Table 2.
Association between water hardness and prevalent UC and CD in the cross-sectional study
| CD | UC | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cases | Model 1 OR (95% CI) | P | Model 2 OR (95% CI) | P | Model 3 OR (95% CI) | P | Cases | Model 1 OR (95% CI) | P | Model 2 OR (95% CI) | P | Model 3 OR (95% CI) | P | ||
| Water hardness (USGS, mg/l) | 0–60 | 695 | ref | ref | ref | 1459 | ref | ref | ref | ||||||
| 60–120 | 347 | 0.90 (0.79–1.02) | 0.096 | 0.91 (0.80–1.04) | 0.158 | 0.91 (0.80–1.04) | 0.151 | 762 | 0.93 (0.86–1.02) | 0.130 | 0.94 (0.86–1.02) | 0.153 | 0.95 (0.87–1.04) | 0.236 | |
| 120–180 | 107 | 0.92 (0.75–1.13) | 0.450 | 0.96 (0.78–1.18) | 0.683 | 0.95 (0.77–1.17) | 0.620 | 232 | 0.96 (0.84–1.11) | 0.583 | 0.97 (0.85–1.12) | 0.694 | 0.98 (0.85–1.13) | 0.797 | |
| > 180 | 654 | 0.87 (0.78–0.97) | 0.011 | 0.90 (0.81–1.00) | 0.058 | 0.88 (0.79–0.99) | 0.027 | 1295 | 0.83 (0.77–0.89) | < 0.001 | 0.84 (0.78–0.91) | < 0.001 | 0.86 (0.80–0.93) | < 0.001 | |
| P for trend | 0.016 | 0.081 | 0.039 | < 0.001 | < 0.001 | < 0.001 | |||||||||
| Water hardness (WHO, mg/l) | < 200 | 1163 | ref | ref | ref | 2474 | ref | ref | ref | ||||||
| ≥ 200 | 640 | 0.90 (0.82–0.99) | 0.029 | 0.92 (0.83–1.02) | 0.098 | 0.90 (0.82–1.00) | 0.048 | 1274 | 0.85 (0.79–0.91) | < 0.001 | 0.86 (0.80–0.92) | < 0.001 | 0.88 (0.82–0.94) | < 0.001 | |
| CaCO3 concentration (per SD) | 0.94 (0.89–0.98) | 0.007 | 0.95 (0.91–1.00) | 0.041 | 0.94 (0.90–0.99) | 0.017 | 0.92 (0.89–0.95) | < 0.001 | 0.92 (0.89–0.96) | < 0.001 | 0.93 (0.90–0.96) | < 0.001 | |||
| Ca concentration (per SD) | 0.92 (0.88–0.97) | 0.001 | 0.93 (0.89–0.98) | 0.008 | 0.93 (0.88–0.97) | 0.002 | 0.93 (0.90–0.97) | < 0.001 | 0.94 (0.91–0.98) | < 0.001 | 0.95 (0.92–0.98) | 0.003 | |||
| Mg concentration (per SD) | 0.99 (0.95–1.04) | 0.814 | 1.00 (0.95–1.05) | 0.985 | 1.00 (0.95–1.05) | 0.918 | 0.99 (0.96–1.03) | 0.624 | 0.99 (0.96–1.03) | 0.626 | 1.00 (0.96–1.03) | 0.895 | |||
Abbreviations: USGS United States Geological Survey, WHO World Health Organization, OR odds ratio, P p-values
Model 1: adjusted for age and sex
Model 2: adjusted for age, sex, CCI scores, BMI, IPAQ physical activity, alcohol consumption, smoking status, ethnicity, TDI and diet quality scores
Model 3: adjusted for age, sex, CCI scores, BMI, IPAQ physical activity, alcohol consumption, smoking status, ethnicity, TDI, diet quality scores, the first five principal components of ancestry genetics and PRS scores
Bold font for USGS and WHO water hardness groups indicates p < 0.025, while bold font for other variables indicates p < 0.05