Forearm haemodynamics in obese normotensive and hypertensive subjects.

Forearm haemodynamics using pulsed Doppler flowmetry were studied in 83 men: 15 non-obese and eight obese normotensive subjects; 30 non-obese and 30 obese hypertensive patients. Mean ages were similar in the four subgroups. The blood pressure of normotensives and hypertensives was identical in obese and non-obese subjects. Blood flow, expressed in ml/min, was significantly higher in obese subjects, whether normotensive or hypertensive. However, when blood flow was expressed per unit litre of forearm volume, it was similar in the four subgroups. Forearm vascular resistance, whether expressed as absolute or normalized values, was significantly higher (P less than 0.001) in non-obese hypertensives. When obese and non-obese hypertensives were compared, the former were characterized by higher values of blood flow velocity and blood flow, and lower values of vascular resistance, whether absolute or normalized values were used. This study shows firstly that forearm vascular resistance in hypertensives is increased exclusively in non-obese subjects, and secondly that obese hypertensives, when compared with non-obese hypertensives, are characterized by a hyperkinetic forearm circulation.