模拟低压低氧环境下的静息能量消耗及预测公式研究

Study on the resting energy expenditure in simulated hypobaric hypoxia environment and prediction formula

目的以间接测热法测定的静息能量消耗(resting energy expenditure,REE)为金标准,结合体成分指标建立能量消耗预测公式,为寻找客观、准确、重复性高及可操作性强的飞行人员REE测量方法提供参考。方法纳入正常体型男性志愿者14名,通过低压舱构建低压低氧战训环境。所有受试者均按要求完成单任务(飞行操作)和双任务(飞行操作+计算任务)。使用体成分分析仪直接测定受试者体重、去脂体重(fat free mass,FFM)、肌肉重(muscle mass,MM)、脂肪重(fat mass,FM)、腰臀比(waist-to-hip ratio,WHR)、内脏脂肪重(visceral fat mass,VFM)及体脂率(body fat percentage,BF%),使用气体代谢仪监测其呼吸频率(respiratory frequency,RF)、CO_(2)产生量(volume of CO_(2),VCO_(2))、最大摄氧量(maximal volume of O_(2),VO_(2max))、潮气量(volume of tidal,VT)、每分通气量(minute ventilation volume,VE)、代谢当量(metablic equivalent,MET)、REE和每公斤体重每日静息能量消耗(REE/kg/d)。统计分析REE与体成分检测指标的相关性,并获得线性回归方程。结果在模拟低压低氧环境下,双任务时受试者的RF、VCO_(2)、VO_(2max)、VE、VT、REE、REE/kg/d、MET和心率略有增加趋势,但和单任务相比,其差异均无统计学意义(P均>0.05);REE与FFM、MM呈正相关(r=0.566、0.570,P=0.035、0.033),而与身高、FM和心率等无相关性(P均>0.05)。线性回归方程显示低压低氧环境下REE预测公式为模型A:REE=60.34×MM-1121(r=0.570,P=0.033),或模型B:REE=55.34×FFM-1073(r=0.566,P=0.035);模型A公式预测值与实测值REE具有正相关性(r=0.570,P=0.033),且误差值为(0.032±358.170)kcal/d,P=1.00>0.05。结论低压低氧环境下正常体型受试者的REE主要决定因素为FFM和MM,通过测定FFM或MM均可方便、准确地预测其REE水平。

Objective To provide references for finding an objective,accurate,highly repeatable and operable measurement method of the resting energy expenditure(REE)for flying personnel by taking the indirect calorimetry measured REE as the gold standard and establishing the formula for predicting REE combined with body composition indexes.Methods Fourteen normal-size male volunteers were chosen as the subjects.The hypobaric hypoxia environment was constructed in the hypobaric chamber.The subjects were asked to complete single task(flight control)and dual task(flight control and calculation).The body weight,fat free mass(FFM),muscle mass(MM),fat mass(FM),waist-to-hip ratio(WHR),visceral fat mass(VFM)and body fat percentage(BF%)were directly measured by body composition analyzer.The respiratory frequency(RF),volume of CO_(2)(VCO_(2)),maximal volume of O_(2)(VO_(2max)),volume of tidal(VT),minute ventilation volume(VE),metablic equivalent(MET),REE and REE/kg/d were measured by gas metabolizer.The correlation between REE and body composition indexes was analyzed and a linear regression equation was obtained.Results In the simulated hypobaric hypoxia environment,the RF,VCO_(2),VO_(2max),VE,VT,REE,REE/kg/d,MET and heart rate of the subjects increased slightly in the dual task,but there were no significant differences between the dual task and the single task(all P>0.05).REE was positively correlated with FFM and MM(r=0.566,0.570,P=0.035,0.033),but not with height,FM and heart rate(all P>0.05).The prediction formula of REE in hypobaric hypoxia environment was Model A:REE=60.34×MM-1121(r=0.570,P=0.033),or Model B:REE=55.34×FFM-1073(r=0.566,P=0.035).There was a positive correlation between the predicted REE and the measured REE(r=0.570,P=0.033)for Model A,and the error value was(0.032±358.170)kcal/d,P=1.00>0.05.Conclusions FFM and MM are the main determinants of REE in normal-size subjects under hypobaric hypoxia environment.Either MM or FFM shows a good prediction effect to REE.