Waist circumference leads to prolonged microvascular reactive hyperemia response in young overweight/obese women

Objectives: Previous data in our laboratory have shown microvascular dysfunction in normoglycaemic subjects with metabolic syndrome (MS). In a step further, we have investigated which clinical parameters related or not to MS would elicit microvascular dysfunction and the need of diagnosing MS for the establishment of microcirculatory impairment in overweight/obese women. Methods: Nineteen lean [23.6 +/- 3.1 years, body mass index (BMI) 21.9 +/- 1.8 kg/m(2)] and 59 overweight/obese [24.6 +/- 3.7 years: BMI 34.4 +/- 5.9 kg/m(2)] sedentary non-smoking women, divided in overweight/obese without (MS negative, n = 36) and obese with MS (MS positive, n = 23) were evaluated. Blood biochemistry, HOMA-IR index and anthropometric variables were determined. Morphological (capillary diameters) and functional [functional capillary density, red blood cell velocity (RBCV) at baseline and peak and time (TRBCVmax) to reach it during post-occlusive reactive hyperemia after 1 min ischemia] microcirculatory variables were examined by nailfold videocapillaroscopy. Results: Compared to controls, overweight/obese MS negative and obese MS positive presented longer TRBCVmax; the presence of two MS components was sufficient to prolong it and the MS diagnosis did not add any significant impairment to the microcirculation. Among clinical parameters investigated, a direct relationship between TRBCVmax and waist circumference and insulin concentrations was found. Conclusion: Our results have shown that microvascular dysfunction is independent of metabolic syndrome diagnosis and could be predicted by the waist circumference on young overweight/obese women, reinforcing the relationship between obesity-related microvascular/metabolic disturbances. (C) 2010 Elsevier Inc. All rights reserved.