The aim of the present study was to evaluate whether high salt intake could potentiate the relation between blood pressure (BP) and albuminuria. We evaluated salt intake and BP control in hypertensive patients in the area of Blida (Algeria).

Data were collected from a cross-sectional sample involving 3571 patients that were followed at a hypertension consultation at hospital. Data collection comprised a physical examination (weight, height and BP) according to standard procedures, albuminuria excretion and a single 24-hour urine collection. We evaluated the relation between BP and albuminuria for all and for each of the 4 quartiles of UNa+ distribution just in subjects not treated with modulators of the renin angiotensin system.

In total, 88.4% of the patients had salt intake higher than the 5g/L recommended by World Health Organization. We failed to observe trend in decreasing salt intake, without gender difference. Significant correlation between salt intake and systolic and diastolic BP was found in the whole group (r=0.32; r=0.18, respectively, both P<0.01), in men (r=0.29; r=0.14, respectively, both P=0.01) and in women (r=0.35; r=0.21, respectively, both P<0.01). Systolic BP (SBP, average 127+16mmHg) correlated with log of albuminuria (average log 0.79+0.36mg/24h) (r=1.05, P<0.02). Quartiles of UNa+ did not differ for age, gender distribution and BMI. The BP control rate was 30.1% among the subjects (mean systolic blood pressure was 145.3±23.4mmHg and diastolic blood pressure was 81.6±10.3). Patients who consumed salt according to recommendations had higher control rate of BP than those who consumed salt above recommendations (62.1% vs. 30.1%; OR=0.5, CI: 0.05–4.72).

Our data suggest that high salt intake potentiates the effect of pressure on the rise of urinary albumin excretion, suggesting a deleterious effect of high salt on the vascular and renal homeostasis partially independent of BP.