Associations between body composition and glycemic control: an exploratory analysis of bioelectrical impedance parameters in adolescents with type 1 diabetes

BACKGROUND: The relationship between body composition and glycemic control in adolescents with type 1 diabetes (T1D) remains insufficiently explored. Clarifying the role of specific body compartments may provide insights into metabolic risk and inform personalized management strategies in this population. Our study aimed to describe body composition in adolescents with T1D and to evaluate the associations between anthropometric and bioelectrical impedance analysis (BIA) derived parameters and markers of glycemic control. METHODS: In this exploratory cross-sectional study, 133 adolescents regularly followed at our Pediatric Diabetes Center between May and December 2024 were consecutively recruited. Inclusion criteria comprised a confirmed diagnosis of T1D, complete pubertal development, and continuous glucose monitoring (CGM) use. Anthropometric measurements and body composition parameters were obtained using BIA. Glycemic control was evaluated through HbA1c, mean 12-month HbA1c, and CGM-derived metrics, including time in range (TIR), time in tight range (TITR). RESULTS: Visceral fat was positively correlated with both point-in-time HbA1c (r = 0.210, p = 0.016) and mean 12-month HbA1c (r = 0.216, p = 0.013), while no associations were observed with other BIA-derived parameters. TITR was independently associated with male sex (β = 0.244; p = 0.049), regular physical activity (β = 0.195; p = 0.041), use of automated insulin delivery systems (β = 0.405; p < 0.001), and BMI z-score (β = - 0.310, p = 0.016). TIR was inversely associated with basal metabolic rate (β = - 0.262, p = 0.012). CONCLUSIONS: In adolescents with T1D, visceral adiposity showed weak but significant associations with both point-in-time and 12-month HbA1c levels. These findings are hypothesis-generating and should be interpreted cautiously given the modest effect sizes and study design. Further longitudinal studies using imaging-based methods are needed to clarify the clinical relevance of these associations.