Fig. 5: Mendelian randomization supports a causal effect of daytime napping on higher blood pressure and waist circumference.
From: Genetic determinants of daytime napping and effects on cardiometabolic health
The MR estimates were calculated using the random-effects inverse-variance weighted method and represent the effect of a one-unit increase in napping category (never, sometimes, usually). Sample sizes reflect either the total sample size (for continuous outcomes) or number of cases and controls (for binary outcomes). A IVW effect estimates for more frequent daytime napping on cardiometabolic outcomes and risk factors. A unit increase in the adiposity and blood pressure measurement represents a standard deviation increase in the corresponding trait. Black boxes show effect estimates, and surrounding lines display 95% confidence intervals. All P values are two-sided. B IVW effect estimates for the effect of adiposity traits on daytime napping frequency. Black boxes show effect estimates, and surrounding lines display 95% confidence intervals. All P values are two-sided. * significant at Bonferroni-corrected alpha threshold and robust in sensitivity analyses. BMI body-mass index, CAD coronary artery disease, CI confidence interval, DBP diastolic blood pressure, HOMA homeostatic model assessment of insulin resistance, HOMAB homeostasis model assessment of β-cell function, LDL low-density lipoprotein, HDL high-density lipoprotein, OR odds ratio, SBP systolic blood pressure, SNP single-nucleotide polymorphism, T2DM type 2 diabetes mellitus, WC waist circumference, WHRadjBMI waist-to-hip ratio adjusted for BMI.
