Effects of alcohol intake on blood pressure and sympathetic nerve activity in normotensive humans: A preliminary report

Although several epidemiological studies have shown an as-sociation between alcohol consumption and high blood pres-sure, the mechanisms involved in the pressor effect of alcohol are not clear. We hypothesized that alcohol might increase blood pressure at least in part by increasing sympathetic nerve activity. In a double-blind, placebo-controlled study of seven normotensive subjects (mean age ± s.e.m. 24.0 ± 1.5 years), we investigated the effects of oral administration of alcohol (0.75 g/kg body weight, diluted in orange juice) or vehicle on arterial blood pressure, heart rate and muscle sympathetic nerve activity, measured directly in the peroneal nerve by mi-croneurography. Plasma ethanol levels increased from 0 (con-trol) to a range of 47.7 ± 7.6 to 53.3 ± 5.0mg/dl 30 min after alcohol intake. This increase in plasma ethanol was ac-companied by a significant increase (P < 0.05) in mean blood pressure, heart rate and sympathetic nerve activity. The vehi-cle did not affect any of these parameters. Our data suggest that acute oral administration of a moderate dose of alcohol induces a pressure effect through activation of sympathetic nervous outflow.