Continuous Glucose Monitoring-Derived Glycemic Profiles and Correlates in Young Adults Ages 18 to 26 Years

Continuous glucose monitoring (CGM) is increasingly applied in populations without diabetes, yet existing reference ranges are largely derived from middle-aged or older adults. This study characterized CGM metrics in young adults without diabetes and examined variation by sex, age, body mass index (BMI), and physical activity (PA).

Participants wore an unmasked Dexcom G7 CGM for up to 10 days under free-living conditions. Glycemic metrics were derived using the iglu R package and summarized as median [IQR]. Associations with sex, age, BMI, and PA were evaluated using Wilcoxon tests, Spearman correlations, and quantile regressions.

A total of 105 participants (age = 21 years [range: 18-26], BMI 23 kg/m² [21-25]; 72% female; 72% non-White) provided ≥48hr of CGM data. Compared with females, males had higher mean sensor glucose (110 [103-119] vs 104 [99-108] mg/dL; P < .01), eA1c (5.4[5.2-5.8] vs 5.2[5.1-5.4]; P < .01), area under the curve (110[102-119] vs 103[99-108]; P = .01), and daily episodes >140 mg/dL (1.6[1.0-2.6] vs 1.3[0.7-2.0]; P = .03). Age correlated with CV (r = .20, P = .04). BMI was inversely correlated with CV (r = -.35), MAGE (r = -.35), and MODD (r = -.27), all P < .001. Physical activity was modestly associated with reduced glycemic burden.

CGM revealed sex differences in young adults-males exhibited higher mean glucose and excursions-while both sexes maintained normoglycemic patterns. Age, BMI, and PA were linked to variability indices. Findings provide CGM reference data for young adults and highlight the importance of biological and behavioral factors in glycemic regulation.