Association between the ratio of insulin-like growth factor-I to insulin-like growth factor binding protein-3 and inflammation in incident automated peritoneal dialysis patients

Abstract

BackgroundThe insulin-like growth factor (IGF) system is known to be associated with inflammation in various populations. However, the association between the IGF system and inflammation has not previously been investigated in automated peritoneal dialysis (APD) patients. Therefore, the aim of this study was to investigate whether the IGF system correlates with inflammation in APD patients. MethodsWe prospectively determined IGF-I activity, the ratio of serum IGF-I concentrations to those of IGF binding protein-3 (IGFBP-3), and inflammatory markers at initiation of APD and after 6months of follow-up in 21 incident APD patients. ResultsThe mean age was 55.2±13.1years, and 11 patients (52.3%) were male. Continuous cyclic PD (CCPD) was performed in 11 patients, and nocturnal intermittent PD (NIPD) in 10 patients. The mean value of IGF-I/IGFBP-3 was 0.21±0.13. At baseline, IGF-I/IGFBP-3 was negatively correlated with high-sensitivity C-reactive protein (hs-CRP) (r=−0.27, P=0.032) and interleukin-6 (IL-6) (r=−0.19, P=0.046) concentrations. After 6months, IGF-I/IGFBP-3 (P=0.048) had decreased significantly, while the hs-CRP (P=0.036) increased significantly in the CCPD group. However, there were no significant changes in IGF-I/IGFBP-3 (P=0.59) and hs-CRP (P=0.14) during 6months in the NIPD group. Furthermore, compared with the NIPD group, IGF-I/IGFBP-3 (P=0.041) decreased greater, whereas hs-CRP (P=0.048) concentrations increased greater in the CCPD group. ConclusionsThe IGF system was significantly associated with inflammatory markers in incident APD patients, and different APD modalities modulate the IGF system and inflammation.