Sleep and exercise may weaken some genetic risks for heart disease

Sleep and regular exercise may blunt the impact of some DNA mutations that raise cardiovascular risk, according to work reported in Nature. The study focused on clonal haematopoiesis, or CH, in which certain gene variants accumulate in blood stem cells and immune cells over time. These mutations can intensify inflammation and promote atherosclerosis, independently of traditional risk factors such as smoking, diabetes or high cholesterol. Previous work had already linked CH to blood cancer risk, but it also turned out to be associated with a 30 to 40 per cent higher death rate, largely because of fatal heart attacks and strokes. In the new study, analysis of genetic data and physical activity levels from more than 91,000 adults in the UK and the US found a 13 per cent drop in the proportion carrying certain CH mutations among those with moderate to vigorous activity. Mouse experiments were more striking: animals engineered with CH mutations and fed a high-cholesterol diet developed smaller plaques when they used an exercise wheel, whereas sleep disruption had the opposite effect. However, the benefit was not universal, because the response varied across the four gene variants studied. As one researcher noted, the findings suggest that behaviour can influence how harmful some mutations become, even though the genes themselves cannot be removed.