Effect of supplementary calcium phosphate on plasma gastrointestinal hormones in a double-blind, placebo-controlled, cross-over human study

Abstract

Gastrointestinal hormones and Ca are associated with bone metabolism. The objective of the present human study was to determine the effect of calcium phosphate on the postprandial circulation of gastrointestinal hormones. A total of ten men participated in the present double-blind, placebo-controlled, cross-over study. The participants were divided into two groups. Of these, one group consumed bread enriched with 1 g Ca (pentacalcium hydroxy-triphosphate, CaP) daily for 3 weeks. The other group consumed placebo bread. After 2 weeks of washout, the intervention was changed between the groups for another 3 weeks. The subjects consumed a defined diet at the beginning (single administration) and at the end (repeated administration) of the intervention periods, and blood samples were drawn at 0, 30, 60, 120, 180 and 240 min. Between 0 and 30 min, the participants consumed a test meal, with or without CaP. The concentrations of gastrointestinal hormones (glucose-dependent insulinotropic polypeptide, glucagon-like peptide (GLP) 1 and GLP2), insulin and glucose were determined. The AUC of GLP1 (total and active) and GLP2 increased significantly after the repeated CaP administrations compared with that after placebo administration. The AUC of insulin and glucose showed no differences between the CaP and placebo administrations. CaP affects the postprandial plasma concentrations of gastrointestinal hormones through the modulation of the intestinal environment, e.g. bile acids and microbiota.

Endomicroscopic and Transcriptomic Analysis of Impaired Barrier Function and Malabsorption in Environmental Enteropathy

“…The absolute concentration of GLP-2 is not easy to establish as different techniques (ELISA, RadioImmunoAssay) have different sensitivities and give different results. Average normal circulating levels have variously been reported as 0.1 ng/ml [ 44 ] or 42pg/ml by RIA [ 45 ] , and 0.4ng/ml [ 46 ] or 30pg/ml by ELISA [ 47 ], and importantly the manufacturers of the ELISA we used report normal concentrations with a lower limit of 3.6 ng/ml, so overall the concentrations in our participants were probably low. Our findings would be consistent with a primary endocrine failure of GLP-2 synthesis rather than a failure of end-organ responsiveness (which would be expected to result in elevated GLP-2 levels).…”

The influence of calcium supplementation on substrate metabolism during exercise in humans: a randomized controlled trial

“…7 The present findings indicate that this does not result in upregulation of these peptides when fasted. Supporting this, others have reported that 1000 mg of calcium supplementation for 3 weeks does not influence fasting concentrations of total GLP-1 or GLP-1 41 although postprandial concentrations were enhanced, suggesting that the acute response that we previously reported 7 translates into chronic adaptation manifesting in the postprandial state.…”

Cytokines and Hormones That Contribute to the Positive Association between Fat and Bone

“…A small clinical study compared the postprandial plasma concentrations of GLP-1 and GLP-2 between a group that had previously consumed calcium phosphate-enriched diet for 3 weeks and a control group. The study showed that postprandial GLP-1 and GLP-2 levels were significantly increased in the group that had calcium phosphate-enriched diet, whereas levels of insulin and glucose showed no differences between the groups (121). …”