Fitness, physical activity confer cardioprotection in genetically susceptible population
Different measures of fitness and physical activity appear to be inversely associated with the risk of developing cardiovascular disease (CVD) in the general population, as well as in individuals with elevated genetic risk for these diseases, according to a study.
Researchers examined grip strength, objective and subjective physical activity, and cardiorespiratory fitness in relation to incident cardiovascular events in a large cohort of 502,635 individuals (mean age 56.5 years; 54 percent female) from the UK Biobank. They also performed a stratified analysis based on genetic risk scores for coronary heart disease (CHD) and atrial fibrillation (AF).
During a median follow-up of 6.1 years, a total of 20,914 incident CVD cases were reported (CHD, n=8,518; AF, n=9,836; ischaemic stroke, n=2,222; haemorrhagic stroke, n=1,116; heart failure, n=3,298). Incident CVD risk was inversely associated with grip strength, physical activity and cardiorespiratory fitness (CHD: respective hazard ratios [HRs] per SD change, 0.79, 0.95 and 0.68; AF: HRs, 0.75, 0.93 and 0.60; CVD: HRs, 0.76, 0.93 and 0.65; ischaemic stroke: HRs, 0.78, 0.95 and 0.68; haemorrhagic stroke: HRs, 0.90, 0.93 and 0.99; heart failure: HRs, 0.59, 0.80 and 0.56).
Subgroup analyses revealed higher grip strength and cardiorespiratory fitness to be associated with reduced risk of incident CHD and AF in each genetic risk score group (p<0.001 for trend in each genetic risk category). Among individuals at high genetic risk for these diseases, high vs low levels of cardiorespiratory fitness reduced the risk of CHD by 49 percent (HR, 0.51; 95 percent CI, 0.38–0.69) and AF by 60 percent (HR, 0.40; 0.30–0.55), whereas high vs low grip strength reduced the respective risks by 31 percent (HR, 0.69; 0.62–0.75) and 39 percent (HR, 0.61; 0.56–0.67).
The present data underscore the importance of lifestyle factors in the prevention of CVD, as well as in genetically predisposed individuals, and suggest that maintaining good fitness can compensate for genetic risk of CHD and AF, researchers said.
Additionally, the study points to the potential advantages of genetic risk profiling for better detection of individuals at increased risk for CVD. Researchers pointed out that informing individuals of the favourable effects lifestyle choices have on the CVD risks could encourage them to adopt a healthier lifestyle.