[Metabolic effects of changes in dietary sodium intake in patients with essential hypertension].

Background: To evaluate the metabolic effects of modification of sodium intake in patients with essential hypertension.

Methods: Thirteen patients with essential hypertension (10 M, median age 51 yrs, range 21-64) followed in random order a low-sodium and a high-sodium diet (50 mmol Na/day vs 250 mmol/day for two weeks each). At the end of each diet an evaluation was made of 24 hour blood pressure (ABPM, Spacelabs 90207) and serum concentration of: glucose, total and HDL cholesterol, uric acid, lipoproteins A, B, Lp(a), total proteins, albumin.

Results: Twenty-four hours systolic and diastolic BP were significantly higher at the end of high sodium diet than of low sodium diet [respectively 132 mmHg (120-161) vs 128 mmHg (109-150); p = 0.008 and 84 mmHg (71-99) vs 81 mmHg (70-95); p = 0.008)]. No significant variations were found as regards serum glucose and lipidic parameters between low and high sodium diets. Serum uric acid was significantly higher following low sodium diet [5.9 mg/dl (4.5-8) vs 4.6 mg/dl (3.4-6.5); p = 0.003)], as well as serum total proteins [7.2 g/dl (6.9-8.2) vs 7 g/dl (6.5-7.8); p = 0.027)]. A significant direct correlation was found between changes of uric acid and total proteins from low to high sodium diet (Spearman's rho = 0.57; p = 0.04).

Conclusions: In patients with essential hypertension a moderate dietary sodium restriction, able to reduce significantly 24 hours arterial pressure, does not worsen serum glucose nor lipids concentration.