Exploring the causal relationship between sedentary behavior and cardiovascular disease: A two-sample Mendelian randomization analysis

Cardiovascular disease (CVD) is the primary cause of death globally. However, the causal association between sedentary behavior (SB) and CVD outcomes remains unknown. Genome-wide association study summary statistics for SB and CVD outcomes were collected from the FinnGen and UK Biobank. Mendelian randomization analyses were applied to explore the causal effects of SB on CVD outcomes by selecting single nucleotide polymorphisms as instrumental variables. Genetically predicted leisure screen time was significantly associated with increased risks of cardiovascular disease (odds ratio [OR] = 1.13, 95% confidence interval [CI]: 1.02-1.24), coronary artery disease (OR = 1.18, 95% CI: 1.08-1.29), heart failure (OR = 1.10, 95% CI: 1.02-1.19), and ischemic stroke (OR = 1.14, 95% CI: 1.04-1.25). Time spent watching TV was also positively associated with cardiovascular disease (OR = 1.32, 95% CI: 1.02-1.72). No significant associations were observed for computer use or driving. This Mendelian randomization study suggests a causal relationship between both genetically predicted leisure screen time and television viewing with increased cardiovascular disease risk, particularly coronary artery disease. No causal effects were observed for using computer or driving. These findings underscore the public health relevance of targeting specific sedentary behaviors in strategies to prevent cardiovascular diseases.