Low-density lipoprotein cholesterol levels are associated with insulin-like growth factor-1 in short-stature children and adolescents: a cross-sectional study

BACKGROUND: Elevated low-density lipoprotein cholesterol (LDL-C) levels in childhood have recently been found to be the strongest predictive risk factor for coronary artery disease in adulthood. There is an increased level of LDL-C in children and adolescents with short stature. However, the underlying factors associated with increased LDL-C levels in children and adolescents with short stature are unknown. In addition, the insulin-like growth factor 1 (IGF-1) level in the short-stature population is usually below the normal reference range. The aim of this study was to investigate the relationship between IGF-1 standard deviation score (IGF-1 SDS) and LDL-C level in children and adolescents with short stature. METHODS: A cross-sectional study was conducted in a single centre of China, 557 short-stature children and adolescents whose height SDS was lower than − 2 SD after adjustment for age and gender were included. The related clinical and laboratory examinations, including anthropometric parameters, lipid profiles, IGF-1 levels and the levels of other cofactors, were assessed in all participants. RESULTS: The univariate analysis results showed a significant negative correlation between IGF-1 SDS and LDL-C levels (P = 0.006). Furthermore, a nonlinear relationship was observed between IGF-1 SDS and LDL-C by smooth curve fitting after adjusting for possible confounders. A multivariate piecewise linear regression model revealed a significant negative correlation between IGF-1 SDS and LDL-C when the IGF-1 level was greater than − 2 SDS (β − 0.07, 95% CI -0.12, − 0.02; P = 0.006). However, we did not observe a significant relationship between IGF-1 SDS and LDL-C when the IGF-1 level was lower than − 2 SDS (β 0.08, 95% CI -0.02, 0.17; P = 0.119). CONCLUSION: This study demonstrated a nonlinear relationship between IGF-1 and LDL-C independent of other potential confounding factors, suggesting that circulating IGF-1 may contribute to the regulation of LDL-C levels, thus meriting further investigation. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12944-019-1062-z) contains supplementary material, which is available to authorized users.