A short abstract incorporating some of the results of the study has been presented at the annual meeting of the European Group for the study of Insulin Resistance (EGIR), Edinburgh, 30 May–1 June 2007.
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Insulin sensitivity increase after calcium supplementation and change in intraplatelet calcium and sodium–hydrogen exchange in hypertensive patients with Type 2 diabetes†
Article first published online: 24 JAN 2009
DOI: 10.1111/j.1464-5491.2009.02673.x
© 2009 The Authors. Journal compilation © 2009 Diabetes UK
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How to Cite
Pikilidou, M. I., Lasaridis, A. N., Sarafidis, P. A., Befani, C. D., Koliakos, G. G., Tziolas, I. M., Kazakos, K. A., Yovos, J. G. and Nilsson, P. M. (2009), Insulin sensitivity increase after calcium supplementation and change in intraplatelet calcium and sodium–hydrogen exchange in hypertensive patients with Type 2 diabetes. Diabetic Medicine, 26: 211–219. doi: 10.1111/j.1464-5491.2009.02673.x
- †
Publication History
- Issue published online: 12 MAR 2009
- Article first published online: 24 JAN 2009
- Accepted 10 January 2009
- Abstract
- Article
- References
- Cited By
Keywords:
- calcium supplementation;
- hyperinsulinaemic clamp;
- insulin sensitivity
Abstract
Aims/hypothesis To investigate the effect of oral calcium (Ca2+) supplementation on insulin sensitivity measured by the euglycaemic hyperinsulinaemic clamp, intraplatelet cationic concentration of Ca2+ ([Ca2+]i) and the transmembrane sodium–hydrogen exchanger (NHE) activity in erythrocytes in subjects with Type 2 diabetes and hypertension.
Patients and methods In this parallel randomized controlled single-blinded trial, 31 patients were allocated to receive either 1500 mg of Ca2+ orally, daily (n = 15) or no treatment (n = 16) for 8 weeks. At baseline and at the end of the 8-week period insulin sensitivity, [Ca2+]i and the first isoform of NHE (NHE-1) activity were measured.
Results At the end of the study, subjects who received Ca2+ supplementation showed higher insulin sensitivity (ΔM-value 0.32 ± 0.5 mmol/min P < 0.05) and lower [Ca2+]i (125.0 ± 24.7 to 80.4 ± 10.6 nmol/l, P < 0.05, mean ± sem) and NHE-1 activity (79.5 ± 10.0 to 52.1 ± 6.4 mmol Na/l red cell/h, P < 0.05). None of the above parameters were changed in the control group. Simple regression analysis demonstrated the change in [Ca2+]i significantly determined insulin sensitivity change (β = −0.36, P < 0.05).
Conclusions/interpretation Oral Ca2+ supplementation improves insulin sensitivity in patients with Type 2 diabetes and hypertension. These changes are likely to be mediated by changes in intracellular ionic Ca2+. NHE-1 activity was also reduced after Ca2+ supplementation but its role in insulin sensitivity requires further investigation.