Cystatin C, Neutrophil Gelatinase-associated Lipocalin, and Pro-atrial Natriuretic Peptide as Biomarkers in the Assessment of Diabetic Nephropathy Patients.
Abstract
Background
Diabetic nephropathy (DN) is a significant microvascular complication linked with diabetes mellitus which leads to chronic kidney disease worldwide. Conventional biomarkers, namely, serum creatinine and albuminuria often fail to detect early renal impairment.
Aim
The study aimed to compare the utility of serum cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), and pro-atrial natriuretic peptide (ANP) for assessing the severity of DN.
Materials And Methods
This prospective, observational study was conducted on 52 DN cases and 52 controls. Clinical and laboratory parameters of all were assessed at baseline. Serum creatinine, cystatin C, NGAL, and pro-ANP of cases were measured at baseline, 6 months and 12 months. Statistical analysis, including group comparison, correlation and regression analysis, receiver operating characteristic (ROC) analysis, and longitudinal analysis, was done on IBM SPSSv26.
Results
At baseline, cases had significantly higher serum creatinine, cystatin C, and NGAL than controls. Pro-ANP was higher in cases but not significant. A significant Pearson's correlation appeared between cystatin C (r = -0.852), creatinine (r = -0.833), pro-ANP (r = -0.553), and estimated glomerular filtration rate (eGFR) (all P < 0.001). No significant correlation was observed between NGAL and eGFR. ROC analysis showed that cystatin C had the highest diagnostic accuracy (area under the curve = 0.995, P < 0.001). Time trend analysis highlighted a significant increase of cystatin C, pro-ANP, and serum creatinine (P < 0.001), but not for NGAL (P = 0.093), with increasing renal impairment over 12 months.
Conclusion
Cystatin C demonstrated strongest correlation with eGFR and highest diagnostic accuracy. Time trend analysis revealed significant increase in cystatin C level over 12 months, highlighting its potential role as biomarker for monitoring DN patients.