高住低练对肥胖青少年内源性大麻素及相关食欲调节激素的影响

The Influences of“Living High-Training Low”on Endocannabinoids and Gastrointestinal Hormones Changes in Obese Adolescents

目的：健康饮食和适当运动减控体重后的食欲增加，有可能导致体重反弹，低氧对食欲调节和代谢的影响越来越引起研究者的关注。以内源性大麻素为靶点，探讨4周“运动与饮食控制”（低住低练）和“低氧舱睡眠结合运动与饮食控制”（高住低练）对胃肠调节激素的影响机制，诠释高住低练减控体重的新机理。方法：志愿参加全封闭式运动减肥的超重和肥胖青少年（1l～15岁）40名，随机分为低住低练组和高住低练组，并进行为期4周的干预。因5人退出实验，最终低住低练组19人，高住低练组16人。低住低练组采用有氧运动与饮食控制的干预方式，根据受试者的健康状况和运动负荷试验确定运动强度，制定个性化的运动处方，营养师根据受试者的基础代谢率制定合理的饮食方案，保证热量和必需营养物质的供给。高住低练组除进行运动和饮食控制干预外，受试者每天晚上睡在低氧房，低氧环境为模拟海拔2700m高度，每天低氧暴露10h。干预结束前、后分别检测肥胖相关的形态学指标、血液生化指标（血常规、糖脂代谢等）以及免疫学指标，并检测血浆中胃肠调节激素（ghrelin、PYY、CCK、MCP-1、GLP-1以及内源性大麻素）分泌水平。结果：1）干预后，低住低练组和高住低练组体重、BMI较干预前均下降，且两组间差异具有显著性（P〈0．05）；2）干预后，低住低练组内源性大麻素呈上升趋势，高住低练组内源性大麻素呈下降趋势，两组间内源性大麻素的差异具有统计学意义（P〈0．05）；3）干预后，其他食欲调节激素变化：低住低练组鲫〈呈下降趋势，高住低练组CCK下降程度减少，两组间∞（的差异具有统计学意义（P〈0．05）；干预后，低住低练组MCP-1呈下降趋势，高住低练组MCP-1呈升高趋势，两组间MCP-1的差异具有统计学意义（P〈0．05）；低住低练受试者CCK浓度下降程度和体重下降程度成正相关（P〈0．05），而高住低练组这种相关性消失。结论：内源性大麻素可能是高住低练减控体重的重要介质，有助于改善低住低练减控体重过程中下降的食欲抑制因子，从而可能有利于维持运动结合饮食减控体重的长期效果。

Objective： Body weight regaining was not uncommon for young people who had lost weight after an exercise and/or diet program. Previous studies presented that the intervention of ＂living high-training low＂ could result in changes of the appetite and metabolism. The pur- pose of this study was to determine if a 4-week ＂living high-training low＂ intervention would influence on youth weight loss and explore the mechanisms underlying the weight loss effect in- duced by endocannabinoids change. Method：Forty overweight and obese adolescents （age at 11 ;15 years） volunteered to participate in the weight-loss program. They were randomly as- signed to two groups, but 5 subjects quitted the study. Therefore, at last, the living low-train- ing low （n= 19） and the living high-training low group （n= 16）. All subjects completed an informed consent document prior to participating in the study. Both groups underwent exercise training and diet intervention. The personalized exercise training program was prescribed based on individual fitness levels. The personalized diet plan was formulated and modified with indi- vidual basal metabolic rate. Subjects were assigned to two different sleeping conditions for four weeks, with the living low-training low group in normal condition but the living high-training low group in a hypoxic room equipped with hypoxia systems that simulated an altitude of 2, 700 meters. Before and after the 4-week intervention, adipose levels, metabolic health-related blood biomarkers, plasma endocannabinoids levels and other gastrointestinal hormones were measured and assessed. Results： After the intervention, both the living low-training low and the living high-training low group experienced a significant decrease in body weight and BMI. However,the effect was much greater on the subjects in the living high-training low group than those of the living low-training low group （P; 0. 0 5 ）. Accompanying the weight loss, plasma endocannabinoids levels exhibited different changes in both groups, with an increase in the living low-training low group but a decrease in the living high-training low group. Other gastrointestinal hormones levels including CCK and MCP-1 also responded differently to the in- tervention. Both hormones decreased in the living low-training low group, while the living high training low group showed no change in CCK but an increase in MCP-1. Conclusions： The findings of the study demonstrated the influence of hypoxia exposure in a traditional exercise- plus-diet weigh loss program on weight loss in obese adolescents. The endocannabinoids and other gastrointestinal hormones might play an important role in mediating such an effect. They might enhance the short- and long-term effect of weight loss via minimizing the compensatory response of appetite induced by exercise and diet.