Type 2 diabetes is an epidemic disease in the United States. The American Association of Clinical Endocrinologists (AACE) estimated that approximately 24 million people had Type 2 diabetes in 2007; nearly 6 million remained undiagnosed.
The Centers for Disease Control predicts that one in three individuals born in 2000 will eventually be diagnosed with diabetes, representing a marked increase in the incidence and prevalence of this disease. One major reason for this trend is Americans’ tendency toward overweight and sedentary lifestyles. (National Institute of Diabetes and Kidney Disease. Diabetes Overview. National Diabetes Information Clearinghouse. NIH Publication No. 09–3873, November 2008)
Proper diet, regular exercise and maintenance of ideal body weight are widely recognized as keystones of diabetes management. Lifestyle modifications that lead to weight loss are more effective than some drugs in improving long-term blood sugar control, decreasing triglyceride levels, and reducing abdominal obesity. (Ripsin C, Kang H, Urban R. Management of blood glucose in type 2 diabetes. Am Fam Phys. 2009;79(1):29-36)
It is not surprising, then, that many diabetics are frustrated after they have begun therapy and embarked on a program of lifestyle changes, only to find their weight going up instead of down. What many of them don’t realize—and what many doctors fail to disclose—is that some of the medications diabetics take to control their blood glucose levels can cause weight gain.
Diabetes Drugs that Cause Weight Gain
Oral Medications
- Thiazolidinediones: These drugs act by increasing the effectiveness of insulin (either naturally produced or injected) and by decreasing the production of glucose in the liver. They typically cause “minor” increases in weight (1 – 5 pounds) over a year or so. Examples include pioglitazone (Actos) and rosiglitazone (Avandia).
- Sulfonylureas: These medications stimulate the secretion of insulin from the pancreas, thereby increasing the levels of insulin in the bloodstream. They ostensibly cause “modest” weight gain (6 – 10 pounds) during the first year of therapy. Examples include glipizide (Glucotrol), glyburide (Micronase, Diabeta, Glynase), and glimeperide (Amaryl).
- Meglitinides: These drugs also stimulate pancreatic insulin secretion. One of them, repaglinide (Prandin), causes weight gain that is somewhat more modest (4 – 5 pounds) than the sulfonylureas.
Injected and Inhaled Medications
- Insulin: This hormone, which is normally produced by the pancreas, is responsible for making glucose available to cells for fuel; it is also instrumental in storing excess glucose as fat. One of the paradoxes of diabetes therapy is insulin’s tendency to increase body weight and fat stores; this tendency persists over the duration of therapy.
Combination Therapy
- The American Diabetes Association recommends oral sulfonylureas as Step 2 agents in the treatment of type 2 diabetes (i.e., they are added to metformin, the recommended first-line agent, if it alone does not lead to effective control). Insulin is added as a Step 3 agent.
- The AACE has developed treatment guidelines that make more liberal use of newer agents and a more aggressive use of combination oral medications.
- Studies show that a reduction of as little as 5% to 10% of a person’s body weight (10 to 20 pounds in a 200-pound patient) can decrease blood glucose levels, increase the effectiveness of insulin, and reduce the need for medications in individuals with type 2 diabetes. The combination of medications that cause weight gain could certainly contribute to ongoing problems with disease management. (American Diabetes Association and American College of Cardiology. Diabetes and Cardiovascular Review, Issue 7: Promoting Weight Loss in Patients with Type 2 Diabetes: Importance and Strategies. 2004)
Diabetics who are disheartened by unsuccessful attempts to lose weight should review their treatment protocols with their physicians. Doctors should consider whether a specific patient is a good candidate for a drug that might cause weight gain; those medications that cause significant weight gain should be avoided whenever possible in patients who are already overweight.
