Vasodilation and visceral fat in elderly subjects: the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study.

BACKGROUND

Although obesity has long been recognised as a cardiovascular risk factor, only in recent years has the role of visceral adipose tissue (VAT) been evaluated. In the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS) study, we related VAT and other obesity indices to endothelium-dependent vasodilation in both capacitance and resistance arteries.

METHODS AND

RESULTS

In this population-based study, 1016 subjects aged 70 were evaluated by the invasive forearm technique with acetylcholine (EDV) and brachial artery ultrasound to assess flow-mediated vasodilation (FMD). Intra-abdominal visceral (VAT) and subcutaneous adipose tissue (SAT) were determined by magnetic resonance imaging in a random sample of 287 subjects. EDV, but not FMD, was inversely related to VAT, SAT, BMI and the waist/hip ratio (r=-0.23, -0.16, -0.21 and -0.11, respectively, p=0.05-0.001 after adjustment for gender). In multiple regression analysis however, only VAT was an independent predictor of EDV. Similar results were obtained for endothelium-independent vasodilation (EIDV, infusion of sodium nitroprusside in the brachial artery).

CONCLUSIONS

Both endothelium-dependent and independent vasodilation in the forearm resistance arteries, but not FMD in the brachial artery, was reduced in elderly subjects with increased intra-abdominal adipose tissue mass. This finding suggests deterioration in general vasoreactivity mainly in resistance arteries in elderly subjects with intra-abdominal obesity.