Alcohol-induced macrocytosis and blood pressure.

The effect of alcohol on blood pressure was studied prospectively in consecutive general practice patients with macrocytosis (MCV greater than or equal to 100 fl). The patients were separated into misuser and non-misuser groups on the basis of the Malmö modified Michigan Alcoholism Screening Test. There was no significant difference in the prevalence of antihypertensive medication between the misuser and non-misuser groups. When patients using antihypertensive medication were excluded and the groups were age-adjusted, male misusers (n = 95) compared to control patients (n = 22) had significantly higher diastolic (88 mmHg and 81 mmHg, respectively, P = 0.001) and systolic (146 mmHg and 137 mmHg, respectively, P less than 0.001) blood pressure values. Female misusers (n = 24), as compared to female non-misusers (n = 59) had significantly higher diastolic (83 mmHg and 82 mmHg, respectively, P = 0.04) but not systolic blood pressure values. Thus, alcohol seems to have a pressor effect predominantly among men. As 72% of men with macrocytosis were alcohol misusers and 41% of them either had elevated systolic or diastolic blood pressure, all patients with macrocytosis should be asked about their alcohol consumption and at least the males should have blood pressure measured.