Association of Functional Decline With Subsequent Diabetes Incidence in U.S. Adults Aged 51 Years and Older: The Health and Retirement Study 1998-2010

OBJECTIVE We assessed whether functional decline and physical disability increase the subsequent risk of diabetes. RESEARCH DESIGN AND METHODS We used a subsample of adults aged 51 years and older with no diabetes at baseline who were followed up to 12 years (1998-2010) in the Health and Retirement Study, an observational study of a nationally representative survey. We assessed baseline disability status and incident disability with subsequent risk of diabetes, accounting for death as a competing risk and controlling for BMI, age, sex, race/ethnicity, net wealth, mother's level of education, respondents' level of education, and time of follow-up. Disability was defined as none, mild, moderate, and severe, based on a validated scale of mobility measures. Diabetes was identified by self-report of a diagnosis from a doctor. Population attributable fraction (PAF) was calculated to assess the percentage of diabetes cases that were attributable to mobility disability. RESULTS The sample included 22,878 adults with an average of 8.7 years of follow-up; 9,649 (41.2%) reported some level of disability at baseline, and 8,175 (35.7%) additional participants developed disability during follow-up; 3,546 (15.5%) participants developed diabetes; and 5,869 (25.6%) died. Regression analyses found a statistically significant dose-response relationship of increased risk of diabetes (28-95%) among those with any level of functional decline, prevalent or incident. Among the subanalytic sample, including incident disability only, the PAF was 6.9% (CI 4.2-9.5). CONCLUSIONS Our findings suggest those who become disabled, even mildly, are at increased risk of developing diabetes. This finding raises the possibility that approaches to prevent disability in older adults could also reduce diabetes incidence.