Metabolic Effects of Interrupting Sedentary Time in Youth In-lab and in Free-living Settings
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 35
- 试验地点
- 2
- 主要终点
- In-Lab: Metabolic responses
研究概览
简要总结
This study is a randomized crossover trial to compare the effectiveness of interrupting SB on glucose homeostasis in the lab and free-living settings. All participants (N=56) will complete one screening visit to determine eligibility, complete at fitness test, and body composition analysis by bioelectrical impedance. After 7-21 days, all participants will complete two 3-hour in-lab oral glucose tolerance tests (spaced 7-21 days apart). Prior to the in-lab OGTT visits, participants will wear an activity monitor for 7 days on the right thigh. The experimental conditions for the OGTTs will be: 1) 3-hour OGTT of continuous sitting; and 2) 3-hour OGTT with sitting interrupted every 30 minutes with 3-minutes of moderate intensity walking on a treadmill. There will be a 7-21 day washout period between the OGTT visits. In addition, a subset of participants (N=12) who meet inclusion criteria and who successfully complete both OGTT visits will complete a second randomized crossover trial in the free-living environment. The experimental conditions for the free-living components will be: 1) 4 days of habitual sedentary behaviors; and 2) 4 days of prompted short exercise breaks during times in which sedentary behaviors have exceeded 30 minutes. Participants in the free-living trial will wear an activity monitor and a continuous glucose monitor.
详细描述
Rationale: Sedentary behavior (SB) can increase risk for type 2 diabetes. Interrupting SB is a promising strategy to reduce risk, but the long-term success is not yet clear and data on the relationship between in-lab and free-living metabolic responses are lacking. A better understanding of the relationship between metabolic responses to sitting and interrupting sitting in the lab and in a naturalistic environment will help us design effective and targeted intervention strategies to prevent type 2 diabetes in youth.
Intervention: Participants (28 healthy weight and 28 overweight/obese youth; ages 11-15 years) from an ongoing longitudinal observational study (HS-12-00446) will complete: a) an in-lab randomized crossover trial of acute metabolic responses to prolonged vs. SB interruptions; and a subset (N=12) will complete b) two 4-day continuous glucose monitoring (CGM) studies of effects of free-living habitual activity vs. SB interruptions on glucose homeostasis.
Objectives/Purpose: The overall goal is to improve metabolic outcomes by interrupting SB in youth with small bouts of exercise. The aim of this study is to investigate whether the metabolic responses to interrupting sitting are the same in a controlled lab setting and a free-living setting. This study will also try to explain why some children respond better to these short interruptions in sitting than others by using three years of physical activity, body fat, and weight trajectory data from an ongoing study (HS-12-00446).
Study Population: The study population will consist of participants currently enrolled in the Mothers and Their Children's Health (MATCH) Study (PI: Dunton; HS-12-00446; ages 11-15 years).Eligible participants will have completed 3 years of semi-annual assessments of body composition, physical activity, and dietary intake in the MATCH study.
Study Methodology: This study is a randomized crossover trial to compare the effectiveness of interrupting SB on glucose homeostasis in the lab and free-living settings. All participants (N=56) will complete one screening visit to determine eligibility, complete at fitness test, and body composition analysis by bioelectrical impedance. After 7-21 days, all participants will complete two 3-hour in-lab oral glucose tolerance tests (spaced 7-21 days apart). Prior to the in-lab OGTT visits, participants will wear an activity monitor for 7 days on the right thigh. The experimental conditions for the OGTTs will be: 1) 3-hour OGTT of continuous sitting; and 2) 3-hour OGTT with sitting interrupted every 30 minutes with 3-minutes of moderate intensity walking on a treadmill. There will be a 7-21 day washout period between the OGTT visits. In addition, a subset of participants (N=12) who meet inclusion criteria and who successfully complete both OGTT visits will complete a second randomized crossover trial in the free-living environment. The experimental conditions for the free-living components will be: 1) 4 days of habitual sedentary behaviors; and 2) 4 days of prompted short exercise breaks during times in which sedentary behaviors have exceeded 30 minutes. Participants in the free-living trial will wear an activity monitor and a continuous glucose monitor.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 11 Years 至 16 Years（Child）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •current/past participant in the MATCH Study
- •good general health
- •fasting plasma glucose <100 mg/dL
- •BMI greater than the 5th percentile
排除标准
- •significant cardiac or pulmonary disease likely to or resulting in hypoxia or decreased perfusion
- •evidence of impaired glucose tolerance or type 2 diabetes
- •presence of other endocrinologic disorders leading to obesity (e.g.: Cushing Syndrome)
- •current or past anti-psychotic drugs use that would affect metabolism
- •non-diet treatment for hypertension or dyslipidemia
- •precocious puberty and/or receiving androgen and estrogen therapy
- •medication use known to affect body composition/weight
结局指标
主要结局
In-Lab: Metabolic responses
时间窗: 3 hours
glucose, insulin, and c-peptide area under the curve
Predictors of in-lab glucose responses
时间窗: 3 years
Independent-sample t-tests will assess if mean in-lab glucose AUC differs within experimental condition by weight status (normal weight or overweight/obese). Independent-sample t-tests will assess if mean AUC values between conditions (delta AUC) differ by weight status. Structural equation models of latent growth curves will be used to assess the relationship between BMI z-score trajectories in the preceding 3 years, in-lab glucose AUC responses by experimental condition. Specifically, models will test if a) the higher the initial BMI z score (year 1), the higher the initial serum value (-10 min); b) the higher the initial BMI z score (year 1), the greater the change in serum AUC between experimental conditions; and c) the greater slope of the BMI z score change, the greater the change in serum AUC between experimental conditions.
Free-living: Glucose responses
时间窗: 4 days
glucose area under the curve
Individual variations in glucose responses in-lab
时间窗: 3 years
Mixed-effects location scale models (MIXREGLS) will test how between-subject (BS) and within-subject (WS) variation in SB in the preceding 3 years are associated with glucose responses to in-lab SB interruptions. The predictors are average 3-year SB level and SB level at each year (variation in SB). The Stage 1 mixed-effects location scale model will examine random effects of between-subject variance (i.e., location) and of within-subject variance (i.e., scale), sex, baseline percent body fat, and baseline age. The Stage 2 model will assess how these variance sources from Stage 1 affect the delta AUC between in-lab prolonged SB and SB interruptions with regards to glucose (the WS effects).
次要结局
- Relationship between in-lab and free-living glucose AUC(5 days)
研究者
Britni Ryan Belcher, PhD, MPH
Assistant Professor of Preventive Medicine
University of Southern California