2028-LB: Investigate Sex- and Fat Depot–Specific Glucose Metabolism after Consuming Carbohydrate-Enriched Diets with (Un)interrupted Prolonged Sitting

Introduction & Objective: Carbohydrate-enriched diets and sedentary behavior are risk factors for diabetes. However, their impacts on glucose metabolism in abdominal and gluteal subcutaneous adipose tissues, especially considering sex differences, remain unexplored.

Methods: Twenty healthy subjects (10 females) [age 30.5±7.5 years, BMI 22.9±2.2 kg/m² (mean±SD)] participated in mixed-feeding trials lasting 320 minutes, with breakfast and lunch containing 77% carbohydrates and either prolonged sitting (SIT) or interrupted prolonged sitting (2 min walking at 6.4 km/h every 20 min) (ACTIVE) in a randomized crossover design. Continuous glucose monitoring (CGM) was inserted simultaneously at abdominal (ABD) and gluteal (GLUT) fat-depots. Body composition was precisely quantified by dual-energy x-ray absorptiometry. Oral glucose tolerance test was performed for measuring insulin sensitivity and resistance. In vitro experiments using paired human abdominal and gluteal preadipocyte cell lines were conducted to investigate molecular mechanisms.

Results: In the SIT trial, GLUT CGM showed a slower increase in interstitial blood glucose (BG) during lunch compared to ABD CGM, particularly in females. Interrupted prolonged siting (ACTIVE trial) led to numerically lower BG levels in both ABD and GLUT CGM, with the most significant impact observed in female ABD CGM. While males with higher insulin resistance and android fat displayed a notable correlation with decreased BG levels in the ACTIVE trial. Our in vitro experiments further revealed steady glucose uptake (GLUT1 expression) and de novo lipogenesis (ChREBP protein) were significantly enhanced in gluteal adipocytes during post-feeding 3 to 6 hours.

Conclusion: Breaking prolonged sitting improves glucose control and gluteal fat depot may play roles to stabilize carbohydrate-enriched diets related hyperglycemia.