Adult diabetes rates have leveled off from 2008–2012 in the United States, following a doubling of the prevalence of the disease from 1990–2008, according to a study in the Sept. 24 issue of JAMA.However, the rates among Hispanic and non-Hispanic black adults continued to increase.

Although there has been an increase in the prevalence and incidence of diabetes in the United States in recent decades, no studies have systematically examined long-term, national trends of this disease, according to background information in the article.

Linda S. Geiss, MA, of the Centers for Disease Control and Prevention, and colleagues analyzed 1980–2012 data for 664,969 adults ages 20 to 79 years from the National Health Interview Survey and determined the annual percentage change in rates of the prevalence and incidence of diagnosed diabetes (type 1 and type 2 combined).

From 1980–2012, the trends in age-adjusted prevalence of diagnosed diabetes in the overall population were similar to those for age-adjusted incidence. The prevalence per 100 persons was 3.5 in 1990, 7.9 in 2008, and 8.3 in 2012. The incidence per 1,000 persons was 3.2 in 1990, 8.8 in 2008, and 7.1 in 2012. Both prevalence and incidence increased sharply from 1990–2008 (for prevalence, 4.5%, for incidence, 4.7%) before leveling off with no significant change during 2008-2012 (for prevalence, 0.6%, for incidence, -5-4%).

The researchers speculate that reasons for the potential slowing of the increase in diabetes may include a slowing in the rate of obesity.

Incidence and prevalence of diabetes ceased growing or leveled off in many population subgroups. However, incidence continued to increase in Hispanic and non-Hispanic black adults and prevalence continued to grow among those with a high school education or less.

“This threatens to exacerbate racial/ethnic and socioeconomic disparities in diabetes prevalence and incidence. Furthermore, in light of the well-known excess risk of amputation, blindness, end-stage renal disease, disability, mortality, and health care costs associated with diabetes, the doubling of diabetes incidence and prevalence ensures that diabetes will remain a major public health problem that demands effective prevention and management programs,” the authors wrote.