Optimal Management for GMI 7.8% and TIR 61%
This patient requires immediate intensification of diabetes therapy, as both the GMI of 7.8% and TIR of 61% fall significantly below the recommended targets of GMI <7% and TIR >70% for most nonpregnant adults with diabetes. 1
Current Glycemic Status Assessment
Your patient's metrics indicate suboptimal control:
- GMI of 7.8% corresponds to an estimated mean glucose of approximately 7.8 mmol/L (140 mg/dL) based on standardized conversion formulas 1, which exceeds the target A1C equivalent of <7% (53 mmol/mol) 1
- TIR of 61% is below the recommended target of >70% for most adults with diabetes 1, 2
- This means the patient is spending approximately 39% of time outside the target range of 70-180 mg/dL (3.9-10.0 mmol/L), representing substantial room for improvement 1
Critical Next Steps
1. Evaluate CGM Data Completeness
- Ensure the patient has at least 14 days of CGM data with ≥70% device active time before making major treatment decisions 1
- Review the standardized Ambulatory Glucose Profile (AGP) report to identify specific patterns 1
2. Assess Time Above and Below Range
You must determine where the 39% out-of-range time is occurring:
- Time Above Range (TAR) >180 mg/dL: Target should be <25% for most adults 1, 2
- Time Below Range (TBR) <70 mg/dL: Must be <4% to ensure safety 1, 2
- Severe hypoglycemia <54 mg/dL: Must be <1% 1
3. Treatment Intensification Strategy
If the problem is predominantly hyperglycemia (high TAR):
- Intensify glucose-lowering therapy by adjusting insulin doses, adding or optimizing non-insulin agents, or implementing automated insulin delivery systems if using insulin 1, 3
- Each 5% improvement in TIR is clinically meaningful, so aim for incremental gains toward the >70% target 2
- Consider targeting a glucose goal of 100 mg/dL if using advanced hybrid closed-loop systems, as this setting predicts the highest TIR achievement 3
If significant hypoglycemia is present (TBR >4%):
- Do not intensify therapy until hypoglycemia is resolved 1
- Reduce insulin doses or adjust timing of glucose-lowering medications 4
- Consider switching to medications with lower hypoglycemia risk (GLP-1 agonists, SGLT2 inhibitors, DPP-4 inhibitors) 5
4. Optimize Modifiable Factors
For patients on insulin pump therapy:
- Set active insulin time to 2 hours if using automated systems, as this predicts optimal TIR without increasing hypoglycemia risk 3
- Maximize time in automated mode (>90% if possible), as this strongly correlates with improved TIR 3
- Minimize system exits and alarms through proper education and troubleshooting 3
Important Caveats
When Less Stringent Goals Are Appropriate
Consider accepting the current GMI of 7.8% and TIR of 61% ONLY if the patient has:
- History of severe hypoglycemia or hypoglycemia unawareness 1, 4
- Limited life expectancy (<10 years) 1, 5
- Advanced microvascular or macrovascular complications where risks of intensive therapy outweigh benefits 1
- Extensive comorbidities or dementia 1, 5
In these cases, a less stringent A1C goal of <8% (64 mmol/mol) and TIR >50% may be more appropriate 1
Common Pitfalls to Avoid
- Do not rely solely on GMI as it may significantly underestimate or overestimate actual HbA1c, particularly at higher glucose levels 6, 7. Always correlate with laboratory A1C testing 6
- Do not ignore the coefficient of variation (CV) - target should be ≤36% to minimize dangerous glycemic variability 1
- Do not intensify therapy without reviewing the complete AGP showing time above range, time below range, and glucose patterns throughout the day 1
- Never target glucose <110 mg/dL as this increases hypoglycemia risk without improving outcomes 5