Continuous glucose monitoring-based evaluation of percentage coefficient of variation (%CV) as a metric of intraday glycemic variability in South India

Hemoglobin A1c (HbA1c) is globally recognized as a reliable biomarker for evaluating glycemic control, but it fails to reflect the short-term glycemic fluctuations. Glycemic variability, particularly intraday fluctuations, provides additional information regarding daily glucose excursions and their associated risks. In this cross-sectional study, thirty-two South Indian rural patients with Type 2 Diabetes Mellitus undergoing continuous glucose monitoring were investigated. Baseline demographic, clinical and biochemical characteristics were recorded. Intraday glycemic variability was assessed as Percentage Coefficient of Variation (%CV). Spearman’s rank correlation analysis was performed to assess the relationship between %CV and other CGM metrics including Time in Range (TIR), Time below Range (TBR), Time above Range (TAR) and average glucose. Mixed-effects linear regression models with random intercepts for participants were constructed to examine the adjusted associations. The mean %CV was 22.03 ± 5.08%. In correlation analysis, %CV demonstrated a positive correlation with TBR (ρ = 0.346), although this did not reach statistical significance (p = 0.053). No significant correlations were observed between %CV and average glucose, TIR, TAR or episode-based glycemic measures. In mixed-effects linear regression analysis, higher intraday %CV was significantly associated with same-day TBR in both unadjusted (β = 0.207; 95% CI 0.139–0.274; p < 0.001) and adjusted models. TAR was not significant in unadjusted models; however, adjusted models including age with insulin and/or sulfonylurea use and age with average glucose showed statistically significant associations. No significant associations were observed between %CV and TIR or average glucose. Within this study population, higher intraday glycemic variability was associated with greater same-day hypoglycemic exposure as reflected by TBR. Larger longitudinal studies are required to determine the temporal and clinical implications of elevated %CV.