Continuous glucose monitoring, or CGM, which tracks blood sugar as it changes over time, may offer important clues to heart and metabolic health in people without diabetes. A new study of approximately 1,300 adults found that higher average glucose and more time spent above 140 milligrams per deciliter were associated with a greater likelihood of high blood pressure and differences in cholesterol levels.
Researchers at Boston University Chobanian & Avedisian School of Medicine analyzed the data. They used glucose monitoring records from Framingham Heart Study participants who had neither diabetes nor cardiovascular disease. The team examined average glucose, glucose fluctuations, and periods of elevated blood sugar, then compared those patterns with markers of cardiovascular and metabolic health. Their findings were published in the journal Diabetes Care.
What The Study Measured Differently Than Standard Tests
Standard screening tests provide a limited snapshot. Fasting plasma glucose measures glucose after a period without food, while hemoglobin A1c reflects average blood sugar over the preceding few months. Both are clinical gold standards for diabetes screening.
However, neither test captures the fluctuations that reveal how blood sugar regulation differs from person to person. Furthermore, CGM provides a continuous, temporal view that standard labs miss.
Consequently, studying CGM in people without diabetes could help researchers identify early patterns of abnormal blood sugar regulation, known as dysglycemia. Scientists call the process of grouping people by these measurable characteristics phenotyping.
“Understanding temporal glucose patterns may be pivotal in uncovering early or intermittent dysglycemia and its downstream cardiometabolic risks. Continuous glucose monitoring may aid this in characterizing the heterogeneity underlying dysglycemia by enabling phenotyping of individuals across the blood sugar continuum,” explains corresponding author Nicole Spartano, PhD, an assistant professor of medicine.
Key Findings From 1,300 Framingham Participants
The Boston University team analyzed CGM data from participants without diabetes or heart disease. They focused on three metrics: average glucose, glycemic variability, and time spent above 140 mg/dL. The analysis showed that higher average glucose and a higher percentage of time above 140 mg/dL were cross-sectionally associated with high blood pressure and distinct cholesterol profiles. Moreover, the findings highlight that even modest elevations within the non-diabetic range may correlate with cardiometabolic markers.
Lead author Bahar Bakhshi, MS, a PhD candidate in the school’s Molecular & Translational Medicine Program, noted the context for this work. “Our findings align with a small but growing body of literature characterizing the cross-sectional associations of CGM measures and health outcomes. Emerging studies have also reported that a higher percentage of time spent at glucose levels >140 mg/dL is longitudinally associated with the development of cardiometabolic outcomes, including type 2 diabetes, among individuals without type 2 diabetes,” says Bakhshi.
Analysis: Can Glucose Patterns Predict Future Disease?
This is the most critical question. The current analysis examined associations at a single point in time, so it could not establish whether glucose patterns predicted future disease in these participants. In other words, the study shows a link, not causation.
Therefore, researchers cannot yet say that CGM patterns will predict who develops hypertension or diabetes. However, other research has begun exploring that longer-term relationship. Emerging longitudinal studies suggest that time above 140 mg/dL may be associated with future development of type 2 diabetes in people without diabetes. Additional studies are needed to determine how these CGM measurements might inform cardiovascular risk assessment in people without diabetes. The findings could also guide future research on preventing both diabetes and cardiovascular disease.
Q&A
Q: Who conducted the study and where was it published?
A: Researchers from Boston University Chobanian & Avedisian School of Medicine analyzed data from the Framingham Heart Study. The results were published in Diabetes Care.
Q: What did the study find in non-diabetics?
A: In about 1,300 adults without diabetes or cardiovascular disease, higher average glucose and more time above 140 mg/dL were linked to higher odds of high blood pressure and differences in cholesterol.
Q: Does this mean CGM can predict heart disease?
A: No. This was a cross-sectional study, so it shows association at one time point, not future prediction. Longitudinal research is still ongoing.
FAQ
1. What is continuous glucose monitoring (CGM)?
CGM is a small wearable sensor that tracks glucose levels throughout the day and night, showing how blood sugar rises and falls after meals, activity, and sleep.
2. What does time above 140 mg/dL mean?
It refers to the percentage of time a person’s glucose stays above 140 mg/dL. While 140 mg/dL is often used as a post-meal threshold, it is not a diagnostic cutoff for diabetes on its own.
3. How is CGM different from HbA1c and fasting glucose?
Fasting glucose shows one point in time, and HbA1c shows a 2-3 month average. CGM reveals fluctuations, spikes, and patterns that those standard tests miss.
4. Should people without diabetes use CGM for heart health screening?
CGM is currently standard for diabetes management, not routine heart screening in non-diabetics. Talk to your doctor before considering CGM for general wellness.
5. What is dysglycemia phenotyping?
It means grouping people by their unique blood sugar patterns to better understand early, intermittent blood sugar dysregulation and its potential health risks.
Disclaimer; This article is for informational purposes only and does not provide medical advice.
