Type 2 Diabetes Mellitus Monitoring Protocol
For adults with type 2 diabetes, measure HbA1c every 6 months if targets are met, or every 3 months if therapy has changed or targets are not being achieved. 1
HbA1c Monitoring
The cornerstone of diabetes monitoring is glycated hemoglobin (HbA1c), which reflects 2-3 month glycemic control 2:
- Every 6 months: For patients meeting treatment goals with stable glycemic control 1
- Every 3 months (quarterly): For patients whose therapy has changed or who are not meeting glycemic goals 2
- Every 12 months: May be appropriate for older adults with stable HbA1c over several years 1
Target HbA1c levels vary by patient characteristics:
- Generally 7.5-8% for older adults 1
- 7-7.5% for healthy older adults with few comorbidities and good functional status 1
- 8-9% for older adults with multiple comorbidities, poor health, and limited life expectancy 1
Self-Monitoring of Blood Glucose (SMBG)
The frequency depends on treatment regimen and hypoglycemia risk 1:
For patients on insulin:
- Type 1 diabetes or intensive insulin therapy: 3+ times daily, up to 6-10 times daily as needed 2, 3
- Basal insulin only: At minimum, check fasting glucose to guide dose adjustments 3
For patients on oral agents without insulin:
- Routine monitoring provides limited benefit unless coupled with treatment adjustment programs 3
- Consider monitoring when assessing hypoglycemia, during illness, or when A1C results may be unreliable 3
Continuous Glucose Monitoring (CGM)
Real-time CGM or intermittently scanned CGM should be offered to adults with type 2 diabetes on multiple daily insulin injections or basal insulin who can use the devices safely 3. Recent evidence shows CGM improves HbA1c by 0.20%, increases time-in-range by 7.41%, and reduces hypoglycemia 4.
Renal Function Monitoring
Measure estimated glomerular filtration rate (eGFR) annually to detect chronic kidney disease 1, 5:
- Use eGFR rather than serum creatinine to guide metformin use 1
- Do not use metformin if eGFR <30 mL/min/1.73 m² 1
Annual spot urine test for microalbumin-to-creatinine ratio to screen for nephropathy 2
Lipid Monitoring
Test lipid panels at least annually in adult patients 2. While lipid monitoring is commonly performed, recent evidence suggests the evidence base for routine lipid testing in stable T2DM patients is weak 5.
Additional Monitoring
Annual assessments:
- Comprehensive foot examination for all patients 2
- Retinal examination by licensed eye care professional 2
- Blood pressure at every routine visit 2
Vitamin B12 monitoring:
- Consider periodic testing in patients taking metformin, particularly those with anemia 6
- However, evidence for routine vitamin B12 screening remains insufficient 5
Tests NOT Routinely Recommended
Based on recent evidence, avoid routine testing for the following unless specific clinical indications exist 5:
- Thyroid function
- Ferritin, folate
- Liver function tests (for metformin monitoring)
- Inflammatory markers (CRP, ESR)
- Bone profile
- Clotting studies
Common Pitfalls
- Overtesting: Many commonly ordered tests lack evidence for routine monitoring 5
- Undertesting HbA1c: Patients not meeting goals require quarterly monitoring, not semi-annual 2
- Ignoring hypoglycemia risk: Patients with severe or frequent hypoglycemia need more frequent contact with healthcare team and possible referral to diabetes educator or endocrinologist 1
- Using serum creatinine alone: Always use eGFR for medication dosing decisions 1