Table 1. Baseline characteristics according to age at menopause.
| Age at menopause (year) | P-value | |||||
| <40 | 40-44 | 45-49 | 50-54 | 55+ | ||
| N (%) | 227 (5) | 467 (10) | 1629 (35) | 2124 (45) | 236 (5) | |
| Age at baseline data collection (year) | 56.5 (9.6) | 60.0 (7.7) | 60.9 (6.6) | 61.6 (6.0) | 62.9 (4.7) | < 0.001* |
| Systolic blood pressure (mmHg) | 128.7 (21.3) | 130.5 (21.5) | 130.6 (21.0) | 133.1 (20.6) | 134.8 (19.0) | < 0.001* |
| Diastolic blood pressure (mmHg) | 77.5 (12.0) | 77.5 (12.2) | 77.2 (11.9) | 78.6 (11.7) | 79.3 (10.8) | 0.003* |
| Total cholesterol (mg/dL) | 199.7 (34.8) | 201.9 (35.5) | 202.7 (33.0) | 205.0 (32.6) | 209.4 (35.0) | 0.003* |
| High density lipoprotein cholesterol (mg/dL) | 50.6 (11.5) | 52.1 (12.5) | 52.3 (12.2) | 52.4 (12.8) | 51.6 (12.8) | 0.275* |
| Body mass index (kg/m2) | 23.6 (3.7) | 23.3 (3.2) | 23.2 (3.2) | 23.3 (3.1) | 24.0 (3.4) | 0.014* |
| History of hypertension(%) | 18.5 | 20.3 | 20.6 | 21.1 | 23.3 | 0.764† |
| History of diabetes mellitus(%) | 5.3 | 3.9 | 3.6 | 3.8 | 5.1 | 0.618† |
| Current smokers (%) | 6.4 | 4.8 | 4.5 | 3.1 | 2.6 | < 0.001† |
| Current alcohol drinkers (%) | 21.4 | 21.8 | 19.2 | 20.6 | 21.4 | 0.702† |
| Having a spouse(%) | 93.8 | 89.4 | 90.7 | 91.2 | 91.5 | 0.403† |
| Type of menopause(%) | 0.031† | |||||
| Natural | 18.9 | 57.4 | 82.6 | 90.5 | 91.9 | |
| Surgical | 77.1 | 38.8 | 12.3 | 3.1 | 2.1 | |
| No answer | 4.0 | 3.9 | 5.1 | 6.4 | 5.9 | |
Mean values (standard deviation) for quantitative data and proportion in percentage for qualitative data are shown.
* : Analysis of variance (ANOVA)
† : Chi-square test (degree of freedom = 4)