Domain-based Basal and Daytime Ambulatory Glycemic Exposure Metrics Derived from Continuous Glucose Monitoring: A Real-world Clinic-based Study
Suresh N. Shinde, Rituparna Suresh Shinde, Succhietra Yogesh BhangaaleyAbstract
Background:
Standard continuous glucose monitoring (CGM) metrics summarize whole-day exposure but do not explicitly localize glycemic burden to nocturnal basal and daytime ambulatory domains.
Objective:
The objective of this study was to evaluate time-normalized domain metrics across oral glucose tolerance test (OGTT)-derived phenotypes and assess their relationships with established CGM measures, robustness, reproducibility, and incremental information.
Methods:
We analyzed paired OGTT and FreeStyle Libre data from 253 clinic participants. CGM was partitioned into 00:00–<06:00 and 06:00–<24:00 domains. Area of basal glycemia (ABG) and area of prandial/daytime ambulatory glycemia (APG) quantified mean nocturnal and daytime exposure; incremental ABG (iABG)/incremental APG (iAPG) and deficit ABG/deficit APG quantified above- and below-anchor exposure relative to 80/90 mg/dL. Participant-level phenotype comparisons, correlations, alternative-anchor and time-window sensitivity analyses, split-period agreement, covariate-adjusted models, repeated cross-validation, and conventional-category analyses were performed.
Results:
Corrected phenotype counts were NoDM 9, increased IR 7, midzone glycemia 26, prediabetes 78, and diabetes 133. Mean ABG/APG increased from 80.45/86.38 mg/dL in NoDM to 112.17/124.99 mg/dL in diabetes. Phenotype effects were significant for ABG (ε
2
= 0.266), APG (0.371), iABG (0.282), and iAPG (0.390; all
Conclusions:
ABG/APG metrics reproducibly localize glycemic exposure to nocturnal and daytime domains. They complement rather than replace established whole-day CGM metrics and require prospective external validation and outcome benchmarking.