Am Fam Physician. 2009;79(7):601-602
Background: Self-monitoring of blood glucose is an accepted component of managing newly diagnosed type 2 diabetes; however, the value of this activity is unclear. O'Kane and colleagues studied the impact of self-monitoring on glycemic control and on patient satisfaction with treatment.
The Study: Participants in the study included 184 adults younger than 70 years who were referred to hospital outpatient clinics in Northern Ireland for newly diagnosed type 2 diabetes. Participants were excluded from the study if they used insulin, had secondary diabetes, or had previous experience of blood glucose monitoring. After an initial assessment visit, the participants were randomly allocated to the self-monitoring or no self-monitoring group.
Patients in the self-monitoring group were provided with glucose monitors, and asked to measure four fasting and four postprandial blood glucose levels every week for one year. These patients were instructed about appropriate responses to high or low readings. Patients in the no-monitoring group were asked not to acquire a glucose monitor or to perform glucose monitoring. All study participants were evaluated in the clinic every three months. Meter readings were downloaded at each clinic visit to monitor concordance with the study protocol. Patients also completed a psychological well-being survey at each visit that included diabetes treatment satisfaction, a diabetes attitude scale, and a well-being questionnaire. The primary outcome measures included A1C levels, incidence of hypoglycemic episodes, and indicators of psychological well-being. Secondary outcomes included use of oral hypoglycemic medications and changes in body mass index (BMI).
Results: Both groups were comparable at baseline in all significant variables. The self-monitoring group was slightly younger (mean age 58 versus 61 years) and heavier (BMI of 34 versus 32 kg per m2) than the group that did not self-monitor. These differences were not significant. Baseline A1C levels were also comparable between the groups (8.8 for the self-monitoring group versus 8.6 for the no self-monitoring group).
Although A1C levels decreased in both groups, no significant differences were found at any clinic visit. The mean A1C at 12 months was 6.9 for both groups. No significant differences were found between groups when comparing BMI, use of hypoglycemic drugs, or reported episodes of hypoglycemia at any time during the study. Patients in the self-monitoring group had significantly worse scores on depression scales and a tendency to worse scores on measures of anxiety. All other measures showed no statistically or clinically significant differences.
Conclusion: The authors conclude that self-monitoring has no effect on glycemic control and is associated with increased levels of depression in newly diagnosed type 2 diabetes. They point to findings from other studies that associate self-monitoring with feelings of distress, depressive symptoms, and anxiety.
editor's note: This study and a companion report1 showing increased costs and lower quality of life in self-monitoring patients challenge us to reconsider routine best practices in patients with type 2 diabetes. An accompanying editorial summarizes the studies in this area and discusses the considerable debate over this issue.2 Some physicians and patients value the ability to self-manage type 2 diabetes; others raise concerns about the possibility of harm (e.g., stress, depression) and increased disease-management costs without clear benefit. Self-monitoring costs are significant (e.g., more than $200 million annually in the United Kingdom). The editorial questions whether this expenditure could be better spent on interventions that have been proven to reduce morbidity and mortality, and improve quality of life for patients with type 2 diabetes.—a.d.w.