Blood Glucose Monitoring for Patients on Basal Insulin and Metformin
Essential Monitoring Strategy
- The American Diabetes Association acknowledges insufficient evidence for optimal monitoring frequency in patients on basal insulin with oral agents, but confirms that assessing fasting glucose with blood glucose monitoring to inform dose adjustments results in lower A1C 2, 3
- Perform fasting blood glucose measurement every morning as the primary determinant for adjusting basal insulin doses, since it directly reflects overnight insulin coverage 1, 2
- Add one additional reading daily, preferably 2-hour postprandial, which paired with premeal concentrations provides an index of glycemic excursion 1
Cost-Saving Strategies
- Use only FDA-approved glucose meters with unexpired test strips purchased from a pharmacy or licensed distributor to ensure accuracy while avoiding counterfeit products 2, 3
- Providers should be aware of differences in accuracy among glucose meters and help patients select appropriate, affordable devices 2
Patient Education Requirements
- Provide a written action plan stating the medication regimen, frequency and timing of expected blood glucose monitoring, and follow-up instructions 1
- Teach patients how to use blood glucose monitoring data to adjust food intake, exercise, or pharmacologic therapy to achieve specific goals 2
Common Pitfalls to Avoid
- Suspect inaccurate readings if home blood glucose tests are inconsistent with A1C testing 4
- Faulty meters or test strips can provide grossly inaccurate readings 4
- Patient's hematocrit level has great influence on test results; blood glucose meters with hematocrit correction can minimize this influence 5
- Other factors that may interfere with glucose readings include vitamin C, salicylic acid, uric acid, bilirubin, and triglycerides 5, 2