause vitamin B12, iron, and folate deficiencies. In addition, BPD-DS has also been shown to cause malabsorption of fat-soluble vitamins A, D, E, and K, zinc, and essential fatty acids (8). Currently, there is very limited research on nutritional deficiencies resulting from VSG. However, it is thought that restrictive procedures, specifically the vertical banded gastroplasty (VBG), which is similar in nature to the VSG, may result in nutrient deficiencies related to

10 decreased intake and avoidance of nutrient-dense foods secondary to intolerances (13). 3

11 4 CHAPTER II. LITERATURE REVIEW Introduction to Bariatric Surgeries Bariatric procedures are divided into one of three categories: restrictive, malabsorptive, or combination. Restrictive procedures are called such because the surgeon creates a small gastric pouch with a narrow outlet that restricts the amount of food a patient can eat at one time. Three common restrictive procedures are performed, VBG, Laparoscopic adjustable gastric banding (LAGB), and VSG (7). Malabsorptive procedures bypass a portion of the small intestine so that less food is absorbed. Combination procedures have both malabsorptive and restrictive components. The BPD-DS is a malabsorptive procedure in which the mixing of gastric and pancreatic enzymes with bile is delayed until the final cm of the ileum. The combination procedure most commonly used is RNY-GB. This uses both a restrictive and a malabsorptive component to result in weight loss. Forming a ml gastric pouch restricts the intake of food while a small portion ( cm) of the small intestine is re-routed. This re-routing results in less absorption as this segment bypasses the distal stomach, duodenum, and a short segment of the jejunum (7). Roux-en-y Gastric Bypass RNY-GB consists of a small gastric pouch about 20 ml constructed by stapling the proximal stomach in size with a stomal outlet of about 1 cm in diameter. The length of the roux-en-y limb varies between cm in length (6). Figure 1. Anatomy of roux-en-y Figure 1. depicts changes made to the stomach and intestines

12 5 during the RNY-GB procedure. Standard RNY-GB is known to cause vitamin B12, iron, and folate deficiencies (8). However, it is also known to be the gold standard bariatric procedure in the United States coming into existence in the 1960 s and currently being the most commonly performed procedure. This has allowed for extensive study of the efficacy of the RNY-GB. RNY-GB results in a long-term weight loss of 49-80% of initial excess body weight (IEBW) and an acceptably low mortality rate less than 1.5%; long-term success was measured in 274 RNY-GB patients where 53% of the super obese patients were able to drop to a BMI of 35 kg/m 2 or less over 5 years (9). General complications with the RNY-GB include anastomotic ulceration and stenosis, hemorrhage, and anastomotic leak leading to peritonitis, internal hernias, staple line disruption, and acute gastric distention (6). Biliopancreatic Diversion with Duodenal Switch BPD-DS has two components. The first component is a limited vertical gastrectomy and the second is a transection of the small intestine approximately 250 cm from the ileocecal valve. The small intestine is then attached at the distal end just below the duodenum, which is preserved on the vertical gastric pouch. The proximal end of the intestine is subsequently attached near the ileocecal valve (6). Figure 2. depicts changes Figure 2. Anatomy of biliopancreatic diversion with duodenal switch made to the stomach and intestines during the BPD-DS procedure. This long limb bypass procedure is a more aggressive form of bariatric surgery because of restricting intake and inducing weight loss by fat malabsorption. Therefore, in addition to vitamin B12, iron, and folate deficiencies, this type of procedure may also affect absorption of fat-soluble

13 6 vitamins A, D, E, and K, zinc, and essential fatty acids (8). Although not as common as the RNY-GB, the BPD-DS procedure has been performed since the mid 1970 s in Italy and made its debut in the United States in Expected weight loss ranges from 73-80% of initial excess body weight (IEBW) and its mortality rate is similar to roux-en-y, 0.5% - 1.9%. A review of long-term results (9 months to over 10 years) was conducted in 987 patients with a mean BMI of 51 kg/m 2. Satisfactory weight loss of more than 50% of IEBW was observed in 99.3% of patients (9). A study of 170 patients receiving the BPD-DS, showed that only 28% of ingested fat is absorbed after surgery, which aided in the 78.1% of excess body weight loss seen in these patients (8). One of the most serious potential nutrition complications is protein malnutrition, resulting in only 57% absorption of ingested protein as a result of intestinal bypass. This protein malabsorption is associated with hypoalbuminemia, anemia, edema, ascites, and alopecia (6). Vertical Sleeve Gastrectomy The frequency of performing VSG has increased significantly over the past 15 years. It is a purely restrictive procedure involving a gastrectomy of the entire greater curvature of the stomach leaving in place a ml gastric tube along the lesser curvature of the stomach (10). Figure 3. depicts changes made to the stomach during the VSG procedure. This surgery was initially invented for use as the first part of the duodenal switch procedure in patients with a BMI over 60 kg/m 2 because of shorter operating time Figure 3. Anatomy of vertical sleeve gastrectomy and no anastomoses (11). The restriction works to reduce the size of the stomach and its distention so the patient feels full

14 7 sooner. Current research has targeted the role of grehlin in weight loss after the VSG. Grehlin is known as the hunger hormone and is predominately secreted in the gastric fundus, which is resected as part of this procedure. Increased satiety from decreased ghrelin production has shown to further trigger increased satiety after surgery (12). Langer, et al found that resection of the fundus after the VSG resulted in lower grehlin levels than after the RNY-GB and VBG. The decrease in grehlin production remained stable up to six months post-operatively. This may explain greater weight loss seen in the VSG than in other purely restrictive procedures (13). The advantages of this type of procedure are that with the preservation of the pyloric sphincter, dumping syndrome is much less common, it does not result in malabsorption, and it can be used in patients with severe anemia and Crohn s disease since the intestinal bypass is not done (12). The disadvantages according to Frezza (12) are its irreversibility and risk of stapling complications. A study by Lee et al (11) looked at two-year follow up data after vertical gastrectomy in 216 patients with a mean BMI of kg/m2. A ml gastric tube was created and results compared with RYGB, LAGB, and DS. Weight loss was on par with the DS and RYGB procedures after just the VSG alone. Complications occurred in 6.3% of patients versus 7.1% of patients after Lap-band. No conversions to open procedures or deaths occurred (11). Normal Digestion and Absorption The primary role of the stomach is to mechanically process food and to regulate the rate that food passes from the stomach into the small intestine. An intact stomach is not necessary for adequate nutrition, as little absorption takes place there (only water and alcohol are absorbed directly through the gastric lining). Nutrients are absorbed throughout the duodenum, jejunum, and ileum, but the greatest absorption takes place in the middle portion of the small intestine.

15 8 Carbohydrates are absorbed primarily in the duodenum and jejunum, fats in the jejunum, and protein in the jejunum and upper ileum. Minerals such as calcium, iron, and magnesium are predominantly absorbed in the duodenum and fat-soluble vitamins are absorbed mostly in the lower duodenum and upper jejunum. Finally, water-soluble vitamins are absorbed in the jejunum and upper ileum (except for B12 which is absorbed in the lower ileum). Therefore, loss of function in any part of the small intestine impacts absorption and nutrient status (2). Nutrient deficiencies appear to be more substantial after malabsorptive procedures such as the RNY-GB and BPD-DS, but they do occur after restrictive procedures such as the VSG and VBG (14). It is postulated that further deficiency in some nutrients result from decreased intake and a tendency to avoid nutrient-dense foods post-operatively because of intolerances. Bloomberg et al s review (14) presents risk and prevalence of protein deficiency, iron deficiency, vitamin B12 and folate deficiency, calcium and vitamin D deficiency, thiamine deficiency, and deficiency of the other fat soluble vitamins A, E, and K with bariatric surgery. These specific nutrient deficiencies are discussed in detail below. Nutritional Deficiencies Protein and Iron Deficiency Protein deficiency can manifest as hypoalbuminemia, anemia, edema, asthenia, and alopecia. It is commonly caused from excessive malabsorption after bypassing segments of the small intestine where protein is primarily absorbed (14). It may also be related to food limitation and intolerances of high protein foods after surgery. Iron deficiency has been found after both restrictive and malabsorptive procedures partly due to bypass of the primary site of absorption in the duodenum and proximal jejunum and related to chronic sources of bleeding such as menstruation or stomal ulceration (14, 16).

16 9 Vitamin B12 Deficiency Vitamin B12 has a complex nature of absorption, which is affected by several facets of restrictive and malabsorptive procedures. First of all, Vitamin B12 must be unbound from food via an acidic gastric environment. Partial gastrectomy greatly reduces the production of stomach acid (21) making it difficult to free B12 from food. Secondly, B12 must bind to intrinsic factor (IF), produced by the stomach, to be absorbed by the body. Marcuard (15) found that IF was no longer found in gastric juices beyond the bypassed gastric pouch. It is therefore postulated the pathogenesis for vitamin B12 deficiency is the inadequate secretion of IF. Finally, the site of B12 absorption into the body is through the terminal ileum, which may be bypassed depending on the length of circumvented intestine. This may exacerbate B12 deficiency in RNY-GB or BPYD-DS patients (22). Vitamin B12 deficiency was found in 36% of patients after gastric bypass at a mean of 22 months postoperatively (14, 15). A dose of 350 ug of B12 was needed to maintain a normal serum level above 150 pmol/l (10). Purely restrictive procedures may not produce the same findings in rate of vitamin B12 and folate deficiency. Patients with the VBG procedure received 350 ug of vitamin B12 for 5 months after surgery and it was found there was no deficiency in B12 or folate, although the mean value for folate fell significantly by 12 months postoperatively (14, 16). Calcium and Vitamin D Deficiency Calcium and Vitamin D deficiency are common after surgery secondary to the bypass of the duodenum and upper jejunum, which are the primary sites of absorption for calcium, and the jejunum and ileum, which are the primary sites of absorption for Vitamin D. Even a relative lack of calcium results in increased production of parathyroid hormone (PTH), which signals a release of calcium from bones increasing the risk of osteoporosis (14). Chapin et al (17) found that

17 10 calcium and vitamin D deficiency occur more often in malabsorptive procedures than in purely restrictive procedures. In a comparison between a group of patients receiving BPD and VBG, the BPD group had significantly lower serum calcium, 25-hydroxyvitamin D, urine calcium excretion, and higher PTH, alkaline phosphatase, and urinary hydroxyproline/creatinine ratios, which is related to higher bone turnover (14, 17). Table 1 summarizes the frequency of protein, iron, vitamin B12, calcium, and vitamin D deficiency found in the above studies. Thiamin Deficiency The risk of thiamine deficiency is a result of reduced intake, frequent vomiting, and malabsorption after bypass of the proximal small intestine. The small intestine is the primary site of absorption for thiamine. However, in a study conducted by Chang et al (2004) 168,010 bariatric patients were followed and the incidence of thiamine deficiency was found to be very low at % (14, 18). Table 1. Summary of protein, iron, vitamin B12, calcium, and vitamin D deficiency (% of subjects) following various bariatric surgeries Study/year Operation/ follow up N % Protein % Iron %Vit B12 %Ca 2+ /Vit deficiency deficiency deficiency D deficiency Brolin et al/2002 RYGB/2 yr yrs 10/51 Skroubis et al/ RYGB/1 yr yrs 2002 Distal RYGB/1 yr 3 25 Kalfarentzos et RYGB/20 mo al/1999 Distal RYGB/20 mo Brolin et al/1992 RYGB/ 43 mo 45 0 Dolan et al/2004 BPD/ BPD-DS/ 28 mo /50 Rabkin et BPD-DS/ 3 yrs al/2004 Skroubis et BPD/ 2 yrs yrs al/2002 Nanni et al/1997 BPD Marceau et BPD/ 79 mo al/1995 Kalfarentzos et VBG/ 4 yrs 32 al/2001 Cooper et VBG/ 1 yr al/1999 Brolin et al/1991 RYGB/ 2 yr Slater et al/2004 BPD/ 4 yr /63 BPD/ 32 mo /50 Newbury et al/2003

18 11 Study/year Operation/ follow up N % Protein deficiency % Iron deficiency %Vit B12 deficiency %Ca 2+ /Vit D deficiency Hamoui et al/2003 BPD-DS/ 9-18 mo /17 Adapted from: Bloomberg, et al 2005 (14) Fat Soluble Vitamin Deficiency Fat-soluble vitamin deficiencies are common after bariatric surgery because the site of absorption (the ileum) is bypassed causing the uptake of fat-soluble vitamins to be restricted to the common channel of the BPD (where the alimentary limb is connected to the biliopancreatic limb) (14). Sixty-one percent of patients became deficient in vitamin A at 28 months after BPD with or without duodenal switch. This high rate of deficiency was found even after an 80% compliance rate with multivitamin supplementation (19). Vitamin E deficiency is uncommon and has not yet been shown to be of clinical significance in patients who are non-compliant with multivitamin supplementation after bariatric surgery (14). There have been few clinical studies researching vitamin K deficiency after bariatric surgery, but the studies that have been done show high rates of deficiency following BPD surgery (50% of BPD patients at 37 months postop and 50% of BPD-DS patients after 23 months post-op) (19). Comparison of Nutritional Deficiencies Following Bariatric Surgeries In a large-scale review, the only significant difference in nutritional deficiencies between groups receiving the RYGB and the BPD were that ferritin deficiency occurred in 37.7% of patients after RYGB and in 15.2% of patients receiving BPD (p = 0.029) (20). One patient receiving RNY-GB and two receiving BPD had albumin levels below 3 g/dl and required total parenteral nutrition for three weeks to correct this deficiency. Furthermore, the two most common deficiencies found were iron and B12. B12 deficiency was estimated to occur at 10.7 months post-operatively in those receiving RYGB and 7.9 months following BPD if no

19 12 supplementation was given. Iron deficiency appears to be a result of malabsorption of ingested iron due to bypass of the duodenum. Iron, folic acid, and B12 deficiency can result in anemia, the most common nutritional complication in this patient population (21). The incidence of deficiencies increased over time in both groups, except for folate, which showed no deficiency. Many patients experienced iron deficiency and anemia, especially menstruating women after gastric bypass surgery. All patients should take a multivitamin containing B12 and folate, along with a calcium supplement according to this review (21). A study by Slater et al (8) compared the rate of fat soluble vitamin deficiency in patients receiving BPD and the results showed the following incidences of deficiency: 69% vitamin A, 68% vitamin K, and 63% vitamin D at four years post-operatively. Vitamin E and zinc deficiency were not shown to increase with time after surgery. Calcium deficiency was shown to increase from 15% to 48% over the four-year study period with an increase in serum parathyroid hormone in 69% of patients at that time. Deficient vitamin A, D, and K values along with calcium and secondary hyperparathyroidism all increased in incidence over time (21). The documentation of nutritional deficiencies following bariatric procedures has become more prevalent over the past few years. However, many of these deficiencies deserve a closer look, especially following some of the newer restrictive procedures, such as the VSG. This paper will serve to explore the risk of nutritional deficiencies following the combination procedures RNY-GB and BPD-DS and the restrictive procedure VSG.

20 13 STATEMENT OF THE PROBLEM Obesity is linked with hundreds of thousands of deaths and billions of dollars in healthcare expenses every year (1). Obesity is also increasing in prevalence exponentially with an increased risk of co-morbidities as weight increases (2,3). Current methods of treating obesity are aimed at preventing and controlling these co-morbidities, but unfortunately conservative medical treatments have been largely unsuccessful (5,6). Bariatric surgery is currently the only treatment modality that results in maintained weight-loss and control of obesity related comorbidities (5). However, a well-documented side effect of bariatric surgery is an increased risk of nutritional deficiencies including protein, iron, folate, B12, calcium, and vitamins A and D (8). The purpose of this study is to investigate and compare potential nutritional deficiencies and complications after RNY-GB, VSG, and BPD-DS. An additional aim is to examine if the surgery with the greatest amount of weight loss also resulted in the greatest prevalence of nutritional deficiencies. It is expected that the surgeries resulting in the most malabsorption will also result in the highest prevalence of nutritional deficiencies. Finally, we will evaluate the role of the registered dietitian (RD) in the care of bariatric patients and look into whether documented concern over vitamin, mineral, and/or nutrient intake is associated with complications following bariatric surgery.

21 14 RESEARCH QUESTIONS 1) Are there differences in the evidence of protein, vitamin A, vitamin B12, folate, calcium, vitamin D, or thiamin deficiencies and anemia among subjects receiving the RNY-GB, BPD-DS, and VSG procedures? 2) Are documented concerns about nutrient intake during the year post-surgery related to abnormal laboratory indices of vitamin, mineral, and protein status? 3) Are there differences in weight loss among patients receiving the RNY-GB, BPD-DS, or VSG procedures? 4) Are there differences in the incidence of serious complications requiring hospitalization among patients receiving the RNY-GB, BPD-DS, or VSG procedures? 5) Are there relationships among nutritional deficiencies, the amount of weight loss, and incidence of serious complications?

22 15 CHAPTER III. METHODS The Advanced Laparoscopic Bariatric Surgical Associates (ALBSA) was established in April 2006 at the Center for Weight Loss Surgery in Bowling Green, Ohio. From their established date through December 2007, 180 morbidly obese adult patients have undergone various bariatric procedures at the institution. This surgical group is one of seven in the greater Toledo, Ohio area, but the only group who offers four different laparoscopic procedures (VSG, LAGB, RNY-GB, and BPD-DS). The present study analyzing this patient population was approved by the Bowling Green State University Human Subjects Review Board # H08T032GE5. A retrospective review of all consecutive patients (n = 119) undergoing bariatric surgery between April 2006 and December 2007 was conducted from prospectively maintained medical records. Charts were excluded for less than 6-month minimum post-operative period and incomplete data; all other patient records were included for the study. From this database of medical records, the nutrient statuses of patients receiving RNY-GB, VSG, or BPD-DS were compared retrospectively. These three bariatric procedures have made up the majority of surgeries performed through ALBSA (RNY-GB 49%, VSG 39%, BPD-DS 12%). All patients were assessed pre-operatively using a multidisciplinary approach (bariatric surgeon, dietitian, psychologist, and internist) in order to select the most favorable type of bariatric procedure and to ensure an optimal physical condition prior to surgery. The selection criteria for the type of bariatric procedure to be performed were the patient s preoperative BMI, personal dietary habits, pre-existing co-morbidities, and what type of surgery individual insurance policies would approve. If the BMI was > 50 with significant co-morbidities and poor dietary habits, BPD-DS was most often recommended. If the BMI was with significant co-morbidities, and poor

23 16 dietary habits, RNYBG was most often recommended. If the BMI was with or without comorbidities, and with good dietary habits, VSG was most often recommended. Nutrition Counseling The registered dietitian s (RD s) role at the Center for Weight Loss Surgery is multifactorial. The RD began interaction with many potential bariatric patients 3-6 months prior to surgery for the purpose of providing nutritional counseling. A medically supervised weight loss (MSWL) program prior to surgery is a requirement of most insurance companies. Table 2 shows the breakdown of patients participating in the MSWL program per type of surgery received. MSWL visits consisted of a one-on-one oral interview and question and answer format with the dietitian. These visits normally lasted minutes. During this time, patients worked on forming dietary, exercise, and lifestyle behavior changes that are helpful in promoting weight loss and avoiding complications after surgery. The RD and patient developed goals at the conclusion of each monthly visit based on individual needs and focused on making positive lifestyle changes. Table 2. Number of patients undergoing medically supervised weight loss for 3 or 6 months per type of surgery performed Surgery Type Length of Medically Supervised Weight Loss Program Prior to Surgery RNY-GB VSG BPD-DS n 3 months (4 total visits) months (7 total visits) All patients met with an RD for an initial bariatric nutrition assessment in which information regarding diet recommendations and requirements before and after surgery was reviewed. This visit normally lasted minutes. All patients were also seen for a preoperative visit 2-3 weeks prior to surgery. The pre-operative visit normally lasted for 15-30

24 17 minutes. The initial bariatric nutrition assessment and pre-operative visit were also set up as a one-on-one oral interviews and question and answer format with the dietitian. At the time of the pre-operative visit, patients were instructed to start a bariatric full liquid diet two weeks before surgery and to start a bariatric clear liquid diet two days prior to their date of surgery. The purpose of this diet was to reduce the size of the liver and to encourage weight loss prior to surgery in order to minimize risk factors during operation. The foods included as part of the full liquid and clear liquid diets are listed in Table 3. Table 3. Foods included in full and clear liquid diet prior to surgery Full Liquid Diet Clear Liquid Diet Pureed soups Sugar-free popsicles Sugar free pudding Fruit2O Skim/soy milk Crystal light No sugar added low fat yogurt Water Diet V8 splash Sugar-free beverages Cream of wheat/rice cereal Ice chips Vegetable juice Sugar-free gelatin High protein drink All patients received similar instructions at assessment for required multivitamin/mineral supplementation and recommended protein intake after surgery, avoidance of alcohol for the first 18 months after surgery, and recommended diet progression after surgery. Table 4 lists vitamin, mineral, and protein recommendations and how they differ per type of bariatric surgery. Table 4. Vitamin, mineral, and protein recommendations per type of bariatric surgery at 0-1 months and 3 + months post-operatively RNY-GB VSG BPD-DS Supplement 0-1 months 3 + months 0-1 months 3 + months 0-1 months 3 + months Optisource 4 tablets 4 tablets 4 tablets 2 tablets 4 tablets 4 tablets Multivitamin Calcium 1000mg Calcium carbonate 1000mg Calcium citrate 1000mg Calcium carbonate 1000mg Calcium citrate 1000mg Calcium carbonate 1000mg Calcium citrate Allergy A&D 1 tablet 1 tablet 0 tablets 0 tablets 3 tablets 3 tablets Protein grams grams grams grams grams grams

25 18 During their hospital stay all patients were directed to start their multivitamin/mineral supplementation beginning one week after their surgery date. For their first post-operative week all patients were given the protein goal of grams per day through the use of protein supplements/drinks. Patients were instructed to advance their diet to full liquids from clear liquids at one week after post-surgery. The amount of protein intake recommended for the remainder of the post-operative period was dependent on the phase of diet and type of bariatric procedure performed. The following table lists the protein requirements after surgery. Table 5. Protein requirements following bariatric surgery per diet phase Clear Liquid Full Liquid Soft/Pureed Maintenance Surgery Type (grams) VSG RYN-GB BPD-DS The multivitamin recommended by the dietitian was Optisource by Resource (Novartis Medical Nutrition, Fremont). The following chart lists the multivitamin and mineral makeup of Optisource. Patients were instructed to take four Optisource multivitamins spaced throughout the day except for patients receiving the VSG. These patients were instructed to cut back to two Optisource multivitamins per day starting three months after surgery. Table 6. Optisource chewable vitamin and mineral supplement Nutrient Unit Amount Per Tablet (2.8 g) % Daily Value a Energy kcal 5 Total Carbohydrate g 1 < 1 Sugars g 1 Vitamin A IU Vitamin C mg Vitamin D IU Vitamin K mcg Thiamin mcg Riboflavin mcg Niacin mg 5 25 Vitamin B 6 mcg Folic Acid mcg Vitamin B 12 mcg Biotin mcg Pantothenic Acid mg

26 19 Nutrient Unit Amount Per Tablet (2.8 g) % Daily Value a Calcium mg Iron mg Phosphorus mg 50 5 Iodine mcg Magnesium mg Zinc mg Selenium mcg Copper mg Manganese mg Chromium mcg Molybdenum mcg Sodium mg 5 < 1 a % Daily Value -the percentage of the recommended daily amounts of a nutrient you get from 1 serving. For the purposes of food labels, the government chose an "average" person as someone who needs 2,000 calories a day. If patients chose not to use this particular type of multivitamin they were encouraged to find a multivitamin comparable in iron, vitamin B12, and thiamin content and one that was chewable for at least the first 3 months after surgery. Additional fat-soluble vitamins were recommended for patients undergoing the bypass procedures (RNY-GB and BPD-DS). The type of fat-soluble vitamin recommended was Allergy A & D (Twinlab, American Fork). This fatsoluble multivitamin contains 10,000 IU of vitamin A from retinyl acetate and 400 IU of vitamin cholecalciferol (D3). All patients were recommended to supplement with 1000 mg of calcium after surgery. Calcium carbonate was acceptable for the first 3 months after surgery because it was more available in a chewable form. Long-term a calcium citrate form of calcium supplement was recommended secondary to better absorption. Additional vitamins/minerals (Fe, Ca, B12, etc.) were recommended if lab values drawn after surgery were below normal. Prophylatic ursodeoxycholic acid and pantoprazole were also prescribed routinely after surgery. Ursodeoxycholic acid was prescribed to help prevent gallstones and pantoprazole was prescribed to limit the production of stomach acid after surgery. An RD and surgeon and/or physician s assistant saw all patients at 1 week, 1 month, and 3 months post-operatively. Additionally, the surgeon and/or physician s assistant saw all patients

27 20 at 6, 12, and 18 months, and then yearly post-operatively. The RD saw patients at these times only if recommended by the surgeon and/or physician s assistant. During post-operative visits the registered dietitian reviewed the amount of protein, fluids, and vitamin/mineral supplementation intake as well as recommended levels of each of these nutrients. Indicators of Nutritional Status Several nutrition parameters were measured and used to identify nutritional deficiencies before and after bariatric surgery. Each patient was required to get blood work drawn within a year prior to his or her surgery date. Most patients chose to get their blood drawn at Wood County Hospital, although a few patients did receive their lab work from other area hospitals/healthcare facilities. After surgery, patients typically received orders for blood to be drawn within the first 3 months post-surgery. After this time blood work was usually ordered at 6-month increments until 18 months. After 18 months blood work was ordered on a yearly basis. Laboratory indices from blood work were stored in patient s charts located in ALBSA offices for review by healthcare professionals. The following chart (Table 7) lists the nutritional parameters that were compared in this study. Table 7. Nutritional parameters studied and laboratory data available during the study period. a Post-Surgery Nutrition Parameters Pre b Surgery month months months months months months n Vitamin B Hydroxy Vitamin D (D1) ,25 Dihydroxy Vitamin D 3 (D2) Vitamin A Albumin Hemoglobin Hematocrit Mean Corpuscular Volume (MCV)

28 21 Post-Surgery Nutrition Parameters Pre b Surgery month months months months months months Total Cholesterol Potassium Calcium Folate Transferrin Total Iron Binding Capacity (TIBC) Transferrin Saturation Ferritin High Density Lipoprotein (HDL) Low Density Lipoprotein (LDL) Phosphorous Thiamin a Counts of subjects with available laboratory data at various times. b Count of subjects with at least one laboratory value available during the 3-18 month postsurgery period. These nutrition parameters were recorded from each patients chart whenever available and entered into Statistical Analysis System (SAS, edition 9.1, Cary, North Carolina) to be compared at the following time intervals: pre-operatively, 3, 6, 12, and 18 months postoperatively. Using statistical analysis, the average and minimum values of the above nutrition parameters were used to determine the incidence of nutritional deficiencies among the three different surgery groups; patients who received RNY-GB, patients who received BPD-DS, and patients who received VSG. Additional information was also collected from patient s charts. Serious complications requiring additional hospitalization was recorded and compared to determine differences between the three types of bariatric procedures. The reasons for hospitalizations and the care plan during the hospital stay were also noted to determine if there were commonalities. Demographic data including weight, height, age, and gender were recorded and controlled for. Percent excess weight loss and total weight loss at the above intervals were also compared

29 22 among the three different surgery groups. Finally the use of multivitamin compliance after surgery was compared in addition to compliance with protein recommendations after surgery. The patient and healthcare provider discussed multivitamin and protein intake during the oral interview at the post-operative visits and this information was recorded in the patient s chart. For the purpose of this study, compliance with multivitamin and protein intake was determined by recording if there was documented concern within the patient s chart by the surgeon, physician s assistant, or RD. Documentation of concern was recorded using a quantitative scale: 0 refers to no concern over multivitamin or protein compliance, 1 refers to some concern over multivitamin or protein compliance, and 2 refers to not being compliant with multivitamin or protein requirements.

30 23 STATISTICAL METHODS The Statistical Analysis System (SAS, Cary North Carolina, edition 9.1) was utilized to analyze the data. Differences among surgeries were tested using analysis of variance (ANOVA) for continuous variables, and Chi Square for nominal data. Repeated measures analysis of variance was used to analyze the effects of time and surgery. Relationships among variables were tested with Pearson s Correlation Coefficients and linear regression models determined by stepwise regression procedures. Nutritional parameter values are compared within one year preoperatively and post operatively at approximately 3-month intervals between the groups. Fisher s exact test for the investigation of differences in proportion (incidence of deficiency) was used to analyze variables. All reported P-values were two-tailed and significant at a level of p 0.05.

31 24 CHAPTER IV. RESULTS A total of 119 procedures were performed over the 15-month study period (59 VSG, 52 RNY-GB, and 8 BPD-DS). Pre-operative characteristics are shown in Table 5. Mean ages were 45.6 years for VSG and BPD-DS and 43.9 years for RNY-GB. Mean age for the entire patient population was Mean weight was pounds, and mean BMI was BPD-DS patients had a higher admission BMI than the other groups (47.7 for VSG, 49 for RNY-GB, and 53.2 for BPD-DS) although initial pre-operative weight was not significantly different among surgery types. Table 8. Pre-operative characteristics of subjects by surgery type a VSG (n=59) RNY-GB (n=52) BPD-DS (n=8) Characteristic Age (y) Mean + SD Range Admission BMI Mean + SD Range Gender, (%) Male Female a VSG, Vertical Sleeve Gastrectomy; RNY-GB, Roux-en-y Gastric Bypass; BPD-DS, Biliopancreatic Diversion with Duodenal Switch. The majority of patients receiving the VSG or RNY-GB were female (81.3% and 84.6%, respectively) where only half of the patients receiving the BPD-DS were female. However, gender was not significantly different between surgeries (p = 0.069). This could be related to the small number of patient s receiving the BPD-DS procedure. All operations were primary except for two that were revisions from VBG. One VBG was revised to VSG and the other was revised to RNY-GB. There was one conversion from laparoscopic to open procedure, which occurred in the BPD-DS group. The first stage procedure, which is equivalent to a VSG, was done when there were excess adhesions or when the patient was too high a risk to be under anesthesia for the

32 25 length of the entire PBD-DS procedure. One patient who was scheduled for RNY-GB and four patients scheduled for BPD-DS only had the first stage procedure. One patient who received VSG and one who received RNY-GB were recommended for revisions by the surgeon secondary to inadequate weight loss/weight regain after surgery. All patients included in the study were a minimum of six months post surgery. An average of 66% of patients completed their six-month post-op visit (64% VSG, 65% RNY-GB, and 87.5% BPD-DS) and 84.2% of eligible patients completed their 12-month follow up visit (80.8% VSG, 88% RNY-GB, and 83% BPD-DS). Finally, 37% of eligible patients completed their 18-month follow up visit (40% VSG, 23% RNY-GB, and 75% BPD-DS). The findings for laboratory values pre-operatively, up to 1 month post-operatively and 3-18 months postoperatively are compiled in Table 6. The post-operative time frame is split into 0-1 months post-surgery and 3-18 months post- surgery to control for the influence of the actual operation on laboratory values in the immediate post-operative period because many of these laboratory values could be influenced by the surgery itself. Research Question 1: Are there differences in the evidence of protein, vitamin A, vitamin B12, folate, calcium, vitamin D, or thiamin deficiencies and anemia among subjects receiving the RNY-GB, BPD-DS, and VSG procedures? The following table (Table 9) lists the normal reference range, the average range post surgery and the percent of abnormal reference ranges within three time periods for several different nutrition parameters. The three time periods were pre-surgery, 0-1 months postsurgery, and 3-18 months post surgery. The percent of abnormal reference ranges were used to identify nutrition deficiencies.

33 26 Table 9. Evidence of nutritional deficiencies pre and post surgery Normal Reference Range Average Post-surgery 3-18 mo** Pre-surgery Incidence of Abnormal Value, % (n) Post-surgery 0-1 month Calcium, mg/dl Below Normal Post-surgery 3-18 months All Surgeries (0/112) 5.6 (5/89) 2.6 (2/78) VSG a 0 (0/53) 7.0 (3/43) 0 (0/35) RYN-GB a 0 (0/51) 2.5 (1/40) 2.8 (1/36) BPD-DS b 0 (0/8) 16.7 (1/6) 14.3 (1/7) p N/A Phosphorus, mg/dl Below Normal All Surgeries (2/90) 14.6 (7/48) 4.4 (3/69) VSG (1/44) 15.8 (3/9) 0 (0/29) RYN-GB (1/40) 16.0 (4/25) 3.1 (1/32) BPD-DS (0/6) 0 (0/4) 25.0 (2/8) p Potassium, meq/l Below Normal All Surgeries (10/116) 21.4 (19/89) 16.7 (13/78) VSG (6/57) 23.3 (10/43) 17.1 (6/35) RYN-GB (4/51) 12.5 (5/40) 11.4 (4/35) BPD-DS (0/8) 66.7 (4/6) 37.5 (3/8) p Vitamin B12, pg/ml Below Normal All Surgeries (2/56) N/A 1.2 (1/70) VSG (0/28) N/A 3.3 (1/30) RYN-GB (2/23) N/A 0 (0/33) BPD-DS (0/5) N/A 0 (0/7) p Folate, ng/ml > 5.2 Below Normal All Surgeries (1/19) N/A 7.4 (5/68) VSG (1/11) N/A 4.0 (1/25) RYN-GB (0/6) N/A 2.9 (1/35) BPD-DS (0/2) N/A 37.5 (3/8) p N/A 0.002

34 Dihydroxy Vitamin D pg/ml Normal Reference Range <30 <20 All Surgeries Albumin, mg/dl Average Post-surgery 3-18 mo** Pre-surgery Incidence of Abnormal Value, % (n) Post-surgery 0-1 month Mild Deficiency Moderate Deficiency 33.3 (6/18) 50 (9/18) N/A VSG a N/A N/A RYN-GB a N/A N/A BPD-DS b N/A N/A Post-surgery 3-18 months 43.1 (29/66) 23.1 (15/66) 37.0 (11/28) 25.9 (7/28) 53.1 (17/32) 9.4 (3/32) 16.7 (1/6) 83.3 (5/6) p < 2.5 Mild Deficiency Moderate Deficiency Severe Deficiency All Surgeries (17/111) 40.4 (23/57) VSG (8/53) 40.7 (11/27) RYN-GB (9/51) 40.0 (10/25) BPD-DS (0/7) 40.0 (2/5) 28.3 (26/92) 7.6 (7/92) 2.2 (2/92) 20.4 (9/44) 4.6 (2/44) 2.3 (1/44) 30 (12/40) 10 (4/40) 2.5 (1/40) 62.5 (5/8) 12.5 (1/8) 0 (0/8) p Total Cholesterol, mg/dl < 140 Below Normal All Surgeries (7/103) 35 (14/40) 27.5 (19/69) VSG (4/49) 46.7 (7/15) 16.7 (5/30) RYN-GB (3/47) 30 (6/20) 22.6 (7/31) BPD-DS (0/7) 20 (1/5) 85.5 (7/8) p Thiamin, ug/dl Below Normal All Surgeries N/A N/A 6.7 (2/30) VSG N/A N/A 0 (0/14) RYN-GB N/A N/A 14.3 (2/14) BPD-DS N/A N/A 0 (0/2) p 0.854