Association between diabetes mellitus and adhesive capsulitis of shoulder: A 2-sample Mendelian randomization study

The objective of this study was to investigate whether there is a causal relationship between diabetes mellitus and adhesive capsulitis of shoulder (ACS). A 2-sample Mendelian randomization analysis was performed using publicly available genome-wide association study statistics. To determine whether diabetes was causally associated with ACS, 2 datasets on diabetes among Europeans from the genome-wide association studies catalogue and ACS among Europeans from FinnGen were extracted and the data were analyzed using inverse variance-weighted, Mendelian randomization 123456123451231 Egger regression, weighted medians, weighted modes and simple modes. Sensitivity analysis and heterogeneity analysis were then used to assess the stability and reliability of the results. Mendelian randomization analysis showed causality between type 1 diabetes and ACS (odds ratio = 0.97, 95% confidence interval = 0.85-1.11, P < .05). No significant causal effect of type 2 diabetes on ACS (odds ratio = 0.97, 95% confidence interval = 0.95-1.13, P = .414). The Cochran Q test showed only a low level of heterogeneity between the type 1 diabetes and ACS data sets (Q = 106.0431, P = .045). Not heterogeneous between type 2 diabetes and ACS. Egger-intercept and funnel plots for data did not show multidirectional and asymmetry at the gene level. The study was the first to find a causal association between type 1 diabetes and the risk of developing ACS in European people. No cause-and-effect genetic link was found between type 2 diabetes and shoulder adhesive capsulitis.