Secular Changes in the Age-Specific Prevalence of Diabetes Among US Adults: 1988-2010

OBJECTIVE To examine the age-specific changes of prevalence of diabetes among U.S. adults during the past 2 decades.RESEARCH DESIGN AND METHODS This study included 22,586 adults sampled in three periods of the National Health and Nutrition Examination Survey (1988-1994, 1999-2004, and 2005-2010). Diabetes was defined as having self-reported diagnosed diabetes or having a fasting plasma glucose level 126 mg/dL or HbA(1c) 6.5% (48 mmol/mol).RESULTS The number of adults with diabetes increased by 75% from 1988-1994 to 2005-2010. After adjusting for sex, race/ethnicity, and education level, the prevalence of diabetes increased over the two decades across all age-groups. Younger adults (20-34 years of age) had the lowest absolute increase in diabetes prevalence of 1.0%, followed by middle-aged adults (35-64) at 2.7% and older adults (65) at 10.0% (all P < 0.001). Comparing 2005-2010 with 1988-1994, the adjusted prevalence ratios (PRs) by age-group were 2.3, 1.3, and 1.5 for younger, middle-aged, and older adults, respectively (all P < 0.05). After additional adjustment for body mass index (BMI), waist-to-height ratio (WHtR), or waist circumference (WC), the adjusted PR remained statistically significant only for adults 65 years of age.CONCLUSIONS During the past two decades, the prevalence of diabetes increased across all age-groups, but adults 65 years of age experienced the largest increase in absolute change. Obesity, as measured by BMI, WHtR, or WC, was strongly associated with the increase in diabetes prevalence, especially in adults <65.