Endocrine Abstracts

JOINT1678

Background and Aims: Limited research exist on the effects of Advanced Hybrid Closed Loop (AHCL) systems on body composition in individuals with type 1 diabetes mellitus (T1DM). This cross-sectional study aimed to compare body composition between patients using AHCL systems (MiniMed 780G® or T:slim X2 Control-IQ®) and those using multiple daily injections (MDI) or patch pumps.

Methods: Patients who had been using the same AHCL system for at least one year (n = 24) were compared to those using MDI (n = 13) or patch pumps (n = 8) combined with a continuous glucose monitoring (CGM) sensor (grouped together as the MDI/patch group, n = 21). MDI users recorded their fast-acting insulin doses with smartpens. Exclusion criteria were conditions affecting body composition and HbA1c >69 mmol/mol. Body composition was assessed using bioelectrical impedance analysis (BIA), three-point skinfold thickness (measured with a plicometer), and handgrip strength (measured with a dynamometer).

Results: A total of 45 patients (mean age: 37±11 years) were included. There were no significant differences between the AHCL and MDI/patch groups in terms of sex, age, BMI, waist circumference, estimated glomerular filtration rate (eGFR), International Physical Activity Questionnaire (IPAQ) score, or HbA1c (52±8 vs. 52±8; P = 0. 932). BIA revealed no significant differences in fat mass percentage (P = 0. 752), fat mass (P = 0. 912), fat-free mass (P = 0. 433), body cell mass (P = 0. 554), total body water (P = 0. 446), or phase angle (P = 0. 998) between the AHCL and MDI/patch groups. Similarly, skinfold thickness and handgrip strength did not differ significantly between groups. AHCL users had significantly higher time in range (TIR: 72±8% vs. 56±16%; P = 0. 001) and time in tight range (TITR: 46±11% vs. 35±12%; P = 0. 007), along with lower time above range (TAR), time below range (TBR), and glucose management indicator (GMI) compared to MDI/patch users. The mean per-kilogram total daily insulin dose did not differ significantly between groups (0. 62±0. 14 U/kg in AHCL users vs. 0. 58±0. 18 U/kg in MDI/patch users; P = 0. 422) and was positively correlated with body cell mass percentage (r = 0. 328, P = 0. 039). Fat mass percentage, in addition to its established associations with sex, BMI, physical activity, and suprailiac skinfold thickness, showed a positive correlation with total cholesterol (r = 0. 359, P = 0. 015) and LDL cholesterol (r = 0. 333, P = 0. 025).

Conclusions: Compared to MDI/patch therapy, AHCL systems were associated with improved glucose profile parameters without significant differences in body composition or insulin dosage. Higher total and LDL cholesterol levels were associated with higher fat mass percentage.