The relationship between serum-free insulin-like growth factor-1 and metabolic syndrome in school adolescents of northeast China

Shuang Xie,1,2 Ranhua Jiang,3 Wanfeng Xu,4 Yu Chen,4 Lei Tang,1 Ling Li,1 Ping Li4 1Department of Endocrinology, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, P.R. China; 2Department of General Medicine (VIP ward), Cancer Hospital of China Medical University, Liaoning Cancer Hospital and Institute, Shenyang, Liaoning Province, P.R. China; 3Department of Endocrinology, Liaoyang Diabetes Hospital, Liaoyang, Liaoning Province, P.R. China; 4Department of Endocrinology, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, P.R. China Purpose: Free insulin-like growth factor-1 (IGF-1) ratio (the ratio of IGF-1/insulin-like growth factor binding protein-3 [IGFBP-3]) was shown to be negatively correlated with metabolic syndrome (MetS) in adults, but it was unknown in Chinese adolescents. Patients and methods: The cross-sectional study enrolled 701 healthy school students (aged 12–16 years, 46.1% females) and 93 of them (18–22 years old, 46.2% females) were followed after 5 years. Results: In the cross-sectional study, the IGF-1/IGFBP-3 ratios were found correlated with low-density lipoprotein cholesterol (LDL-C; r= -0.071, P<0.05) and diastolic blood pressure (r= -0.077, P=0.034). A lower IGF-1/IGFBP-3 ratio was an independent risk factor for MetS (OR =2.348, 95% CI: 1.040–5.303), hypertension (OR=1.729, 95% CI: 1.040–5.303), and increased LDL-C (OR=1.841, 95% CI: 1.230–2.755). In the follow-up study, all the participants were >18 years old. We found a lower baseline ratio of IGF-1/IGFBP-3 in adolescence was an independent risk factor for MetS in adulthood (OR=10.724, 95% CI: 1.032–11.403) and also indicated a higher body mass index (β=-1.361, 95% CI: -2.513 to -0.208) after 5 years. Conclusion: The lower IGF-1/IGFBP-3 ratio was an independent risk factor for MetS, hypertension, and high LDL-C in adolescents of northeast China and was also a predictive marker for MetS and increased body mass index in the adulthood. Keywords: IGF-1, IGFBP-3, adolescent, metabolic syndrom