Free dissociable IGF-I: Association with changes in IGFBP-3 proteolysis and insulin sensitivity after surgery
2016 (English)In: Clinical Nutrition, ISSN 0261-5614, E-ISSN 1532-1983, Vol. 35, no 2, 408-413 p.Article in journal (Refereed) PublishedText
Background: Patients receiving a carbohydrate drink (CHO) before major abdominal surgery display improved insulin sensitivity postoperatively and increased proteolysis of IGFBP-3 (IGFBP-3-PA) compared to patients undergoing similar surgery after overnight fasting. Aims: We hypothesized that serum IGFBP-3-PA increases bioavailability of circulating IGF-I and preserves insulin sensitivity in patients given CHO. Design: Matched control study. Methods: At Karolinska University Hospital, patients given CHO before major elective abdominal surgery (CHO,n = 8) were compared to patients undergoing similar surgical procedures after overnight fasting (FAST,n = 10). Results from two different techniques for determination of free-dissociable IGF-I (fdIGF-I) were compared with changes in IGFBP-3-PA and insulin sensitivity. Results: Postoperatively, CHO displayed 18% improvement in insulin sensitivity (hyperinsulinemic clamp) and increased IGFBP-3-PA vs. FAST. As determined by IRMA, fdIGF-I increased by 48 +/- 25% in CHO while fdIGF-I decreased by 13 +/- 18% in FAST (p < 0.01 vs. CHO, when corrected for duration of surgery). However, fdIGF-I determined by ultra-filtration decreased similarly in both groups (-22 +/- 8% vs. -25 +/- 8%, p = 0.8) and IGFBP-1 increased similarly in both groups. Patients with less insulin resistance after surgery demonstrated larger increases in fdIGF-I by IRMA (r = 0.58, p < 0.05). Fifty-three % of the variability of the changes in fdIGF-I by IRMA could be explained by changes in IGFBP-3-PA and total IGF-I levels (p < 0.05), while IGFBP-1 did not contribute significantly. Conclusion: During conditions when serum IGF-I bioavailability is regulated by IGFBP-3 proteolysis, measurements of fdIGF-I by IRMA is of physiological relevance as it correlates with the associated changes in insulin sensitivity. (C) 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
Place, publisher, year, edition, pages
CHURCHILL LIVINGSTONE , 2016. Vol. 35, no 2, 408-413 p.
Insulin resistance; IGF-I; IGFBP-3; Proteolysis; IGF bioavaialbility; Free dissociable IGF
IdentifiersURN: urn:nbn:se:liu:diva-127746DOI: 10.1016/j.clnu.2015.03.003ISI: 000373865200015PubMedID: 25817945OAI: oai:DiVA.org:liu-127746DiVA: diva2:927511
Funding Agencies|Karolinska Institute; Swedish Medical Research Council [11634, 09101, 4224]; Swedish Diabetes Association; Fredrik and Ingrid Thurings foundation; Swedish Society of Medicine; Torsten and Ragnar Soderbergs Foundation; Wera Ekstroms foundation; Swedish Freemansons foundation; Marta and Gunnar V. Philipsons Foundation; Erling-Persson Family Foundation; Nyckelfonden, Orebro, Sweden2016-05-122016-05-122016-05-12