Introduction The relationship of demographic and anthropometric factors on satiation and gastric functions is incompletely understood. Optimal methodology to assess meal intake factors and postprandial GE has not been established. Current test meals are small and may not be sufficient to assess satiation and postprandial responses. GS measures gastric meal retention only. MRI measures gastric content volume (meal and secretions).
Aim This study assessed the effects of age, sex and obesity on maximum tolerated volume (MTV) assessed by nutrient drink test (NDT) in healthy volunteers (HVs). GS and MRI assessed gastric function and GE after ingestion of a 400 ml liquid test meal (same nutrient drink) that triggered sensation of fullness in >90% HVs.
Methods Adult HVs were recruited and stratified by sex and age aiming to study 10 men and women in age groups <40, 40–60, >60 yrs. Exclusions included history of GI surgery and obesity (BMI>30 kg/m2). MTV was assessed at screening by NDT (0.75 kcal/ml at 40 ml/min), all HVs ingested >400 ml. Eligible participants were randomised to gastric imaging by GS and MRI on two separate days. HVs ingested 400 ml liquid nutrient at 40 ml/min. Gastric content volume was monitored over 4 h. GS and MRI measured GE half-time [T50], GErate maximum and[ml/min]. Univariate and multiple linear regression models assessed the effects of demographic and anthropometric parameters on gastric function.
Results 53 HVs completed the study (6–10 in each group). MTV associated with male sex (R2=20%, p<0.001), height (R2=9%, p=0.016) and weight (R2=15%, p<0.003) but not age (R2=4%, p>0.1) or obesity (WC or BMI, both p>0.1). On multivariate analysis GS T50 andwere negatively associated with male sex (R2=12%, p<0.005), height (R2=30%, p<0.001) and weight (R2=23%, p<0.001) but not age (R2=1%, p>0.1) or obesity (BMI or WC, both p>0.1). Similar associations were not present with MRI indicating gastric content by GS and MRI do not provide the same information.
Conclusion HVs that are male, tall and heavy ingest more before MTV is reached; but no independent association with obesity was seen. These factors were associated with slower gastric emptying assessed by GS. A simple explanation is that large individuals have larger stomachs that can accommodate large volumes. 400 ml achieves lower relative gastric filling in large than small stomachs and does account also for slower GE.
Competing interests None declared.