The effect of physical activity on haematological predictors of cardiovascular risk - evidence of a dose response

Cardiovascular disease is a major cause of morbidity and mortality in the developed world. Large epidemiological studies have reported a strong association between increases in haematological factors and increased cardiovascular risk. Haematological risk factors predicted cardiovascular disease at least as strongly as traditional risk factors such as blood lipid concentrations. Lifestyle factors such as physical activity level could significantly reduce risk. The aim of this study was to determine the effect of physical activity level on haematological predictors of cardiovascular risk. Healthy subjects (156) were recruited. Physical activity in subjects was assessed by IPAQ physical activity questionnaire. Blood was collected and blood cell counts were determined by automated cell counter; neutrophil elastase was determined by ELISA. Increased levels of physical activity were associated with reduced red cell (p = 0.001), white cell (p = 0.002) and platelet counts (p = 0.001) and with reduced plasma neutrophil elastase concentration (p = 0.001). There was a continuous linear relationship between increase in physical activity and decrease in haematological risk factors. Hence, the authors conclude that increased levels of physical activity improve the flow properties of blood and thus reduce the risk of developing cardiovascular disease. Even small increases in activity result in some reduction in cardiovascular risk.