Premium
IGF‐I SYSTEM TEMPORAL RESPONSES TO CALORIC RESTRICTION DURING CONTINUOUS MONITORING OF INTERSTITIAL GLUCOSE
Author(s) -
Nindl Bradley Charles,
Rarick Kevin R.,
Scofield Dennis E.,
Pierce Joseph R.,
Stanger Michael J.,
Adam Gina E.,
Lieberman Harris R.
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.991.24
Subject(s) - context (archaeology) , endocrinology , carbohydrate , medicine , chemistry , caloric theory , crossover study , igfbp3 , placebo , bioavailability , zoology , biology , growth factor , pharmacology , receptor , paleontology , alternative medicine , pathology
IGF‐I declines during caloric restriction, but few data are available that provide temporal resolution for IGF‐I and IGF‐I binding protein (BP) responses within the context of altered dietary intakes. This study examined temporal responses of the IGF‐I system and glucose concentrations during altered dietary intakes. A double‐blind, placebo‐controlled crossover design was used in which 27 subjects (24±yr) underwent 3, 48‐hr experimental treatments: 1) caloric restriction (CR) (313±9 kcal), 2) carbohydrate diet condition (CHO) (4566±111 kcal), and 3) carbohydrate‐fat (CHO/F) diet condition (4611±114 kcal). The MiniMed continuous glucose monitoring system measured interstitial glucose every 5 minutes. Blood was sampled periodically (6 timepoints total) for IGF‐I, IGFBPs‐1 and 3. A repeated measures ANOVA was used for statistical analysis (p < 0.05). Diet effects indicated IGFBP‐1 increased during CR (CR (33 ng/ml > CHO (17 ng/ml) = CHO/F (18 ng/ml) and glucose decreased during CR (CR (85 mg/dl < CHO (99 mg/dl) = CHO/F (97 mg/dl) with no changes for IGF‐I or IGFBP‐3. Also, IGFBP‐1 increased (~250%) from baseline after only 24 hrs, while IGF‐I declined (~7%) only after 48 hrs. IGFBP‐1 increased during CR, but was not altered with diets differing in CHO/F content. IGF‐I bioavailability is influenced by nutritional stress, independent of changes in IGF‐I.