The pressor and metabolic effects of alcohol in normotensive subjects.

Changes in blood pressure, pulse rate, and plasma catecholamines, renin activity, cortisol, and calcium were studied in 16 normotensive subjects (eight with a family history of hypertension) for 5 hours following ingestion of alcohol-free and alcohol-loaded beer. Both systolic and diastolic blood pressure rose after alcohol consumption; maximum responses occurred at peak blood alcohol concentrations and were significantly higher than those seen after placebo. Pulse rate was also significantly higher after alcohol ingestion and continued to rise throughout the study. There was no difference in the pressor response to alcohol between the groups with and without a family history of hypertension. No difference was found in plasma norepinephrine or epinephrine levels between alcohol and placebo phases. However, subjects with no family history of hypertension had significantly higher plasma norepinephrine levels (p less than 0.01) than did those with a family history during both the alcohol and placebo phases, although baseline blood pressures were not significantly different. Plasma epinephrine level was similar in both groups. Plasma renin activity was unchanged throughout, but plasma cortisol fell during both phases. Plasma calcium showed a small but significant fall with alcohol consumption in both groups (p less than 0.001). These results indicate that in normotensive subjects alcohol ingestion causes a rise in systolic and diastolic blood pressure that is not influenced by a family history of hypertension. This effect does not appear to be sympathetically mediated but may be due to a direct vasoconstrictor effect of alcohol, possibly with an alcohol-induced shift in intracellular calcium.