Secular changes in prediabetes indicators among older-adult Americans, 1999-2010

Sex-specific prediabetes estimates are not available for older-adult Americans.

To estimate prediabetes prevalence, using nationally representative data, in civilian, non-institutionalized, older U.S. adults.

Data from 7,995 participants aged ≥50 years from the 1999-2010 National Health and Nutrition Examination Surveys were analyzed in 2013. Prediabetes was defined as hemoglobin A1c=5.7%-6.4% (39-47 mmol/mol [HbA1c5.7]), fasting plasma glucose of 100-125 mg/dL (impaired fasting glucose [IFG]), or both. Crude and age-adjusted prevalences for prediabetes, HbA1c5.7, and IFG by sex and three age groups were calculated, with additional adjustment for sex, age, race/ethnicity, poverty status, education, living alone, and BMI.

From 1999 to 2005 and 2006 to 2010, prediabetes increased for adults aged 50-64 years (38.5% [95% CI=35.3, 41.8] to 45.9% [42.3, 49.5], p=0.003) and 65-74 years (41.3% [37.2, 45.5] to 47.9% [44.5, 51.3]; p=0.016), but not significantly for adults aged ≥75 years (45.1% [95% CI=41.1, 49.1] to 48.9% [95% CI=45.2, 52.6]; p>0.05). Prediabetes increased significantly for women in the two youngest age groups, and HbA1c5.7 for both sexes (except men aged ≥75 years), but IFG remained stable for both sexes. Men had higher prevalences than women for prediabetes and IFG among adults aged 50-64 years, and for IFG among adults aged ≥75 years. Across demographic subgroups, adjusted prevalence gains for both sexes were similar and most pronounced for HbA1c5.7, virtually absent for IFG, but greater for women than men for prediabetes.

Given the large, growing prediabetes prevalence and its anticipated burden, older adults, especially women, are likely intervention targets.