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 coffee consumption, cigarette smoking, alcohol intake and physical activity habits. Setting: The multicentre HARVEST trial, involving 17 Hospital Centres in Northeast Italy. Subjects: 351 borderline to mild hypertensive men (mean age ± SEM 22.7 ± 0.47 years), never treated for hypertension. Interventions: Office and 24-hour blood pressure measurement, supine and standing PRA levels, and urinary catecholamines output. Main outcome measures: PRA levels according to coffee intake and physical 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 moderate (n = 223) and heavy (n = 34) drinkers. A weaker negative association was found between coffee use and PRA on standing. Office and whole-day blood pressure and heart rate, and urinary catecholamines did not differ according to coffee intake. Supine PRA was lower in the subjects performing regular physical activity than in the inactive subjects. Office and whole-day diastolic blood pressure and heart rate, and urinary norepinephrine were lower in the active than in the sedentary men. No relationship was found between PRA measured either in the supine or the upright posture and tobacco or alcohol use. In a multiple linear regression model supine PRA was negatively correlated with age, coffee consumption and physical activity habits. Conclusions: Chronic coffee intake and physical training showed an inverse relationship with PRA in mild hypertensive men, while tobacco and alcohol use were unrelated to PRA.