Table 2.
Age and gender-adjusted* baseline characteristics of participants by BMD (n=1365).
| BMD in the calcaneus (g/cm2) | |||||
|---|---|---|---|---|---|
| Overall | ≤0.33 | ≥0.33–0.66 | >0.66 | P-value | |
| N=1365 | N=445 | N=465 | N=445 | ||
| Age, years; mean (SE) | 48.69 (0.30) | 56.15 (0.73) | 47.24 (0.82) | 43.96 (1.30) | <0.001 |
| Women; % (SE) | 51.0 (1.6) | 82.4 (5.2) | 53.4 (5.4) | 21.0 (4.7) | <0.001 |
| BMI, kg/m2; mean (SE) | 26.15 (0.30) | 24.36 (0.50) | 25.94 (0.46) | 27.64 (0.67) | <0.001 |
| Smoking status | |||||
| Never; % (SE) | 44.7 (4.1) | 36.3 (7.6) | 41.5 (6.6) | 42.3 (7.7) | 0.27 |
| Former; % (SE) | 28.4 (3.4) | 28.3 (6.5) | 33.1 (5.6) | 31.1 (6.2) | 0.50 |
| Current; % (SE) | 27.0 (3.8) | 35.4 (7.5) | 25.4 (6.0) | 26.6 (7.2) | 0.07 |
| Cumulative smoking, pack-year; mean (SE) | 8.46 (0.88) | 10.85 (1.43) | 9.58 (1.47) | 9.23 (1.80) | 0.33 |
| Urine cotinine > 500 mg/dl; % (SE) | 1.48 (0.07) | 1.60 (0.13) | 1.47 (0.11) | 1.48 (0.14) | 0.10 |
| Alcohol intake status | |||||
| Never; % (SE) | 37.9 (3.8) | 38.5 (7.5) | 37.8 (6.2) | 35.0 (7.1) | 0.40 |
| Former; % (SE) | 8.7 (2.4) | 8.1 (4.3) | 9.4 (4.0) | 9.1 (4.6) | 0.78 |
| Current; % (SE) | 53.5 (4.0) | 53.5 (7.6) | 52.8 (6.5) | 55.9 (7.5) | 0.53 |
| eGFR < 60 ml/min/1.73m2; % (SE) | 7.0 (1.7) | 8.4 (3.5) | 6.0 (2.7) | 6.5 (3.1) | 0.61 |
| High education; % (SE) | 77.6 (2.2) | 75.6 (4.0) | 78.6 (3.8) | 81.0 (3.9) | 0.05 |
| Physical activity, METs min/week; mean (SE) | 3262 (275) | 2947 (366) | 3036 (393) | 3653 (676) | 0.02 |
| Urine As levels (μg/g); geometric mean (95% CI) | 66.25 (52.29, 83.95) | 58.50 (36.82, 92.96) | 74.00 (51.55, 106.21) | 72.31 (45.77, 114.24) | 0.11 |
| Urine Asb (μg/g); geometric mean (95% CI)** | 50.44 (30.74, 82.78) | 51.73 (21.82, 122.62) | 51.30 (24.41, 107.80) | 69.38 (26.17, 183.89) | 0.62 |
| Asb-corrected urine As (μg/g); geometric mean (95% CI) | 6.71 (5.80, 7.77) | 6.28 (4.75, 8.31) | 6.98 (5.51, 8.84) | 6.77 (5.13, 8.92) | 0.51 |
| Urine Cd (μg/g); geometric mean (95% CI) | 0.38 (0.33, 0.45) | 0.41 (0.30, 0.54) | 0.38 (0.30, 0.49) | 0.39 (0.30, 0.52) | 0.97 |
| Plasma Se (μg/l); geometric mean (95% CI) | 84.7 (81.2, 88.3) | 82.8 (76.6, 89.4) | 84.7 (79.8, 90.0) | 85.7 (78.7, 93.3) | 0.29 |
*
Age and sex are very strong, non modifiable, determinants of BMD. We, thus, accounted for sex and age because we wanted to descriptively assess other determinants independently than age and sex.
**
Subset of 284 participants with measured urine As species.
Abbreviatons: SE, standard error; eGFR, estimated glomerular filtration rate; CI, confidence interval