Causal relationship between the duration of mobile phone use and risk of stroke: A Mendelian randomization study

This study investigates the causal relationship between the duration of mobile phone use (DMPU) and risk of stroke using Mendelian randomization (MR) analysis. Independent single nucleotide polymorphisms from genome-wide association study datasets were employed as instrumental variables to estimate the effects of DMPU on the risk of stroke, intracerebral hemorrhage, ischemic stroke, and its subtypes (cardioembolic infarction, small-vessel disease, large artery atherosclerosis [LAAS]). Inverse-variance weighting was utilized as the primary MR method and sensitivity analyses were performed. Ninety single nucleotide polymorphisms associated with stroke from genome-wide association study datasets were selected as instrumental variables. Inverse-variance weighted analysis showed a significant causality between DMPU and an increased risk of LAAS (odds ratio [OR] = 1.120; 95% confidence interval [CI] = 1.005-1.248; P = .040). No genetic association was found for stroke (OR = 1.000; 95% CI = 0.999-1.001, P = .677), intracerebral hemorrhage (OR = 1.020; 95% CI = 0.912-1.140, P = .734), ischemic stroke (OR = 1.020; 95% CI = 0.979-1.062, P = .344), cardioembolic infarction (OR = 1.066; 95% CI = 0.974-1.166, P = .166), and small-vessel disease (OR = 1.052; 95% CI = 0.944-1.173, P = .356). MR-Egger regression (intercept = 2.75 × 10⁻3; P = .888) suggested multidimensionality was unlikely to bias the results; Cochran Q test and funnel plot showed no heterogeneity or asymmetry, indicating the robustness of present findings. The current investigation confirmed a causal relationship between DMPU and an increased risk of LAAS, suggesting significant implications for public health initiatives and policy development.