Table 4

HRs for the association of the change in body mass index (BMI) with dementia incidence by the baseline BMI category

BMI change over 2 years*Underweight (<18.5 kg/m2)Normal/overweight (18.5–25 kg/m2)Obesity (≥25 kg/m2)
nCaseHR (95% CI)nCaseHR (95% CI)nCaseHR (95% CI)
Men
 Decrease of >10%2620.40 (0.10 to 1.64)5741091.27 (1.05 to 1.54)390661.27 (0.99 to 1.63)
 Decrease of 5<−10%122190.89 (0.55 to 1.46)24864301.20 (1.09 to 1.33)13962131.19 (1.02 to 1.38)
 Stable at ±5%758125Ref16 7242304Ref7447946Ref
 Increase of 5<−10%234511.34 (0.97 to 1.87)24393571.00 (0.89 to 1.11)579720.99 (0.77 to 1.25)
 Increase of >10%170421.48 (1.04 to 2.10)7851421.24 (1.04 to 1.46)7590.97 (0.51 to 1.88)
Women
 Decrease of >10%1771.92 (0.88 to 4.23)6571641.15 (0.98 to 1.35)6661541.13 (0.96 to 1.33)
 Decrease of 5<−10%73181.16 (0.70 to 1.93)22664911.10 (1.00 to 1.21)20034341.11 (1.00 to 1.23)
 Stable at ±5%45898Ref12 6102466Ref94381783Ref
 Increase of 5<−10%159320.92 (0.61 to 1.39)23605211.13 (1.03 to 1.24)9711840.97 (0.83 to 1.13)
 Increase of >10%167481.15 (0.80 to 1.64)9622451.25 (1.10 to 1.43)207400.93 (0.68 to 1.27)
  • *The BMI change over 2 years was calculated as follows: (BMI at baseline−BMI in 2004 or 2005)/BMI at baseline.

  • †Adjusted for age, household income, smoking, drinking, physical activity, total cholesterol level, atrial fibrillation, congestive heart failure, diagnosis of diabetes mellitus and fasting blood sugar control and hypertension.