Effects of lifestyle factors on leukocytes in cardiovascular health and disease

Exercise, stress, sleep and diet are four distinct but intertwined lifestyle factors that influence the cardiovascular system. Abundant epidemiological, clinical and preclinical studies have underscored the importance of managing stress, having good sleep hygiene and responsible eating habits and exercising regularly. We are born with a genetic blueprint that can protect us against or predispose us to a particular disease. However, lifestyle factors build upon and profoundly influence those predispositions. Studies in the past 10 years have shown that the immune system in general and leukocytes in particular are particularly susceptible to environmental perturbations. Lifestyle factors such as stress, sleep, diet and exercise affect leukocyte behaviour and function and thus the immune system at large. In this Review, we explore the various mechanisms by which lifestyle factors modulate haematopoiesis and leukocyte migration and function in the context of cardiovascular health. We pay particular attention to the role of the nervous system as the key executor that connects environmental influences to leukocyte behaviour. In this Review, Swirski and co-workers discuss how lifestyle factors modulate haematopoiesis and leukocyte migration in the context of cardiovascular homeostasis and disease, with particular focus on the role of the nervous system as the key executor connecting environmental influences to leukocyte behaviour. Key points Cardiovascular disease (CVD), and atherosclerosis in particular, is driven by chronic underlying inflammation, leading to plaque destabilization by the infiltration of leukocytes. The risk of CVD is only partly driven by genetic predisposition; the exposome, consisting of environmental and personal factors, has an important role in the inflammatory progression of CVD. Modification of lifestyle factors such as exercise, stress, sleep patterns and diet holds the potential to help in both reducing disease burden and revealing the effects that these factors have on the immune system. Findings from the past decade highlight the connection between the hypothalamic–pituitary–adrenal axis and the sympathetic nervous system, and modifiable lifestyle factors and the cardiovascular system. Improving our understanding of the influence of the nervous system on the exposome, as well as on CVD and the immune system, can potentially help to lower CVD burden and its complications.