Introduction
Connective tissue growth factor (CTGF), a major promoter of fibrosis, has been linked to diabetic complications. The aim of this observational case–control study was to investigate urinary connective tissue growth factor (uCTGF) as a marker of diabetic nephropathy and diabetic retinopathy (DR) in a cohort of patients with type 2 diabetes mellitus (T2DM).
Patients and methods
The study included 60 patients with T2DM (group A: 20 patients with normoalbuminuria; group B: 20 patients with microalbuminuria, and group C: 20 patients with macroalbuminuria) and 20 age-matched and sex-matched healthy participants as controls. Thorough clinical evaluation and fundus examination were done to determine the presence of DR. Laboratory workup included glycated hemoglobin, serum creatinine level, estimated glomerular filtration rate (eGFR) using modification of diet in renal disease (MDRD) formula, urine albumin to creatinine ratio (UACR), and uCTGF measurements.
Results
uCTGF levels showed a stepwise increase in group A (116.2±33.4), group B (197.9±75.7), and group C (365.5±197.3) (<0.001). In patients with T2DM, uCTGF showed significant positive correlation with UACR (=0.731, <0.001) and HA1c (=0.230, =0.038) but negative correlation with eGFR (=−0.421, <0.001). uCTGF was an independent predictor of eGFR (β coefficient=−0.042, =0.017) and UACR (β coefficient=0.720; <0.001). In contrast, patients with DR had no significantly different uCTGF level from patients without retinopathy (329.18±47.149 vs. 252.02±27.3, =0.067).
Conclusion
In the present study, uCTGF was significantly associated with markers of nephropathy but not with retinopathy in patients with T2DM.