Table 2.
Baseline characteristics of study subjects according to the duration of hormone therapy
| Duration of OC use (years) | Duration of HRT (years) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Never (n = 175,294) | < 1 (n = 19,927) | ≥ 1 (n = 14,367) | P | Never (n = 167,530) | < 2 (n = 23,832) | 2–5 (n = 9845) | ≥ 5 (n = 8381) | P | |
| Age (years) | 62.96 ± 8.45 | 61.59 ± 7.37 | 62.70 ± 7.12 | < 0.0001 | 63.62 ± 8.45 | 59.10 ± 6.87 | 59.35 ± 6.36 | 61.43 ± 60 | < 0.0001 |
| BMI (kg/m2) | 24.21 ± 3.18 | 24.35 ± 3.08 | 24.61 ± 3.12 | < 0.001 | 24.33 ± 3.22 | 24.00 ± 2.96 | 23.78 ± 2.86 | 23.85 ± 2.79 | < 0.0001 |
| Systolic BP (mmHg) | 125.55 ± 15.98 | 125.06 ± 15.71 | 126.15 ± 15.62 | < 0.0001 | 126.30 ± 16.04 | 122.65 ± 15.08 | 122.07 ± 15.01 | 122.77 ± 15.19 | < 0.0001 |
| Diastolic BP (mmHg) | 76.82 ± 10.01 | 76.55 ± 9.99 | 76.82 ± 9.95 | 0.0019 | 77.14 ± 10.04 | 75.59 ± 9.80 | 75.20 ± 9.74 | 75.04 ± 9.68 | < 0.0001 |
| Fasting glucose (mg/dL) | 100.52 ± 25.38 | 100.40 ± 24.65 | 101.41 ± 25.07 | 0.0002 | 101.29 ± 26.27 | 98.14 ± 20.76 | 97.26 ± 20.47 | 96.81 ± 20.59 | < 0.0001 |
| Total cholesterol (mg/dL) | 206.66 ± 46.53 | 205.79 ± 41.49 | 204.82 ± 45.48 | < 0.0001 | 207.16 ± 46.96 | 205.86 ± 44.10 | 202.37 ± 38.71 | 198.73 ± 38.30 | < 0.0001 |
| HDL (mg/dL) | 57.38 ± 36.31 | 56.87 ± 30.07 | 56.86 ± 31.51 | 0.0468 | 57.30 ± 36.50 | 57.68 ± 32.82 | 57.26 ± 28.92 | 56.09 ± 27.50 | 0.0059 |
| LDL (mg/dL) | 125.19 ± 80.79 | 124.31 ± 60.11 | 123.64 ± 64.17 | 0.0309 | 125.16 ± 74.84 | 125.18 ± 60.46 | 123.93 ± 113.57 | 122.51 ± 121.11 | 0.0105 |
| Smoking status | 0.208 | < 0.0001 | |||||||
| Never | 168,431 (96.08) | 19,019 (95.44) | 13,638 (94.93) | 161,079 (96.15) | 22,713 (95.30) | 9334 (94.81) | 7962 (95.00) | ||
| Ex-smoker | 1901 (1.08) | 320 (1.61) | 253 (1.76) | 1773 (1.06) | 371 (1.56) | 177 (1.80) | 153 (1.83) | ||
| Current smoker | 4962 (2.83) | 588 (2.95) | 476 (3.31) | 4678 (2.79) | 748 (3.14) | 334 (3.39) | 266 (3.17) | ||
| Alcohol consumptiona | < 0.0001 | < 0.0001 | |||||||
| None | 158,564 (90.46) | 17,410 (87.37) | 12,499 (87.00) | 152,177 (90.84) | 20,603 (86.45) | 8447 (85.80) | 7246 (86.46) | ||
| Mild | 15,998 (9.13) | 2390 (11.99) | 1759 (12.24) | 14,633 (8.73) | 3085 (12.94) | 1337 (13.58) | 1092 (13.03) | ||
| Heavy | 732 (0.42) | 127 (0.64) | 109 (0.76) | 720 (0.43) | 144 (0.60) | 61 (0.62) | 43 (0.51) | ||
| Levels of income | 0.0034 | < 0.0001 | |||||||
| Medical aid + 1st quartile (the lowest) | 36,339 (20.73) | 4079 (20.47) | 2833 (19.72) | 34,427 (20.55) | 5190 (21.78) | 2022 (20.54) | 1612 (19.23) | ||
| 2nd quartile | 30,713 (17.52) | 3454 (17.33) | 2435 (16.95) | 29,337 (17.51) | 4276 (17.94) | 1697 (17.24) | 1292 (15.42) | ||
| 3rd quartile | 44,113 (25.17) | 5060 (25.39) | 3610 (25.13) | 42,234 (25.21) | 5957 (25.00) | 2503 (25.42) | 2089 (24.93) | ||
| 4th quartile (the highest) | 64,129 (36.58) | 7334 (36.80) | 5489 (38.21) | 61,532 (36.73) | 8409 (35.28) | 3623 (36.80) | 3388 (40.42) | ||
| Regular exercise | 30,862 (17.61) | 4005 (20.10) | 3028 (21.08) | < 0.0001 | 28,011 (16.72) | 5330 (22.36) | 2372 (24.09) | 2182 (26.04) | < 0.0001 |
| Hypertension | 91,855 (52.40) | 10,346 (51.92) | 8262 (57.51) | < 0.0001 | 91,657 (54.71) | 10,477 (43.96) | 4322 (43.90) | 4007 (47.81) | |
| Diabetes mellitus | 28,077 (16.02) | 3155 (15.83) | 2643 (18.40) | < 0.0001 | 28,809 (17.20) | 2891 (12.13) | 1121 (11.39) | 1054 (12.58) | |
| Dyslipidemia | 69,087 (39.41) | 8101 (40.65) | 6126 (42.64) | < 0.0001 | 67,068 (40.03) | 9434 (39.59) | 3712 (37.70) | 3100 (36.99) | |
| Age at menarche (years) | 16.57 ± 1.83 | 16.49 ± 1.83 | 16.56 ± 1.81 | < 0.0001 | 16.63 ± 1.81 | 16.30 ± 1.86 | 16.25 ± 1.82 | 16.35 ± 1.84 | |
| Age at menopause (years) | 49.83 ± 4.15 | 50.13 ± 4.15 | 50.24 ± 4.19 | < 0.0001 | 49.88 ± 4.14 | 50.07 ± 4.00 | 50.04 ± 4.18 | 49.41 ± 4.78 | |
| Duration of fertility (years) | 33.26 ± 4.54 | 33.65 ± 4.52 | 33.68 ± 4.54 | < 0.0001 | 33.25 ± 4.55 | 33.78 ± 4.33 | 33.79 ± 4.43 | 33.06 ± 4.98 | |
| Duration of OC use (years) | < 0.0001 | ||||||||
| Never | 144,214 (86.08) | 17,651 (74.06) | 7295 (74.1) | 6134 (73.19) | |||||
| < 1 | 13,738 (8.20) | 3817 (16.02) | 1301 (13.21) | 1071 (12.78) | |||||
| ≥ 1 | 9578 (5.72) | 2364 (9.92) | 1249 (12.69) | 1176 (14.03) | |||||
| Duration of HRT (years) | < 0.0001 | ||||||||
| Never | 144,214 (82.27) | 13,738 (68.94) | 9578 (66.67) | ||||||
| < 2 | 17,651 (10.07) | 3817 (19.15) | 2364 (16.45) | ||||||
| 2–5 | 7295 (4.16) | 1301 (6.53) | 1249 (8.69) | ||||||
| ≥ 5 | 6134 (3.50) | 1071 (5.37) | 1176 (8.19) | ||||||
Data are expressed as the mean ± standard deviation, SD, or n (%)
Abbreviations: BMI body mass index, BP blood pressure, HDL high-density lipoprotein, LDL low-density lipoprotein, OC oral contraceptives, HRT hormone replacement therapy
aAlcohol consumption: mild = up to 30 g (equivalent to 3 drinks) a day; heavy = more than 30 g a day