Causal associations of obesity with chronic kidney disease and arterial stiffness: a Mendelian randomization study.

Abstract

PURPOSE\nObservational studies have associated obesity with chronic kidney disease (CKD) and arterial stiffness, but the causality remains unclear. We aimed to investigate the causality of obesity with CKD and arterial stiffness using Mendelian randomization (MR) analysis.\n\n\nMETHODS\nWe genotyped 14 body mass index (BMI)-associated variants validated in East Asians in 11384 Chinese adults. A genetic risk score based on the 14 variants and the 14 individual single nucleotide polymorphisms were respectively used as instrumental variables (IVs). CKD was defined as estimated glomerular filtration rate <60\xa0mL/min/1.73 m 2. Arterial stiffness was defined as brachial-ankle pulse wave velocity >1550\xa0cm/s.\n\n\nRESULTS\nUsing the genetic risk score as the IV, we demonstrated causal relations of each 1-standard deviation increment in BMI with CKD (odds ratio [OR]: 2.36; 95% confidence interval [CI]: 1.11-5.00) and arterial stiffness (OR: 1.71; 95% CI: 1.22-2.39). Using the 14 single nucleotide polymorphisms individually as IVs, each 1-standard deviation increment in BMI casually associated with CKD (OR: 2.58; 95% CI: 1.39-4.79) and arterial stiffness (OR: 1.87; 95% CI: 1.24-2.81) in the inverse-variance weighted analysis, and MR-Egger regression revealed no evidence of horizontal pleiotropy (Both P for intercept≥0.34). The causality between obesity and CKD was validated in two-sample MR analysis among Europeans (681275 of Genetic Investigation of ANthropometric Traits and 133413 of CKD Genetics).\n\n\nCONCLUSIONS\nThis study provided novel insights into causality of obesity with CKD and arterial stiffness, highlighting the importance of weight management for primary prevention and control of subclinical vascular diseases.