Diabetes and obesity: A co-epidemic?
Diabetes and obesity: A co-epidemic?
More than half of U.S. adults that are diagnosed with diabetes are overweight or obese, the CDC estimates. Obese patients with type 2 diabetes, the form of the disease that affects 90% to 95% of those diagnosed, face further potential long-term health complications including heart disease, stroke and microvascular disease in the form of neuropathy, nephropathy and retinopathy.1-3
While studies from the CDC suggest that the rates of obesity appear to be holding steady at nearly one-third of the adult U.S. population, prevalence has been increasing among children and adolescents since 1980.4 These dramatic increases in overweight and obesity are thought to be one of the main reasons why type 2 diabetes is becoming more common.
The most current estimates from the CDC's National Health and Nutrition Examination Survey (NHANES) study found that 16.9% of children and adolescents ages 2 years to 19 years are obese. More specifically, approximately 10% of children aged younger than 5 years, 20% of those ages 6 to 11 years, and 18% of children ages 12 to 19 are obese.5
Epidemiological evidence from the past 20 years has demonstrated that the increasing incidence of type 2 diabetes parallels the increasing prevalence of obesity.7
Relationship between obesity and type 2 diabetes
Although there is a clear link between obesity and type 2 diabetes, the precise mechanisms involved are not completely understood. Not all obese people develop type 2 diabetes; yet almost all patients with type 2 diabetes are obese.
Researchers have suggested that several factors may play a role in the relationship between type 2 diabetes and obesity, including adipokines and proinflammatory cytokines; insulin resistance; deranged fatty acid deposition and metabolism; and cellular processes such as mitochondrial dysfunction and endoplasmic reticulum stress.
Additionally, the location of fatty deposits in the abdominal area has been linked with heightened risk for developing type 2 diabetes, with some adipose tissue types affecting glucose control more than others, research suggests.8
Lifestyle modification therapy
Weight loss is recommended for all overweight or obese individuals with diabetes. Data from the Diabetes Prevention Program (DPP), a large study involving a cohort at high risk for diabetes, showed that lifestyle interventions promoting weight loss and physical activity reduced type 2 diabetes by nearly 60% during a three-year period.
Even very modest weight reductions can help lower insulin resistance in overweight and obese individuals. In it's current practice guidelines, the American Diabetes Association targets weight loss for patients with impaired fasting glucose, or HbA1c levels ranging from 5.7% to 6.4%, at 5% to 7% of body weight. It is possible to achieve these results with just 150 minutes of moderate physical activity each week. 9
Greater improvements in glycemic control can be achieved when weight loss targets increase to 10% to 15% of body weight, data from the Look AHEAD (Action for Health in Diabetes) study, which involved more than 5,000 overweight and obese people with diabetes, indicate.10
Six oral medication classes are currently available for glycemic control: sulfonylureas, meglitinides, biguanides, thiazolidinediones, alpha-glucosidase inhibitors and depeptidyl peptidase-4 (DPP-4) inhibitors. Because some are known to cause weight gain, not all are recommended for use in overweight or obese patients.
Metformin is a popular first-line medication option for overweight and obese patients with type 2 diabetes. A biguanide, it works by inhibiting the amount of glucose made in the liver, and improves the body's ability to use available glucose without causing weight gain. Metformin reduced the risk of type 2 diabetes 31 % among Diabetes Prevention Program participants and was highly effective in adults with a BMI of 35 or lower.
Recent studies indicate metformin is an effective therapy for improving glucose control in children as young as 6 years old. It is currently FDA-approved as a type 2 diabetes treatment for adults and children aged 10 years and older.11-12
1. National Institutes of Diabetes and Digestive and Kidney Diseases. Weight-Control Information Network. NIH Publication Number 04–4158: Updated February 2010.2. Puska P et al. World Health Organization. Obesity and Overweight Fact Sheet.
3. Centers for Disease Control and Prevention. National diabetes fact sheet: national estimates and general information on diabetes and prediabetes in the United States, 2011. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, 2011.Centers for Disease Control and Prevention. Morb Mort Wkly Rep. 2004:53(45);1066-1068.
All online documents accessed August 16, 2011.