Rates of diabetes-related complications-acute myocardial infarction (AMI), lower-extremity amputations, stroke, end-stage renal disease (ESRD), and death from hyperglycemic crisis-have dropped substantially over the past 20 years, even as the overall percentage of Americans 20 years old and older with diabetes continues to rise, from an estimated 5.5% in the early 1990s to 9.3% in 2010. Two recent studies report that diabetes care may have improved during the past two or three decades, but obesity and inadequate prevention continue to feed the epidemic-especially among ethnic and racial minorities.

The first study, by Gregg and colleagues, found impressive declines in the rates of AMI (a 67.8% decrease); strokes and amputations (about 50%); deaths from hyperglycemic crisis, such as ketoacidosis (64.4%); and ESRD (28.3%) from 1990 to 2010. Although the findings are limited by a lack of data differentiating complications related to type 1 and type 2 diabetes, overall declines in the rates of AMI, stroke, amputations, and ESRD outpace those in the nondiabetic population. The declines may be partly attributed to increasing and earlier use of preventive measures, such as coronary artery and lower-extremity venous stenting.

The second study, by Selvin and colleagues, looked at glycated hemoglobin (HbA_1c) and fasting glucose levels in nonpregnant, noninstitutionalized Americans ages 20 or older. Data came from clinical assessments in two time periods: 1988 to 1994 and 1999 to 2010. The data showed improvement of glycemic control in patients with diabetes, with the prevalence of HbA_1c levels less than 7% increasing from 50.9% in the earlier period to 58.8% in the later period. Although the prevalence of diabetes overall (previously diagnosed and undiagnosed diabetes [indicated by the HbA_1c level measured during clinical assessment]) increased steadily, far outstripping the growth of the population, rates of undiagnosed diabetes plateaued, which is likely a reflection of improved screening. And, most troubling, none of the improvements was seen in the non-Hispanic black or Mexican American populations.

Michelle D. Lynne, a veteran diabetes educator, thinks the data show that health care workers are putting evidence-based research into practice, but she worries that declines in funding for historically underused patient and professional education programs will threaten improved outcomes.-Sibyl Shalo Wilmont, BSN, RN

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