Abstract
Background: Diabetic nephropathy (DN) is the leading microvascular complication of diabetes mellitus, progressively impairing renal function and ultimately leading to end-stage renal disease (ESRD). Glycemic control, particularly reflected by glycated hemoglobin (HbA1c), is widely recognized as the principal modifiable risk factor for DN. Early identification of incipient nephropathy is critical to prevent irreversible renal damage.
Objective: To evaluate the relationship between glycemic control markers (HbA1c, fasting blood sugar) and early renal dysfunction markers (serum creatinine, urea, blood urea nitrogen [BUN], and urine albumin-to-creatinine ratio [ACR]) in patients with type 2 diabetes mellitus, and to determine the diagnostic performance of HbA1c for predicting incipient nephropathy.
Methods: A hospital-based cross-sectional study was conducted at Riphah International University Faisalabad Campus involving 100 adult patients with type 2 diabetes mellitus over six months (November 2024 – April 2025). Biochemical parameters including HbA1c, fasting blood sugar (FBS), serum creatinine, serum urea, BUN, and urinary ACR were measured. Complete blood count (CBC) parameters were also assessed. Statistical analyses included independent t-tests, one-way ANOVA, Pearson correlation, simple and multiple linear regression, and receiver operating characteristic (ROC) curve analysis.
Results: Among 100 participants (mean age 51.0 ± 15.9 years; 50% male), 61% had uncontrolled glycemia (HbA1c ≥ 7%). Mean HbA1c was 8.14 ± 2.47% and mean FBS was 172.3 ± 45.0 mg/dL. Patients with uncontrolled glycemia demonstrated significantly higher serum creatinine (1.87 vs 1.29 mg/dL), urea (56.6 vs 36.0 mg/dL), and BUN (26.4 vs 16.8 mg/dL), with significantly lower eGFR (51.5 vs 68.8 mL/min/1.73 m²; all p < 0.001). Microalbuminuria was present in 76% of participants. HbA1c correlated significantly with serum creatinine (r = +0.292, p = 0.003), urea (r = +0.308, p = 0.002), BUN (r = +0.307, p = 0.002), and eGFR (r = −0.288, p = 0.004). ROC analysis demonstrated an AUC of 0.723 for HbA1c in predicting albuminuria, with an optimal cut-off of 7.20% (sensitivity 60%, specificity 87%). Hemoglobin emerged as the strongest independent predictor of urinary ACR in multivariable analysis (standardised β = −0.364).
Conclusions: Glycemic control strongly predicts early renal dysfunction in type 2 diabetic patients. HbA1c at a threshold of 7.2% effectively identifies incipient nephropathy. Integration of HbA1c, urinary ACR, eGFR, and hemoglobin provides a robust biochemical framework for early detection and monitoring of diabetic nephropathy in clinical practice.