RELATIONSHIP OF PLASMA-RENIN ACTIVITY WITH CAFFEINE INTAKE AND PHYSICAL-TRAINING IN MILD HYPERTENSIVE MEN

To study the relationship between plasma renin activity (PRA) and coff ee consumption, cigarette smoking, alcohol intake and physical activit y habits. Setting: The multicentre HARVEST trial, involving 17 Hospita l Centres in Northeast Italy. Subjects: 351 borderline to mild hyperte nsive men (mean age +/- SEM 22.7 +/- 0.47 years); never treated for hy pertension. Interventions: Office and 24-hour blood pressure measureme nt, supine and standing PRA levels, and urinary catecholamines output. Main outcome measures: PRA levels according to coffee intake and phys ical activity status. Results: Coffee intake showed a major effect on PRA. Supine PRA levels were 40% higher in the subjects abstaining from coffee (n = 94) than in the coffee drinkers and was similar in the mo derate (n = 223) and heavy (n = 34) drinkers. A weaker negative associ ation was found between coffee use and PRA on standing. Office and who le-day blood pressure and heart rate, and urinary catecholamines did n ot differ according to coffee intake. Supine PRA was lower in the subj ects performing regular physical activity than in the inactive subject s. Office and whole-day diastolic blood pressure and heart rate, and u rinary norepinephrine were lower in the active than in the sedentary m en. No relationship was found between PRA measured either in the supin e or the upright posture and tobacco or alcohol use. In a multiple lin ear regression model supine PRA was negatively correlated with age, co ffee consumption and physical. activity habits. Conclusions: Chronic c offee intake and physical training showed an inverse relationship with PRA in mild hypertensive men, while tobacco and alcohol use were unre lated to PRA.