Lifestyle factors and rotator cuff injury: A Mendelian randomization analysis of smoking, alcohol, and coffee consumption

The causal relationship between some lifestyles and rotator cuff injury is unclear. This study aims to elucidate the genetic causality between smoking initiation, alcohol intake frequency, and coffee consumption in relation to rotator cuff injury. We conducted a 2-sample Mendelian randomization (MR) analysis utilizing summary-level data from extensive genome-wide association studies. Single nucleotide polymorphisms achieving genome-wide significance (P < 5 * 10-8) were employed as instrumental variables for each exposure. The inverse variance weighted method served as the principal statistical technique, complemented by the weighted median, MR-Egger regression, and MR-PRESSO methods for sensitivity analyses, accommodating some of the assumptions inherent in IVs. The initiation of smoking was found to have a genetically predictive inverse association with rotator cuff injury incidence. The inverse variance weighted approach indicated a pooled odds ratio for rotator cuff injury of 0.70 (95% confidence interval 0.58-0.85; P = 3 * 10-4) per standard deviation increase in smoking initiation rates. Similarly, coffee consumption demonstrated a negative genetic causality with rotator cuff injury, evidenced by an odds ratio of 0.46 (95% confidence interval 0.29-0.72; P = 8 * 10-4). Conversely, alcohol consumption did not show a statistically significant causal relationship with rotator cuff injury incidence. The findings suggest a genetic predisposition that links smoking initiation and coffee consumption with a decreased risk of rotator cuff injury. Conversely, the genetic evidence to assert a causal relationship between alcohol intake and rotator cuff injury was found to be inconclusive.