ObjectiveTo investigate the haemodynamic effects of insulin and their relationship to insulin resistance in essential hypertension.DesignGroup comparison between patients with essential hypertension and normal controls.SettingOutpatient clinics serving the greater Belfast area.PatientsEleven patients with essential hypertension and eight age-, sex- and weight-matched control subjects were recruited. Administration of all antihypertensive agents to the hypertensive patients was stopped 6 weeks prior to the study.MethodsLeg blood flow was measured using venous occlusion plethysmography. Insulin action was assessed using the hyperinsulinaemic euglycaemic clamp technique.ResultsThe hypertensive subjects were insulin-resistant compared with the normal controls. Insulin infusion resulted in similar increases in calf blood flow in the two groups. There was no correlation between calf blood flow and measurements of insulin sensitivity in either group.ConclusionsDifferences in whole-body glucose uptake in hypertensive and control subjects are not likely to be related to differences in insulin-induced stimulation of muscle blood flow.