Sedentary lifestyle and hallux valgus: Unraveling the causal pathways and the mediating role of calcium homeostasis through mendelian randomization.

Abstract

The causal relationships between hallux valgus (HV), sedentary behavior and calcium homeostasis remain unclear. This study aimed to explore these associations using Mendelian randomization (MR) analysis. Leisure screen time (LST) was used as an indicator of sedentary behavior, while seven traits and three diseases were selected to represent calcium homeostasis. Two-sample MR was performed to assess the causal effect of sedentary behavior and calcium homeostasis on HV. Two-step MR was conducted to quantify the mediating roles of calcium homeostasis-related traits in the association between sedentary behavior and HV. Our results showed that longer LST was strongly associated with higher risk of HV (odds ratio (OR) = 1.1902, 95 %CI = 1.0129-1.3986, p = 0.0343). By contrast, serum calcium (S-Ca) levels were negatively associated with HV risk (OR = 0.7530, 95 %CI = 0.5675-0.9992, p = 0.0494). Mediation analyses found that S-Ca played an important mediating role in the effect of LST on HV (proportion mediated = 10.4 %). Our results extend the understanding of the pathogenesis of HV, and highlight the importance of preoperative metabolic optimization and postoperative behavioral and calcium supplementation strategies to enhance surgical outcomes and mitigate recurrence.