Correlation between HbA1c and Fructosamine in Determining Glycemic Control in Thalassemic Population with Type II Diabetes in Sri Lanka

• Published in: Indian journal of clinical biochemistry Vol. 34; no. S1; p. S143
• Main Authors: Senanayake, U.E, Kottahachchi, D.C, Dayanath, B.K.T.P, Warnakulasuriya, T, Premawardhana, A, Siyambalapitiya, S, Gunathilaka, P.A.C.K, Ranawaka, S.S.D.M
• Format: Journal Article
• Language: English
• Published: Springer 24.05.2022
• Subjects: Blood sugar; Blood sugar monitoring; Diabetes therapy; Diabetics; Glycosylated hemoglobin
• ISSN: 0970-1915; 0974-0422

HbA1c is considered not reliable in diagnosing and monitoring diabetes in thalassemic patients due to assay interferences and shortened life span of red cell making diagnosis and monitoring of glycemic control a challenge. Our aim was to evaluate the correlation between HbA1c and fructosamine in determining glycemic control in thalassemic patients with type II diabetes in Sri Lanka. A prospective study was carried out among 33 thalassemic (Beta thalassemia major, E-beta thalassemia, thalassemia intermedia) patients with diabetes. Glucose monitoring by two fasting and one postprandial capillary blood glucose measurements per week were done using glucometers for a period of three months. Blood was drawn from participants every 20 days for HbA1c and fructosamine. HbA1c was measured by both HPLC and capillary electrophoresis. The median for fasting, postprandial glucose and fructosamine among the thalassemic patients were 135.88 mg/dL (IQR: 111.78-179.30), 177.80 mg/dL (IQR:156.40-220.25) and 420.30 [micro]mol/L (IQRG65.55-523.65). The median HbA1c values from capillary and HPLC methods were 9.3% (IQR: 7.7-10.9) and 9.1% (IQR:7.5-11.2) respectively. There was good correlation between the HbA1c values (capillary electrophoresis) and fructosamine levels ([r.sup.2]=0.653, P<0.001), mean fasting glucose (r=0.526, p=0.002), and mean postprandial glucose (0.489, p=0.004) values. There was also good correlation between the HbA1c values assessed by HPLC method and fructosamine (r2=0.505, p=0.001, fasting glucose (r=0.441, p=0.001), postprandial glucose (0.537, p=0.001) values. The two methods to assess HbA1c correlated significantly with each other (r=0.816, P<0.001). When the cut off value of HbA1c (capillary) is 7.0% for the population, the sensitivity and specificity for control of diabetes (defined as fructosamine <330 [micro]mol/L) are 90.9% and 37.5%, respectively (area under the curve: 0.800).