Diuresis related to cold exposure.

Abstract

To the Editor.— We read with great interest the observations of Blume et al relating hyperosmolality and serum arginine vasopressin (AVP) levels to high-altitude exposure of trained mountaineers. The lack of ambient or core temperature data opens to question the conclusion that altitude is the sole cause of these changes. A cold exposure-associated diuresis in humans has been reported in the literature. 2,3 Radomski and Boutelier 4 found that repeated cold exposure in warmly dressed humans would blunt this cold-associated diuresis. Segar and Moore 3 measured serum AVP levels in human subjects placed in cold and warm chambers and concluded that serum AVP levels increased with heat exposure and decreased with cold exposure. The elevation of serum AVP levels was associated with diuresis in these subjects. The combined effect of altitude and cold exposure should be considered in subjects with unchanged serum AVP concentration and hyperosmolal serum, as found by