Effect of Ethanol on Parathyroid Hormone and Calcitonin Secretion in Man

Abstract

Ingestion of 0.8 g/kg ethanol in 1 hr by normal man caused significant increases in both serum PTH and plasma CT concentrations, with peak values of 139% of baseline at 2 hr for PTH and of 138% at 3 hr for CT. Serum Ca did not change during the period of observation. Incubation of bovine parathyroid slices in 1.25 mM Ca Eagle media with 0.05% or 0.3% ethanol caused significant increases in PTH secretion to 122% and 166% of baseline respectively. Therefore: (1) in vitro, ethanol can be demonstrated to directly stimulate PTH secretion, (2) in vivo, ethanol ingestion induces an increase in PTH without detectable hypocalcemia, suggesting (a) prompt PTH secretion and action to compensate for a hypocalcemic effect of ethanol, so that actual hypocalcemia is not detectable, and/or (b) direct parathyroid stimulation. Though the exact mechanisms are unclear, the data indicate that ethanol, in amounts often ingested by social drinkers, increases both PTH and CT secretion, and therefore may modify Ca homeostasis.