Therapeutic goal of diabetes mellitus.

Madam,

The recent report by Lahiri et al., on therapeutic goal of diabetes mellitus is very interesting.[1] Lahiri et al., found that “Knowledge of diabetes was significantly high among higher educated; poor among women, house-wives, and rural people.”[1] We agree with this conclusion. However, some issues on this work should be mentioned. The important problem is the definition of good control of glucose homeostasis among the subjects. There is no clear definitive definition in this work. The authors referred to blood glucose in this work which might not be acceptable in laboratory medicine. Indeed, the good clinical chemistry parameter to determine the control of blood glucose in diabetic patients should be hemoglobin A1C or fructosamine.

Madam,

Thanks to the readers for their interest in article, “Junctures to the therapeutic goal of diabetes mellitus: Experience in a tertiary care hospital of Kolkata.” We failed to adopt HbA1c in our study because:

The study was conducted in a Government hospital of under-resourced country where poor people come for free treatment. HbA1c, a technically difficult expensive assay and rarely appropriate in tropical laboratories,[1] is not routinely done here for out-patient-department (OPD) patients. Though Fructosamine measurement is easier, cheap, and has close correlation with HbA1c (r=0.686, P<0.001), but can’t be regarded as substitute of HbA1c because of its 30% sensitivity.[1] Moreover, HbA1c can be influenced by hemoglobinopathies and anemia which is common in under-resourced countries.

Ours was a cross-sectional study for 3 months. Assessment of HbA1c level would require a follow- up study for a longer time.

Monitoring of stringent glycemic control by HbA1c level has been suggested to prevent various microvascular and macrovascular complications of diabetes mellitus (DM) caused by high fasting plasma glucose (FPG) and postprandial glucose (PPG), respectively.[2] There is some disagreement among researchers as to the overall glycemic control measured by HbA1c. Bonara et al. showed that HbA1c levels are more closely related to preprandial than the postprandial glucose levels.[3] In contrast, Avignon et al.[4] found that PPG and extended postlunch plasma glucose was more reliable in predicting poor glycemic control than prebreakfast or prelaunch plasma glucose. However, most researchers agree that the best predictor of HbA1C is mean plasma glucose (MPG), composite/average of both FPG and PPG.[5] de Vegt et al.[6] reported that degree of risk conferred by the 2-h PPG concentration was nearly twice that conferred by HbA1c level. As per recent studies even moderate postprandial hyperglycemia (148–199 mg/dl) promotes atherosclerosis and also may have direct adverse effects on the endothelium than does fasting hyperglycemia.[5] American Diabetic Association (ADA) 2003 defined normal FPG and PPG as 100 and <140 mg/dl. Report of WHO-IDF (International Diabetic Federation) consultation, 2006 used 110 mg/dl FPG and <140 mg/dl PPG as normal.[5] The IDF and American College of Endocrinology (ACE) recommended PPG of <135 and <140 mg/dl, respectively, for diabetics and HbA1c goal level of ≤6.5% than that of ≤7.0% by ADA.[5] In present study, the WHO cut-off values have been adopted. Why the diabetic will be exposed to higher level of plasma glucose (FPG 100 to 125 mg/dl as per ADA and 110 to 125 mg as WHO cut-off) persistently? The U.K. Prospective Diabetes Study (UKPDS) demonstrated that aiming at a normalization of FPG (<110 mg/dl) in type 2 diabetes resulted in 1% lower levels of HbA1c and risk of chronic complications of the disease. Baral et al. revealed that level of HbA1c in mild carbohydrate intolerance mostly depend on the level of rise in post prandial glucose (where the variation is wide, as in IGT) but not on the narrow variance in fasting plasma glucose level as found in IFG.[7] So according to Ceriello,[8] best we need the glucose triad of FPG, PPG, and HbA1c for comprehensive glycemic control! That is not feasible in our setting. Both FPG and PPG together cost less than HbA1c estimation and were used as because the later can’t predict the formers exactly rather an average of them.