Faculty Collaboration Database

Effects of acute caloric restriction compared to caloric balance on the temporal response of the IGF-I system. Metabolism 2013 Feb;62(2):179-87

Date

08/22/2012

Pubmed ID

22906764

DOI

10.1016/j.metabol.2012.07.004

Scopus ID

2-s2.0-84872685566 (requires institutional sign-in at Scopus site)   23 Citations

Abstract

OBJECTIVE: Insulin-like growth factor-I (IGF-I) is a key regulator of metabolism during altered energy states. The IGF-I system components respond to prolonged caloric restriction but it is not clear if this system responds similarly to acute caloric restriction. The purpose of this study was to characterize the IGF-I system response to acute caloric restriction with a secondary purpose of determining if two isocaloric diets with different ratios of carbohydrate to fat alter the IGF-I system under conditions of caloric balance.

MATERIALS/METHODS: A double-blind, placebo-controlled crossover design was used in which 27 subjects underwent three, 48-h experimental treatments: 1) caloric restriction 2) carbohydrate and 3) carbohydrate/fat. Blood was sampled periodically (6 time points total) for IGF-I (total and free), IGFBPs1-4, insulin and glucose. ANOVAs were used with significance set at P<0.05.

RESULTS: Total IGF-I decreased 7% during CR (P=0.051) and remained stable during CHO and CHO/F. Free IGF-I decreased 43% during CR (P<0.05) and remained stable during CHO and CHO/F. IGFBP-1 increased by 445% during CR (P<0.05) compared to CHO and CHO/F with no changes for IGFBP-2, IGFBP-3 and IGFBP-4. There was no change in glucose or insulin during CR over the course of the study. Insulin and glucose increased (P<0.05) after a meal in both the CHO and CHO/F groups with no difference between these two groups.

CONCLUSION: Our findings indicate that free IGF-I decreases and IGFBP-1 increases during caloric restriction, but they are not altered with diets differing in carbohydrate and fat content. Changes in free IGF-I and IGFBP-1 are sensitive to caloric restriction, and their measurement may be valuable in monitoring the physiological response to refeeding in those consuming suboptimal calories.

Author List

Henning PC, Scofield DE, Rarick KR, Pierce JR, Staab JS, Lieberman HR, Nindl BC

Author

Kevin Richard Rarick PhD Assistant Professor in the Pediatrics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Blood Glucose
Caloric Restriction
Cross-Over Studies
Dietary Carbohydrates
Dietary Fats
Double-Blind Method
Female
Food Deprivation
Humans
Insulin
Insulin-Like Growth Factor Binding Proteins
Insulin-Like Growth Factor I
Male
Young Adult