Comparison of Hemoglobin A1c and Fasting Glucose Criteria to Diagnose Diabetes Among People With Metabolic Syndrome and Fasting Glucose Above 100 mg/dL
The aim of this study was to compare hemoglobin A1c (HbA1c) and fasting glucose for the diagnosis of diabetes among people with metabolic syndrome and fasting glucose >100 mg/dL. It studied 142 consecutive individuals with metabolic syndrome and fasting glucose >100 mg/dL but without a self-reported history of diabetes who visited the outpatient lipid and obesity clinic. HbA1c ≥ 6.5% and fasting glucose ≥ 126 mg/dL were used separately to define diabetes. Overall, 29.5% of patients had both HbA1c ≥ 6.5% and fasting glucose ≥126 mg/dL, 25.3% had HbA1c≥6.5% but fasting glucose <126 mg/dL, and 9.1% had HbA1c < 6.5% but fasting glucose ≥ 126 mg/dL. A greater proportion of patients reached a diagnosis of diabetes based on the HbA1c criterion (n=78, 54.9%) compared with the fasting glucose criterion (n=55, 38.7%, P=.000). A large proportion of patients (44.8%) with impaired fasting glucose (fasting glucose 100–125 mg/dL) would be classified as diabetics using the HbA1c criterion. Implication of the HbA1c criterion may increase the rate of diabetes diagnosis among people with metabolic syndrome and fasting glucose > 100 mg/dL.
From this study we conclude that the prevalence of diabetes may not be the same when diagnosis is based on A1C compared with diagnosis with fasting glucose, and one method may identify different individuals than the other as measurements of glucose levels and A1C reflect different aspects of glucose metabolism. This study shows that a significantly greater proportion of patients reached a diagnosis of diabetes based on the A1C criterion (54.9%) compared with the fasting glucose criterion (38.7%) among individuals with the metabolic syndrome and fasting glucose >100 mg/dL. If also confirmed by larger studies, implication of the A1C criterion may largely increase the rate of diabetes diagnosis among people with the metabolic syndrome and a fasting glucose >100 mg/dL. This will have important health and economic consequences.
REFERENCE:
www3.interscience.wiley.com/journal/123476648/abstract?CRETRY=1&SRETRY=0
