Table 3.
Associations of season of birth with risk of dementia and of Alzheimer’s disease, Rotterdam study, the Netherlands, 1990–2018
| Season of birth | n/N | Model 1 | Model 2 | Model 3 | |||
|---|---|---|---|---|---|---|---|
| HR | 95% CI | HR | 95% CI | HR | 95% CI | ||
| All-cause dementia | |||||||
| Winter (Dec., Jan., Feb.) | 491/3204 | 1.15 | 1.01–1.31 | 1.16 | 1.02–1.32 | 1.13 | 0.99–1.29 |
| Spring (Mar., Apr., May.) | 458/3330 | 1.12 | 0.98–1.28 | 1.12 | 0.98–1.28 | 1.10 | 0.96–1.26 |
| Summer (Jun., Jul., Aug.) | 428/3256 | 1.00 | Referent | 1.00 | Referent | 1.00 | Referent |
| Fall (Sep., Oct., Nov.) | 473/3174 | 1.17 | 1.03–1.33 | 1.17 | 1.03–1.33 | 1.10 | 0.96–1.26 |
| Alzheimer’s disease | |||||||
| Winter (Dec., Jan., Feb.) | 377/3204 | 1.23 | 1.06–1.43 | 1.23 | 1.06–1.43 | 1.20 | 1.03–1.40 |
| Spring (Mar., Apr., May.) | 335/3330 | 1.14 | 0.98–1.33 | 1.14 | 0.98–1.33 | 1.13 | 0.96–1.32 |
| Summer (Jun., Jul., Aug.) | 309/3256 | 1.00 | Referent | 1.00 | Referent | 1.00 | Referent |
| Fall (Sep., Oct., Nov.) | 336/3174 | 1.15 | 0.99–1.35 | 1.15 | 0.99–1.35 | 1.08 | 0.92–1.26 |
CI confidence interval, HR hazard ratio, n number of dementia cases, N total sample size
Model 1 is adjusted for age and sex. Model 2 is additionally adjusted for education. Model 3 is additionally adjusted for ethnicity, body mass index, systolic blood pressure, diastolic blood pressure, smoking, history of diabetes mellitus, alcohol use, total cholesterol, high-density lipoprotein cholesterol, APOE ε4 genotype, history of heart failure, history of coronary heart disease, history of stroke and depressive symptoms