Diabetes Stats Illuminate Need for Prevention

After looking at data from the National Health and Nutrition Examination Surveys (NHANES), which included over 26,000 U.S. adults and spanned from 1988 through 2012, researchers have reported in JAMA that in 2011-2012, 10% of the adult population had diabetes.

Much more alarmingly, the study found that in that year 38% of U.S. adults had prediabetes. Prediabetes is diagnosed when blood sugar levels are elevated, but not quite to the threshold that demarcates diabetes.

The Data
For the commonly used Fasting Plasma Glucose test, during which people refrain from eating for eight hours before their blood is drawn, results are interpreted as follows:

  • Normal if your blood sugar is less than 100 mg/dL
  • Prediabetes if your blood sugar is 100-125 mg/dL
  • Diabetes if your blood sugar is 126 mg/dL or higher

Age-standardized diabetes prevalence was higher among African Americans, Hispanics and Asians (at over 20%). Prevalence among whites was 11%.

In the big picture from 1988 to 2012, diabetes prevalence increased, but the authors note that this is significantly due to a rise in diagnosed cases. Still, by every metric prevalence increased: among each age group, both sexes, every racial and ethnic group, and every education level and income level—with a particularly rapid increase among non-Hispanic black and Mexican American participants. Undiagnosed diabetes dropped over the study period—a small silver lining in the otherwise fairly stark findings.

Prevention
The Lancet Diabetes & Endocrinology has published a long-term follow-up to the Diabetes Prevention Program (DPP), finding diet and exercise continue to be the best ways to prevent type 2 diabetes.

The DPP involved almost 2,800 adults in a randomized trial, in which they were assigned to a behavioral lifestyle intervention (diet and exercise), the medication metformin (e.g., Glucophage) or placebo.

The interventions lasted about three years. All participants were offered lifestyle training at the end of the DPP, with the vast majority then followed for over a decade in the Outcomes Study.

The primary outcomes were the development of diabetes and the prevalence of microvascular disease. Also known as small vessel disease, this is a narrowing of the small arteries in the heart most commonly seen in people with diabetes and/or high blood pressure.

During a total 15 years' follow-up, diabetes incidence was reduced by 27% in the lifestyle group and 18% in the metformin group, relative to the placebo group. In women only, the lifestyle intervention reduced risk for microvascular complications by about 20% relative to metformin or placebo.

Those who did not develop diabetes in the first place had a lower prevalence of microvascular complications than those who did develop diabetes. The authors point out that this result highlights the importance of diabetes prevention.

Diet and Exercise Recommendations
People who are overweight are more likely to see their prediabetes turn into diabetes. Experts say that losing as little as 5% to 10% of your body weight can make a positive difference.

Moderate exercise for at least 30 minutes a day helps prevent and manage diabetes. Though this can include as simple an activity as brisk walking, aerobic exercise—after checking with your doctor if you are sedentary—is ideal.

And finally, lean protein, fiber-rich fruits and vegetables, legumes and whole grains are much more effective in preventing spikes in blood sugar than highly refined carbs and foods with added sugar. Controlling serving sizes and overall caloric intake is also important, something that consuming filling, high-fiber foods can help you do.

JAMA, 2015, Vol. 314, No. 10, pp. 1021-1029, http://jama.jamanetwork.com/article.aspx?articleid=2434682

The Lancet Diabetes & Endocrinology, published online Sept. 13, 2015, http://www.thelancet.com/journals/landia/article/PIIS2213-8587%2815%2900291-0/abstract

Ann. Rheum. Dis., 2015, Vol. 74, No. 5, pp. 851-858, http://www.ncbi.nlm.nih.gov/pubmed/24395557

Mayo Clinic, http://www.mayoclinic.org/drugs-supplements/glucosamine/safety/hrb-20059572

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