Joint association of genetic risk and accelerometer-based step count with cardiovascular disease: a UK-Biobank cohort study

BackgroundThis population-based prospective cohort study aimed to investigate whether accelerometer-measured step count is associated with incident cardiovascular disease (CVD), independently from genetic risk. MethodsThe study included participants in the UK Biobank with valid accelerometer and genetic data and without prevalent CVD at baseline. Genetic risk for CVD was categorised as low (1st fifth), moderate (2nd-4th fifths), and high (5th fifth). Median daily step count was categorised as low (<6,500), moderate (6,500-12,499), and high ([&ge;]12,500). The association of genetic risk and step count with incident CVD, defined as a composite of coronary artery disease and ischaemic stroke, was examined using adjusted Cox proportional hazards models. ResultsOf 84,286 participants, 4,847 were diagnosed with CVD during follow-up (median 7.9 years). High genetic risk and low daily step count had a log-additive association with incident CVD. In low genetic risk individuals, step count was not associated with incident CVD. However, in the moderate and high genetic risk groups, those with low step counts had 24% (HR 1.24; 95% Confidence Interval [CI] 1.10-1.40) and 37% (HR 1.37; 95% CI 1.14-1.65) higher risk of incident CVD compared to those with high step counts. There was an inverse dose-response association between the hazard of CVD and step counts up to 10,000 steps/day, which then plateaued in moderate and high genetic risk groups. ConclusionsHigh daily step count was associated with lower CVD risk in individuals with moderate and high genetic risk, indicating that walking should be encouraged for all, especially those predisposed to CVD.