Glucose Self-monitoring in Non–Insulin-Treated Patients With Type 2 Diabetes in Primary Care Settings
- 1 Clinical Question
- 2 Bottom Line
- 3 Major Points
- 4 Guidelines
- 5 Design
- 6 Population
- 7 Interventions
- 8 Outcomes
- 9 Criticisms
- 10 Funding
- 11 Further Reading
In patients with type 2 diabetes who are non-insulin-treated, does self-monitoring blood glucose levels compared to not self-monitoring, improve hemoglobin A1c levels or health-related quality of life (HRQOL) in a primary care practice?
Self-monitoring of blood glucose (SMBG) levels is not necessary for people with non-insulin-treated T2DM as it does not produce a significant difference in glycemic control or quality of life.
Whether or not patients with non-insulin-dependent T2DM should perform self-monitoring of blood glucose levels has been debated for some time. Previous trials have studied this topic and several showed the benefit of SMBG on glycemic control2-5, while others have shown no benefit6-10. Those studies that demonstrate the benefit of SMBG on glycemic control hypothesize that monitoring makes patients more aware of their levels, which can encourage lifestyle changes if necessary. Although this may provide benefit, one must consider the burden testing places on patients. The general consensus regarding this topic so far has been that even though SMBG may or may not be clinically beneficial, it is only truly valuable to the patient when they are provided feedback on their SMBG results.
Therefore, with a pragmatic, open-label randomized trial with three arms, the effectiveness of self-monitoring on hemoglobin A1c levels and HRQOL were able to be analyzed. Within the three arms, two arms were allowed to test their blood glucose via meters and receive their glucose levels immediately while the one arm did not test their glucose levels at all. In conclusion, there was found to be no significant difference Self-monitoring of blood glucose resulted in no significant differences in glycemic control across all groups, nor significant differences in HRQOL.
Although the study randomized individuals into three arms, many individuals did not remain within their groups after the baseline visit. The population resembled those who would be seen in a primary care practice with T2DM, however there are no baseline diet or exercise regimens recorded.
SMBG in patients that are non-insulin dependent is not recommended. While self testing will not hurt patients, it is very costly and has little effect on lowering blood glucose levels and improving their overall quality of life.
Neither the ADA or the AACE guidelines contain recommendations that reflect the results of this trial. However, the Society of Internal Medicine, in its “Choosing Wisely” campaign urges physicians not to recommend SMBG in non-insulin dependent patients with T2DM.1
- Pragmatic, open-label randomized trial
- 450 total patients randomized
- 152 patients randomized to receive no SMBG
- 150 patients randomized to receive SMBG with no messaging
- 148 patients randomized to receive SMBG with enhanced messaging
- Setting: 15 primary care practices in North Carolina
- Enrollment between January 2014 and July 2015
- Participants were reassessed at 52 weeks after randomization
- Intention-to-treat analysis performed
- Primary outcome: glycemic control (Hemoglobin A1c)
Eligible patients with type 2 non–insulin-treated diabetes that were:
- 30 years or older
- Established with a primary care physician at a participating practice
- Hemoglobin A1c levels higher than 6.5% but lower than 9.5% within the 6 months preceding screening (obtained from electronic medical record)
- Willing to comply with the results of random assignment into a study group
- Patient planned to see an endocrinologist in the upcoming year
- Patient currently or planned to use insulin during the study period
- Patient planned to become pregnant or relocate in the next year, or had other conditions that would put them at risk in following study protocol
- Participants who initiated insulin use during the study or who were not sufficiently compliant with their assigned treatment.
- Participants who uploaded a meter reading fewer than 80% of their days in the study
- In the no testing arm participants were excluded who admitted to ever testing with any regularity during the study.
- Age 61
- Sex: Male 46%, Female 54%
- Race: Black 32.9%, White 62%, other 5.1%
- Ethnicity: Non-latino hispanic 98.2%
- <highschool 5.6%
- high school/some college 60.4%
- college or higher 34.1%
- Testing preference:
- Any SMBG 39.6%
- no SMBG 21.6 %
- no preference 38%
- Diabetes Medications
- Metformin 79.6%
- Sulfonylurea 35.8%
- Thiazolidinedione 4.7%
- GLP-1 agonist 3.8%
- DPP-4 inhibitor 8.9%
- Diabetes characteristics: Duration of disease 1 year or less
- BMI 33
- Low Health Literacy 38.2%
- Comorbidities 0-10%
- Use of SMBG 92.4%, currently 75.1%
Three interventions were utilized throughout this trial. They include 1) no SMBG testing; 2) standard once daily SMBG testing with patient feedback of immediate glucose values; and 3) once daily SMBG testing with enhanced patient feedback of immediate glucose values along with automated feedback messaging to educate and motivate the patients delivered via a Telcare meter. Each meter evaluated blood glucose value, time of day, and relationship to food intake. Patient’s daily monitoring was used by the study team once provided through uploaded data via the meters. Clinicians received access to this data for the patients who used the meters and treatment options were provided based on American Diabetes Association Standards of Care. Participants were reassessed at 52 weeks.
Presented as no SMBG vs. SMBG no messaging vs. SMBG with messaging
- Hemoglobin A1c Change
- 0.04 vs. -0.05 vs. -0.10 (p value = 0.74)
- Physical score Change
- -0.43 vs 0.07 vs -0.35 (p value= 0.48)
- Mental score Change
- -0.94 vs -0.71 vs -1.39 (p value= 0.90)
There was no significant difference in patient-reported outcomes by the Problem Areas in Diabetes, Diabetes Symptom Checklist, Diabetes Empowerment Scale, Diabetes Treatment Satisfaction, or the Communication Assessment Tool. Among all groups there were no significant differences in insulin initiation. A significant difference was found in the Summary of Diabetes Self-Care Activities between all groups, but this occured because of the influence of the SMBG intervention.Patients in both SMBG groups who were taking a GLP-1 agonist at baseline were slightly significantly more likely to increase their dose compared with patients in the no SMBG group (P = .02). Also, patients in the SMBG with messaging group were again slightly significantly more likely to start using thiazolidinedione (P = .01). All other medication comparisons did not yield statistically significant results.
Analyses exploring the effect of subgroups (prior experience using SMBG, T2DM duration, baseline glycemic control, baseline insulin secretagogue use, age, race/ethnicity, health literacy, and number of baseline comorbidities) did not demonstrate and significant interactions with glycemic control. The only significant interaction identified was a lower reported HRQOL for African Americans in the SMBG with messaging group than the non-testing group
- 0 finger stick infections
- 1 severe hypoglycemia (secondary to urosepsis, recurrent bladder neoplasm, and acute kidney injury)
- 62 hospitalizations
- 2 deaths (1 during cardiac surgery and 1 owing to amyotrophic laterals sclerosis)
Internal Criticisms (see Limitations in article)
- The researchers recognize that even though the study was designed with real-world clinical settings in mind, the team admits they did not engage with patients beyond the baseline visit, and the clinicians also had minimal interaction with the study team. As a result of this, the researchers do not have data on what the clinicians did with the summary of blood glucose results.
- Within the study, not all patients adhered to the group to which they were randomized, but per-protocol analyses were not significantly different from intent-to-treat analyses. This could result could possibly be the result of those participating being good with self-care, and in this case the automated system would be less beneficial than in other populations.
- The study population included patients with T2DM not using insulin, meaning these results cannot be generalized to patients with T2DM that are insulin users.
- The participants enrolled in the study were patients of primary care practice within a single health system, but the researchers state the population was typical of those found in primary care practices nationally.
- No documentation of patient’s baseline diet and exercise regimens.
Funding was provided by Outcomes Research Institute Award CE-12-11-4980, National Center for Advancing Translational Sciences and National Institutes of Health, through Grant Award Number UL1TR001111.
- Role of the Funder/Sponsor: The following contributors: The Patient-Centered Outcomes Research Institute, National Center for Advancing Translational Sciences, and the National Institutes of Health. These participants had no influence over the design, conduct and publication of the study. Specific areas of the study in which no role was played included collection, management, analysis, and interpretation of the data; also preparation, review and approval of the study.
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