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) | ||||||
| n | Case | HR (95% CI) | n | Case | HR (95% CI) | n | Case | HR (95% CI) | |
| Men | |||||||||
| Decrease of >10% | 26 | 2 | 0.40 (0.10 to 1.64) | 574 | 109 | 1.27 (1.05 to 1.54) | 390 | 66 | 1.27 (0.99 to 1.63) |
| Decrease of 5<−10% | 122 | 19 | 0.89 (0.55 to 1.46) | 2486 | 430 | 1.20 (1.09 to 1.33) | 1396 | 213 | 1.19 (1.02 to 1.38) |
| Stable at ±5% | 758 | 125 | Ref | 16 724 | 2304 | Ref | 7447 | 946 | Ref |
| Increase of 5<−10% | 234 | 51 | 1.34 (0.97 to 1.87) | 2439 | 357 | 1.00 (0.89 to 1.11) | 579 | 72 | 0.99 (0.77 to 1.25) |
| Increase of >10% | 170 | 42 | 1.48 (1.04 to 2.10) | 785 | 142 | 1.24 (1.04 to 1.46) | 75 | 9 | 0.97 (0.51 to 1.88) |
| Women | |||||||||
| Decrease of >10% | 17 | 7 | 1.92 (0.88 to 4.23) | 657 | 164 | 1.15 (0.98 to 1.35) | 666 | 154 | 1.13 (0.96 to 1.33) |
| Decrease of 5<−10% | 73 | 18 | 1.16 (0.70 to 1.93) | 2266 | 491 | 1.10 (1.00 to 1.21) | 2003 | 434 | 1.11 (1.00 to 1.23) |
| Stable at ±5% | 458 | 98 | Ref | 12 610 | 2466 | Ref | 9438 | 1783 | Ref |
| Increase of 5<−10% | 159 | 32 | 0.92 (0.61 to 1.39) | 2360 | 521 | 1.13 (1.03 to 1.24) | 971 | 184 | 0.97 (0.83 to 1.13) |
| Increase of >10% | 167 | 48 | 1.15 (0.80 to 1.64) | 962 | 245 | 1.25 (1.10 to 1.43) | 207 | 40 | 0.93 (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.