Zinc Alpha 2 Glycoprotein as an Early Biomarker of Diabetic Nephropathy in Type 2 Diabetes Mellitus Patients

Background and objectives Microalbuminuria is an early sign of diabetic nephropathy (DN). However, pathological abnormalities occur before the onset of microalbuminuria. Renal impairment progresses in about 50% of cases in type 2 diabetes mellitus (T2DM) without significant albuminuria. Diabetes mellitus (DM) is linked with obesity, metabolic syndrome, and lifestyle changes, where adipokines play an important role. Zinc alpha 2 glycoprotein (ZAGP) is an adipokine, and in this study, it was assessed as a potential biomarker for early DN as well as its progression. Materials and methods This study was a cross-sectional case-control study conducted at a tertiary hospital in northern India. T2DM patients aged 18-65 years old were included in the study and were divided into four groups based on their albuminuria level. This study included 160 participants, with 40 participants in each group. Group I included healthy volunteers, while Groups II, III, and IV were normoalbuminuric, microalbuminuric, and macroalbuminuric diabetic patients, respectively. The groups were evaluated for demographic variables, biochemical parameters, urine albumin-creatinine ratio (UACR), and serum ZAGP. Data between the groups were compared statistically. Results This study included 160 participants, with 40 participants in each group. There was a significant difference between the groups based on the serum ZAGP (p<0.001). Serum ZAGP was significantly negatively correlated with serum creatinine, glycosylated hemoglobin (HbA1c), serum cholesterol, serum triglyceride, low-density lipoprotein (LDL) cholesterol, and UACR. ZAGP was positively correlated with the estimated glomerular filtration rate (eGFR). Conclusion The present study showed that ZAGP was an early biomarker of diabetic nephropathy, and its value decreased as DN progressed. It also suggested that ZAGP, an adipokine, has an anti-inflammatory mechanism of action and its depletion worsens the disease.