Dissociation Between Muscle and Skin Sympathetic Nerve Activity in Essential Hypertension, Obesity, and Congestive Heart Failure

Abstract

Essential hypertension, obesity, and congestive heart failure are characterized by an increase in muscle sympathetic nerve activity. Whether in these conditions skin sympathetic nerve activity is also increased has never been systematically examined, however. In 10 untreated mild essential hypertensive, 12 untreated normotensive obese, 10 mild (New York Heart Association class II) heart failure, and 10 normotensive lean healthy control subjects, we measured beat-to-beat arterial blood pressure (Finapres technique), body mass index, and postganglionic sympathetic nerve activity in skeletal muscle and skin areas (microneurographic technique, peroneal nerve). The muscle and skin nerve measurements were made in a randomized sequence. All data were obtained with the subject supine in a quiet, semidark environment at constant temperature over of 30 minutes each, separated by a 20- to 30-minute interval. Blood pressure was increased only in hypertensive and body mass index only in obese subjects. Muscle sympathetic nerve activity quantified as bursts/min was markedly and significantly (P