Younger age at onset of T2D is associated with an increased risk for subsequent dementia, according to a study published in JAMA. Researchers examined whether younger age at T2D onset is more strongly associated with the incidence of dementia in a population-based study in the United Kingdom, established in 1985-1988, which had linkage to electronic health records until March 2019. During a median follow-up of 31.7 years, the researchers identified 1,710 cases of diabetes and 639 cases of dementia among 10,095 participants. Compared with participants without diabetes at age 70, the hazard ratio (HR) for dementia was 2.12 (95% confidence interval [CI], 1.50-3.00), 1.49 (95% CI, 0.95-2.32), and 1.11 (95% CI, 0.70-1.76) for participants with diabetes onset more than 10 years earlier, 6-10 years earlier, and 5 years earlier or less, respectively, in multivariable-adjusted analyses. A graded association between age of onset of T2D and dementia was indicated by the linear trend test. In analyses adjusted for sociodemographics, health behaviors, and health-related measures, at age 70, every 5-year younger age at onset of T2D was significantly associated with an HR of dementia of 1.24 (95% CI, 1.06-1.46).
