Urine Sodium in 3 Consecutive Days Urine collected from Hypertensive and their Normotensive Relatives

Abstract

Epidemiological and experimental studies have shown that salt sensitivity, which is a heritable trait, is a hallmark to hypertension in blacks. Previous studies on twenty-four hour urinary sodium were either incomplete or yielded contradictory results possibly from incomplete urine collection.
This study attempted complete urine collection, which involves collection of urine in three consecutive days from the hypertensives and their first degree normotensive relatives that share the same salty diet with them.
Seventy-three subjects comprising 21 hypertensives and 52 first degree normotensive relatives of the hypertensives that share the same salty diet with them participated in the study. Mean arterial pressure, pulse rate and average daily urinary sodium for three days were determined.
The results showed no difference between daily urinary sodium in group 1 (Hypertensive) and II (Normotensive relatives of hypertensive patients) for the first and second days. There was significant difference between day 2 and day 3 urine sodium output (p<0.05). The result also showed that hypertensives had higher mean arterial pressure (t=4.9, p=0.0001), excreted less sodium (t=3.2, p=0.002) for 3 days compared to their normotensive relatives. This study supports the hypothesis that hypertensive blacks have impaired renal handling of sodium load.


NQJHM Vol. 14 (3&4) 2004: pp. 240-243