Leptin and endothelial function in the elderly: The Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study

Abstract Background Leptin levels are elevated in obese humans. Several studies have shown an association between hyperleptinemia and development of atherosclerosis and cardiovascular disease (CVD), but the relationship between leptin and vascular function remains unclear. Aim To evaluate associations between circulating plasma leptin and measures of vascular function in a large sample of elderly individuals from the community. Methods This cross-sectional study included 1016 subjects aged 70 (50% women) from the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). The invasive technique forearm plethysmography with intra-arterial infusions of acetylcholine and sodium nitroprusside was used for estimation of endothelial dependent vasodilatation (EDV) and endothelial independent vasodilatation (EIDV), respectively, in resistance arteries, and the non-invasive technique ultrasound assessed flow mediated vasodilation (FMD) in conduit arteries. The aortic augmentation index (AoAI), a surrogate measure of arterial stiffness, was evaluated by pulse wave analysis. Associations of vascular function, arterial stiffness and blood pressure with leptin were explored. Results In sex-adjusted models, high levels of leptin were inversely associated with EDV and EIDV. These associations remained after stratification for sex, traditional risk factors of CVD and insulin resistance, but were attenuated after taking a measure of obesity (body mass index) into account. In addition, leptin associated with arterial stiffness and systolic and diastolic blood pressure. Conclusion Hyperleptinemia associated inversely with vasodilatation in resistance arteries. Furthermore, hyperleptinemia associated with arterial stiffness and hypertension. These associations were attenuated after adjusting for body mass index suggesting that leptin may be the mediator between obesity and impaired vascular function.