Reduced endothelial and exercise vasodilator function in the legs of obese versus lean and overweight Postmenopausal women

Obesity is a chronic disease negatively affecting endothelial function and commonly arises in aging women. Increased storage of adipose tissue combined with the onset of menopause may further reduce nitric oxide (NO) bioavailability, impairing endothelium-dependent and exercise vasodilation. Exercise vasodilation in obese (OB) individuals compared to that of lean (LN) and overweight (OW) controls has not yet been examined in aging women. Purpose: To examine potential differences in endothelium-dependent and exercise vasodilation in upper- and lower-limbs of OB, LN and OW postmenopausal women. Methods: Endothelium-dependent vasodilation of the brachial artery (BA) and superficial femoral artery (FA) were assessed using flow-mediated dilation (BA-FMD and FA-FMD). Blood flow and vascular conductance of BA (BA-BF, BA-VC) and FA (FA-BF, FA-VC) were measured during graded handgrip and plantarflexion exercises. Body mass index (BMI) was recorded and body composition was measured using DEXA. Results: FA-FMD was significantly reduced in OB (OB: 2.58 ± 0.38% vs LN: 4.25 ± 0.22% and OW: 4.23 ± 0.42%, p = 0.008). FA-BF (LN: 640 ± 56 mL/min, OW: 616 ± 48 vs OB: 462 ± 52 mL/min, p < .001) and FA-VC (LN: 623 ± 49 mL100mmHg/min, OW: 585 ± 42 mL100mmHg/min vs OB: 409 ± 45 mL*100mmHg/min, p < .001) during the final stage of plantarflexion exercise were significantly reduced in OB. There were no differences in BA-FMD or BA-BF and BA-VC during handgrip exercise. BMI was negatively correlated to FA-BF (r = -.386, p < .015) and FA-VC during the 3rd stage of plantarflexion exercise (r = -.456, p < .001). FA-FMD was correlated to FA-BF (r = .423, p = .007) and FA-VC during the 3rd stage of plantarflexion exercise (r = .417, p = .021). After adjusting for covariates, BMI was significantly negatively associated with FA-BF (b = -41.1, R2 = .55, p = .027) and FA-VC (b = -46.0, R2 = .56, p = .007). FA-FMD was positively associated with FA-BF (b = 38.5, R2 = .55, p = .048) after adjustment for covariates. Conclusions: Leg endothelium-dependent and exercise vasodilation are reduced in OB compared to OW and LN postmenopausal women. Reduced endothelial function and increased body mass relative to height are associated with reduced blood flow and vascular conductance in postmenopausal women.

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