The potential association between sedentary behaviors and risk of temporomandibular disorders: evidence from Mendelian randomization analysis

The role of sedentary behaviors in temporomandibular disorders (TMD) has not been thoroughly investigated. This study aims to investigate the potential association between sedentary behaviors and TMD using Mendelian randomization (MR) analysis. The MR method was employed to assess the causal association between sedentary behaviors and the risk of TMD. Genetic variants associated with sedentary behaviors, such as watching TV (Television), using computers and driving, were used as instrumental variables (IVs). MR analysis was performed using inverse variance-weighted (IVW) and weighted median methods, alongside MR-Egger regression to assess pleiotropy and statistical heterogeneity. Furthermore, leave-one-out analyses were conducted to assess whether any single SNP (single nucleotide polymorphism) or subset of SNPs influenced the results. Our analysis identified a significant association between driving time and the risk of temporomandibular disorders (IVW: OR (Odd ratio) = 2.797, 95% CI (Confidence interval) = 1.148-6.811, p = 0.024; weighted median OR = 4.271, 95% CI = 1.226-14.871, p = 0.023). In contrast, no significant associations were observed between time spent watching TV and using a computer and TMD risk. The robustness of the findings was confirmed through sensitivity analyses, including leave-one-out analysis. This study provides evidence of a potential genetic link between prolonged driving and TMD risk, suggesting that individuals frequently engaged in long-duration driving should be monitored for TMD symptoms. Further research is warranted to explore the complex interactions between sedentary behaviors and TMD, incorporating longitudinal and comprehensive assessments.