AIM: To evaluate selected factors influencing resting energy expenditure(REE) in obese female subjects.METHODS: Seventy seven 61 obese Caucasian women [mean age of 52.93 ± 13.45 years, and mean body mass index(BM...AIM: To evaluate selected factors influencing resting energy expenditure(REE) in obese female subjects.METHODS: Seventy seven 61 obese Caucasian women [mean age of 52.93 ± 13.45 years, and mean body mass index(BMI) of 41.78 ± 11.54 kg/m2] were enrolled; measurements of resting metabolic rate(RMR) by a ventilated, open-circuit system, indirect calorimeter were performed after an overnight fast. Body composition as well as medications, physical parameters, blood samples, disease pattern, and smoking were considered. RESULTS: RMR was significantly associated with body weight(r = 0.732, P < 0.001), body height(r = 0.401,P = 0.008), BMI(r = 0.504, P < 0.001), waist circumference(r = 0.602, P < 0.001), mid-upper arm circumference(r = 0.417, P = 0.006), mid-upper arm muscle circumference(r = 0.344, P = 0.028), total body water(r = 0.339, P = 0.035), body temperature(r = 0.409, P = 0.007), smoking(P = 0.031), serum T4 levels(r = 0.331, P = 0.036), obstructive sleep apnoea syndrome(OSAS; P = 0.023), impaired glucose tolerance(IGT; P = 0.017) and impaired glycaemic status, including hyperinsulinism, IGT and diabetes mellitus(P = 0.003).CONCLUSION: Future research should be prompted to optimize the procedure of indirect calorimetry to achieve clinical benefits in obese subjects.展开更多
Small mammals that are specialists in homeothermic thermoregulation reduce their self-maintenance costs of normothermy to survive the winter.By contrast,heterothermic ones that are considered generalists in thermoregu...Small mammals that are specialists in homeothermic thermoregulation reduce their self-maintenance costs of normothermy to survive the winter.By contrast,heterothermic ones that are considered generalists in thermoregulation can lower energy expenditure by entering torpor.It is well known that different species vary the use of their strategies to cope with harsh winters in tem-perate zones;however,ittle is still known about the intraspecific variation within populations and the associated external and internal factors.We hypothesized that yellow-necked mice Apodemus flavicollis decrease their resting metabolic rate(RMR)from autumn to winter,and then increase it during spring.However,since the alternative for seasonal reduction of RMR could be the develop-ment of heterothermy,we also considered the use of this strategy.We measured body mass(mp),RMR,and body temperature(Tb)of mice during 2 consecutive years.In the 1st year,mice decreased whole animal RMR in winter,but did not do so in the 2nd year.All mice entered torpor during the 2nd winter,whereas only a few did so during the first one.Mice showed a continuous in-crease of mb,which was steepest during the 2nd year.The relationship between RMR and mb var-ied among seasons and years most likely due to different mouse development stages.The mb gain at the individual level was correlated positively with RMR and heterothermy.This indicates that high metabolism in winter supports the growth of smaller animals,which use torpor as a compen-satory mechanism.Isotope composition of mice hair suggests that in the 1st year they fed mainly on seeds,while in the 2nd,they likely consumed significant amounts of less digestible herbs.The study suggests that the use of specialist or generalist thermoregulatory strategies can differ with environmental variation and associated differences in developmental processes.展开更多
Sympatric reptiles are the ideal system for investigating temperature-driven coexistence. Understanding thermally physiological responses of sympatric lizards is necessary to reveal the physiological mechanisms that u...Sympatric reptiles are the ideal system for investigating temperature-driven coexistence. Understanding thermally physiological responses of sympatric lizards is necessary to reveal the physiological mechanisms that underpin the sympatric occurrence of reptiles. In this study, we used three lizard species, Eremias argus, E. multiocellata, and Phrynocephalus przewalskii, which are sympatric in the Inner Mongolia desert steppe, as a study system. By comparing their resting metabolic rates(RMR) and locomotion at different body temperatures, we aimed to better understand their physiological responses to thermal environments, which may explain the sympatric occurrence of these lizards. Our results showed that E. argus had significantly higher RMR and sprint speed than E. multiocellata, and higher RMR than P. przewalskii. In addition, the optimal temperature that maximized metabolic rates and locomotion for E. argus and E. multiocellata was 36°C, whereas for P. przewalskii it was 39°C. Our study revealed the physiological responses to temperatures that justify the sympatric occurrence of these lizards with different thermal and microhabitat preferences and active body temperatures. Eremias argus and E. multiocellata, which have lower body temperatures than P. przewalskii, depend on higher RMR and locomotion to compensate for their lower body temperatures in field conditions. Our study also highlights the importance of using an integrative approach, combining behavior and physiology, to explore the basis of sympatric occurrence in ectothermic species.展开更多
目的:探讨不同体重指数(body mass index,BMI)青年男性静息能量消耗(resting energy expenditure,REE)的特点,比较常见静息代谢率(resting metabolic rate,RMR)预测方程与间接测热法的差异。方法:以2017年12月至2021年6月于北京大学第...目的:探讨不同体重指数(body mass index,BMI)青年男性静息能量消耗(resting energy expenditure,REE)的特点,比较常见静息代谢率(resting metabolic rate,RMR)预测方程与间接测热法的差异。方法:以2017年12月至2021年6月于北京大学第三医院运动医学科进行静息代谢测试的30名青年男性为研究对象,采用间接测热法测定RMR,采用生物电阻抗法测定体成分。分析研究对象REE的特点,并与11个常见预测方程的推算值进行比较,通过配对t检验和组内相关系数(intra-class correlation coefficient,ICC)评估两者差异。结果:30名青年男性的平均年龄为(26.93±4.16)岁,整体RMR为(1960.17±463.11)kcal/d(1 kcal=4.1868 kJ),其中BMI正常者的RMR为(1744.33±249.62)kcal/d,显著低于超重或肥胖者[(2104.06±520.32)kcal/d](P<0.01),但体质量校正后,BMI正常者的RMR显著高于超重或肥胖者[(24.02±2.61)kcal/(kg·d)vs.(19.98±4.38)kcal/(kg·d),P<0.01];不同BMI受试者的RMR与体质量、脂肪量、去脂体重、体表面积、细胞外液呈显著正相关(P均<0.05)。11个预测方程的预测值与实测值的一致性均不佳(ICC均<0.75),其中,超重或肥胖青年男性采用世界卫生组织(World Health Organization,WHO)推荐使用的RMR预测方程的预测值与实测值的一致性相对较高(ICC=0.547,P<0.01)。结论:不同BMI青年男性的RMR存在显著差异,超重或肥胖者要考虑体质量矫正后的RMR情况。不同预测方程的预测值与RMR的实测值一致性较差,建议通过间接测热法准确测定RMR。对于超重和肥胖的青年男性可以考虑采用WHO推荐使用的预测方程计算RMR,但有必要建立适用于不同BMI人群的RMR预测方程。展开更多
The resting metabolic rate ( RMR ) of birds correlates broadly with the climate of origin. In order to study the characteristics of thermoregulation in Little buntings and Chestnut buntings, are measured their resting...The resting metabolic rate ( RMR ) of birds correlates broadly with the climate of origin. In order to study the characteristics of thermoregulation in Little buntings and Chestnut buntings, are measured their resting metabolic rate ( RMR )at ambient temperature ( T a) ranged from 5℃ to 30℃ and calculated thermal conductance. The results are mainly as follows. 1. Thermal neutral zone ( TNZ ) for Little buntings ranged from 20℃ to 25℃ and for Chestnut buntings from 25℃ to 32 5℃. 2. The minimum metabolic rate of Little buntings and Chestnut buntings were 4 19 ml O 2/g·hr and 3 99 ml O 2/g·hr, respectively, which were 181% and 146% of the expected values that calculated from their body mass according to Aschoff and Pohl (1970). Above the upper critical temperature, RMR and T b increased. 3. The minimum thermal conductance ( C ) of Little buntings and Chestnut buntings were 0 26 ml O 2/g·hr·℃ and 0 23 ml O 2/g·hr·℃, respectively, which were 138% and 140% of the predicted values calcalated according to Aschoff (1981). In conclusion, the adaptation of Little buntings and Chestnut buntings to environmental climate were by the means of the slight higher level RMR and thermal conductance, and high intensity of chemical thermoregulation.展开更多
文摘AIM: To evaluate selected factors influencing resting energy expenditure(REE) in obese female subjects.METHODS: Seventy seven 61 obese Caucasian women [mean age of 52.93 ± 13.45 years, and mean body mass index(BMI) of 41.78 ± 11.54 kg/m2] were enrolled; measurements of resting metabolic rate(RMR) by a ventilated, open-circuit system, indirect calorimeter were performed after an overnight fast. Body composition as well as medications, physical parameters, blood samples, disease pattern, and smoking were considered. RESULTS: RMR was significantly associated with body weight(r = 0.732, P < 0.001), body height(r = 0.401,P = 0.008), BMI(r = 0.504, P < 0.001), waist circumference(r = 0.602, P < 0.001), mid-upper arm circumference(r = 0.417, P = 0.006), mid-upper arm muscle circumference(r = 0.344, P = 0.028), total body water(r = 0.339, P = 0.035), body temperature(r = 0.409, P = 0.007), smoking(P = 0.031), serum T4 levels(r = 0.331, P = 0.036), obstructive sleep apnoea syndrome(OSAS; P = 0.023), impaired glucose tolerance(IGT; P = 0.017) and impaired glycaemic status, including hyperinsulinism, IGT and diabetes mellitus(P = 0.003).CONCLUSION: Future research should be prompted to optimize the procedure of indirect calorimetry to achieve clinical benefits in obese subjects.
基金J.S.B.was supported by a grant from Polish National Science Center on the basis of decision number 2019/35/D/NZ8/03626.
文摘Small mammals that are specialists in homeothermic thermoregulation reduce their self-maintenance costs of normothermy to survive the winter.By contrast,heterothermic ones that are considered generalists in thermoregulation can lower energy expenditure by entering torpor.It is well known that different species vary the use of their strategies to cope with harsh winters in tem-perate zones;however,ittle is still known about the intraspecific variation within populations and the associated external and internal factors.We hypothesized that yellow-necked mice Apodemus flavicollis decrease their resting metabolic rate(RMR)from autumn to winter,and then increase it during spring.However,since the alternative for seasonal reduction of RMR could be the develop-ment of heterothermy,we also considered the use of this strategy.We measured body mass(mp),RMR,and body temperature(Tb)of mice during 2 consecutive years.In the 1st year,mice decreased whole animal RMR in winter,but did not do so in the 2nd year.All mice entered torpor during the 2nd winter,whereas only a few did so during the first one.Mice showed a continuous in-crease of mb,which was steepest during the 2nd year.The relationship between RMR and mb var-ied among seasons and years most likely due to different mouse development stages.The mb gain at the individual level was correlated positively with RMR and heterothermy.This indicates that high metabolism in winter supports the growth of smaller animals,which use torpor as a compen-satory mechanism.Isotope composition of mice hair suggests that in the 1st year they fed mainly on seeds,while in the 2nd,they likely consumed significant amounts of less digestible herbs.The study suggests that the use of specialist or generalist thermoregulatory strategies can differ with environmental variation and associated differences in developmental processes.
基金Animal Ethics Committees at the Institute of Zoology, Chinese Academy of Sciences approved the ethics and protocol (IOZ14001) for the collection, handling, and husbandry of the study animalsBI J. H. (No.31660615) and SUN B. J. (No. 31870391 and 31500324) are supported by grants from the National Natural Science Foundation of China
文摘Sympatric reptiles are the ideal system for investigating temperature-driven coexistence. Understanding thermally physiological responses of sympatric lizards is necessary to reveal the physiological mechanisms that underpin the sympatric occurrence of reptiles. In this study, we used three lizard species, Eremias argus, E. multiocellata, and Phrynocephalus przewalskii, which are sympatric in the Inner Mongolia desert steppe, as a study system. By comparing their resting metabolic rates(RMR) and locomotion at different body temperatures, we aimed to better understand their physiological responses to thermal environments, which may explain the sympatric occurrence of these lizards. Our results showed that E. argus had significantly higher RMR and sprint speed than E. multiocellata, and higher RMR than P. przewalskii. In addition, the optimal temperature that maximized metabolic rates and locomotion for E. argus and E. multiocellata was 36°C, whereas for P. przewalskii it was 39°C. Our study revealed the physiological responses to temperatures that justify the sympatric occurrence of these lizards with different thermal and microhabitat preferences and active body temperatures. Eremias argus and E. multiocellata, which have lower body temperatures than P. przewalskii, depend on higher RMR and locomotion to compensate for their lower body temperatures in field conditions. Our study also highlights the importance of using an integrative approach, combining behavior and physiology, to explore the basis of sympatric occurrence in ectothermic species.
文摘目的:探讨不同体重指数(body mass index,BMI)青年男性静息能量消耗(resting energy expenditure,REE)的特点,比较常见静息代谢率(resting metabolic rate,RMR)预测方程与间接测热法的差异。方法:以2017年12月至2021年6月于北京大学第三医院运动医学科进行静息代谢测试的30名青年男性为研究对象,采用间接测热法测定RMR,采用生物电阻抗法测定体成分。分析研究对象REE的特点,并与11个常见预测方程的推算值进行比较,通过配对t检验和组内相关系数(intra-class correlation coefficient,ICC)评估两者差异。结果:30名青年男性的平均年龄为(26.93±4.16)岁,整体RMR为(1960.17±463.11)kcal/d(1 kcal=4.1868 kJ),其中BMI正常者的RMR为(1744.33±249.62)kcal/d,显著低于超重或肥胖者[(2104.06±520.32)kcal/d](P<0.01),但体质量校正后,BMI正常者的RMR显著高于超重或肥胖者[(24.02±2.61)kcal/(kg·d)vs.(19.98±4.38)kcal/(kg·d),P<0.01];不同BMI受试者的RMR与体质量、脂肪量、去脂体重、体表面积、细胞外液呈显著正相关(P均<0.05)。11个预测方程的预测值与实测值的一致性均不佳(ICC均<0.75),其中,超重或肥胖青年男性采用世界卫生组织(World Health Organization,WHO)推荐使用的RMR预测方程的预测值与实测值的一致性相对较高(ICC=0.547,P<0.01)。结论:不同BMI青年男性的RMR存在显著差异,超重或肥胖者要考虑体质量矫正后的RMR情况。不同预测方程的预测值与RMR的实测值一致性较差,建议通过间接测热法准确测定RMR。对于超重和肥胖的青年男性可以考虑采用WHO推荐使用的预测方程计算RMR,但有必要建立适用于不同BMI人群的RMR预测方程。
文摘The resting metabolic rate ( RMR ) of birds correlates broadly with the climate of origin. In order to study the characteristics of thermoregulation in Little buntings and Chestnut buntings, are measured their resting metabolic rate ( RMR )at ambient temperature ( T a) ranged from 5℃ to 30℃ and calculated thermal conductance. The results are mainly as follows. 1. Thermal neutral zone ( TNZ ) for Little buntings ranged from 20℃ to 25℃ and for Chestnut buntings from 25℃ to 32 5℃. 2. The minimum metabolic rate of Little buntings and Chestnut buntings were 4 19 ml O 2/g·hr and 3 99 ml O 2/g·hr, respectively, which were 181% and 146% of the expected values that calculated from their body mass according to Aschoff and Pohl (1970). Above the upper critical temperature, RMR and T b increased. 3. The minimum thermal conductance ( C ) of Little buntings and Chestnut buntings were 0 26 ml O 2/g·hr·℃ and 0 23 ml O 2/g·hr·℃, respectively, which were 138% and 140% of the predicted values calcalated according to Aschoff (1981). In conclusion, the adaptation of Little buntings and Chestnut buntings to environmental climate were by the means of the slight higher level RMR and thermal conductance, and high intensity of chemical thermoregulation.
