Counterpoint: Self-Monitoring of Blood Glucose in Type 2 Diabetic Patients not Receiving Insulin

Abstract

Most people would agree that treatment plans, especially those that have invasive components and/or are expensive, should result in improved clinical outcomes. Self-monitoring of blood glucose (SMBG), as part of a treatment plan, fulfills both of these criteria but does have the potential to improve outcomes by lowering glycemia and thereby decreasing diabetic retinopathy, nephropathy, and neuropathy. In insulin-requiring patients, A1C levels are inversely related to the frequency of SMBG measurements (1–7), attesting to the beneficial effect of this component of the treatment plan. However, simply measuring blood glucose is ineffective. In one study (8), increased frequency of SMBG resulted in lower A1C levels only in those who self-adjusted their insulin doses, not in the insulin-requiring patients who did not (strongly suggesting that acting on the values is necessary). What about type 2 diabetic patients not receiving insulin? A large number of studies have been carried out to answer this question, and the evidence is distinctly underwhelming. Randomized clinical trials are considered the best approach to evaluate these kinds of clinical questions, and six studies in which the patients were randomized have been published. In the earliest one, which included both insulin- and non–insulin-requring patients and lasted for 6 months (2), 68 non–insulin-requiring patients were randomized to SMBG, 72 to measuring urine glucose semiquantitatively (both groups being asked to do so twice every other day), and 68 to a control group. Compliance with requested SMBG testing was 50%. The baseline A1C levels were 7.8, 8.5, and 7.7%, respectively. The changes in A1C levels in each group at the end of the study were −0.4, −0.1, and −0.5%, respectively, which were not statistically significant. In a second study (9), 27 patients were randomized to SMBG and 27 to measuring urine glucose semiquantitatively, both before each meal every other day. …