Table 4.
Odds ratio (95% confidence interval) of reduced BMD and Hazard ratio (95% confidence interval) of fractures incidence, by urine Asb-corrected As, Cd and plasma Se levels in the subsample of individuals older than 50 years.
| OR (95% CI) of reduced BMD (N=702) | HR (95% CI) of incident osteoporosis-related fractures (N=638) | |||||
|---|---|---|---|---|---|---|
| Cases/No cases | Model 1a | Model 2b | Cases/No cases | Model 1 | Model 2 | |
| Urine Asb-corrected As | ||||||
| Tertil 1 | 100/108 | 1.00 (Reference) | 1.00 (Reference) | 25/183 | 1.00 (Reference) | 1.00 (Reference) |
| Tertil 2 | 119/130 | 0.91 (0.60, 1.38) | 0.89 (0.58, 1.35) | 19/204 | 0.90 (0.45, 1.79) | 0.80 (0.39, 1.65) |
| Tertil 3 | 105/140 | 0.75 (0.49, 1.15) | 0.72 (0.47, 1.10) | 22/185 | 1.26 (0.66, 2.4) | 1.27 (0.66, 2.45) |
| 80th vs 20th | 324/378 | 0.79 (0.60, 1.05) | 0.78 (0.59, 1.03) | 66/572 | 1.07 (0.71, 1.62) | 1.09 (0.71, 1.66) |
| p-value | 0.10 | 0.08 | 0.76 | 0.70 | ||
| Urine Cd | ||||||
| Tertil 1 | 99/118 | 1.00 (Reference) | 1.00 (Reference) | 26/171 | 1.00 (Reference) | 1.00 (Reference) |
| Tertil 2 | 97/137 | 0.77 (0.50, 1.20) | 0.75 (0.48, 1.17) | 22/195 | 0.97 (0.51, 1.83) | 0.99 (0.53, 1.85) |
| Tertil 3 | 128/123 | 1.14 (0.76, 1.72) | 1.14 (0.75, 1.73) | 18/206 | 0.75 (0.38, 1.46) | 0.75 (0.39, 1.46) |
| 80th vs 20th | 324/378 | 1.14 (0.86, 1.50) | 1.13 (0.85, 1.50) | 66/572 | 1.13 (0.81, 1.58) | 1.09 (0.80, 1.50) |
| p-value | 0.37 | 0.40 | 0.477 | 0.586 | ||
| Plasma Se | ||||||
| Tertil 1 | 122/117 | 1.00 (Reference) | 1.00 (Reference) | 20/196 | 1.00 (Reference) | 1.00 (Reference) |
| Tertil 2 | 102/133 | 0.70 (0.47, 1.06) | 0.68 (0.45, 1.03) | 18/191 | 1.03 (0.52, 2.01) | 1.09 (0.55, 2.16) |
| Tertil 3 | 100/128 | 0.75 (0.50, 1.13) | 0.70 (0.46, 1.06) | 28/185 | 1.44 (0.77, 2.7) | 1.67 (0.91, 3.04) |
| 80th vs 20th* | 324/378 | 0.61 (0.38, 0.97) | 0.57 (0.36, 0.91) | 66/572 | 1.96 (0.95, 4.06) | 2.25 (1.13, 4.49) |
| p-value* | 0.006 | 0.003 | 0.02 | 0.01 | ||
Model 1 adjusted by age (years), sex (men, women), BMI (kg/m2) and high education (no, yes).
Model 2 is model 1 further adjusted for physical activity (METs min/week), urine cotinine categories (<34, 34–500, ≥500), glomerular filtration rate (ml/min/1.73m2), cumulative-tobacco smoking (pack-years), smoking status, and alcohol intake status (never, former, current).
Urine As was adjusted for urine Asb. The 80th and 20th percentiles of urine biomarker distributions were 13.5 and 3.5 μg/g for Asb-corrected As and 0.76 and 0.20 μg/g for Cd. The corresponding percentiles of plasma Se distribution were 103.7 and 68.9 μg/L.
Association obtained from regression models with plasma Se modelled as restricted quadratic splines with knots at the 10th, 50th and 90th percentiles. The p-value of non-linearity was obtained from a wald-test of the spline terms. Other p-values in the table were obtained from a wald test of the regression coefficient for log-transformed urine arsenic and cadmium.