South Korea Study: Real-Time CGM and Digital Coaching Deliver Fast Blood Sugar Results

A study from South Korea offers compelling evidence that pairing continuous glucose monitors (CGM) with personalized digital health coaching can produce meaningful blood sugar improvements in as little as eight weeks — a finding with significant implications for the millions of Americans managing type 2 diabetes and prediabetes.

What the Researchers Did

Scientists at Kangbuk Samsung Hospital's Healthcare Data Center in Seoul enrolled 110 adults with either type 2 diabetes (T2DM) or prediabetes in a prospective cohort study. Over eight weeks, participants wore real-time CGM devices that fed live glucose data into a digital coaching platform. Coaches used that data to deliver personalized guidance on eating habits and physical activity. Researchers tracked fasting blood glucose (FBG), HbA1c, BMI, and lifestyle behaviors before and after the intervention.

Participants were divided into three groups based on their glycemic variability (GV) — essentially how wildly their blood sugar fluctuated throughout the day. This grouping allowed researchers to identify who benefited most.

Key Findings

All three groups showed meaningful improvements, but the biggest winners were those with the highest blood sugar swings (the T3 group). Their results included:

• HbA1c dropped from 7.39% to 6.82% — a reduction that in US clinical terms moves patients meaningfully closer to the American Diabetes Association's (ADA) target of below 7.0% for most adults with type 2 diabetes.
• Fasting blood glucose (FBG) also declined significantly. To put this in US units: an FBG improvement from approximately 133 mg/dL toward the ADA's pre-meal target of 80–130 mg/dL is clinically meaningful.
• Physical activity scores increased significantly in the highest-variability group (p = 0.005).
• All three groups reported healthier dietary habits after the eight-week program.

Why the South Korean Perspective Matters

South Korea has built one of the world's most advanced digital health infrastructure systems, giving researchers there unique access to large-scale, tech-integrated chronic disease management data. South Korean healthcare systems have rapidly adopted CGM and telehealth coaching in ways that the US is still scaling up. This study essentially provides a roadmap — and real-world proof — of what's possible when digital tools are fully integrated into diabetes care.

Why This Matters for US Patients

Approximately 38 million Americans have diabetes and another 98 million have prediabetes, according to the CDC. Despite widespread CGM availability in the US, many patients use the devices without structured coaching to act on the data. This South Korean study suggests that the combination — not the CGM alone — is what drives results. For US patients, this reinforces the value of asking your care team about digital coaching programs alongside CGM use. The ADA already supports CGM for type 2 patients on non-insulin regimens, and this research adds international weight to expanding that recommendation further. If you have high blood sugar variability, the data suggest you may have the most to gain.

Bottom Line

Eight weeks of real-time glucose monitoring paired with personalized digital coaching produced significant HbA1c and lifestyle improvements — especially for patients whose blood sugar fluctuates the most. Talk to your doctor about whether a structured CGM coaching program is right for you.

Source: Park, Choi, Lee. "Impact of real-time continuous glucose monitoring and personalized digital health coaching on glycemic control and lifestyle in patients with type 2 diabetes and prediabetes." Primary Care Diabetes (2026). DOI: 10.1016/j.pcd.2025.12.002. PMID: 41390265.