Soluble Klotho and fibroblast growth factor 23 levels in diabetic nephropathy with different stages of albuminuria

• Published in: Journal of investigative medicine Vol. 64; no. 6; pp. 1128 - 1133
• Main Authors: Inci, Ayca, Sari, Funda, Coban, Melahat, Olmaz, Refik, Dolu, Suleyman, Sarıkaya, Metin, Yılmaz, Necat
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01.08.2016; Sage Publications Ltd
• Subjects: Albuminuria - complications; Case-Control Studies; Diabetic Nephropathies - blood; Diabetic Nephropathies - complications; Female; Fibroblast Growth Factors - blood; Glucuronidase - blood; Humans; Male; Middle Aged; Regression Analysis; Renal Insufficiency, Chronic - blood; Renal Insufficiency, Chronic - complications; Solubility; Chronic; Kidney Failure; Diabetic Nephropathies; Proteinuria; Kidney Failure, Chronic
• ISSN: 1081-5589; 1708-8267
• DOI: 10.1136/jim-2016-000142

The relationship between soluble Klotho (s-Klotho) levels, fibroblast growth factor 23 (FGF23) levels, and albuminuria in patients with diabetic chronic kidney disease (CKD) remains unclear. A total of 109 patients with type 2 diabetes (mean age 61.63±9.77 years), at the outpatient clinic of the Antalya Research and Training Hospital Nephrology Unit between January and June 2014, as well as 32 healthy controls (mean age 49.53±7.32 years) were enrolled for this cross-sectional study. Patients were classified into three groups according to their urinary albumin creatinine ratio (UACR), normoalbuminuria (UACR<30 mg/g), microalbuminuria (UACR 30–300 mg/g), and macroalbuminuria (UACR>300 mg/g). The blood was analyzed for FGF23, s-Klotho, parathyroid hormone (PTH), P, Ca, creatinine, and 25-hydroxyvitamin D3 (25hD) levels. Creatinine, s-Klotho, FGF23, and PTH levels were significantly higher and 25hD levels were significantly lower in the patient group than in the healthy controls (p<0.001). Between the groups according to UACR, 1-way analysis of variance revealed statistically significant differences for creatinine (p<0.001), 25hD (p<0.001), PTH (p=0.002), Ca (p=0.002), and albumin levels (p<0.001). A statistically significant positive correlation was found between s-Klotho and FGF23 (r=0.768; p=0.001), and between FGF23 levels and UACR (r=0.768; p=0.001). In conclusion, the results of the present study suggest that s-Klotho levels are significantly elevated in patients with diabetes and s-Klotho levels decreased with increasing albumin excretion in our patients despite a reduction in estimated glomerular filtration rate.