By David Fiore, MD

Professor of Family Medicine, University of Nevada, Reno

Dr. Fiore reports no financial relationships relevant to this field of study.

SYNOPSIS: In this pragmatic randomized trial, self-monitoring blood glucose did not lead to lower hemoglobin A1c levels or improvement in health-related quality-of-life measures.

SOURCE: Young LA, Buse JB, Weaver MA, et al. Glucose self-monitoring in non-insulin-treated patients with type 2 diabetes in primary care settings: A randomized trial. JAMA Intern Med 2017;177:920-929.

As of 2015, type 2 diabetes affects about 30 million Americans, comprising > 12% of all U.S. adults.1 Although the need for self-monitoring of blood glucose (SMBG) levels in patients injecting insulin is well established, there is controversy regarding the need for non-insulin-using patients to monitor their blood sugar. Despite this uncertainty, and mounting evidence that self-monitoring is not helpful, 35-75% of patients with noninsulin-dependent diabetes routinely monitor their glucose levels.2 The American Diabetes Association 2016 guidelines state, “SMBG results may be useful for guiding treatment and/or self-management for individuals using less frequent insulin injections or noninsulin therapies.”3 The American Association of Diabetes Educators recommended SMBG as “an important complement to the measurement of A1c levels.”4

In this context, Young et al examined three approaches of SMBG in non-insulin-using diabetic patients. The study was a “pragmatic, open-label, randomized trial” of 450 patients in three arms, randomized between January 2014 and July 2015 in 15 rural primary care practices in North Carolina. As defined by Patsopoulos, a pragmatic trial “is designed to test interventions in the full spectrum of everyday clinical settings in order to maximize applicability and generalizability. The research question under investigation is whether an intervention actually works in real life. The intervention is evaluated against other ones (established or not) of the same or different class, in routine practice settings.”5 This is in contrast to an “explanatory trial,” in which all variables are controlled carefully so that investigators can determine if the intervention works under ideal conditions. Type 2 diabetic patients > 30 years of age with hemoglobin A1c (HbA1c) levels > 6.5% but < 9.5% were assigned randomly to one of the following three protocols: no SMBG, standard once-daily SMBG consisting of glucose values immediately reported to the patient through the meter, or enhanced once-daily SMBG consisting of glucose values immediately reported to the patient plus automated, tailored messaging delivered to the patient through a Telcare meter. The two primary measures were changes at one year from baseline in HbA1c and health-related quality of life (HRQOL) using physical and mental component scores of the Short-Form 36. Multiple secondary outcomes also were measured and reported. Young et al reported that there was “no evidence that SMBG led to improved glycemic control” at one year, nor were there any differences in HRQOL at one year.

COMMENTARY

Although this study was not very large, it confirms findings of other studies, and a Cochrane review, that indicate that SMBG is not helpful in patients with non-insulin-dependent type 2 diabetes.6 The pragmatic design of this study provides a unique component and reconfirms that SMBG is unlikely to provide benefit to most of these patients. However, this study design is better suited to examining interventions that appear beneficial in the more stringently designed “explanatory” studies, which often are the initial studies (and frequently industry-sponsored), than for interventions, which even in “explanatory studies,” are of questionable value. Although the authors examined multiple secondary endpoints, they did not evaluate depression or anxiety caused by more frequent SMBG, which is unfortunate, since prior studies have linked more frequent SMBG to increases in these negative outcomes.7 I believe these results, and other data on SMBG in non-insulin-dependent diabetics, can reassure us that “less is more.” Further, we can follow the Society of General Internal Medicine “Choosing Wisely” recommendations confidently and not recommend SMBG to patients with type 2 diabetes who are not taking insulin.8

REFERENCES

  1. Centers for Disease Control and Prevention. National Diabetes Statistics Report, 2017. Available at: http://bit.ly/2tnbN35. Accessed Aug. 21, 2017.
  2. Harris MI; National Health and Nutrition Examination Survey (NHANES III). Frequency of blood glucose monitoring in relation to glycemic control in patients with type 2 diabetes. Diabetes Care 2001;24:979-982.
  3. [No authors listed]. Standards of medical care in diabetes-2016: Summary of Revisions. Diabetes Care 2016;39(Suppl 1):S4-5. doi: 10.2337/dc16-S003.
  4. American Association of Diabetes Educators. Position Statement: Self-Monitoring of Blood Glucose Using Glucose Meters in the Management of Type 2 Diabetes. Issued Dec. 3, 2014. Available at: http://bit.ly/2v6VZy1. Accessed Aug. 21, 2017.
  5. Patsopoulos NA. A pragmatic view on pragmatic trials. Dialogues Clin Neurosci 2011;13:217-224.
  6. Malanda UL, Welschen LM, Riphagen II, et al. Self-monitoring of blood glucose in patients with type 2 diabetes mellitus who are not using insulin. Cochrane Database Syst Rev 2012;1:CD005060. doi: 10.1002/14651858.CD005060.pub3.
  7. Franciosi M, Pellegrini F, De Berardis G, et al. The impact of blood glucose self-monitoring on metabolic control and quality of life in type 2 diabetic patients. Diabetes Care 2001;24:1870-1877.
  8. Choosing Wisely, an initiative of the ABIM Foundation. Society of General Internal Medicine: Don’t recommend daily home finger glucose testing in patients with type 2 diabetes mellitus not using insulin. Available at: http://bit.ly/2v6X3SL. Accessed Aug. 21, 2017.