Assessment Of Energy Expenditure And Body Composition In Cancer Patients

BACKGROUND:Generally,cancer patients display elevated energy expenditure and abnormal substrate metabolism,which result in the alternation in body composition. There are few studies on the relationship between energy expenditure,substrate metabolism and body composition,which still remains vacant in China.This study aims to study their relationship and contribute to the clinical monitoring and intervention.OBJECTIVE:1.To evaluate resting energy expenditure in cancer patients by indirect calorimetry.2.To find out the relationship between energy expenditure and substrate metabolism.3.To assess body composition in cancer patients by bioelectrical impedance method.METHODS:Cross-sectional study.REE,carbohydrate oxidation and fat oxidation of cancer patients and non-cancer subjects were measured by indirect calorimetry with a ventilated canopy.Multi-frequency bioelectrical impedance appliance was applied to assess intracellular fluid,extracellular fluid and total body water.Fat mass,fat free mass of the patients were calculated respectively for the evaluation of body composition.The influences of cancer type,disease duration,pathological stages and liver metastasis on energy expenditure,body composition were further analyzed.RESULTS:A total of 714 cancer patients and 642 control subjects were recruited, including 150 esophageal cancer patients,154 gastric cancer patients,148 colon cancer patients,128 pancreatic cancer patients,134 non-small cell lung cancer patients.Cancer patients showed no difference in mREE with controls(1471.14±157.57 kcal/d vs 1448.04±187.62 kcal/d,P=0.161),but they had higher mREE/FFM and mREE/pREE than controls(31.56±4.43 kcal/d/kg vs 30.31±4.07 kcal/d/kg,P=0.000;108.29±14.07%vs 102.51±12.57%,P=0.000).46.7%of cancer patients were hypermetabolic(mREE more than 110%pREE of Harris-Benedict), 43.5%normal metabolic,9.8%hypometabolic(mREE less than 90%pREE of Harris-Benedict),while 25.2%of control patients were hypermetabolic,56.5% normal metabolic,18.3%hypometabolic.Fat oxidation of cancer patients was higher than controls,while carbohydrate oxidation and npRQ is lower(77.53±11.10 g/min vs 66.99±12.50 g/min,P=0.000;69.00±10.73 g/min vs 89.00±10.12 g/min,P=0.000; 0.786±0.013 vs 0.812±0.014,P=0.000).Cancer patients showed higher ECF,lower ICF,but total water between the two groups showed no difference(16.33±2.33L vs 15.29±2.47L,P=0.000;19.30±3.46L vs 20.66±3.18L,P=0.000;35.63±5.49L vs 35.95±5.55L,P=0.291),cancer patients had higher TW/BW and ECF/BW,lower ICF/BW(57.10±6.93%vs 54.71±6.05%,P=0.000;26.26±3.49%vs 23.26±2.80%, P=0.000;30.84±4.16%vs 31.45±3.50%,P=0.002).Cancer patients exhibited lower body fat,body fat proportion and fat free mass,higher fat free mass proportion compared with controls(15.54±7.52 kg vs 17.92±7.12 kg,P=0.000;24.04±9.28%vs 26.44±8.10%,P=0.000;47.42±7.46 kg vs 48.33±7.44 kg,P=0.024;75.96±9.28%vs 73.56±8.10%,P=0.000),and body cell mass of the cancer patients was lower (26.44±4.73 kg vs 28.30±4.35 kg,P=0.000).Further analysis found differences in terms of energy expenditure and substrate metabolism between patients with difference tumor types,different stages or different disease durations,but no difference between patients with and without liver metastasis.CONCLUSION:1.Elevated energy expenditure is common in cancer patients.2. Substrate metabolism of the cancer patients features in increased fat oxidation, decreased glucose utilization,and decreased npRQ,which is correlative with the elevated energy consumption.3.Tumor type,stages and disease duration are probably the influential factors of energy expenditure,substrate metabolism.4.Fat mass and fat free mass lose in proportion in cancer patients,the former part changes more significantly.Body cell mass diminishes in cancer patients.Increased TW/BW and ECF/BW,decreased ICF/BW are found in cancer patients.