Authors: Elena Kamycheva Vivian Berg Rolf Jorde
Publish Date: 2012/10/30
Volume: 43, Issue: 2, Pages: 412-418
Abstract
Both altered GHIGFI axis and low serum levels of 25hydroxyvitamin D 25OHD are linked to measures of metabolic syndrome Our hypothesis was that there is a relation between GH IGFI and 25OHD and that vitamin D supplementation may have an effect on the levels of GH IGFI and IGFI/IGFBP3 ratio 318 overweight and obese subjects completed a oneyear randomized intervention with either 40000 or 20000 IU cholecalciferol per week or placebo GH IGFI IGFBP3 and measures of insulin resistance were evaluated at baseline and at the end of study There was a significant relation between entities of GHIGFI axis and insulin resistance Subjects with severe obesity had significantly lower serum 25OHD and had a significant linear decline in IGFI/IGFBP3 ratio with increasing serum 25OHD quartiles Vitamin D status was an independent predictor of GHIGFI axis and supplementation with vitamin D decreased IGFI/IGFBP3 ratio in subjects without severe obesity No corresponding effect of vitamin D supplementation on BMI or insulin resistance was observed Adverse effects of GHIGFI axis on glucose metabolism and the development of metabolic syndrome may be in part associated with the changes in vitamin D statusThe study was supported by a grant from The Northern Norway Regional Health Authority The superb assistance by the staff at the Clinical Research Unit and by Inger Myrnes and Astrid Lindvall at the Department of Medical Biochemistry University Hospital of Northern Norway is gratefully acknowledged We are grateful for the generous supply of calcium tablets from Nycomed Norway
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