#2902 How does IGF-1 levels relate to different stages of chronic kidney disease

Abstract

Abstract Background and Aims Insulin like growth factor-1 (IGF-I) influences glomerular filtration rate (GFR).Chronic kidney disease (CKD) influences the IGF/GH axis also. Serum IGF-I level is proposed to be a risk factor for renal and cardiovascular complications which is accentuated in CKD. This study is undertaken to observe the level of serum IGF-1 in different stages of chronic kidney disease and its association with cardio-metabolic risk factors Method This cross-sectional pilot study included consecutive 102 CKD patients of advanced renal failure (CKD3-5). Also 52 healthy subjects (free from any known disease) served as healthy referent for IGF-1 level. Stable CKD subjects ( < 15% deviation of eGFR in 3 months) from OPD of study center were included as cases. Information on socio-demographic and clinical characteristics with medical histories was collected from all in a predesigned data collection sheet Urine spot samples and fasting blood samples were collected and stored at −80°C for future analyses. The four-variable Modification of Diet in Renal Disease (MDRD) study equation was used for calculation of the eGFR using enzymatic creatinine. IGF-I was determined by ELISA method. Results Mean age was of CKD subjects was 50.45 ± 10.45 years with male-49% female-51%. Most common primary disease responsible for CKD was GN (53%) followed by DM (21%), HTN (13.0%) and rest others. The IGf-1 level was 297 ± 107 (range 79-588) in CKD patients and in healthy it was 246 ± 82 (114-529) ng/ml, (p < 0.004). The IGF-1 value at 25th percentile of healthy was only present in 12.7% of CKD and above 75th it was present in 42% of CKDs (p < 0.11). Study subjects in CKD 3 was 36%, in 4- 44% and in 5- 24%. The serum IGF-1 levels at CKD 3, 4 and 5 was 246 ± 82, 278 ± 95 and 328 ± 101 ng/ml, (p < 0.014); Hb% 11.1 ± 1.4, 11.3 ± 1.5 and 10.6 ± 1.5 g% (p < 0.001); calcium 9.5 ± 1.4, 9.6 ± 1.4 and 8.9 ± 1.0 mg% (P < 0.014); phosphate 3.6 ± 1.1, 3.6 ± 0.4 and 4.2 ± 1.0 mg%(p < 0.02); iPTH 24 ± 27, 22 ± 16 and 61 ± 82 pg/ml (p < 0.01) and albumin 4.5 ± 1.1, 4.56 ± 1.4 and 8.9 ± 1.0 mg%, (p < 0.04) respectively in 3 stages. The correlation study showed only a negative association of IGF-1 with eGFR (p < 0.01).The logistic regression analysis showed (taking in consideration of cardio-metabolic risk factors) only a significant association of eGFR with IGF-1. Conclusion The Serum IGF-1 level had an increasing value along with alterations in other biochemical parameters at advancing stage of CKD. This increase in IGF-1 value seems to be a reflection of progressing CKD rather than a causal relation to other cardio-metabolic risk markers.