Table 1.
Weighted characteristics of the study sample.
| Male (n=3565) | Female (n=3476) | P value | |
|---|---|---|---|
| Age (years) | 33.65 ± 8.62 | 34.42 ± 8.84 | < 0.001 |
| Race/ethnicity (%) | 0.261 | ||
| White | 57.74 | 58.06 | |
| Black | 11.6 | 12.89 | |
| Mexican American | 12.4 | 11.61 | |
| Other race | 18.25 | 17.44 | |
| Educational level, n (%) | < 0.001 | ||
| Less than high school | 12.6 | 11.37 | |
| High school | 23.4 | 17.96 | |
| More than high school | 64 | 70.67 | |
| Ratio of family income to poverty (%) | 2.90 ± 1.62 | 2.72 ± 1.61 | < 0.001 |
| Moderate activities (%) | <0.001 | ||
| No | 25.87 | 29.9 | |
| Yes | 74.13 | 70.1 | |
| Body mass index (kg/m2) | 28.72 ± 6.22 | 28.99 ± 7.62 | 0.104 |
| Alkaline phosphatase (u/l) | 66.96 ± 21.76 | 63.42 ± 21.16 | < 0.001 |
| Serum calcium (mmol/l) | 2.37 ± 0.08 | 2.32 ± 0.08 | < 0.001 |
| Serum phosphorus (mmol/l) | 1.20 ± 0.19 | 1.21 ± 0.17 | 0.054 |
| Serum uric acid (umol/l) | 361.15 ± 71.95 | 272.74 ± 61.75 | < 0.001 |
| Total cholesterol (mmol/l) | 4.92 ± 1.02 | 4.79 ± 0.90 | < 0.001 |
| Triglyceride (mmol/l) | 1.93 ± 1.72 | 1.40 ± 1.20 | < 0.001 |
| Glycohemoglobin (%) | 5.41 ± 0.77 | 5.37 ± 0.71 | 0.026 |
| Blood urea nitrogen (mmol/l) | 4.80 ± 1.39 | 4.04 ± 1.33 | < 0.001 |
| Serum creatinine (umol/l) | 85.06 ± 16.67 | 65.22 ± 20.21 | < 0.001 |
| Urinary albumin creatinine ratio (mg/g) | 18.81 ± 215.08 | 23.62 ± 123.91 | 0.257 |
| Total protein (g/l) | 72.30 ± 4.14 | 71.21 ± 4.06 | < 0.001 |
| Average caffeine intake (g/day) | 0.15 ± 0.18 | 0.13 ± 0.15 | < 0.001 |
| Lumbar bone mineral density (g/cm2) | 1.03 ± 0.15 | 1.06 ± 0.14 | < 0.001 |
Continuous variables are presented as Mean ± SD, P-value was calculated by a weighted linear regression model. Categorical variables are presented as %, P-value was calculated by chi-square test.