The Link Between Obesity and Diabetes The Rapid Evolution and Positive Results of Bariatric Surgery Michael E. Farkouh, MD, MSc Peter Munk Chair in Multinational Clinical Trials Director, Heart and Stroke Richard Lewar Centre Professor Of Medicine University of Toronto
Obesity Trends* Among U.S. Adults BRFSS, 1990, 2000, 2010 (*BMI 30, or about 30 lbs. overweight for 5 4 person) 1990 2000 2010 No Data <10% 10% 14% 15% 19% 20% 24% 25% 29% 30%
For adults, overweight and obesity ranges are determined by using weight and height to calculate a number called the "body mass index" (BMI). BMI is used because, for most people, it correlates with their amount of body fat. See the following table for an example: BMI Height Weight Range BMI Considered 5' 9" 124 lbs or less Below 18.5 Underweight 125 lbs to 168 lbs 18.5 to 24.9 Healthy weight 169 lbs to 202 lbs 25.0 to 29.9 Overweight 203 lbs or more 30 or higher Obese Other methods of estimating body fat and body fat distribution include measurements of skinfold thickness and waist circumference, calculation of waist-to-hip circumference ratios, and techniques such as ultrasound, computed tomography, and magnetic resonance imaging
Approaches to Obesity Control Obesity requires long-term treatment Weight loss of 0.5-9 kg associated with: 53% reduction in cancer deaths 44% reduction in diabetes associated mortality 20% reduction in total mortality Survival increased 3-4 months for every kg of weight loss Modest, sustainable weight loss can be achieved Gregg EW et al. Ann Intern Med. 2003
The Challenge: Randomized Controlled Trial of Weight-Loss Maintenance Svetky LP et al., JAMA 2008;299:1139
The Mediterranean Pyramid: Is it enough? PREDIMED trial (n=7400) Primary prevention 30% relative risk reduction Bach-Faig et al. Public Health Nutr. 2011
Look AHEAD: Long-term Type 2 Diabetes Lifestyle Intervention Trial (N Engl J Med 2013; 369:145-154)
Look AHEAD CV Outcomes The Look AHEAD Research Group. N Engl J Med 2013;369:145-154.
Bariatric Operative Approaches Restrictive Procedures Vertical banded gastroplasty Gastric banding Gastric Sleeve Combined Procedures Roux-en-Y gastric bypass Biliopancreatic diversion
Incidence of type 2 diabetes Figure in non-diabetic patients undergoing bariatric surgery: a 7-year population-based study 7-year DM rate 4.3 vs. 16.2% UK-wide BMI> or = 30 2167 bariatric vs. 2167 control (matched for age, BMI, A1c, sex, index year) Booth H, et al. The Lancet Diabetes and Endocrinology 2014 SourDOI:10.1016/S2213-8587(14)70214-1)
Bariatric Surgery and CV outcomes: Systematic review of 18 studies with mean follow-up of 58 months Excess weight loss (EWL) 54% Baseline N of subjects contributing 19,021 % Resolution Corrected effect Improvement estimates (95% CI) Hypertension 44.4% 62.5% 0.36 (0.31 to 0.42) Diabetes mellitus 24.0% 73.2% 0.26 (0.21 to 0.31) Hyperlipidaemia 43.6% 65.2% 0.34 (0.28 to 0.40) Baseline Follow-up Blood Pressure (mm Hg) Systolic 140.2 129.6 Diastolic 87.6 80.2 Lipid profile (mg/dl) Total cholesterol 213.6 184.5 LDL 115.5 90.5 Heart. 2012 Dec;98(24):1763-77
Systematic Review & Meta-Analysis T2DM resolved or improved in 87% of patients following bariatric surgery 100% 87% 81% 87% 85% 99% 80% 60% 40% 20% 0% Total Gastric Banding Gastroplasty Gastric Bypass BPD/DS Resolved Resolved or Improved Systematic review & meta-analysis reviewing 621 studies including 135,246 patients Overall, T2DM 87% resolved or improved (78% resolved) for patients after bariatric surgery Buchwald H, Estok R, Farbach K, et al. Weight and Type 2 Diabetes after Bariatric Surgery: Systematic Review and Meta-analysis. Am J Med. 2009;122(3):248-256. Figure adapted from source data. Data included includes 621 studies with 888 treatment arms & 135,246 patients; 103 treatment arms with 3188 patients reported on resolution of diabetes. 12
Mingrone Study HbA1c Levels at 2 Years Mingrone, G, et. al., N Engl J Med 2012; 366:1577-1585 13
STAMPEDE: 3-Year Schauer PR et al. N Engl J Med 2014;370:2002-2013
2006-2013: 43,732 patients undergoing bariatric surgery in Michigan JAMA. 2014;312(9):959-961.
Sjostrom, 16 L et. al. JAMA 2012; 307(1):56-65 Bariatric Surgery Prevents CV Events Are Insulin Levels Better Than BMI in Guiding Bariatric Surgery?
Cohort Of 1600 Obese Patients with Diabetes 56% fewer diabetes prescriptions were filled for bariatric surgery patients 3-year matched cohort analysis covering 1,616 obese patients with diabetes (808 per cohort) Six months post-surgery, only 34% of surgery patients had filled a prescription for diabetes medication in the previous three months, compared to 90% of control patients (p<0.001) This difference is sustained to the end of the study period (three years) Klein S, et al. Obesity. 2011;19:581-587. Figure adapted from study data.
UHC Database: Surgery Data Morbidity & complication rates of laparoscopic bariatric surgery are similar to other laparoscopic general surgery procedures Outcomes of laparoscopic procedures in general surgical operations between 2006 and 2009 Operations N Utilization of laparoscopy LOS* (days) Complications* Mortality * Bariatric surgery 54,885 90.0% 2.3 ± 2.8 6.3% 0.06% Cholecystectomy 54,782 81.4% 3.3 ± 3.8 8.3% 0.18% Antireflux surgery 8,339 79.3% 2.9 ± 4.3 10.7% 0.02% Appendectomy 51,077 71.5% 1.6 ± 1.3 3.5% 0.02% Colectomy 21,761 18.9% 5.6 ± 4.6 21.5% 0.54% Ventral hernia repair 25,885 8.1% 3.2 ± 3.4 14.0% 0.24% Rectal resection 2,392 7.4% 6.9 ± 5.1 25.0% 0.57% * Outcome of laparoscopic operations; LOS: length of stay Source: Nguyen B, Richardson JF, Smith B et al. Utilization of laparoscopy in general surgical operations at academic centers. 2012 ASMBS Abstracts. PL-106. 18
Long-term Outcomes of Bariatric Surgery: National Institutes of Health Symposium Deficiencies in Knowledge of Long-term Bariatric Surgery Area of Knowledge Gap Issues and Problems Potential Study Designs Incidence of surgical complications Predictors of surgical outcomes Overall mortality/survival T2DM remission T2DM microvascular complications Standards for completeness of follow-up and management of missing data are needed Very little data available to inform which patient should undergo which procedure Data from observational trials only Little data on durability of remission No data on long-term microvascular disease Comparative safety of surgical procedures; analyses of EMR databases Comparative safety of surgical procedures; analyses of EMR databases Long-term observational and RCTs; analyses of EMR databases Long-term observational and RCTs; analyses of EMR databases Long-term observational and RCTs; analyses of EMR databases
Area of Knowledge Gap Issues and Problems Potential Study Designs Cardiovascular events (stroke and myocardial infarction) Mental health outcomes including suicidality, alcohol, substance abuse, and other risk-taking behaviors Data from 2 observational studies only Comprehensive, longterm data lacking for most mental health outcomes Cancer Data from 2 observational studies Long-term observational and RCTs; analyses of EMR databases Long-term studies with focus on mental health outcomes; analyses of EMR databases Long-term studies with accurate cancer incidence; analyses of EMR databases Reproductive outcomes Very little data available Shorter and longer term observational studies; analyses of EMR databases Cost and health care use Lack of data with standard reporting of cost and use outcomes Shorter and longer term data with cost and health care use; analyses of EMR databases outcomes in surgical vs control groups
Future Considerations We should press for CV outcomes trials The duration of diabetes may play a role: consideration of earlier surgery instead of the current salvage approach Lowering the BMI threshold from 35 to 30 would have the potential for high public health impact Insulin and glucose levels may be superior to BMI in identifying those most likely to benefit Are safer strategies/ non-invasive devices on the horizon: Zerona?