ADVANTAGES AND DISADVANTAGES OF INSULIN THERAPIES IN TYPE I DIABETES

Transcription

1 ADVANTAGES AND DISADVANTAGES OF INSULIN THERAPIES IN TYPE I DIABETES

2 ABSTRACT Purpose The purpose of this paper is to investigate the advantages and disadvantages of using continuous subcutaneous insulin infusion (CSII) versus multiple daily insulin injections (MDII) in the type I diabetic patient. This research was performed in order to aid the healthcare provider in choosing insulin therapies appropriate for their patient population. Several factors were analyzed, including cost, convenience, and compliance. Methods Research was performed by using accredited, peer-reviewed articles as well as medical textbooks. The articles, studies, and textbooks utilized during research were all current literature that was published within the last 10 years. The studies that were conducted consisted of males and females of all ages and from all over the world. All individuals that were evaluated were type I diabetic patients using either MDII or CSII. Results The information derived from the research resulted in beneficial knowledge for healthcare providers regarding both the advantages and disadvantages of MDII and CSII. CSII proved to be favorable for patients that are uncontrolled or that are unable to tolerate multiple injections daily. MDII was more advantageous for those patients that needed a simplistic means of administering insulin in addition to patients that are unable to afford the higher cost of CSII. Conclusions The data confirmed that each patient needs to be evaluated on a case-by-case scenario in order to determine which form of therapy will be best for their individual lifestyle and

3 expectations. Overall, both forms of insulin therapy are able to control type I diabetic patients' blood glucose levels within optimal ranges when administered and managed correctly.

4 INTRODUCTION Type I diabetes affects approximately 1 million people in the United States. 1 Currently, about 1 in 400 children and adolescents have type I diabetes. 2 This form of diabetes is a devastating illness due to the lack of insulin secretion by the pancreatic islet beta cells. In type I diabetes, pancreatic islet beta cells, which produce insulin, are generally destroyed by a viral or autoimmune process at some point during childhood or adolescence. Therefore, this form of diabetes is often referred to as juvenile diabetes. Without insulin to counteract glucose, blood sugar levels rise, which is known as hyperglycemia. When insulin secretion is halted, the patient often begins to suffer from polyuria (excessive urination), polydipsia (excessive thirst), and weight loss. 3 If these common signs are not further investigated or are overlooked, the patient typically will present to their physician or emergency department in diabetic ketoacidosis (DKA) and the diagnosis will be made. DKA consists of hyperglycemia >250 mg/dl, blood ph of <7.25, and blood bicarbonate of <16 meq/l. 1 In addition, the patient may experience nausea, diarrhea, vomiting, abdominal pain or lethargy. 1 The patient will commonly be in distress and exhibit kussmaul respirations. This form of breathing consists of a compensatory response of hyperventilation in order to correct the acidotic, low ph. If not corrected, DKA can lead to coma. The diagnosis of type I diabetes is formally made based on several different criteria. A random blood glucose that is 200 mg/dl or a fasting blood glucose that is 126 mg/dl is evidence of diabetes. 3 In addition, symptoms of polyuria, polydipsia, or unexplained weight loss are necessary to establish the diagnosis. 3 Furthermore, ketones are often found in the blood, urine, or both. Normally, the human body processes glucose to use

5 as energy, but if this process is malfunctioning then the body begins to breakdown fat. 1 Ketones are produced when the body breaks down fat stores for energy and is often found in diabetics urine or blood due to improper glucose utilization. Also, pancreatic islet autoantibodies are usually present in the blood. 1 Uncontrolled, diabetes can be a detrimental disease and can result in many short-term and long-term side effects. Short-term side effects that can be life-threatening include DKA due to hyperglycemia or over utilization of insulin leading to hypoglycemia. Hypoglycemia occurs when blood sugar levels are around 54 mg/dl and causes the patient to have symptoms such as sweating, hunger, nausea, tremors, and anxiety. 1 If blood glucose levels continue to fall, confusion, blurred vision, tiredness, headache and speech difficulty can occur. 1 If hypoglycemia persists even longer, loss of consciousness or seizures can take place. 1 Long-term side effects can develop due to uncontrolled, consistently elevated blood glucose levels. Common long-term complications include kidney failure, blindness, hypertension, atherosclerotic heart disease, stroke, and amputations. 2 Therefore, it is of utmost importance to maintain blood glucose within optimum levels. Type I diabetes requires insulin in order to achieve optimal blood glucose levels. Diabetic patients should try to maintain their blood sugar levels between mg/dl. Furthermore, a hemoglobin A1c (HbA1c) level of 7% or less is the desired goal for diabetic patients. HbA1c measures how well blood glucose has been controlled over the prior 2-3 months by calculating what percentage of glucose is attached to the red blood cells. 4 Diabetic patients are able to achieve these daily blood glucose and longterm HbA1c goals by using insulin.

6 Diabetic patients need rapid-acting insulin as well as long-acting insulin in order to attain targeted blood glucose levels. Rapid-acting insulin is given as boluses around meal times. This form of insulin enables diabetics to counteract against the extra carbohydrates that are consumed when eating. In addition, if a diabetic obtains a random, elevated blood glucose reading, then they can administer a bolus of rapidacting insulin in order to bring down the glucose to an optimal level. Rapid-acting insulin generally peaks within 1 hour of administration. 1 Long-acting insulin is used to maintain a basal level of insulin secretion. Therefore, this form of insulin never peaks and allows the diabetic patient to achieve a flat, baseline insulin level over the course of 24 hours. 1 Combined, rapid-acting and long-acting insulin act as a pseudopancreas allowing the diabetic patient to receive pulses of insulin as well as a steady secretion of insulin throughout the day. Two forms of insulin therapies that are available to diabetics include continuous subcutaneous insulin infusion (CSII) and multiple daily insulin injections (MDII). Both CSII and MDII utilize rapid-acting and long-acting insulin. CSII was first developed in 1960, but was not until recently an insulin therapy that could be used practically. 5 Also known as the insulin pump, CSII allows the patient to receive insulin through a catheter that is attached to the skin. The catheter is connected to tubing which in turn is connected to the insulin pump. The insulin pump is about the size of a pager and is where the insulin is stored. In addition, the insulin pump has an electronic screen that allows for programming basal insulin levels as well as administering boluses of insulin as needed. The insulin pump and tubing can be disconnected from the catheter in order to bathe, swim, or to allow for sexual intimacy. 5 Multiple daily insulin injections

7 require the diabetic patient to administer rapid and long-acting insulin throughout the day via a prefilled insulin pen or a syringe. This method necessitates the diabetic patient to give themselves a long-acting insulin shot, generally in the morning and at night, and multiple shots throughout the day with meals and snacks. Both CSII and MDII require the diabetic patient to check their blood glucose levels using a glucometer and applying blood via a finger prick. Newer insulin pumps allow the blood glucose to be checked through the catheter; however, the majority of diabetic patients are still using the standard pump that requires incremental glucometer testing. Both CSII and MDII are excellent therapies that allow diabetic patients to achieve optimal blood glucose levels. However, what are the pros and cons of using one form of therapy over the other? Furthermore, does either therapy allow the diabetic patient to obtain better daily blood glucose levels in addition to improving HbA1c levels long-term? This study was conducted by compiling accredited, peer-reviewed articles in order to compare the facts regarding CSII and MDII and conclude if either therapy is superior over the other for use by the type I diabetic patient.

8 LITERATURE REVIEW Continuous subcutaneous insulin infusion has recently become more popular for use in type I diabetic patients of all ages. The insulin pump has several disadvantages as well as advantages to being used by diabetics. Continuous subcutaneous insulin infusion provides the patient with flexibility and tight blood glucose control, but insulin pumps commonly malfunction and cause skin irritation. There are many benefits when using the insulin pump in the type I diabetic patient, such as convenience and improved quality of life. According to Scheidegger et al., 78 type I diabetic patients that were changed from MDII to CSII were given a questionnaire to be completed in regards to quality of life. 6 Upon switching from MDII to CSII, this patient population reported improved satisfaction due to fewer dietary restrictions, more flexibility, less daily hassle, and decreased physical complaints. 6 In addition, these patients felt less fearful about having hypoglycemic episodes. 6 The patients in this study also felt that the burden of having an object attached to their body was offset by lack of restrictions and convenience of the insulin pump. 6 Furthermore, Retnakaran et al. compared 139 type I diabetic patients and found that the insulin pump allowed for improvement of HbA1c levels as well as decreased hypoglycemic events due to tighter glycemic control. 7 Patients with HbA1c levels that started off at a baseline of at least 10 or higher had greater improvements using CSII. 7 The patients with an HbA1c baseline above 10 using CSII had reduced HbA1c levels of.65% greater than that of similar patients using MDII. 7 On average, 2.2 and 2.0 hypoglycemic events occurred per week for patients using CSII and MDII respectively. 7 Additionally, Weinzimer et al. conducted a study observing 65 young children that began using the insulin pump and concluded

9 there was a 53% reduction of severe hypoglycemic episodes. 8 HbA1c levels improved amongst the children from 7.4 ± 1.0% to 7.0 ±.9%. 8 The children and the caregivers of the children experienced improved quality of life. 8 Overall, continuous subcutaneous insulin infusion led to tighter blood glucose control which resulted in improved HbA1c levels and decreased hypoglycemic events. Also, insulin pump use improved quality of life due to convenience, reassurance, and flexibility. Although many patients have benefitted from the use of the insulin pump, several disadvantages have been recognized. One of the major concerns when using CSII is the fear of the insulin pump malfunctioning. It is not uncommon for insulin pumps to become dislodged or occluded without the patient realizing there is a problem. This can lead to serious consequences, such as hyperglycemia. According to Guilhem et al., 232 out of 640 insulin pumps malfunctioned within a median time of 15.1 months. 9 Therefore, this study found a 36% rate of insulin pump failure that was not contributed to user errors. 9 Another concern in regards to using the insulin pump is risk of epidermal complications. The most common problem when using the insulin pump is skin infection at the catheter site. 10 Lenhard et al. conducted a study observing 78 children and adolescents and found that 20-21% reported allergic skin reactions while 29-36% reported skin infections. 11 In order to prevent skin infections, care should be taken to rotate the catheter every 2-3 days and use antibiotic ointment as needed. 5 In addition, weight gain is another negative side effect of using the insulin pump. On average, patients gain 10 pounds when beginning therapy with CSII due to decreased glycosuria. 10 Another concern when using the insulin pump is the complexity of the instrument. In order to be able to use the pump correctly, the patient or caregiver must

10 have the cognitive abilities to understand and use the device. 5 The insulin pump is a very beneficial tool to control diabetes, but care must be taken when using the device in order to detect if the pump is malfunctioning. Additionally, the patient must maintain good hygiene of the injection site to prevent infection and properly understand the equipment before beginning to use CSII. Multiple daily insulin injections is another effective form of insulin therapy that enables optimal blood glucose levels to be attainable by type I diabetics. As with CSII, this form of therapy also has several advantages and disadvantages. MDII is cost efficient and is not prone to malfunction, but this form of insulin administration can often be embarrassing and painful. There are several benefits of MDII, such as decreased cost and simplicity. Multiple daily insulin injections are more commonly used by type I diabetics than the insulin pump. This form of therapy has been around longer, whereas the insulin pump is a sophisticated technology that has recently become popular. The insulin pump requires advanced understanding and technical knowledge in order to be able to be used. 5 In contrast, MDII is a more simplistic form of insulin therapy that may be preferred by some patients due to being user friendly. Rapid-acting and long-acting insulin is now available in pre-filled insulin pens. The patient must attach a single use needle to the pen and adjust the dial to the number of desired units of insulin to be administered. Patients are also able to perform MDII using syringes to draw up desired units of insulin from vials. Piscopo et al. concluded that type I diabetic patients find insulin pens to be simpler to use and allow for an improved quality of life in comparison to using a syringe and vial. 12 Therefore, more patients who perform MDII are choosing to use the pre-filled

11 pen over the syringe. 12 In addition to being simplistic, MDII are more cost efficient than CSII. The cost of the insulin pump, supplies, and regular physician management of CSII is greater than that of MDII. 13 Furthermore, Karagianni et al. found that CSII results in an increase in cost as well as an increase in required self care. 14 Multiple daily insulin injections are also beneficial because they allow for a depot of long-acting insulin to be maintained within the body, thus decreasing the likelihood of the patient going into DKA quickly. The diabetic patient injects themselves with long-acting insulin generally in the morning and at night, which allows a reservoir of basal insulin to be established and maintained. In contrast, the insulin pump gives small pulses of basal insulin throughout the day and does not form a reservoir, which can cause diabetic ketoacidosis to occur more quickly. 10,13 Multiple daily insulin injections also provide the user with confidence that rapid-acting and long-acting insulin is administered. The patient directly injects themselves with insulin via the pen or syringe, reassuring themselves that insulin was received and preventing worry in regards to an insulin pump malfunction. Overall, the benefits of MDII include simplicity, cost efficiency, reliability, and patients not going into DKA as swiftly. There are also several disadvantages for type I diabetics performing MDII. Peyrot et al. found that approximately 20% of diabetic patients intentionally do not perform insulin injections due to inconvenience, embarrassment, or pain. 15 Many participants in the study felt as though their lives were based around when insulin needed to be administered. 15 MDII users complain of embarrassment, particularly when having to use an insulin pen or syringe in a public place, such as a restaurant. Common sites for insulin injections are the upper arm and lower abdomen, which are often hard to access

12 in public places due to clothing. In addition, performing MDII is a painful task to endure several times during the day. On average, the type I diabetic will administer between 5-6 injections per day. In contrast, the insulin pump catheter can be injected once and remain in the same place for 2-3 days. Peyrot et al. also concluded that insulin omission is more common in younger populations and tends to decrease as age increases. 15 Overall, the major disadvantages of MDII are the emotional and physical side effects that prevent the patient from wanting to use this form of therapy. Many insulin dependent patients will avoid injections due to pain and being self conscious. In conclusion, both CSII and MDII allow diabetics to achieve optimal blood glucose levels. However, there are pros and cons to both forms of therapy that should be considered before a type I diabetic patient begins either form of insulin administration.

13 DISCUSSION The decision to begin a type I diabetic patient on CSII versus MDII is an important choice for a healthcare provider to make. Therefore, the evidence above is very beneficial for a doctor, physician assistant, or nurse practitioner to consider before beginning insulin therapy. For example, insulin pump therapy is proven to be exceptionally beneficial in uncontrolled diabetic patients. Healthcare providers should therefore consider this therapy in all patients with poor HbA1c levels in order to be able to achieve greater improvement and maintenance of these levels over time. Furthermore, MDII are frequent and painful, therefore patients that omit injections due to these reasons or young children who are unable to tolerate and comprehend the multiple injections may benefit from CSII therapy. Due to the increased costs of CSII, healthcare providers should consider implementing MDII in lower socioeconomic patient populations. In addition, patients that are unable to understand and execute the insulin pump due to complexity should be started on MDII. Overall, insight into the benefits and risks of these two forms of insulin therapy should be weighed by the provider in order to determine which regimen would be most advantageous for each, individual patient's lifestyle and expectations. There are many directions that diabetes treatment could take that should be further investigated and considered for future use in the type I diabetic patient. For example, as technology continues to progress, the possibility of CSII becoming the gold standard for insulin administration in the type I diabetic patient. Currently, both forms of therapy are adequate, but eventually CSII may surpass MDII and become the first line treatment option preference for providers and patients. In the future, if insulin pumps were able to

14 accurately determine the current blood sugar and administer insulin correctly without receiving clearance by the patient, then the user would be able to experience even more freedom and convenience. Additionally, pancreas transplantation is a possibility for diabetic patients. If transplantation is successful, the patient is cured of diabetes and no longer needs insulin administration. Currently, this procedure is very risky with 1-2 out of 10 people dying within the first year after the surgery. 16 Most fatalities are a result of transplant rejection or due to being on high dosages of immunosuppressive agents. Pancreas transplantation has higher success rates if a kidney transplant from the same donor is performed concurrently. 16 This surgery may be more beneficial and have higher success rates in the future as better techniques are utilized and further experience is gained. As technology improves and knowledge progresses, highly sophisticated insulin pumps and refined pancreas transplant operations may allow diabetic patients to live a more normal, carefree life. Overall, insulin therapies have advanced dramatically in convenience and sophistication over the past 50 years. Both the insulin pump and insulin injections are able to achieve optimal blood glucose levels and therefore prevent short-term and long-term side effects in the type I diabetic patient. The patient's lifestyle as well as the ability to comply with therapy should be considered before determining whether MDII or CSII would be the preferred treatment modality. Topics such as flexibility, compliance, cost, and convenience should be discussed with the patient and reviewed by the healthcare provider in order to choose the most favorable insulin therapy on a case-by-case basis.

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16 8. Weinzimer, S, Ahern, J, Doyle, E, Vincent, M, Dziura, J, Steffen, A, et al. Persistence of Benefits of Continuous Subcutaneous Insulin Infusion in Very Young Children With Type I Diabetes: A Follow-up Report. Pediatrics. 2004: 114, Guilhem, I, Balkau, B, Lecordier, F, Malecot, J.M., Elbadii, S, Leguerrier, A.M., et al. Insulin Pump Failures are Still Frequent: A Prospective Study over 6 Years from 2001 to Diabetologia. 2009: 52, Lenhard, M, Reeves, G. Continuous Subcutaneous Insulin Infusion A Comprehensive Review of Insulin Pump Therapy. Archives of Internal Medicine. 2001: 161, Schober, E, Rami, B. Dermatological side effects and complications of continuous subcutaneous insulin infusion in preschool-age and school-age children. Pediatric Diabetes. 2009: 10, Piscopo, M, Chiesa, G, Bonfanti, R, Viscardi, M, Meschi, F, Chiumello, G. Quality of Life and New Devices in the Management of Type 1 Diabetes in Children and Adolescents. Acta Bio Medica. 2003: 74, Pickup, J, Renard, E. Long-Acting Insulin Analogs Versus Insulin Pump Therapy for the Treatment of Type 1 and Type 2 Diabetes. Diabetes Care. 2008: 31, Karagianni, P, Sampanis, C, Katsoulis, C, Miserlis, G, Polyzos, S, Zografou, I, et al. Continuous subcutaneous insulin infusion versus multiple daily injections. Hippokratia. 2009: 13,

17 15. Peyrot, M, Rubin, R, Kruger, D, Travis, L. Correlates of Insulin Injection Omission. Diabetes Care. 2010: 33, American Diabetes Association. Pancreas Transplantation. Accessed June 7, 2011.