Table 7.
Association between water hardness and the risk of CD by genetic susceptibility
| Low genetic risk | High genetic risk | |||||
|---|---|---|---|---|---|---|
| P for interaction | HR (95% CI) | P | HR (95% CI) | P | ||
| Water hardness (USGS, mg/l) | 0–60 | ref | ref | ref | ||
| 60–120 | 0.250 | 0.87 (0.65–1.16) | 0.342 | 0.92 (0.75–1.14) | 0.211 | |
| 120–180 | 0.124 | 0.35 (0.17–0.70) | 0.003 | 0.66 (0.45–0.97) | 0.035 | |
| > 180 | 0.794 | 0.74 (0.57–0.95) | 0.019 | 0.89 (0.75–1.07) | 0.457 | |
| P for trend | 0.008 | 0.162 | ||||
| Water hardness (WHO, mg/l) | < 200 | ref | ref | ref | ||
| ≥ 200 | 0.427 | 0.83 (0.66–1.05) | 0.127 | 0.94 (0.80–1.10) | 0.446 | |
| CaCO3 concentration (per SD) | 0.348 | 0.88 (0.79–0.99) | 0.032 | 0.95 (0.88–1.02) | 0.171 | |
| Ca concentration (per SD) | 0.272 | 0.90 (0.80–1.01) | 0.085 | 0.97 (0.90–1.05) | 0.462 | |
| Mg concentration (per SD) | 0.655 | 0.02 (0.81–1.05) | 0.226 | 0.95 (0.88–1.04) | 0.285 | |
Abbreviations: USGS United States Geological Survey, WHO World Health Organization, HR hazards ratio, P p-values
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
Bold font for USGS and WHO water hardness groups indicates p < 0.025, while bold font for other variables indicates p < 0.05