Association of education attainment and risk of connective tissue diseases

We employed two-sample Mendelian randomization (MR) to assess the genetic causal relationship between educational attainment (EA) and risk of five common connective tissue diseases (CTDs).

Educational attainment (self-reported at age ≥30 years) was obtained from a meta-analysis of years of schooling in 766 345 participants of European ancestry from genome-wide association studies (GWAS). A total of 1265 signals associated with EA were identified. Genetic data for five CTDs [rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc), polymyositis (PM), and dermatomyositis (DM)] were obtained from the FinnGen consortium. Two-sample MR analyses were performed separately for EA and the five CTDs.

We found a negative causal relationship between EA and RA (OR_IVW = 0.627, 95% CI = 0.537-0.732, p < .001), and SLE (OR_IVW = 0.341, 95% CI = 0.123-0.944, p = .038). There were no genetic causal association between EA and SSc (OR_IVW = 0.647, 95% CI = 0.351-1.195, p = .164), PM (OR_IVW = 0.938, 95% CI = 0.320-2.746, p = .907), or DM (OR_IVW = 0.754, 95% CI = 0.351-1.619, p = .468). None of the analyses revealed any horizontal pleiotropy or heterogeneity.

Our findings indicated a potential causal association between EA and RA, SLE, emphasizing the need for further investigation and potential integration of EA into clinical practice to enhance treatment strategies.