Renal and gastrointestinal potassium excretion in humans: new insight based on new data and review and analysis of published studies.
OBJECTIVE
Little is known about the relationship between the renal and gastrointestinal excretion of potassium in humans. This information is important in light of strong associations of potassium intake with hypertension and occlusive stroke.


METHODS
We determined the relationship between fecal and urinary excretion of potassium under both fixed and variable potassium intakes using our unpublished archival data and published data of others. Twenty-five subjects were evaluated.


RESULTS
On a fixed, low oral potassium intake (61.2 +/- 4.7 mmol/day; mean +/- SD), there was an inverse relationship between fecal and urinary potassium excretion (r = -0.66, p = 0.040). In studies in which potassium intake varied between 61-135 mmol/day, fecal and urinary potassium excretions were positively correlated (r = 0.58, p = 0.024). Considerable within-and-between-subject variation was observed in the relationship between fecal and urinary potassium excretion.


CONCLUSIONS
Inter-individual variation in fecal potassium excretion may arise from both variation in dietary potassium intake and intrinsic individual differences in the renal versus gastrointestinal handling of potassium.
Klevay
Leslie M
LM
Department of Agricultrue, Agricultural Research Service, Human Nutrition Research Center, Grand Forks, North Dakota, USA.
Bogden
John D
JD
Aladjem
Mordechay
M
Sandstead
Harold H
HH
Kemp
Francis W
FW
Li
Wenjie
W
Skurnick
Joan
J
Aviv
Abraham
A
D000328:Adult; D005243:Feces / Q000737:chemistry*; D041981:Gastrointestinal Tract / Q000378:metabolism*; D005772:Gastrointestinal Transit; D006801:Humans; D007408:Intestinal Absorption; D007668:Kidney / Q000378:metabolism*; D008297:Male; D011188:Potassium / Q000032:analysis / Q000493:pharmacokinetics* / Q000652:urine*; D017419:Potassium, Dietary / Q000008:administration & dosage / Q000493:pharmacokinetics*
D017419:Potassium, Dietary; D011188:Potassium