An association between post-meal bile acid response and bone resorption in normal subjects

Background: The mechanism surrounding bone suppression after a meal may involve several mediators, but is yet to be clarified. Bile acids (BA) function as signalling molecules in response to feeding, and may be directly involved in bone suppression acutely after a meal. The aim of this study was to test the hypothesis that BA are involved in the acute bone suppression observed after a meal.

Methods: A prospective study in which samples collected from volunteers fed a 400Kcal test meal after an overnight fast were analysed for parathyroid hormone (PTH), BA, and carboxyterminal of type 1 collagen telopeptide (CTX). The study was carried out in 10 healthy male volunteers. Ethical approval was obtained from the Local Research and Ethics Committee at King's College Hospital.

Results: Total BA, glycine conjugated bile acids (GCBA), PTH and CTX showed a response to meal ingestion. There was a negative correlation between percentage change in PTH and CTX (R-2=-0.82, P=0.004), and between PTH and GCBA (R-2=-0.39, P=0.005).

Conclusion: This study demonstrated an association between GCBA and PTH suppression after a meal. The drop in PTH concentration after a meal may be responsible for the suppression of bone resorption as observed by the decrease in CTX concentration.