Endocrine Abstracts

Endothelial dysfunction is assessed noninvasively by measuring flow-mediated dilation (FMD). However, FMD is strongly dependent on arterial size, which contributes to a wide range of FMD values. It was previously shown that FMD is greater in small arteries, because the shear stimulus during postocclusion hyperemia is greater in small arteries. We aimed to investigate the predictive value of brachial arterial size on FMD in 44–61 years old Turkish women while adjusting for a number of covariates.

Method: We examined FMD of 507 voluntary women participating in a study on predictors of natural menopause. FMD was evaluated in women who used no medications in the previous 15 days. Predictors of FMD were evaluated in univariate and multivariate regression models (UVA & MVA). Variables including age, body mass index, menopause status, current smoking, alcohol use, socioeconomic factors and chronic diseases (diabetes mellitus and hypertension) are included as predictors. A stepwise model selection algorythm was used in MVA with a cut off P value of 0.15.

Results and conclusion: Mean age was 50, mean brachial artery diameter was 3.69±0.50 mm. The mean absolute FMD value was 0.30±0.22 mm and mean percent dilatation of FMD was 8.4±6.4%. Postmenopausal women compromised 46%.

In both UVA & MVA, the most significant determinant of FMD was basal brachial artery diameter. Greater basal diameter is associated with worse FMD. Other significant predictors included menopausal status, perceived economic status and presence of health insurance. Our findings support a strong association between arterial size and FMD. Baseline arterial diameter should be taken into account when investigating predictors of FMD.