Many patients with type 2 diabetes consider finger-prick blood tests key for keeping blood glucose levels under control. But according to a new study, they are unlikely to be beneficial for patients who are not receiving insulin therapy.
Researchers found that self-monitoring of blood glucose (SMBG) for 1 year failed to improve blood glucose control or health-related quality of life (HRQOL) in patients with type 2 diabetes who were not treated with insulin.
Senior study author Dr. Katrina Donahue, of the School of Medicine at the University of North Carolina in Chapel Hill, and colleagues believe that their findings raise questions about the value of SMBG for many patients with type 2 diabetes.
"Of course, patients and providers have to consider each unique situation as they determine whether home blood glucose monitoring is appropriate," says Dr. Donahue.
"But the study's null results suggest that self-monitoring of blood glucose in non-insulin treated type 2 diabetes has limited utility. For the majority, the costs may outweigh the benefits."
The team's findings were recently reported in JAMA Internal Medicine.
Type 2 diabetes and blood glucose control
According to the American Diabetes Association, around 29.1 million people in the United States have diabetes. Type 2 diabetes is the most common form, accounting for around 90 to 95 percent of all cases.
In type 2 diabetes, the body is unable to effectively use insulin, which is a hormone that helps to regulate blood glucose levels. As a result, glucose accumulates in the blood.
Left untreated, high blood glucose levels can lead to severe complications, including kidney disease, stroke, and nerve damage.
While some patients with type 2 diabetes require insulin therapy, the majority of patients are able to manage their condition through diet, exercise, and medication, such as metformin.
Dr. Donahue and colleagues note that most patients with type 2 diabetes who do not receive insulin therapy perform SMBG, as it is often recommended by their doctor. SMBG usually involves an at-home finger-prick blood test that provides a blood glucose reading.
SMBG is generally accepted as essential for good blood glucose control, but some researchers have questioned its worth for type 2 diabetes patients in the absence of insulin therapy.
For this latest study, Dr. Donahue and colleagues sought to gain a better understanding of how SMBG affects hemoglobin A1c levels - an indicator of long-term blood glucose control - and HRQOL for patients with type 2 diabetes who are not treated with insulin.
Routine SMBG offered no significant benefits
The research included 450 patients with type 2 diabetes, who were an average age of 61 years. None of the patients were receiving insulin therapy for their condition. At study baseline, around 75 percent of the patients were performing SMBG.
For the study, patients were randomly allocated to one of three groups for 12 months: one group performed SMBG once daily; one group engaged in once-daily SMBG, enhanced with automated, tailored messages of encouragement delivered via a Telcare meter; and one group did not engage in SBMG at all.
The hemoglobin A1c levels of each patient were measured at study baseline and 1 year after, and their HRQOL was assessed at both time points using a series of questionnaires.
The researchers found that there were no significant differences in hemoglobin A1c levels and HRQOL between the groups that performed SMBG and those that did not.
What is more, there were no significant differences in incidences of low blood sugar, or hypoglycemia, hospitalizations, or emergency room visits between the three groups, nor was there any difference in the number of patients who needed to start insulin therapy during the study period.
Based on their results, the researchers suggest that healthcare professionals might want to reconsider recommending routine SMBG for type 2 diabetes patients who are not treated with insulin.
The authors conclude:
"Routine self-monitoring of blood glucose levels does not significantly improve hemoglobin A1c levels or HRQOL for most patients with non-insulin-treated type 2 diabetes; patients and clinicians should consider the specifics of each clinical situation as they decide whether to test or not to test."