ABSTRACT
BACKGROUND: HbA1c is considered the gold standard of long-term glycemic control and is recommended as a routine test for every diabetic patient. However, its common use in clinical practice has some problems related to lack of standardization and its relative cost. Recent studies have suggested, that postprandial blood glucose could be better than a fasting sample, as a marker of diabetes control. The objective of the present study was to evaluate the relative value of plasma glucose samples at different times of the day, and easy and accessible programs for home blood and urinary glucose measurements compared with HbA1c in assessing the mean glycemic control of type 2 diabetic patients. METHODS: Sixty type 2 diabetic patients were instructed to do home blood and urine glucose monitoring for two months, at the end, plasma glucose profiles were obtained. RESULTS: The mean of all the capillary BG measurements had the best correlation with the HbA1c (r = 0.84, p < 0.001), followed by the mean of the capillary BG measurements before breakfast and supper (r = 0.82, p < 0.001), and the 2 hr. postbreakfast plasma glucose (r = 0.79 p < 0.001). The fasting PG had a low correlation (r = 0.65, p < 0.001), but a good sensitivity to predict a fair or a poor metabolic control. Diabetes duration and type of treatment explained 17% and 28% of variance in HbA1c levels. CONCLUSIONS: A bimonthly fasting PG correlated well with the glycosylated hemoglobin and is the easiest and cheapest way of monitoring glycemic control in type 2 diabetic patients with some preserved insulin reserve (diabetes for less than 10 years and on treatment with only one hypoglycemic agent). A sample of capillary BG, fasting, once per week correlates better with the HbA1c than a fasting PG every 2-3 months. The 2 hr and 5 hr postbreakfast PG have a good correlation with the HbA1c, but are not a substitute for doing BG monitoring. Glycosuria may be a useful parameter to rule out a fair or poor metabolic control in some patients.
