Does Daily Self-Monitoring of Blood Sugar Levels Improve Blood Sugar Control and Quality of Life for Patients with Type 2 Diabetes Who Do Not Use Insulin? -- The Monitor Trial

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What was the research about?

With type 2 diabetes, a person’s blood sugar levels become higher than normal because the body doesn’t make or use the hormone insulin correctly. Keeping blood sugar levels normal can help prevent health problems that affect the heart, brain, eyes, limbs, and kidneys. Many people with type 2 diabetes use diet, exercise, and medicine to manage their blood sugar levels. They may also prick their fingers and measure their blood sugar levels with personal monitors daily. People can then adjust their diets and exercise in response to the blood sugar levels. But checking takes time, the supplies can be costly, and the health benefits are not clear.

This study focused on people with type 2 diabetes who don’t take insulin. The study compared people who did and didn’t check their blood sugar levels daily to see which group did a better job keeping their blood sugar at good levels. The study looked at what happened if patients who checked their blood sugar levels also received text messages explaining their blood sugar levels. The study also looked at the effects of checking blood sugar levels daily on the people’s quality of life.

What were the results?

At the end of the one-year study, there were no differences, on average, in blood sugar levels and quality of life between people who checked their blood sugar daily and those who didn’t. People who tested their blood sugar levels daily had slightly lower blood sugar levels in the middle of the study than those who didn’t test. But this difference didn’t last until the end of the study. Among people who checked their blood sugar levels, there were no differences in blood sugar levels or quality of life between those who did and didn’t receive text messages.

Who was in the study?

The study included 450 people with type 2 diabetes in North Carolina. The people in the study were 31 to 92 years old. They didn’t take insulin, but most of them took other medicine, such as metformin or a sulphonylurea, to treat their diabetes.

What did the research team do?

The research team assigned people with type 2 diabetes to one of three study groups by chance. People in one group didn’t check their own blood sugar levels for a year. People in the other two groups checked their own blood sugar levels daily. People in both of these groups received their blood sugar level results right away. People in one of the blood sugar testing groups also got text messages with information about what their levels may mean.

The research team took the people’s blood at the start of the study and again a year later. They did a test to measure A1C in the blood samples. This test shows a person’s average blood sugar levels during the past three months. Doctors and patients use the A1C test to find out if people are managing their diabetes well. The research team looked at people’s health records to see their A1C levels between the beginning and the end of the study. The team also surveyed people about their quality of life at the start and the end of the study. The research team compared the results of the A1C test and the survey among the three groups.

What were the limits of the study?

The study didn’t have enough people from different races and ages to find out if blood sugar level testing may help manage blood sugar levels in specific groups of people. The study included people only from North Carolina. The results may be different for people from other places. People in the study didn’t always test their blood sugar levels exactly as instructed by the research team. Results may be different if people tested their blood sugar levels every day as instructed. Doctors didn’t always review the results of the blood sugar level tests or give advice about the results.

Future research could look at whether interaction, such as texting, between doctors and patients with type 2 diabetes about patients’ blood sugar level results improves patients’ blood sugar levels or quality of life.

How can people use the results?

People with type 2 diabetes who don’t use insulin can use these results to ask their doctors if they should check their blood sugar levels daily. Checking blood sugar levels daily didn’t help people in this study manage their blood sugar levels better than those who didn’t. But blood sugar level testing may be useful in some situations, such as before or after a change in diabetes medicine or to inform treatment decisions.

Objective

To assess the effects of three approaches for self-monitoring of blood glucose levels on glycemic control and health-related quality of life for patients with non-insulin-treated type 2 diabetes mellitus

Study Design

This randomized controlled trial examined the effects of three approaches for self-monitoring of blood glucose in patients with non-insulin-treated type 2 diabetes. The primary outcomes were glycemic control, as measured by reduction in A1C levels, and health-related quality of life, as measured by the 36-Item Short Form Survey. Secondary outcomes included patient-reported outcomes for self-care, treatment satisfaction, sense of self-efficacy, communication between patient and healthcare provider, hypoglycemia frequency, and healthcare use.

The study included 450 patients from 15 primary care clinics in North Carolina. The patients, ages 31 to 92 years, had A1C levels between 6.5% and 9.5% in the past six months.

Researchers randomized patients without blinding to one of the three treatment groups:

• Daily blood glucose self-monitoring with immediate delivery of blood glucose values and automated, tailored patient feedback via text messages describing the meaning of the values
• Daily blood glucose self-monitoring with immediate delivery of blood glucose values
• No daily glucose monitoring

Researchers recorded patients’ medical histories, heights, weights, A1C levels, and quality of life scores at the outset of the study. All study participants received printed educational materials that described blood glucose goals and symptoms of hypoglycemia and hyperglycemia. After approximately one year, researchers obtained patient A1C levels from blood samples and again assessed health-related quality of life. Researchers obtained A1C levels from electronic medical records for the three-, six-, and nine-month time points. Researchers assessed secondary outcomes using questionnaires at enrollment and at approximately one year. Using analysis of covariance, the researchers compared changes in outcomes among the three groups from baseline through one year.

Results

The research team found no statistically significant differences after one year in glucose control (A1C levels) or health-related quality of life among the three groups.

The study revealed statistically significant improvement in A1C levels in both blood glucose self-monitoring groups at the three-, six-, and nine-month time points; however, this improvement disappeared by the end of the year, with A1C levels returning to baseline values.

The study identified no differences in the patient-reported secondary outcomes among the three groups.

Limitations

The study could not reveal whether glucose self-monitoring affects demographic subgroups of patients differently because it was not powered to detect clinically meaningful differences between subgroups. The study included only patients from North Carolina. The findings may not be generalizable to other geographic regions. Interactions between healthcare providers and patients to review glucose readings were minimal, and this lack of interaction may have affected patient outcomes. Patient compliance in the blood glucose self-monitoring groups decreased during the study, and some patients in the no-monitoring group reported some monitoring. These limitations reflect real-life situations in which patients may not measure their blood glucose levels in a manner consistent with monitoring protocols.

Conclusions and Relevance

Daily self-monitoring of blood glucose, even when combined with automated, tailored patient feedback, did not improve patient outcomes compared with no self-monitoring. Monitoring did not provide any long-term benefit to blood glucose control or health-related quality of life for patients with non-insulin-treated type 2 diabetes. Given the patient burden associated with self-monitoring, patients and healthcare providers should consider whether routine blood glucose self-monitoring is helpful for individual patients.

Future Research Needs

Future studies could examine the effects of daily blood glucose self-monitoring in different patient subgroups. Future studies could also address whether interaction that is more direct, such as two-way messaging, between healthcare providers and patients who are performing daily blood glucose monitoring is beneficial for glycemic control and patient quality of life.