Shanthi Balasubramanian, Revathy Carnagarin, Manjula Devi Arcot Jagdeeshwaran
Associate Professor, Department of Biochemistry.
J Clin Diagn Res. 2013 Jan;7(1):15-7. doi: 10.7860/JCDR/2012/4881.2659. Epub 2012 Sep 18.
Protein glycation is a spontaneous reaction that is believed to play a key role in the pathogenesis of many clinical disorders. The glycation of proteins is enhanced by elevated glucose concentrations. The major form of protein glycation with a clinical consideration is glycated haemoglobin (HbA1c). The HbA1c fraction is abnormally elevated in chronic hyperglycaemic diabetic patients and it correlates positively with the glycaemic control. However, increased glycated haemoglobin levels have been documented in iron de.ciency anaemic patients without any history of diabetes.
The aim of this study was to determine the effect of IDA on the HbA1c levels in nondiabetic patients, so as to consider IDA as an important factor which influenced the HbA1c levels, while monitoring the glycaemic status of diabetics.
Fifty non-diabetic, anaemic patients and 50 age-matched healthy subjects were enrolled in this study. The patients who had glucose tolerance abnormalities (impaired glucose tolerance or diabetes mellitus), haemoglobinopathies, haemolytic anaemia, infestation, chronic alcohol ingestion and chronic renal failure were excluded from the study. Haematologic investigations were done and the fasting and postprandial glucose and HbA1c levels were measured in all the subjects.
The mean HbA1c (7.6 ± 0.5%) level in the patients with IDA was higher than that in the control group (5.5% ± 0.8) (p < 0.001). There were no differences in the levels of fasting and postprandial glucose between the IDA and the control groups (p > 0.05). The haemoglobin, serum ferritin, fasting and postprandial glucose, and the HbA1c levels were normal in the control group (p > 0.05).
HbA1c is not affected by the blood sugar levels alone, and there are various confounding factors when HbA1c is measured, especially that of iron de.ciency, which is the commonest of the de.ciency diseases worldwide. It is hence prudent to rule out IDA before making a therapeutic decision, based on the HbA1c levels.
蛋白质糖基化是一种自发反应，被认为在许多临床疾病的发病机制中起关键作用。血糖浓度升高会增强蛋白质的糖基化。临床上主要关注的蛋白质糖基化形式是糖化血红蛋白（HbA1c）。在慢性高血糖糖尿病患者中，HbA1c比例异常升高，且与血糖控制呈正相关。然而，在无糖尿病病史的缺铁性贫血患者中也有糖化血红蛋白水平升高的记录。
本研究的目的是确定缺铁性贫血（IDA）对非糖尿病患者HbA1c水平的影响，以便在监测糖尿病患者血糖状态时，将IDA视为影响HbA1c水平的一个重要因素。
本研究纳入了50名非糖尿病贫血患者和50名年龄匹配的健康受试者。排除葡萄糖耐量异常（糖耐量受损或糖尿病）、血红蛋白病、溶血性贫血、寄生虫感染、长期饮酒和慢性肾衰竭的患者。进行血液学检查，并测量所有受试者的空腹和餐后血糖以及HbA1c水平。
IDA患者的平均HbA1c水平（7.6±0.5%）高于对照组（5.5%±0.8）（p<0.001）。IDA组和对照组之间的空腹和餐后血糖水平无差异（p>0.05）。对照组的血红蛋白、血清铁蛋白、空腹和餐后血糖以及HbA1c水平均正常（p>0.05）。
HbA1c并非仅受血糖水平影响，在测量HbA1c时存在多种混杂因素，尤其是缺铁，缺铁是全球最常见的缺乏性疾病。因此，在基于HbA1c水平做出治疗决策之前，排除IDA是谨慎之举。
