(P41-13-26) Postprandial Glucose Dynamics From Continuous Monitoring Reveal Distinct Subtypes of Type 2 Diabetes

Objectives: Optimizing postprandial glucose response (PPGR) in individuals with type 2 diabetes (T2D) is crucial for improving glycemic control and reducing diabetes-related complications. CGM provides insights into PPGR dynamics. In this study, we investigated PPGR profiles to identify pathophysiological distinct subtypes of type 2 diabetes.

Methods: Using four-hour CGM data after a standardized breakfast, 100 individuals with T2D were clustered via k-means based on glucose peak, iAUC₀-₄h, average positive slopes before (mean rise) and after (mean fall) the peak, and the difference between final and fasting glucose. A subgroup of 50 individuals repeated the standardized breakfast while undergoing postprandial venous glucose/insulin sampling. Clinical/metabolic parameters were compared across PPGR clusters using one-way ANOVA.

Results: Three PPGR clusters were identified. Cluster 1 (n=19) showed the highest glucose peak and iAUC₀-₄h, with glucose levels remaining above baseline 4h post-breakfast. Cluster 2 (n=56) and 3 (n=25) had similarly lower peaks and iAUCs₀-₄h compared with Cluster 1, with Cluster 2 exhibiting a slower glucose rise and fall than Cluster 3. No significant differences in age, sex, BMI, or diabetes duration was found between the clusters. However, compared to Cluster 3, Cluster 1 showed lower β-cell function (HOMA2-B%: 77.42±25.64 vs. 104.96±43.94), higher insulin resistance (HOMA-IR: 7.94±3.27 vs. 4.84±2.78), and a reduced capacity to compensate through increased insulin secretion, as indicated by a lower Disposition Index: 1.02±0.67 vs. 2.37±1.05 (all p< 0.05). Cluster 2 did not differ significantly in HOMA2-B% (94.46±31.59) or HOMA-IR (5.99±3.36) from the other clusters, but showed a reduced early postprandial insulin secretion compared to Cluster 3, as indicated by a lower 60-min Insulinogenic index (0.84±0.58 vs. 1.67±1.07, p< 0.05).

Conclusions: CGM-based dynamic parameters allowed identification of T2D subtypes with similar clinical profiles but distinct degrees of impairment in insulin secretion and sensitivity. This approach goes beyond conventional postprandial metrics and supports the potential of CGM-based profiling to inform precision management strategies in T2D.

Funding Sources: Swedish Foundation for Strategic Research, JPI-HDHL-METADIS CarbQ4health