Search

Objective: To assess the efficacy of non pharmacological primary prevention of hypertension., Methods: Analysis of all the available trials with a minimal one-year follow-up and one recently study with 8 weeks follow-up. The outcomes consisted in blood pressure changes and incidence of hypertension at the end of the study., Results: Five reviewed randomized controlled trials with a minimal one year follow-up and one recently study with eight weeks follow-up assessed the following intervention: advice about sodium restriction, weight reduction, physical exercise and relaxation, a diet rich in fruits vegetables and low fat dairy foods. All the results were available according to the "intention to treat principle". The feasibility appeared to be initially good, but decreased with time, confirming the difficulty of long term prevention. The prevention effect was mild with a decrease in hypertension incidence of a few percent (2%) and blood pressure decrease of only a few mmHg reduction (mean of 3 mmHg). Three community studies were reviewed. The prevention interventions were carried out on entire populations. The feasibility was bad (great number of lost-follow-up). The results on the blood pressure incidence were available in only one study and the blood pressure decrease estimates were heterogeneous, so the results cannot be generalized., Conclusion: The primary prevention of hypertension shows disappointing results when the intervention duration is above one year. It leaves little hope for a significant effect on blood pressure dependent cardiovascular events.

Serum concentration of ionic calcium and the effect of dietary salt restriction on serum total calcium was studied in patients with essential arterial hypertension. The concentration of serum ionic calcium was significantly lower than in controls in all the evolutive stages of the disease (p less than 0.005; p less than 0.005; p less than 0.001). During salt restriction serum total calcium rises significantly (p less than 0.005) as compared with the values found under a salt containing diet. It was suggested that increased chronic ingestion of sodium or restriction of dietary salt produces alterations in Na-Ca exchanges across semipermeable membrane of the smooth muscle.

Serum concentration of Na, K, Ca, Mg and inorganic phosphate as well as serum levels of Zn and Cu were determined in control subjects and in patients with essential arterial hypertension (EAH) divided according to the stage of the disease. No significant differences were found between the serum mean levels of Na, K, Ca, Mg, Zn and Cu in controls and in patients with EAH. A significant decrease of the serum Zn was noted in the third stage of EAH. A number of cases with hypomagnesemia and/or hypopotassemia probably caused by a long term uncontrolled therapy was also detected. The concentration of inorganic phosphate was significantly lower in patients with EAH associated with overweight than in hypertensive patients with normal body weight and in controls. It is considered that a sustained study of the complex interrelationship between electrolyte interaction and the functional aspects of the arterial wall could still contribute to a better understanding of pathogenic aspects of EAH and of its complications including those subsequent to modern diuretic therapy.

Propranolol (160--240 mg/24 h) and Oxprenolol (80--240 mg/24 h) were given for different periods of time to 13 and, respectively, 7 patients with essential arterial hypertension stage II. Both these beta-blocking drugs induced a significant fall in plasma renin activity : after ten days of treatment, platelet adhesiveness decreased in the patients with a basal level over 50% and increased in those with basal level below 30% (p < 0.01). When this treatment was given for 30 consecutive days, platelet adhesiveness decreased even in the latter patients. The drugs were also found to accelerate dilute blood clot lysis time in patients who presented a delayed lysis time before therapy. Thus, it is inferred that both propranolol and oxprenolol eliminate, at least partly, several factors involved in the pathogenesis of atherosclerosis, a frequent complication of essential arterial hypertension.