Serum 1, 5 Anhydroglucitol and Glycated Haemoglobin as Markers of Hyperglycemia in Type 2 Diabetes Mellitus at University Teaching Hospital, Lusaka, Zambia

Abstract

Background: Diagnosis and monitoring of diabetes has long been premised on fasting blood glucose and a hemoglobin-dependent biomarker, glycated hemoglobin A1c (HbA1c), a variant of hemoglobin A. However, adjuncts to these markers, such as 1,5 anhydroglucitol (1,5AG), have since been introduced as surrogate markers for diabetes. Poor glycemic control overtime leads to micro and macro vascular complications; thus, it is important to utilize biomarkers that would predict poor control. Aims: In this study, we aimed to determine the diagnostic characteristics of 1,5 AG and HbA1c serum levels as biomarkers of hyperglycaemia in Type 2 Diabetes Mellitus (T2DM) at University Teaching Hospital, Lusaka, Zambia. Methods: This cross-sectional study was conducted on 86 adult participants with T2DM and non-diabetics ranging from 20 to 80 years. The threshold was set at various cutoff points for glycated hemoglobin A1c and 1,5 AG, respectively. Data were coded and analyzed using multivariate methods for diagnostic efficiency, associations and comparison of means. Results: We found that more women participated in the study while the prevalence of diabetes was high in 41 to 70 year old group. Most of the participants were overweight (BMI 25-29.9Kg/m2) among T2DM. HbA1c was more specific (92%) and sensitive (95.9%) than self-glucose test 75.8% specific and 76.0% sensitive, respectively. 1,5 AG and FPG had sensitivity and specificity of 50.0 and 52.5, 78.0% and 28.0%, respectively. Serum HbA1c mean (7.75±0.34%) was significantly higher in diabetics than non-diabetics (4.36± 1.6%), p˂0.001. Serum 1,5 AG mean was higher (61.6±10.1ng/dL) in diabetics than non-diabetic participants (52±4.46), p˂0.451 but without statistical significance. Self-glucose test was significantly higher in diabetics (p˂0.001). Serum Fasting Plasma Glucose (FPG) was also significantly higher in diabetics (p˂0.001). Glucose levels correlated positively with HbA1c in diabetics with statistical significance (r=0.446, p=0.001). 1,5 AG was poorly correlated with HbA1c without statistical significance in diabetics (r=0.123, p=0.298). Glucose and 1,5 AG equally correlated negatively without statistical significance (r=0.016, p=0.896). Conclusion: The results of this study showed that HbA1c was a more reliable and robust predictor of diabetes than 1,5 AG. However, FPG and self-glucose could be utilized as substitutes. The concentrations of HbA1c, FGP, Self-glucose, cholesterol and triglycerides were higher in diabetics than healthy non-diabetic participants suggesting poor control of glycaemia overtime and predisposition to diabetic complications.