Salt intake and blood pressure in Nigerian hypertensive patients

Discretionary salt intake (habitual) of male and female Nigerian hypertensive patients presenting in hospital was assessed and this was correlated with their blood pressure. Their salt intake was assessed by questionnaires and direct interview following detailed explanation. They were categorised into low, moderate and high salt intake groups according to a standard criterion. The 114 hypertensive patients (52 males; 62 females) were aged 26-80 years (mean 52.2+/-1.8 (S.E.M.) males; 53.7+/-1.7 females, P=0.5). Those on medication were generally poorly compliant with uncontrolled blood pressure at presentation. Fifty percent belonged to the moderate salt intake group. No female reported high salt intake. In the males, the mean DBP in the high salt intake group was significantly higher than in the moderate and low intake groups (123.5+/-4.4, 108.3+/-3.9 and 99.3+/-7.7 mmHg; P<0.02 and P<0.009, respectively). There was no significant difference between the mean DBP of the low and moderate salt intake groups (P>0.1). The SBP is also consistently higher from the low to the high salt intake groups (162.1+/-15.5, 179.3+/-7.4 and 180.8+/-7.6 mmHg, respectively), although the difference is not statistically significant (P>0.1). The BMI did not differ between the salt groups (P>0.5) and there was no correlation between BMI and blood pressure (P>0.05). The study suggests that the higher the salt intake, the higher the blood pressure, particularly the diastolic, in male hypertensive patients. The picture in the female is unclear, since none reported a high salt intake. Reduced salt intake might, therefore, be beneficial in black hypertensive patients, in the setting of common presentation at the stage of cardiac decompensation.