Plasma Albumin Concentration Is a Predictor of HbA1c Among Type 2 Diabetic Patients, Independently of Fasting Plasma Glucose and Fructosamine

Abstract

The importance of the HbA1c assay for evaluation of long-term glucose control is well established (1–3). However, data for HbA1c and average plasma glucose, in spite of their strong correlation (4–7), show considerable scatter: for a given HbA1c level, average blood glucose generally varies by ∼5 mmol/l (7). This hampers interpretation of the HbA1c values of individual patients. In this study of a large sample of type 2 diabetic patients, we investigated the possibility of statistical association between HbA1c concentration and levels of the main glycatable circulating proteins other than hemoglobin (albumin and globulins). The diabetes outpatient clinics of our center are attended by most local diabetic patients requiring insulin or oral antidiabetics. We enrolled 4,158 diabetic patients who, in this complex in the years 1998–2003, were prescribed insulin or oral antidiabetics for type 2 diabetes diagnosed using American Diabetes Association criteria (8) and who, for glucose control monitoring, underwent regular determination of fasting HbA1c accompanied, for research purposes, by determination of total protein concentration, albumin, globulins, creatinine, hemoglobin, fructosamine, and glucose; age, sex, duration of diabetes, and type of therapy were also recorded. For this report, we considered for each patient the first such profile obtained within the study period. Urinary albumin excretion (normal range …