Is Self-Monitoring of Blood Glucose Appropriate for All Type 2 Diabetic Patients?

Abstract

OBJECTIVE—We sought to determine whether self-monitoring of blood glucose (SMBG) is associated with better glycemic control in type 2 diabetes. RESEARCH DESIGN AND METHODS—We used cross-sectional and longitudinal data from type 2 diabetic participants in the observational, community-based Fremantle Diabetes Study (FDS) who reported SMBG status at study entry (n = 1,286) and annual reviews over 5 years (n = 531). RESULTS—At study entry, 70% of patients performed SMBG, with a median of four tests per week (interquartile range two to seven). Patients with shorter diabetes duration; who were attending diabetes education, diabetes-related clinics, or medical specialists; who were taking insulin with or without oral hypoglycemic agents (OHAs); and who were self-reporting hypoglycemic events were more likely to use SMBG. Both cross-sectional and longitudinal FDS data showed that HbA1c (A1C) was not significantly different between SMBG users and nonusers, either overall or within diabetes treatment groups (diet, OHAs, and insulin with or without OHAs). There was also no independent cross-sectional relationship between A1C and SMBG frequency. The average annual societal cost of using SMBG (in year 2000 Australian dollars [A$], excluding glucometers) was A$162 per type 2 diabetic patient or A$51 million when projected to the Australian diagnosed type 2 diabetic population. CONCLUSIONS—Neither SMBG testing nor its frequency was associated with glycemic benefit in type 2 diabetic patients regardless of treatment. Our data did not include methods of SMBG delivery and application, factors that require further assessment in the evaluation of SMBG utility in non–insulin-treated type 2 diabetes. SMBG may be still of value in the identification and prevention of hypoglycemia and in dose adjustment in insulin-treated patients.