1-C-propionate breath testing as a surrogate endpoint to assess efficacy of liver-directed therapies in methylmalonic acidemia (MMA).

Purpose: To develop a safe and noninvasive in vivo assay of hepatic propionate oxidative capacity.

Methods: A modified 1-C-propionate breath test was administered to 57 methylmalonic acidemia (MMA) subjects, including 19 transplant recipients, and 16 healthy volunteers. Isotopomer enrichment (CO/CO) was measured in exhaled breath after an enteral bolus of sodium-1-C-propionate, and normalized for CO production.

The Effects of Interrupting Sitting Time on Affect and State Anxiety in Children of Healthy Weight and Overweight: A Randomized Crossover Trial.

Purpose: Sedentary time relates to higher anxiety and more negative affect in children. This study assessed whether interrupting sitting over 3 hours is sufficient to influence state anxiety, positive affect, or negative affect, and tested weight status as a moderator.

Methods: Analyses were the second (preplanned) purpose of a larger study.

Quantification of the Capacity for Cold-Induced Thermogenesis in Young Men With and Without Obesity.

Objective: Cold exposure increases energy expenditure (EE) and could have a role in combating obesity. To understand this potential, we determined the capacity for cold-induced thermogenesis (CIT), the EE increase above the basal metabolic rate at the individualized coldest tolerable temperature before overt shivering.

Design: During a 13-day inpatient protocol, we quantitated the EE of 12 lean men and 9 men with obesity at various randomly ordered ambient temperatures in a room calorimeter.

Effects of Interrupting Sedentary Behavior With Short Bouts of Moderate Physical Activity on Glucose Tolerance in Children With Overweight and Obesity: A Randomized Crossover Trial.

Objective: Sedentary children have greater risk of developing abnormalities in glucose homeostasis. We investigated whether interrupting sedentary behavior (sitting) with very short periods of walking would improve glucose metabolism without affecting dietary intake in children with overweight or obesity. We hypothesized that interrupting sitting with short bouts of moderate-intensity walking would decrease insulin area under the curve (AUC) during an oral glucose tolerance test (OGTT) compared with uninterrupted sitting.

Effects of Interrupting Children's Sedentary Behaviors With Activity on Metabolic Function: A Randomized Trial.

Context: Limited data suggest that interrupting sedentary behaviors with activity improves metabolic parameters in adults.

Objective: We tested whether interrupting sitting with short, moderate-intensity walking bouts improved glucose tolerance in children.

Design: Participants underwent two experimental conditions in random order on different days: continuous sitting for 3 hours or sitting interrupted by walking (3 min of moderate-intensity walking every 30 min).