Timing of Capillary Blood Glucose Monitoring

For Patients on Insulin

The American Diabetes Association recommends that patients on multiple daily insulin injections check capillary blood glucose at least 3 times daily before meals and at bedtime, with many requiring 6-10 checks daily including before meals and snacks, at bedtime, occasionally postprandially, prior to exercise, when suspecting hypoglycemia, after treating hypoglycemia until normoglycemic, and before critical tasks like driving 1, 2, 3
Patients on intensive insulin regimens should check before each meal and snack to guide prandial insulin dosing, with a frequency associated with better glycemic control (0.2% A1C reduction per additional daily check) 2, 4, 5
Checking at bedtime assesses overnight insulin needs and prevents nocturnal hypoglycemia, while occasional postprandial checks help assess meal coverage 1, 6
The American Diabetes Association acknowledges that checking prior to exercise prevents exercise-induced hypoglycemia, and checking when suspecting hypoglycemia and after treatment until normoglycemic is crucial 2, 3, 4, 5
Checking before critical tasks such as driving is also recommended 4, 5

Patients on oral agents without insulin should check capillary blood glucose daily, with frequency sufficient to achieve glycemic goals, though optimal frequency has not been established 1, 5, 6
Checking fasting glucose assesses overnight glycemic control, and occasional postprandial checks help understand the impact of meals and medications 5, 8
Frequency should be individualized based on medication type, glycemic stability, and treatment goals 1, 5, 6

For patients eating, check immediately before each meal, while for patients not eating or NPO, check every 4-6 hours 2
For patients on intravenous insulin, check every 30 minutes to 2 hours as required for safe titration 2

Never rely solely on sliding-scale insulin in hospitalized patients; use basal-bolus regimens with scheduled monitoring 2
Ensure meter accuracy by using FDA-approved devices with unexpired strips from licensed distributors, and consider hematocrit levels and other interfering substances that may affect test results 8