Effects of Low-Sodium Diet vs. High-Sodium Diet on Blood Pressure, Renin, Aldosterone, Catecholamines, Cholesterol, and Triglyceride (Cochrane Review)

BACKGROUND The question of whether reduced sodium intake is effective as a health prophylaxis initiative is unsolved. The purpose was to estimate the effects of low-sodium vs. high-sodium intake on blood pressure (BP), renin, aldosterone, catecholamines, and lipids. METHODS Studies randomizing persons to low-sodium and high-sodium diets evaluating at least one of the above outcome parameters were included. Data were analyzed with Review Manager 5.1. RESULTS A total of 167 studies were included. The effect of sodium reduction in: (i) Normotensives: Caucasians: systolic BP (SBP) -1.27 mm Hg (95% confidence interval (CI): -1.88, -0.66; P=0.0001), diastolic BP (DBP) -0.05 mm Hg (95% CI: -0.51,0.42; P=0.85). Blacks: SBP -4.02 mm Hg (95% CI: -7.37, -0.68; P=0.002), DBP -2.01 mm Hg (95% CI:-4.37, 0.35;P=0.09). Asians: SBP -1.27 mm Hg (95% CI: -3.07,0.54; P=0.17), DBP -1.68 mm Hg (95% CI: -3.29, -0.06; P=0.04). (ii) Hypertensives: Caucasians: SBP -5.48 mm Hg (95% CI: -6.53, -4.43; P<0.00001), DBP -2.75 mm Hg (95% CI: -3.34, -2.17; P<0.00001). Blacks: SBP -6.44 mm Hg (95% CI: -8.85, -4.03; P=0.00001), DBP -2.40 mm Hg (95% CI:-4.68, -0.12; P=0.04). Asians: SBP -10.21 mm Hg (95%CI:-16.98, -3.44; P=0.003), DBP -2.60 mm Hg (95% CI: -4.03, -1.16; P=0.0004). Sodium reduction resulted in significant increases in renin (P<0.00001), aldosterone (P<0.00001), noradrenaline (P<0.00001), adrenaline (P<0.0002), cholesterol (P<0.001), and triglyceride (P<0.0008). CONCLUSIONS Sodium reduction resulted in a significant decrease in BP of 1% (normotensives), 3.5% (hypertensives), and a significant increase in plasma renin, plasma aldosterone, plasma adrenaline, and plasma noradrenaline, a 2.5% increase in cholesterol, and a 7% increase in triglyceride.