What is the use case for Continuous Glucose Monitoring (CGM) in individuals without a diagnosis of diabetes?

Use Cases for Continuous Glucose Monitoring (CGM) Without a Diabetes Diagnosis

Current guidelines do not support the use of continuous glucose monitoring (CGM) for screening or diagnosis of prediabetes or diabetes due to insufficient evidence. 1

Primary Indicated Uses of CGM

• CGM is primarily recommended for patients with diagnosed diabetes, particularly:
  • Type 1 diabetes patients 1
  • Type 2 diabetes patients on intensive insulin therapy (multiple daily injections or insulin pump) 1
  • Patients with problematic hypoglycemia (frequent, nocturnal, or unawareness) 1, 2
  • Pregnant women with type 1 diabetes to improve HbA1c levels and neonatal outcomes 1

Potential Use Cases Without Diabetes Diagnosis

While not officially recommended in guidelines, several potential use cases for CGM in non-diabetic individuals have emerged:

1. Prediabetes Monitoring and Management

• May help identify glycemic abnormalities in high-risk individuals with prediabetes (A1C 5.7-6.4%) 1, 3
• Could potentially detect postprandial glucose excursions not captured by traditional testing methods 3
• Might provide insights into glucose patterns that predict increased risk of developing diabetes 4

2. Educational Tool for Lifestyle Modification

• CGM can facilitate understanding of glucose changes resulting from diet, exercise, stress, and sleep 1
• May motivate patients to establish healthier lifestyle habits by providing immediate feedback 1, 4
• Could potentially improve patient adherence to preventive interventions 1

3. Research Applications

• Valuable tool for assessing and guiding treatment in clinical research settings 1
• Helps characterize pharmacodynamics and glycemic variability in research studies 5
• Enables rigorous evaluation of new forms of therapy 5

4. Specific High-Risk Populations

• Individuals with polycystic ovary syndrome (PCOS) 3
• Patients after renal transplantation 3
• Individuals with acute coronary syndrome 3
• People with strong family history of type 2 diabetes and obesity 3, 4

Limitations and Concerns

• Current guidelines explicitly state there is "insufficient evidence to support the use of CGM for screening or diagnosis of prediabetes or diabetes" 1
• The accuracy of CGM devices is lowest in the hypoglycemic ranges, which is a critical limitation 2
• Regulatory inadequacy exists regarding "off-label" CGM distribution to people without diabetes 6
• Lack of consistent and high-quality evidence supporting CGM utility in people not living with diabetes 6
• Potential adverse effects on eating habits in non-diabetic individuals 6
• Cost considerations - CGM is relatively expensive and may not be cost-effective for those without diabetes 1

Key Considerations for Clinical Practice

• CGM requires proper education and training for effective use 1
• Patients need to understand that CGM measures interstitial fluid glucose, which lags behind blood glucose by 5-15 minutes 7
• Sensor accuracy can be affected by medications, temperature, humidity, and altitude 1
• Skin reactions due to irritation or allergy should be assessed and addressed 1

Emerging Trends

• Growing interest in using CGM for health and wellness optimization in non-diabetic populations 4
• Potential application in elite athletics for performance optimization 4
• Development of specific "metabolic glucotypes" from CGM tracings that may predict diabetes risk 4

While there may be theoretical benefits to using CGM in individuals without diabetes, current clinical guidelines do not support this practice due to insufficient evidence. Any use of CGM in non-diabetic individuals should be approached with caution and realistic expectations about its limitations.