SALT RESTRICTION - EFFECTS ON LIPIDS AND INSULIN PRODUCTION IN HYPERTENSIVE PATIENTS

The object of the study was to evaluate blood pressure, insulin and gl ucose metabolism, and serum lipids in hypertensive patients, during 8 weeks on a moderately salt-restricted diet. A double-blind, cross-over study was conducted with hypertensive patients following a moderately salt-restricted diet. Patients were randomised to sodium capsules in one period and placebo capsules during the other period. After a 1-mon th run-in period, 13 males and three females with mild to moderate ess ential hypertension (mean age 50 years) complied with a salt-reduced d iet. They were randomized to a salt-supplemented group (5 capsules of 10 mmol sodium per capsule) or a salt reduced diet group (5 capsules o f placebo) with cross-over after 8 weeks. Serum insulin, insulin C-pep tide, and glucose were measured, fasting and 30 min after a 75-g gluco se load. Serum lipids and lipoproteins constituting an atherogenic ind ex were measured, along with blood pressure and 24-h urine excretion o f sodium and chloride. Non-significant reductions of systolic and dias tolic blood pressure (4 mmHg, p=0.06, and 2 mmHg, p=0.13, respectively ) were observed during the reduced-salt period. The changes observed f or fasting insulin, insulin C-peptide, glucose, serum lipids and the a therogenic index were also nonsignificant. It is concluded that modera te salt restriction seems not to adversely influence insulin resistanc e or serum lipids in hypertensive patients.