Endocrine Abstracts

Objective: IGF1 has almost 50% amino acid sequence homology with insulin and elicits nearly the same hypoglycaemic response. Studies showed that low and high IGF1 levels are related to impaired glucose tolerance and to a higher risk of type two diabetes. The aim of the present study was to evaluate the association between IGF1 level and insulin resistance in a Danish general population.

Research Design and Methods: From the cross-sectional Health2006 study 3354 adults aged 19 – 72 years were included. The homeostasis model assessment of insulin resistance (HOMA-IR) was used as the index to estimate insulin resistance. Serum IGF1 levels were determined by an immunoassay and grouped into quintiles (Q1–Q5). Linear or multinomial logistic regression analyses were performed.

Results: In the study population 520 subjects (15.5%) had increased HOMA-IR values above 2.5. After adjustment for age, sex, physical activity and waist-to-height ratio, an U shaped association between IGF1 and HOMA-IR was found. Low IGF1 [Q1: OR 1.64 (95% CI 1.15; 2.33), P<0.01] as well as high IGF1 [Q5: OR 1.96 (95% CI 1.38; 2.79), P<0.01] levels were related to a higher odds of increased HOMA-IR values compared to subjects with intermediate (Q3) IGF1 levels. These associations remained statistically significant after the exclusion of subjects with type two diabetes mellitus and by using the updated computer HOMA2-IR model.

Conclusions: In conclusion, low- as well as high-normal IGF1 levels, are both related to insulin resistance. The biological mechanism of this complex phenomenon has to be elucidated in more detail for future risk stratification.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.