Purpose: This study aims to examine the interactive effect of fluoride burden with calcitonin receptor (CTR) gene polymorphisms on the risk of fluoride (F) bone injury and provide the basis for determination of F bone injury risk factors.
Methods: In this case-control study, a total of 119 cases and 126 controls were enrolled from 2 aluminum plants in Hubei province. F burden (UF) was measured by F ion-selective electrode method. The CTR gene polymorphisms were determined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Logistic regression analysis was used to estimate multivariate-adjusted odds ratios, 95% confidence intervals (CI).
Results: The odds of developing F bone injury for participants in the moderate F burden group versus the mild F burden group were 4.1 (95% CI: 1.9, 8.7); the heavy F burden group versus the mild F burden group were 14.1 (95% CI: 6.5, 30.6). The odds of developing F bone injury for participants with the TC & TT genotypes versus the CC genotype were 2.6 (95% CI: 1.4, 4.7). The interactions between TC & TT genotypes and moderate, heavy F burden were significant (OR = 14.4; OR = 40.3).
Conclusion: The interactive effect of F burden and CTR genotype was significant, which increased the F bone injury risk.