1. Sixteen 44-year-old males with chronic high alcohol intake were investigated. Seventeen 44-year-old males with low alcohol intake from the same population served as controls.
2. Plasma noradrenaline concentrations did not differ significantly between individuals with high and low alcohol intake, neither at rest nor after acute stimulation induced by ambulation for 15 min. However, 63% (10 out of 16) of the individuals with high intake showed resting values within the upper quartile range for individuals with low intake.
3. Plasma renin concentration was twice as high (P < 0.01) in the group with high alcohol intake as in the group with low intake.
4. Systolic as well as diastolic blood pressure was significantly higher (P < 0.01) in the group with high intake compared with the group with low intake.
5. Sympathetic nerve activity, as defined from measurements of plasma noradrenaline concentration, is not uniformly increased in individuals with chronic high alcohol intake. The mechanisms behind the increased plasma renin level as well as the possible role of the renin-angiotensin system in alcohol-induced hypertension remain unsettled.