TABLE 1.
Characteristics of Study Population
| Variable | All (n = 9961) | Women (n = 4958) | Men (n = 5003) |
|---|---|---|---|
| Age (yr) | |||
| Mean ± SD | 47.1 ± 18.7 | 46.6 ± 18.4 | 47.6 ± 19.0* |
| 20–29 (n; %) | 2130 (21.4%) | 1038 (20.9%) | 1093 (21.8%) |
| 30–39 (n; %) | 2061 (20.7%) | 1106 (22.3%) | 956 (19.1%) |
| 40–49 (n; %) | 1677 (16.8%) | 854 (17.2%) | 823 (16.%) |
| 50–59 (n; %) | 1126 (11.3%) | 569 (11.5%) | 558 (11.2%) |
| 60–69 (n; %) | 1380 (13.9%) | 639 (12.9%) | 741 (14.8%) |
| 70–79 (n; %) | 983 (19.9%) | 479 (9.7%) | 505 (10.1%) |
| 80+ (n; %) | 604 (6.1%) | 273 (5.5%) | 331 (6.6%) |
| Race/ethnicity (n; %) | |||
| White | 3979 (40%) | 1957 (39%) | 2026 (40%) |
| Black | 3050 (31%) | 1617 (33%) | 1433 (29%)† |
| Mexican American | 2932 (29%) | 1384 (28% | 1546 (31%)‡ |
| Total hip BMD (mg/cm2) (mean ± SD) | 0.97 ± 0.18 | 0.91 ± 0.17 | 1.02 ± 0.17† |
| Body mass index (kg/m2) (mean ± SD) | 27.3 ± 5.6 | 27.9 ± 6.5 | 26.8 ± 4.6† |
| Height (m) (mean ± SD) | 1.67 ± 0.98 | 1.60 ± 0.71 | 1.74 ± 0.75† |
| 25(OH)D concentrations (nM) | |||
| Mean ± SD | 62.6 ± 27.2 | 57.8 ± 26.8 | 67.4 ± 27.1† |
| <50 (n; %) | 3677 (37%) | 2267 (46%) | 1410 (28%) |
| 50–74 (n; %) | 3410 (34%) | 1571 (32%) | 1839 (37%) |
| 75+ (n; %) | 2874 (29%) | 1120 (22%) | 1758 (35%) |
| Physical activity (METs) | |||
| Mean ± SD | 93.3 ± 127.3 | 74.9 ± 108.6 | 111.8 ± 141.5† |
| Percent with 0 METs | 22% | 27% | 17% |
| Poverty/income ratio (mean ± SD) | 2.1 ± 1.81 | 2.0 ± 1.7 | 2.3 ± 1.9† |
| Uncorrected calcium intake (mg/d) (mean ± SD) | 749 ± 503 | 647 ± 439 | 850 ± 542† |
| Measurement error corrected calcium intake (mg/d; based on one repeat intake assessment) (mean ± SD)§ | 776 ± 257 | 724 ± 224 | 827 ± 277† |
| Any estrogen intake | |||
| Never (n; %) | 1782 (35.9%) | ||
| Former (n; %) | 2355 (47.5%) | ||
| Current (n; %) | 741 (15.0%) | ||
| Missing (n; %) | 80 (1.6%) | ||
| Smoking | |||
| Never (n; %) | 4790 (48.1%) | 2991 (60.3%) | 1799 (35.9%)† |
| Former (n; %) | 2427 (24.4%) | 800 (14.1%) | 1628 (32.5%)† |
| Current 1–10 (n; %) | 1311 (13.2%) | 564 (11.4%) | 748 (14.9%)† |
| Current 11–20 (n; %) | 973 (9.8%) | 424 (8.6%) | 549 (11.0%)† |
| Current 21+ (n; %) | 460 (4.6%) | 179 (3.6%) | 283 (5.7%)† |
*
p < 0.05.
†
p < 0.0001.
‡
p < 0.001.
§
Calcium intake variable used in the analyses