Increased plasma norepinephrine levels in previously pre-eclamptic women

Abstract

A history of pre-eclampsia increases the risk of cardiovascular morbidity by mechanisms yet unknown. The aim of the present study was to assess whether plasma norepinephrine (NE) levels are increased 5-6 years after pre-eclamptic pregnancy and to investigate associations with pathophysiological mechanisms of cardiovascular disease: insulin sensitivity, vascular function and arterial pressure. A total of 28 women with previous pre-eclampsia and 20 controls were examined. Blood pressure (BP) and plasma levels of NE and endothelin-1 (ET-1) were measured at rest and after standing for 5 min. Insulin sensitivity was assessed with minimal model analysis and vascular function was assessed using venous occlusion plethysmography and pulse wave analysis. Twenty-four-hour BP measurements were carried out. Women with previous pre-eclampsia had higher levels of NE at rest (P=0.02), which did not associate significantly with insulin sensitivity or overall vasodilatory capacity. The 24-h mean of systolic and diastolic blood pressures (BPs) and heart rate did not differ between the groups (P=0.30, P=0.10 and P=0.46, respectively), and there was no significant association with NE levels. ET-1 levels were similar between the groups, but a positive correlation with systolic (P=0.04) and diastolic (P=0.03) BPs in the upright position was shown in the patient group. Increased levels of plasma NE are sustained in women with previous pre-eclampsia and may contribute to the increased risk for cardiovascular disease in these women.