Do Postprandial Glucose Levels add Important Clinical Information When Fasting Glucose Levels are Near Normal in Non-Insulin-Dependent Patients with Type 2 Diabetes?

Abstract

Background: Practice guidelines recommend that both fasting and postprandial blood glucose measurements be performed to achieve glycemic targets, yet few type 2 diabetes patients engage in postprandial glucose (PPG) testing. The purpose of this study was to determine if PPG testing provides important additional clinical information beyond fasting plasma glucose (FPG) tests in well-controlled, non-insulin-dependent type 2 diabetes patients. Methods: Subjects were recruited from 8 pharmacies and instructed to perform daily FPG tests during days 1 to 7 (run-in phase) and daily FPG and PPG tests during days 8 to 21 (test phase). Results: The mean FPG from 362 tests ( n = 52 subjects) in the run-in phase was 7 mmol/L (SD 1.4). In the test phase, the mean FPG was 7 mmol/L (SD 1.6) and the mean PPG was 8.4 mmol/L (SD 2.2) from 700 tests. For FPG tests in the recommended target range of 4 to 7 mmol/L, 87% (322/370) of corresponding (same-day) PPG tests were within the target range of 5 to 10 mmol/L. In subjects whose mean FPG was 4 to 7 mmol/L, 87% of PPG tests were also within target limits. Conclusion: Community pharmacists are often asked by patients how frequently they should be monitoring their blood glucose, but the evidence supporting self-monitoring of blood glucose (SMBG) in non-insulin-dependent type 2 diabetes patients is conflicting and unclear. Given the results from this small study, testing PPG may be unnecessary for non-insulin-dependent type 2 diabetes patients achieving FPG targets, but further study is required.