Efficiency of glycosylated hemoglobin (HbA1c) as a predictive marker for diabetic complications

Abstract

Glycosylated hemoglobin (HbA1c) is a key biomarker for assessing long-term glycemic control in individuals with diabetes mellitus, providing insight into average blood glucose levels over the past two to three months. This review evaluates the efficacy of HbA1c as a predictive marker for diabetic complications, which are categorized into microvascular (including retinopathy, nephropathy, and neuropathy) and macrovascular (primarily cardiovascular diseases). Extensive research demonstrates a strong correlation between elevated HbA1c levels and increased risks of complications, with landmark studies such as the Diabetes Control and Complications Trial (DCCT) and the United Kingdom Prospective Diabetes Study (UKPDS) establishing the benefits of maintaining HbA1c below 7% in reducing complications. However, the use of HbA1c is not without limitations, including interindividual variability, the inability to capture daily glucose fluctuations, and the potential for misleading results due to conditions such as hemoglobinopathies. As a result, while HbA1c remains a cornerstone in diabetes management and a valuable tool for predicting the risk of complications, a multifaceted approach that incorporates additional glucose monitoring methods is essential for optimizing patient care. This review aims to highlight both the strengths and limitations of HbA1c, as well as the need for ongoing research to enhance its predictive accuracy in clinical settings.