Muscle microvascular reactivity and its associations with arterial stiffness and aortic pressures in postmenopausal women with abdominal obesity and hypertension.

Hypertension is associated with obesity and vascular dysfunction in postmenopausal women (PMW). We examined the impact of obesity and hypertension on forearm muscle microvascular reactivity and its associations with macrovascular function and visceral adipose tissue (VAT) in PMW aged 50-69 years. They were classified by waist circumference (WC) and systolic blood pressure (SBP) as non-obese (PMW-NOB, n = 15) and obese non-hypertensive (PMW-OB, n = 17), and obese hypertensive (PMW-HTN, n = 17). Microvascular function was measured by near-infrared spectroscopy-derived tissue oxygen saturation indices (reperfusion magnitude [TSIRMag], hyperemic response [TSIHRes], and area under the curve [TSIAUC2min]) during reactive hyperemia. Macrovascular function was assessed by aortic stiffness (carotid-femoral pulse wave velocity [cfPWV]) and pressures (SBP, pulse [PP], augmentation [AP], forward wave [Pf], and backward wave [Pb]) using arterial tonometry. Abdominal obesity was assessed by WC and dual-energy x-ray absorptiometry-derived VAT. WC and VAT, but not body mass index, were higher in PMW-HTN compared to PMW-NOB and PMW-OB (P < 0.01). TSIHRes and TSIAUC2min were lower in PMW-HTN compared to PMW-NOB and PMW-OB (P < 0.05). cfPWV, aortic SBP, PP, AP, Pf, Pb (all P < 0.05), and VAT (P < 0.01) were higher while plasma arginine was lower (P < 0.05) in PMW-HTN compared to PMW-NOB and PMW-OB. TSIHRes and TSIAUC2min were inversely associated with cfPWV, aortic pressures, and VAT (all P < 0.05). Our findings suggest that abdominal obesity with hypertension is characterized by micro- and macrovascular dysfunction in PMW. Greater VAT is associated with impaired microvascular reactivity, aortic stiffening, and increased aortic pressures.