Assessment of Glycated Hemoglobin (HbA1c) and Serum Fructosamine as Predictors of Microvascular Complications in Type 2 Diabetes Mellitus

Background: Microvascular complications such as retinopathy, nephropathy, and neuropathy are major causes of morbidity in type 2 diabetes mellitus (T2DM). Glycated hemoglobin (HbA1c) is the standard marker for long-term glycemic control, whereas serum fructosamine reflects short-term fluctuations. Their comparative predictive value for complications remains under evaluation. Objective: To assess and compare the prognostic value of fructosamine and HbA1c in detecting microvascular complications among T2DM patients. Methods: This multicenter cross-sectional study was conducted from February 2024 to February 2025 in tertiary care hospitals across Pakistan. One hundred patients with ≥5 years of T2DM were enrolled. HbA1c was measured by high-performance liquid chromatography and fructosamine by nitroblue tetrazolium assay. Neuropathy was assessed clinically and with nerve conduction studies where indicated; retinopathy by dilated fundus examination; and nephropathy by urine albumin-to-creatinine ratio and eGFR. ROC curve analysis, logistic regression, and correlation were performed. Results: Mean age was 55.2 ± 8.6 years; mean diabetes duration 10.1 ± 4.3 years. Retinopathy, nephropathy, and neuropathy were present in 42%, 36%, and 49% of patients, respectively. Fructosamine was significantly associated with neuropathy (348.7 vs 294.3 µmol/L, p < 0.01), while HbA1c was higher in retinopathy (9.1% vs 7.5%, p < 0.001) and nephropathy (8.9% vs 7.7%, p < 0.01). ROC analysis showed fructosamine better predicted neuropathy (AUC 0.76), HbA1c predicted retinopathy (AUC 0.83) and nephropathy (AUC 0.80). Combined use improved diagnostic accuracy (AUC 0.87). Conclusion: Fructosamine adds predictive value for neuropathy, while HbA1c remains superior for retinopathy and nephropathy. Their combined assessment enhances identification of T2DM patients at risk of microvascular complications.