Abstract

Objective

IGF-I may be a marker of later metabolic and cardiovascular disease. The interactions between IGF-I and glucose metabolism are multifactorial, and there is potential confounding from several secondary effects. In this study, we examined the interaction between IGF-I and glucose metabolism in a large cohort of clinically well-characterized elderly twins.

Design

A total of 303 twin pairs of the same gender (606 twins) were included in the study; 125 monozygotic and 178 dizygotic twin pairs.

Methods

A clinical examination including a standard oral glucose tolerance test (OGTT) and anthropometric measurements was performed.

Results

The heritability estimates were high for IGF-I and IGFBP-3 (h2: 0.65 (95% CI: 0.55–0.74) and 0.71 (0.48–0.94), respectively) and for insulin secretion (h2 = 0.56, P < 0.0001), whereas the heritability estimates for insulin sensitivity were low (h2 = 0.14, P = 0.11). In a multiple regression analysis (adjusting for age, gender and twin status), there was a negative association between IGF-I and insulin sensitivity (B: −0.13, SE 0.03, P < 0.0001) and IGF-I and disposition index (B: −0.05, SE 0.02, P < 0.001) in the entire cohort of 606 twins. The associations between IGF-I and both DI and HOMA-S did not differ between the DZ and MZ twins. Forty-five twin pairs were discordant for T2D, but the discordant twins had similar concentrations of IGF-I or IGFBP-3.

Conclusions

There was a high heritability for IGF-I and IGFBP-3, but a low heritability for insulin secretion and insulin sensitivity in a group of elderly twins. In addition, we found a strong negative relationship between IGF-I and insulin sensitivity, which did not seem to be strongly genetically determined.

This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://dbpia.nl.go.kr/journals/pages/open_access/funder_policies/chorus/standard_publication_model)
You do not currently have access to this article.