Objective: This study examined the association between baseline body mass index (BMI), percent weight change, and the risk of dementia in patients newly diagnosed with type 2 diabetes.
Research Design and Methods: Using the South Korean National Health Insurance Service-National Health Screening Cohort database, we identified 167,876 subjects aged ≥40 years diagnosed with new-onset type 2 diabetes between 2007 and 2012. Their weight changes were monitored for about 2 years after diagnosis, with follow-ups occurring for an average for 3.5 years. The hazard ratios (HRs) and 95% confidence intervals (CIs) of all-cause dementia, Alzheimer’s disease (AD), and vascular dementia (VD) were estimated using multivariable Cox proportional hazards regression models.
Results: We identified 2563 incident dementia cases during follow-up. Baseline BMI among patients with new-onset type 2 diabetes was inversely associated with the risk of all-cause dementia and AD, independent of confounding variables (P for trend <0.001). Percent weight change during the two years after a diagnosis of type 2 diabetes, showed significant U-shape associations with the risk of all-cause dementia (P <0.001) and AD (P = 0.018) development; the HRs of both diseases increased significantly when weight loss or gain was greater than 10%. Additionally, weight gain greater than 10% was associated with increased risk of VD.
Conclusions: A lower baseline BMI was associated with increased risks of all-cause dementia and AD in patients with new-onset type 2 diabetes. Weight loss or weight gain after diagnosis of diabetes was associated with increased risk of all-cause dementia and AD. Weight gain was associated with increased risk of VD.
H. Kwon: None. S. Yoo: None. M. Lee: None. G. Nam: None.