Table 1.
Weighted characteristics of the study population based on age at menarche
| Characteristics | Age at menarche (years) | P value | ||
|---|---|---|---|---|
| ≤ 12 (n = 570) | 13–15 (n = 538) | ≥ 16 (n = 87) | ||
| Age (years), mean (95% CI) | 53.02 (52.45, 53.58) | 53.77 (53.26, 54.27) | 52.30 (51.06, 53.55) | 0.095 |
| Years since menopause (years), mean (95% CI) | 8.68 (7.88, 9.48) | 7.77 (6.99, 8.55) | 9.03 (7.38, 10.68) | 0.088 |
| Body mass index (kg/m2), mean (95% CI) | 30.83 (29.97, 31.68) | 29.23 (28.21, 30.24) | 27.89 (26.36, 29.41) | < 0.001 |
| Lumbar spine BMD (g/cm2), mean (95% CI) | 1.00 (0.98, 1.02) | 0.98 (0.96, 1.00) | 0.92 (0.89, 0.95) | < 0.001 |
| Race, percent (95% CI) | 0.136 | |||
| Non-Hispanic white | 67.53 (61.38, 73.14) | 64.66 (58.13, 70.70) | 57.01 (42.03, 70.81) | |
| Non-Hispanic black | 12.64 (9.77, 16.21) | 13.82 (10.54, 17.91) | 18.44 (11.48, 28.28) | |
| Mexican American | 7.39 (5.28, 10.25) | 6.22 (4.35, 8.81) | 3.23 (1.24, 8.16) | |
| Other race | 12.43 (9.46, 16.18) | 15.30 (12.36, 18.78) | 21.32 (12.52, 33.90) | |
| Education level, percent (95% CI) | 0.586 | |||
| Less than high school | 12.05 (8.72, 16.41) | 13.30 (9.64, 18.07) | 14.10 (6.72, 27.20) | |
| High school | 26.72 (22.36, 31.58) | 22.31 (16.98, 28.74) | 30.89 (17.77, 48.03) | |
| More than high school | 61.24 (54.70, 67.39) | 64.39 (56.84, 71.29) | 55.01 (38.36, 70.61) | |
| Family PIR, percent (95% CI) | 0.269 | |||
| < 1.3 | 16.59 (13.21, 20.63) | 18.28 (13.72, 23.94) | 16.30 (8.63, 28.65) | |
| 1.3–3.5 | 31.51 (26.93, 36.48) | 25.27 (21.23, 29.78) | 41.44 (25.71, 59.13) | |
| ≥ 3.5 | 45.05 (38.87, 51.39) | 49.76 (42.18, 57.36) | 38.34 (23.71, 55.43) | |
| Missing | 6.85 (4.56, 10.17) | 6.69 (4.36, 10.13) | 3.93 (1.57, 9.52) | |
| Total calcium (mmol/L), percent (95% CI) | 0.003 | |||
| T1 (1.900–2.300) | 33.63 (28.74, 38.88) | 23.74 (19.22, 28.94) | 30.13 (18.63, 44.83) | |
| T2 (2.301–2.375) | 33.94 (28.93, 39.34) | 38.41 (33.76, 43.28) | 19.12 (11.32, 30.44) | |
| T3 (2.376–2.750) | 30.05 (24.95, 35.70) | 34.39 (28.92, 40.32) | 41.73 (26.97, 58.15) | |
| Missing | 2.38 (1.15, 4.87) | 3.45 (1.61, 7.24) | 9.01 (3.43, 21.65) | |
| Serum phosphorus (mmol/L), percent (95% CI) | 0.070 | |||
| T1 (0.743–1.130) | 24.48 (20.86, 28.50) | 32.16 (26.08, 38.91) | 22.51 (12.88, 36.34) | |
| T2 (1.131–1.259) | 34.16 (28.19, 40.68) | 26.62 (21.02, 33.10) | 37.36 (21.93, 55.88) | |
| T3 (1.260–1.905) | 39.05 (33.43, 44.98) | 37.76 (31.72, 44.21) | 31.11 (17.54, 48.95) | |
| Missing | 2.31 (1.10, 4.79) | 3.45 (1.61, 7.24) | 9.01 (3.43, 21.65) | |
| Smoking behavior, percent (95% CI) | 0.749 | |||
| Never | 56.92 (51.34, 62.34) | 57.68 (50.46, 64.59) | 60.74 (43.71, 75.50) | |
| Former | 19.64 (15.39, 24.72) | 21.58 (16.69, 27.43) | 24.43 (12.36, 42.56) | |
| Current | 23.44 (18.74, 28.90) | 20.74 (16.35, 25.95) | 14.83 (5.68, 33.48) | |
| Age started smoking, mean (95% CI) | 18.21 (17.17, 19.25) | 18.17 (17.26, 19.08) | 19.20 (16.13, 22.26) | 0.776 |
| Alcohol consumption, percent (95% CI) | 0.584 | |||
| Non-drinker | 14.68 (11.26, 18.92) | 14.91 (11.37, 19.30) | 27.02 (15.04, 43.64) | |
| Moderate drinker | 34.51 (29.39, 40.02) | 34.27 (27.28, 42.02) | 23.86 (12.31, 41.14) | |
| Heavy drinker | 39.54 (33.96, 45.40) | 37.90 (31.52, 44.71) | 36.88 (22.48, 54.07) | |
| Missing | 11.27 (8.33, 15.08) | 12.93 (9.20, 17.86) | 12.24 (4.01, 31.76) | |
| Parity, percent (95% CI) | 0.026 | |||
| 0–1 | 16.78 (12.61, 21.99) | 19.08 (15.12, 23.78) | 22.38 (10.67, 41.04) | |
| 2–3 | 62.66 (58.13, 66.97) | 49.65 (44.39, 54.92) | 52.05 (36.58, 67.13) | |
| ≥ 4 | 9.79 (7.56, 12.60) | 14.52 (10.96, 18.99) | 8.30 (3.49, 18.45) | |
| Missing | 10.77 (7.27, 15.67) | 16.75 (12.01, 22.88) | 17.28 (7.53, 34.90) | |
| Female hormone use, percent (95% CI) | 28.67 (23.66, 34.26) | 26.01 (20.79, 32.00) | 25.60 (14.02, 42.05) | 0.750 |
| Vigorous activities, percent (95% CI) | 29.65 (24.72, 35.10) | 25.68 (20.64, 31.46) | 32.53 (17.51, 52.28) | 0.525 |
| Moderate activities, percent (95% CI) | 60.75 (53.61, 67.47) | 67.11 (61.76, 72.06) | 64.24 (47.20, 78.32) | 0.290 |
| Arthritis, percent (95% CI) | 40.67 (35.38, 46.19) | 36.13 (29.39, 43.46) | 27.43 (15.60, 43.61) | 0.177 |
| Thyroid disease, percent (95% CI) | 22.76 (18.59, 27.56) | 16.11 (12.08, 21.16) | 25.12 (12.19, 44.76) | 0.129 |
| Liver disease, percent (95% CI) | 3.60 (2.35, 5.47) | 5.93 (3.13, 10.95) | 9.66 (2.81, 28.34) | 0.218 |
| Kidney disease, percent (95% CI) | 2.55 (1.25, 5.15) | 2.83 (1.21, 6.49) | 1.26 (0.26, 5.81) | 0.782 |
| Diabetes, percent (95% CI) | 11.81 (8.37, 16.42) | 10.59 (7.30, 15.12) | 4.72 (1.94, 11.04) | 0.496 |
CI confidence interval, BMD bone mineral density, PIR poverty income ratio, T tertile