A simple way to estimate mean plasma glucose and to identify Type 2 diabetic subjects with poor glycaemic control when a standardized HbA1c assay is not available.Diabet Med. 2006 Oct; 23(10):1151-4.DM
To evaluate the relationship between HbA(1c) and fasting plasma glucose (FPG) and postprandial plasma glucose (PPG) levels, and to estimate the mean plasma glucose (mPG) derived from FPG and PPG that would predict Type 2 diabetic subjects with poor glycaemic control.
FPG, PPG and HbA(1c) values from 565 Type 2 diabetic patients (247 men and 318 women) were recorded. Linear regression analysis and Pearson's correlation was used to determine the relationship between HbA(1c), FPG and PPG. FPG and PPG were included as explanatory variables of HbA(1c) in linear regression analysis.
The American Diabetes Association's objective of achieving an HbA(1c) level < 7.0% was obtained in 26.2% of the patients. The coefficients of FPG and PPG which determined HbA(1c) were similar. Therefore, mPG was calculated using the equation (FPG + PPG)/2. Pearson's correlation coefficient for HbA(1c) and FPG, PPG and mPG were 0.723 (P < 0.0001), 0.734 and 0.761 (P < 0.0001), respectively. A mPG cut-off value of 10 mmol/l predicted an HbA(1c) > 7% in the whole population, with a sensitivity of 84.2% and specificity of 80.4%. The area was high (0.90) in receiver-operating characteristic (ROC) curve analysis performed to examine the performance of mPG to predict HbA(1c) > 7%.
The mPG derived from FPG and PPG correlates strongly with HbA(1c). We therefore suggest that using a cut-off of 10 mmol/l for mPG may be appropriate in diabetes management in the primary-care setting, where most management of Type 2 diabetes occurs.