What are the recommended times to check Blood Glucose (BG) levels when on basal and bolus insulin therapy?

Blood Glucose Monitoring Recommendations for Basal-Bolus Insulin Therapy

For patients on basal-bolus insulin therapy, blood glucose monitoring should be performed 6-10 times daily, including before meals and snacks, at bedtime, occasionally postprandially, before exercise, when hypoglycemia is suspected, after treating hypoglycemia until normoglycemic, and before critical tasks like driving. 1

Monitoring Schedule for Intensive Insulin Regimens

Multiple Daily Injections (MDI) or Insulin Pump Therapy:

• Before meals and snacks (pre-prandial)
• At bedtime
• Occasionally 2 hours after meals (post-prandial)
• Prior to exercise
• When hypoglycemia is suspected
• After treating hypoglycemia (until normoglycemic)
• Before and while performing critical tasks (e.g., driving)

This comprehensive monitoring approach is essential as it allows patients to evaluate their individual response to therapy and assess whether glycemic targets are being safely achieved 1. Research shows that increased monitoring frequency is significantly associated with lower A1C levels (0.2% reduction per additional check per day) and fewer acute complications 1.

Monitoring for Basal Insulin Only Regimens

For patients using only basal insulin (without bolus insulin):

• Daily fasting/pre-breakfast measurements are essential to assess the appropriateness of the basal insulin dose 1
• Consider twice daily monitoring (fasting plus a second BG concentration – ideally 2-hour post-prandial) as long as HbA1c and BG concentrations remain at goal 1

Special Considerations

Hypoglycemia Prevention:

Blood glucose monitoring is particularly crucial for insulin-treated patients to monitor for and prevent hypoglycemia 1. Traditional finger-prick monitoring may underestimate the prevalence of hypoglycemia, with research showing that only 10% of hypoglycemic events are detected by standard monitoring schedules 2.

Postprandial Monitoring:

While pre-meal testing is standard, postprandial testing is also important as approximately 69% of postprandial hyperglycemic excursions can be identified through structured monitoring 2. This is particularly relevant for adjusting bolus insulin doses.

Meter Accuracy:

Use only FDA-approved meters with unexpired strips purchased from a pharmacy or licensed distributor 1. Be aware that there is substantial variation in the accuracy of widely used blood glucose monitoring systems 1.

Common Pitfalls to Avoid

1. Insufficient monitoring frequency: Many patients don't test frequently enough to make appropriate insulin adjustments.

2. Not linking monitoring to action: Blood glucose monitoring alone doesn't lower blood glucose levels. The information must be integrated into clinical and self-management plans 1.

3. Ignoring environmental factors: Medications, high-dose vitamin C, and hypoxemia can interfere with glucose meter accuracy 1.

4. Relying solely on pre-meal values: This can miss significant post-meal excursions and hypoglycemic events 2.

By following these structured monitoring recommendations, patients on basal-bolus insulin therapy can optimize their glycemic control, reduce complications, and improve overall outcomes related to morbidity and mortality.