Link between stress and hypertension

Hypertension is the leading global risk for mortality. Immune cell activation and inflammation are fundamental to the pathogenesis of hypertension and cardiovascular disease development. However, how immune cells get activated and promote inflammation in the context of hypertension and how factors such as psychological stress may exacerbate this disease is still unknown. The EU-funded 'Stress-induced hypertension and the role of the neuroimmune system' (SIHI) project aimed to examine neuroimmune mechanisms in the development of inflammation associated with hypertension and to explore novel treatment interventions.

Previous studies have found that inflammation is a contributing factor in the genesis of various forms of experimental hypertension. Currently, clinical interventions such as renal denervation (RD) and carotid sinus nerve denervation (CSD) target the autonomic nervous system to treat hypertension. However, the effects of these blood pressure-lowering strategies on the immune system are unknown.

In this study, RD and CSD were performed in the spontaneously hypertensive rat (SHR) model, followed by flow cytometry to examine tissue infiltration of CD3+ T lymphocytes in the aorta and brainstem. Compared to the control group, arterial pressure and renal sympathetic nerve activity in the SHR was significantly lowered following both RD and CSD. The percentage of infiltrating CD3+ T lymphocytes in the brainstem as well as the aorta were significantly reduced following RD.

These findings suggest that there is significant systemic CD3+ cell infiltration in the SHR and that targeting the autonomic nervous system may lower tissue inflammation associated with hypertension.

Project studies will provide new information for the central and peripheral mechanisms that mediate inflammatory diseases such as hypertension. They also may provide a better understanding for the link between the negative impact of stress on hypertension and cardiovascular disease development.