Impaired skeletal muscle and skin microcirculatory function in human obesity

Background Obesity is associated with exaggerated blood pressure and systemic vascular resistance responses to mental stress. Objective To test the hypothesis that skin and muscle microvascular dilatation in response to mental stress is blunted in obesity. Design and methods Blood pressure, heart rate and forearm and skin blood flow responses to mental stress were compared in 23 obese and 23 age- and lean normotensive individuals. Results Blood pressure was almost identical in both obese (mean 94 +/- 1 mmHg) and lean (93 +/- 2 mmHg) individuals. The increase in blood pressure during stress was similar in obese and lean individuals (2.0 +/- 0.9% compared with 3.1 +/- 4.0%; P = 0.8). Forearm vascular resistance decreased during mental stress in groups, but this decrease was significantly blunted in obese individuals compared with controls (decreases of 14 +/- 4% and 26 +/- 3%; P < 0.01). Skin microcirculatory dilatation was also significantly blunted in obese individuals compared with controls (decreases of 5 +/- 2 and 17 +/- 4%; P = 0.02). Conclusions Normotensive obese individuals exhibit markedly impaired muscle and skin microcirculatory responses to mental stress. The increased propensity of obese individuals to develop hypertension under conditions of chronic psychosocial stress may underlie obesity-related hypertension and cardiovascular disease. (C) 2002 Lippincott Williams Wilkins.