A prospective UK cohort study revealed that younger age at diabetes onset was associated with higher risk of subsequent dementia. The study included 10 095 participants (67.3% men; aged 35-55 years in 1985-1988), with a total of 1710 cases of diabetes and 639 cases of dementia recorded over a median follow-up of 31.7 years. Dementia rates per 1000 person-years were 8.9 in participants without diabetes at age 70 years, and 10.0 for participants with diabetes onset up to 5 years earlier, 13.0 for 6 to 10 years earlier, and 18.3 for more than 10 years earlier. In multivariable-adjusted analyses, compared with participants without diabetes at age 70, the hazard ratio (HR) of dementia in participants with diabetes onset more than 10 years earlier was 2.12, 1.49 for diabetes onset 6 to 10 years earlier, and 1.11 for diabetes onset 5 years earlier or less; linear trend test indicated a graded association between age at onset of type 2 diabetes (T2D) and dementia. At age 70, every 5-year younger age at onset of T2D was significantly associated with an HR of dementia of 1.24 in analyses adjusted for sociodemographic factors, health behaviors, and health-related measures. The findings support the hypothesis that brain metabolic dysfunction is a driver of dementia and that a certain threshold of high glucose might be required to ultimately see hyperglycemia- induced brain injury. Source: https://jamanetwork.com/
