A study of 48-hour faecal and urinary electrolyte excretion in normotensive black and white South African males.
Previous studies have shown that 24-h urinary sodium (Na) excretion is similar in blacks and in whites. However, a significantly lower potassium (K) excretion by blacks, with a consequent rise in the Na:K excretion ratio, has been observed. Faecal electrolyte excretion has not been measured. Ten normotensive blacks and 11 normotensive whites on a free diet were studied. Simultaneous 48-h urine and faecal collections were made. The results of the urinary measurements were in accordance with those of previous studies, in that 24-h urinary K excretion by blacks (38.2 +/- 12.4 mmol) was significantly lower than that of whites (78.3 +/- 16.6 mmol). As a result, there was a significantly higher urinary Na:K ratio in the black group. The mean 24-h faecal K excretion of the black group (15 +/- 7.3 mmol) was not significantly lower, even when corrected for weight, than that of the white group (20.8 +/- 10.8 mmol). It is concluded that the low urinary K excretion of South African urban blacks, compared with whites, is a reflection of a lower dietary K intake.
R J
RJ
Barlow
M A
MA
Connell
F J
FJ
Milne
D000328:Adult; D044383:Black People; D001794:Blood Pressure; D004032:Diet; D004231:Diuresis; D005243:Feces / Q000032:analysis; D006801:Humans; D008297:Male; D011188:Potassium / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*; D014505:Urban Population; D014882:Water-Electrolyte Balance; D044465:White People
D012964:Sodium; D011188:Potassium