[Myocardial morphological changes related to sodium intake in normotensive and hypertensive patients never treated...

Several factors have been implicated in the pathogenesis of myocardial hypertrophy, and the role of sodium has recently been suggested. In the present study, we assessed the influence of dietary sodium on the degree of left ventricular hypertrophy (LVH) and LV structure in 30 normotensive (NT) subjects aged 34 +/- 11 years (mean +/- SD) and 50 patients (39 +/- 10 years) with mild essential hypertension EH (canal blood pressure 154 +/- 16/96 +/- 11 mmHg), who had never received antihypertensive drugs. Posterior wall thickness (PWT) and left ventricular mass (LVM) were measured by M-mode echocardiography and urinary sodium excretion (UNa, mmol/24h) was taken as an index of sodium intake. In NT and EH, LVM was directly correlated with UNa (r = 0.48 and 0.49; p less than 0.006 and 0.002, respectively). A stepwise multiple regression analysis confirmed that UNa was a determinant of LVM independently of sex, age, and body weight in the two groups. In NT the correlation with UNaV was the result of an increase of the end-diastolic diameter without change in PWT whilst in EH it was the consequence of an increase in wall thickness (R = 0.49, p less than 0.0001) without a modification of LV diameter. These results suggest that salt intake may be an important determinant of cardiac structural adaptation in both NT and EH subjects; however, only EH have a salt sensitive LV wall hypertrophy.