Management of GMI 6.8%
A GMI of 6.8% indicates excellent glycemic control that is already below the standard target of 7%, and no treatment intensification is warranted—instead, focus on maintaining current therapy and potentially consider deintensification if the patient is on multiple glucose-lowering medications or experiencing hypoglycemia. 1
Understanding GMI in Clinical Context
GMI (Glucose Management Indicator) is a calculated estimate of A1C derived from continuous glucose monitoring (CGM) mean glucose, but it should not be treated as equivalent to laboratory A1C. 2 The correlation between GMI and actual A1C is only moderate (r = 0.68-0.71), with substantial variability—36-43% of patients show discordance ≥0.5 percentage points between GMI and laboratory A1C. 3
- GMI of 6.8% corresponds to an estimated average glucose of approximately 148 mg/dL, which represents good glycemic control 2
- However, you should verify this GMI with a laboratory A1C measurement before making major treatment decisions, as GMI can overestimate or underestimate true A1C by more than 0.5% in a significant proportion of patients 3
Current Glycemic Status Assessment
Your patient's GMI of 6.8% is:
- Below the standard A1C target of <7% (53 mmol/mol) recommended for most nonpregnant adults 1
- Already at a level associated with significant reduction in microvascular complications 1
- In a range where further lowering provides diminishing returns in complication reduction 1
Recommended Management Approach
Primary Action: Maintain Current Therapy
Continue the patient's current diabetes regimen without intensification, as the GMI indicates glycemic control is already at target. 1
Evaluate for Potential Deintensification
Consider reducing diabetes medications if the patient meets any of these criteria: 1
- Currently on multiple glucose-lowering agents (especially insulin, sulfonylureas, or meglitinides) 1
- Experiencing any hypoglycemia (time below range >4% or glucose <70 mg/dL) 1
- Has limited life expectancy or significant comorbidities where treatment burden outweighs benefits 1
- Older adult with frailty or high hypoglycemia risk 1
Assess CGM Metrics Beyond GMI
Review the complete CGM profile, not just GMI: 1
- Time in Range (TIR) goal: >70% for most adults (70-180 mg/dL) 1
- Time below range goal: <4% for glucose 54-69 mg/dL 1
- Time below range goal: <1% for glucose <54 mg/dL 1
- Glucose coefficient of variation: ≤36% to assess glycemic variability 1
If time below range exceeds these targets, deintensify therapy immediately to reduce hypoglycemia risk, even if GMI appears acceptable. 1
Monitoring Strategy
- Obtain laboratory A1C measurement to confirm GMI accuracy, as discordance is common 3
- Continue CGM wear for at least 14 days to ensure accurate GMI calculation (though 7-10 days provides reasonable estimates) 4
- Monitor for hypoglycemia at each clinical encounter, asking specifically about symptomatic and asymptomatic episodes 1
- Reassess glycemic goals every 3-6 months based on individualized patient factors including age, comorbidities, life expectancy, and hypoglycemia risk 1
Critical Pitfalls to Avoid
Do not intensify therapy based solely on GMI of 6.8%—this increases risk of hypoglycemia without clinical benefit and represents overtreatment. 5 Starting or increasing insulin at this GMI level would lead to unnecessary treatment burden, weight gain, and hypoglycemia risk. 5
Do not ignore discordance between GMI and laboratory A1C—up to 43% of patients show clinically significant differences, particularly in type 2 diabetes. 3 GMI performs poorly as an A1C estimate and should complement, not replace, laboratory testing. 6
Do not use GMI as the sole metric for glycemic assessment—prioritize mean CGM glucose and time in range metrics over GMI for clinical decision-making. 6 The raw mean glucose value (approximately 148 mg/dL for GMI 6.8%) is more interpretable and avoids confusion from GMI-A1C discordance. 6