Long-term moderate sodium restriction does not adversely affect the serum HDL/total cholesterol ratio

Abstract

We examined the effect of long-term moderate sodium restriction on the HDL/total cholesterol ratio within a randomised trial of the effect of mineral salt on blood pressure (BP). Eighty nine untreated hypertensive men and women aged 55-75 years were included in the analysis. During 24 weeks, 46 subjects used a low sodium, high potassium, high magnesium salt and 43 controls used common salt. Serum cholesterol levels were measured at baseline and at the end of the trial. After 24 weeks, 24 h urinary sodium was decreased by 41 mmol (95% Cl 23-60 mmol, P < 0.0001) in the mineral salt group compared with the controls. Serum total cholesterol was decreased in both groups, but 0.45 mmol/l (95% Cl 0.12-0.78, P = 0.01) more in the controls than in the mineral salt group after adjustment for age, sex and changes in body weight, serum total protein and potassium excretion. Serum HDL-cholesterol was decreased by 0.07 mmol/l in the controls and increased by 0.06 mmol/l in the mineral salt group, yielding a difference of 0.14 mmol/l (95% Cl 0.05-0.22 mmol/l, P = 0.003). The change in HDL/total cholesterol ratio was more favourable in the mineral salt group than in the controls (0.014 and 0.004 units, respectively, P = 0.014). We conclude that long-term moderate sodium restriction does not adversely affect the serum HDL/total cholesterol ratio and is a safe dietary measure for lowering BP.