Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Greifswald, Germany.
Diabetes Care. 2012 Apr;35(4):768-73. doi: 10.2337/dc11-1833. Epub 2012 Feb 28.
IGF-I has an almost 50% amino acid sequence homology with insulin and elicits nearly the same hypoglycemic response. Studies showed that low and high IGF-I levels are related to impaired glucose tolerance and to a higher risk of type 2 diabetes. The aim of the current study was to evaluate the association between IGF-I level and insulin resistance in a Danish general population.
Included were 3,354 adults, aged 19-72 years, from the cross-sectional Health2006 study. The homeostasis model assessment of insulin resistance (HOMA-IR) was used as the index to estimate insulin resistance. Serum IGF-I levels were determined by an immunoassay and grouped into quintiles (Q1-Q5). Linear or multinomial logistic regression analyses were performed.
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, a U-shaped association between IGF-I and HOMA-IR was found. Low IGF-I (Q1: odds ratio [OR] 1.65 [95% CI 1.16-2.34], P < 0.01) as well as high IGF-I (Q5: 1.96 [1.38-2.79], P < 0.01) levels were related to a higher odds of increased HOMA-IR values compared with subjects with intermediate (Q3) IGF-I levels. These associations remained statistically significant after the exclusion of subjects with type 2 diabetes and by using the updated computer HOMA2-IR model.
Low- and high-normal IGF-I 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.
IGF-I 与胰岛素有近 50%的氨基酸序列同源性，并且几乎会引起相同的降血糖反应。研究表明，IGF-I 水平低和高与糖耐量受损以及 2 型糖尿病风险增加有关。本研究旨在评估丹麦普通人群中 IGF-I 水平与胰岛素抵抗之间的关系。
本研究纳入了来自横断面 Health2006 研究的 3354 名年龄在 19-72 岁的成年人。使用稳态模型评估的胰岛素抵抗指数（HOMA-IR）作为估计胰岛素抵抗的指标。通过免疫测定法测定血清 IGF-I 水平，并将其分为五组（Q1-Q5）。进行线性或多项逻辑回归分析。
在研究人群中，有 520 名（15.5%）受试者的 HOMA-IR 值高于 2.5。在调整年龄、性别、体力活动和腰高比后，发现 IGF-I 与 HOMA-IR 之间存在 U 形关联。低 IGF-I（Q1：比值比 [OR] 1.65 [95%CI 1.16-2.34]，P < 0.01）和高 IGF-I（Q5：1.96 [1.38-2.79]，P < 0.01）水平与 HOMA-IR 值升高的几率较高相关与中间（Q3）IGF-I 水平的受试者相比。排除 2 型糖尿病患者后，这些关联仍然具有统计学意义，并且使用更新的计算机 HOMA2-IR 模型也是如此。
低正常和高正常 IGF-I 水平均与胰岛素抵抗有关。为了进行未来的风险分层，需要更详细地阐明这种复杂现象的生物学机制。
