Objective: To evaluate the left ventricular mass (LVM) reduction induced by dietary sodium restriction.
Patients and methods: A simple sodium-restricted diet was advised in 138 treated hypertensives. They had to avoid common salt loads, such as cheese and salt-preserved meat, and were switched from regular to salt-free bread. Blood pressure (BP), 24-h urinary sodium (UNaV) and LVM were recorded at baseline, after 2 months. and after 2years.
Results: In 76 patients UNaV decreased in the recommended range after 2 months and remained low at 2 years. In 62 patients UNaV levels decreased after 2 months and then increased back to baseline at 2 years. Initially the two groups did not differ in terms of BP (134.3 ± 16.10 / 80.84 ± 12.23 vs.134.2 ± 16.67 / 81.55 ± 11.18 mmHg, mean ± SD), body weight (72.64 ± 15.17 vs.73.79 ± 12.69 kg), UNaV (161.0 ± 42.22 vs.158.2 ± 48.66 mEq/24 h), and LVM index (LVMI; 97.09 ± 20.42 vs.97.31 ± 18.91 g/m2). After 2years. they did not differ in terms of BP (125.3 ± 10.69 / 74.97 ± 7.67 vs.124.5 ± 9.95 / 75.21 ± 7.64 mmHg) and body weight (71.14 ± 14.29 vs.71.50 ± 11.87 kg). Significant differences were seen for UNaV (97.3 ± 23.01 vs.152.6 ± 49.96 mEq/24 h) and LVMI (86.38 ± 18.17 vs.103.1 ± 21.06 g/m2). Multiple regression analysis: UNaV directly and independently predicted LVMI variations, either as absolute values (R2 = 0.369; β = 0.611; p < 0.001), or changes from baseline to +2years. (R2 = 0.454; β = 0.677; p < 0.001). Systolic BP was a weaker predictor of LVMI (R2 = 0.369; β = 0.168; p = 0.027; R2 = 0.454; β = 0.012; p = 0.890), whereas diastolic BP was not correlated with LVMI. The prevalence of left ventricular hypertrophy decreased (29/76 to 15/76) in the first group while it increased in the less compliant patients (25/62 to 36/62; Chi2p = 0.002).
Conclusion: LVM seems linked to sodium consumption in patients already under proper BP control by medications.
Keywords: blood pressure; hypertension; left ventricular hypertrophy; left ventricular mass; low-sodium diet; sodium consumption.