Table 1 Baseline characteristics of the study populationa
From: Association between depression and young-onset dementia in middle-aged women
Characteristics | 40–60-year-old women | |
|---|---|---|
Premenopausal women | Postmenopausal women | |
N = 946,931 | N = 674,420 | |
Age at recruitment (years) | 45.0 ± 4.0 | 54.8 ± 3.6 |
Smoking status | ||
Nonsmoker | 899,439 (95.0) | 646,036 (95.8) |
Ex-smoker | 15,167 (1.6) | 8,129 (1.2) |
Current smoker | 32,325 (3.4) | 20,255 (3.0) |
Drinking | ||
Non | 679,530 (71.8) | 562,053 (83.3) |
Mild | 256,474 (27.1) | 107,262 (15.9) |
Heavy | 10,927 (1.1) | 5,105 (0.8) |
Regular exercise | 163,687 (17.3) | 136,003 (20.2) |
BMI level | ||
< 18.5 | 26,462 (2.8) | 11,785 (1.8) |
≥ 18.5, < 23 | 465,842 (49.2) | 252,262 (37.4) |
≥ 23, < 25 | 221,228 (23.4) | 181,507 (26.9) |
≥ 25, < 30 | 204,117 (21.5) | 202,373 (30.0) |
≥ 30 | 29,282 (3.1) | 26,493 (3.9) |
Low income | 234,652 (24.8) | 162,413 (24.1) |
Diabetes mellitus | 33,548 (3.5) | 58,620 (8.7) |
Hypertension | 132,592 (14.0) | 219,133 (32.5) |
Dyslipidemia | 101,959 (10.8) | 201,405 (29.9) |
Chronic kidney disease | 39,628 (4.2) | 35,781 (5.3) |
Depression | 31,336 (3.3) | 39,885 (5.9) |
Age at menarche | ||
≤ 12 | 41,863 (4.4) | 9,849 (1.5) |
13–14 | 297,848 (31.5) | 109,848 (16.3) |
15–16 | 433,982 (45.8) | 287,705 (42.6) |
> 16 | 173,238 (18.3) | 267,018 (39.6) |
Age at menopause | N/A | |
< 40 | 8,688 (1.3) | |
40–44 | 30,946 (4.6) | |
45–50 | 192,025 (28.5) | |
51–54 | 390,605 (57.9) | |
≥ 55 | 52,156 (7.7) | |
Parity | ||
0 | 35,357 (3.7) | 15,575 (2.3) |
1 | 126,347 (13.3) | 59,051 (8.8) |
≥ 2 | 785,227 (83.0) | 599,794 (88.9) |
Duration of breast feeding | ||
No | 172,324 (18.2) | 62,816 (9.3) |
< 6 month | 229,361 (24.2) | 62,580 (9.3) |
≥ 6, < 12 month | 249,258 (26.3) | 145,539 (21.6) |
≥ 12 month | 295,988 (31.3) | 403,485 (59.8) |
Duration of oral contraceptive use | ||
No | 821,407 (86.8) | 568,036 (84.2) |
< 12 month | 92,184 (9.7) | 67,737 (10.1) |
≥ 12 month | 33,340 (3.5) | 38,647 (5.7) |
Hormone replacement therapy (yes) | N/A | 135,159 (20.0) |