Effect of dietary counselling on blood pressure and arterial plasma catecholamines in primary hypertension.

There is still a need of support for nonpharmacologic treatment of uncomplicated, mild-to-moderate essential hypertension. We investigated whether a low sodium-based diet implemented by a nutritionist could lower blood pressure and affect sympathetic activity. Middle-aged, otherwise healthy men with never-treated essential hypertension (n = 95) were randomized to an intervention group, a blood pressure control group, and a time control group. The intervention group was advised to use less sodium chloride in their diet, and if necessary, less saturated fat and decrease body weight. They attended regular clinic visits as did the blood pressure control group. After 1 year, the intervention group had achieved on average 72 mmol/24 h lower urinary sodium excretion (P < .001) and a decrease in body weight of 2.7 +/- 0.5 kg (P < .001). Both supine and standing mean blood pressure were on average 8 to 10 mm Hg lower after intervention compared with the two control groups (P < .001). Arterial plasma epinephrine, measured in all 40-year-old subjects (n = 30), decreased in parallel in all three groups (P < .05), indicating some habituation to the invasive procedure and clinic visits. However, the decrease in norepinephrine was significant (P < .001) only in the intervention group; it correlated with the weight loss (r = 0.76, P < .05) and was significantly higher (P < .05) than in both control groups. These results suggest that broad dietary advice (ie, low intake of sodium chloride, saturated fat and energy), implemented by a nutritionist, may have a significant blood pressure lowering effect and a favorable sympathicolytic effect in uncomplicated, mild-to-moderate essential hypertension.