Blood Glucose Monitoring for Patients on Basal Insulin Plus One Oral Agent

Initial Monitoring Strategy

• The American Academy of Pediatrics recommends twice-daily blood glucose monitoring, consisting of morning fasting glucose and one additional reading, preferably 2-hour postprandial, for patients newly started on basal insulin with one oral agent 1, 2, 3, 4
• The fasting glucose measurement is the primary determinant for adjusting basal insulin doses, as it directly reflects overnight insulin coverage 1, 2, 3, 4
• The 2-hour postprandial reading paired with premeal concentrations provides an index of glycemic excursion 1, 3

Evidence Quality and Context

• The American Diabetes Association acknowledges that evidence is insufficient regarding optimal monitoring frequency for 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 5, 6
• The American Diabetes Association reiterates this position, noting limited evidence for specific monitoring schedules in this population 7

Monitoring After Achieving Glycemic Control

• Once treatment goals are met, monitoring frequency can be decreased based on clinical context, considering the medication regimen, HbA1c levels, and patient willingness 1, 2, 3, 4
• Some continued blood glucose testing is recommended for all patients with type 2 diabetes, even after achieving targets 1, 2, 3, 4

Common Pitfalls and Clinical Pearls

• If fasting blood glucose concentrations are at target but daytime readings remain elevated, the basal-only regimen may be insufficient, and consider adding a meglitinide or short-acting insulin before meals 1, 2, 3, 4
• The basal insulin regimen is associated with risk of overnight or fasting hypoglycemia, and daily fasting measurements help detect this pattern early 1, 2, 3, 4

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, 2, 3
• Set clear expectations through shared goal-setting between patient and clinician 1, 2, 3

Alternative Monitoring Technologies

• Continuous glucose monitoring (CGM) may be offered for adults on basal insulin who can use devices safely, providing more comprehensive glycemic data and detecting more hypoglycemic episodes than capillary monitoring alone 7
• Patients using CGM still need capability to perform self-monitoring of blood glucose for calibration and verification 8