Influence of posture on serum potassium changes during standard glucose tolerance test.

Serum potassium (SK) decreased in a significantly greater extent (p less than 0.005) in the recumbent (0.91 +/- 0.11 mmol/L) than in the upright position (0.57 +/- 0.07 mmol/L) in the course of the standard glucose tolerance test (StGTT) in 12 normal people. The clinical implications with special respect to "paradoxical hyperkalemia" are discussed.