RELATION OF INSULİN RESİSTANCE WİTH FIBROBLAST GROWTH FACTOR 23 IN NON-DIABETIC AUTOSOMAL DOMINANT POLYCYSTIC KIDNEY DISEASE

Melahat Coban^*

Department of Nephrology, Antalya Training and Research Hospital, Antalya, Turkey

Introduction:  Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder with the development of chronic kidney disease (CKD). Our study aims to examine the relationship between insulin resistance and fibroblast growth factor-23 (FGF-23) in non-diabetic ADPKD (NDADPKD) patients.

Materials and methods: This cross-sectional study was conducted with 77 NDADPKD patients with a mean age of 47 ± 14.3 years. The patients were compared with the healthy control group composed of 47 subjects with similar age and gender. In terms of renal functions, serum creatinine estimated glomerular filtration rate (eGFR), and spot urine protein/creatinine ratio (UPCR) were determined. The serum levels of FGF-23 and soluble klotho (s-KL) were determined by the enzyme-linked immunosorbent assay. For the diagnosis of insulin resistance, the homeostasis model assessment of insulin resistance (HOMA-IR) was used.

Results: The means of FGF-23 and s-KL were 397.32 ± 360.29 pg/mL and 19.09±3.83 ng/mL, respectively. Total cholesterol (T-C), triglyceride (Tg), low density lipoprotein cholesterol, high density lipoprotein cholesterol were 189±38 mg/dL, 143±67 mg/dL, 112±30 mg/dL, 52±17 mg/dL, respectively. The mean glycosylated hemoglobin (HbA1c), fasting insulin, C-peptide, HOMA-IR were found to be 5.6±0.8, 9.38±8.35 pg/mL, 4.02±2.78 ng/mL, 2.44±2.69 mg/dL, respectively. The levels of creatinine, UPCR, FGF-23, C-peptide were high, and those of the eGFR and s-KL were low in the NDADPKD patients compared to the healthy control group. As the stage of CKD progressed, creatinine, UPCR, FGF-23, C-peptide increased compared to the early stages, while eGFR and s-KL decreased. The HOMA-IR was found to have a significant relationship with BMI, T-C, Tg (p=0.003), fasting insulin, C-peptide. HOMA-IR was not found to have a significant relationship with serum FGF-23 and s-KL. 

Conclusions: There was no difference in NDADPKD patients in terms of the development of insulin resistance compared to healthy individuals. There is no relationship between the development of insulin resistance and serum levels of FGF-23 in patients with NDADPKD.