Frequency of blood glucose monitoring in relation to glycemic control in patients with type 2 diabetes

OBJECTIVE--The aim of the study was to investigate the relationship between blood glucose level, measured as HbA(1c), and frequency of self-monitoring in patients with type 2 diabetes. Daily self-monitoring is believed to be important for patients treated with insulin or oral agents to detect asymptomatic hypoglycemia and to guide patient and provider behavior toward reaching blood glucose goals. RESEARCH DESIGN AND METHODS--A national sample of patients with type 2 diabetes was studied in the third National Health and Nutrition Examination Survey. Data on therapy for diabetes, frequency of self-monitoring of blood glucose, and HbA(1c) values were obtained by structured questionnaires and by clinical and laboratory assessments. RESULTS--According to the data, 29% of patients treated with insulin, 65% treated with oral agents, and 80% treated with diet alone had never monitored their blood glucose or monitored it less than once per month. Self-monitoring at least once per day was practiced by 39% of those taking insulin and 5-6% of those treated with oral agents or diet alone. For all patients combined, the proportion of patients who tested their blood glucose increased with an increasing HbA(1c) value. However, when examined by diabetes therapy category, there was little relationship between HbA(1c) value and the proportion testing at least once per day or the proportion testing at least once per week. CONCLUSIONS--In this cross-sectional study of patients with type 2 diabetes, the increase in frequency of self-monitoring of blood glucose with increasing HbA(1c) value was associated with the higher proportion of insulin-treated patients in higher HbA(1c) categories. Within diabetes therapy categories, the frequency of self-monitoring was not related to glycemic control, as measured by HbA(1c) level.