AUTHOR=Zhang Guangyang , Cai Yuanqing , Liang Jialin , Zhang Jianan , Jing Zhaopu , Lv Leifeng , Zhang Rupeng , Song Jidong , Dang Xiaoqian , Song Qichun TITLE=Causal relationships between rheumatism and dyslipidemia: A two-sample Mendelian randomization study JOURNAL=Frontiers in Endocrinology VOLUME=Volume 13 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2022.961505 DOI=10.3389/fendo.2022.961505 ISSN=1664-2392 ABSTRACT=Background: Dyslipidaemia is often observed in rheumatic diseases, such as ankylosing spondylitis (AS), rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), yet it remains to be detected whether rheumatic diseases have a causal effect on dyslipidaemia. Methods: Significant (P < 5×10-8) and independent (r2 < 0.1) single-nucleotide polymorphisms in genome-wide association studies were selected as instrumental variables to conduct Mendelian randomization (MR) analysis. Inverse variance weighted, weighted median, and MR‒Egger regression were adopted for the causal inference. Subsequently, sensitivity analysis was conducted to assess the stability and reliability of MR. Results: The MR results revealed positive causal relationships of AS with total cholesterol (TC) (β=0.089; 95% CI= 0.050 to 0.128; P=6.07×10-6), low-density lipoprotein (LDL) (β=0.087; 95% CI=0.047 to 0.127; P=1.91×10-5) and high-density lipoprotein (HDL) (β=0.043; 95% CI=0.001 to 0.074; P=0.009). There was no causal effect of RA on TC (β= 0.008, 95% CI= 4.86×10-4 to 0.017, P = 0.064), LDL (β= 6.4×10-4, 95% CI= -0.008 to 0.007, P = 0.871) or HDL (β= 0.005, 95% CI= -0.003 to 0.013, P = 0.200). Additionally, SLE had negative causal links for TC (β = -0.025; 95% CI= -0.036 to -0.015; P=4.42×10-6), LDL (β= -0.015, 95% CI= -0.025 to -0.005; P = 0.003) and HDL (β = -0.013; 95% CI= -0.021 to -0.004; P=0.004). The results were stable and reliable. Conclusion: This study suggested positive causal effects of AS on TC, LDL and HDL, and negative causal effects of SLE on these cholesterol levels, which could provide much help for the pathogenesis and treatment of rheumatic disease patients with dyslipidaemia.