THE RELATIONSHIP BETWEEN SERUM OSTEOGLYCIN AND DIABETIC NEPHROPATHY IN PATIENTS WITH TYPE 2 DIABETES MELLITUS

Osteoglycin (OGN) is a key modulator of the circuit among bone, pancreas, and hypothalamus, responsible for glucose homeostasis, bone formation, and energy balance. This study aimed to evaluate the association between serum OGN levels and diabetic nephropathy (DN), as well as to assess its potential as a biomarker for disease presence and severity. Additionally, it explored the utility of OGN as an early detection marker for DN in the Egyptian population. Four groups were enrolled in the study: Group I (control group) included 23 healthy subjects; Group II included 23 normoalbuminuric type 2 diabetic patients; Group III included 23 type 2 diabetic patients with microalbuminuria; and Group IV included 23 type 2 diabetic patients with macroalbuminuria. Laboratory investigations included fasting blood glucose (FBG), glycated hemoglobin (HbA1c), complete blood count (CBC), kidney function tests, liver function tests, and lipid profile. The estimated glomerular filtration rate (eGFR) was calculated. Serum C-peptide and OGN levels were determined using enzyme-linked immunosorbent assay (ELISA). Significantly lower OGN levels were detected in the control group and diabetic normoalbuminuric groups compared with micro- and macroalbuminuric diabetic patients (p<0.001 for each). Additionally, significantly higher OGN levels were detected among macroalbuminuric patients than diabetic patients with microalbuminuria (p=0.04). Moreover, there were statistically significant negative correlations between serum OGN and high-density lipoprotein-cholesterol (HDL-C), total protein, serum albumin, eGFR, and C-peptide. Furthermore, statistically significant positive correlations were detected between serum OGN and total cholestenol, triglycerides (TG), low-density lipoprotein-cholesterol (LDL-C), FBG, HbA1c, systolic blood pressure, creatinine, blood urea nitrogen (BUN), and albumin-creatinine ratio (ACR). HbA1c, LDL-C, ACR, BUN, and HDL independently correlated with serum OGN. Furthermore, serum OGN was a good predictor of macroalbuminuria with 87% sensitivity and specificity. It was also a good predictor of macroalbuminuria with 82.6% sensitivity and 78.3% specificity. In conclusion, serum OGN levels were significantly associated with markers of kidney function and protein levels in patients with type 2 diabetes mellitus (T2DM). Serum OGN served as a discriminatory biomarker for the early detection of DN with high sensitivity and specificity.