| ObjectiveBariatric surgery in obese patients results in a dramatic weight loss and a decrease in body fat and lean tissue（skeletal muscle mass）content in different body mass components and may affect the skeletal health of the patient.We measured the whole body and different parts of obese patients before and early after laparoscopic sleeve gastrectomy（LSG）by quantitative computed tomography（QCT）and dual-energy X-ray absorptiometry（DXA）.The parameters of body composition and bone mineral density of the whole body and different parts of the body before and early after laparoscopic gastrectomy（LSG）were measured,and the characteristics of the changes of these indexes and the differences of the changes of body composition in different parts of the body were compared to explore the dynamic time-series changes of body composition and bone mineral density in obese patients undergoing LSG in the short term and to provide an objective basis for early intervention.Materials and MethodsThe clinical data of 50 patients who underwent LSG and underwent QCT and DXA follow-up examinations before and 3 and 6 months after surgery in Shanghai10th People’s Hospital from June 2015 to December 2018 were retrospectively analyzed.Collect anthropometric parameters（height,weight）of patients,record the physical composition and lumbar bone mineral density parameters measured by QCT and DXA examinations,and calculate the skeletal muscle mass index（SMI）measured by QCT,and the limb skeletal muscle mass index（ASMI）derived from DXA scanning parameters.The parameters measured by QCT include total adipose tissue（TAT）,visceral adipose tissue（VAT）,skeletal muscle mass（SMA）,subcutaneous adipose tissue（SAT）,and volumetric bone mineral density（v BMD）of lumbar cancellous bone at the lumbar vertebral level.DXA measurements body composition parameters including fat mass（FM）,lean soft tissue（LST）,and area bone mineral density（a BMD）of the whole body,trunk,and limbs.To explore the changes in physical composition of patients undergoing bariatric surgery in the early stages of their entire body and different regions,longitudinally compare the changes in various indicators at different time points,and analyze the correlation between the quantitative results of the two imaging examinations.Results1.Compared with the baseline data before operation,in addition to the reduction of BMI,the quantitative fat content and lean tissue content of the whole body and various parts of the patients with weight loss were significantly decreased by two imaging examinations at 3 and 6 months after operation（P<0.05）.Comparison between preoperative baseline and 3 months after surgery,the BMI of patients decreased by19.78%±5%,and the TATQCT,SATQCT,VATQCT,LSTQCTand SMAQCTmeasured by QCT decreased 31.07%±10.41%,28.03%±10.37%,35.13%±16.31%,22.69%±11.28%,18.1%±10.68%respectively;The FMDXAand LSTDXAof the whole body,trunk and limbs measured by DXA were decreased 24.85%±8.09%,16.31%±4.78%,27.07%±9.05%,18.02%±6.96%,20.99%±10.69%,15.46%±6.12%,with significant difference（P<0.05）.Comparison between preoperative baseline and 3months after surgery,the skeletal muscle mass index SMIQCTand ASMIDXAdecreased17.65%±10.2%,15.46%±6.12%,with significant difference（P<0.05）.Comparison between preoperative baseline and 6 months after surgery,the BMI of patients decreased 25.88%±7.7%,and the TATQCT,SATQCT,VATQCT,LSTQCTand SMAQCTmeasured by QCT decreased 44.4%±12.39%,42%±13.78%,47.67%±14.06%,20.49%±6.68%,16.98%±10.46%,respectively;The FMDXAand LSTDXAof the whole body,trunk and limbs measured by DXA were decreased（32.22%±12.03%,17.6%±6.29%,35.72%±12.32%,18.87%±5.99%,31.72%11.88%,17.84%±11.85%）.Respectively,6 months after surgery,the skeletal muscle mass index SMIQCTand ASMIDXAdecreased 17.8%±9.31%,17.84%±11.85%,,with significant difference（P<0.05）.Fat reduction is the most significant in different parts of the body.The amount of fat tissue reduction in different parts is:visceral adipose tissue>trunk>limbs.2.The BMD of the patients with weight loss decreased significantly at 6 months after operation,although the decrease at 3 months after operation was not statistically significant.The v BMD and a BMD decreased at 6 months after operation（5.81%±5.75%,3.78%±7.93%,P<0.05）.3.The parameters related to fat,muscle and BMD measured by QCT and DXA at three different time points（preoperative baseline,3 months and 6 months after operation）showed moderate to high linear correlation at three different time points（preoperative,3 months and 6 months after operation）.The correlation coefficients r between TATQCTand total body FMDXAwere 0.766,0.843,and 0.79 before and 3 and 6months after surgery,respectively（P<0.001）;The correlation coefficients r between VATQCTand VATDXAwere 0.725,0.862,and 0.682,and 0.79 before and 3 and 6months after surgery,respectively（P<0.001）.The correlation coefficients r between LSTQCTand total body LSTDXAwere 0.766,0.8,and 0.858 before and 3 and 6 months after surgery,respectively（P<0.001）,The correlation coefficients r between SMAQCTand total body LSTDXAwere 0.874,0.882,and 0.942 before and 3 and 6 months after surgery,respectively（P<0.001）,The correlation coefficients r between SMIQCTand total body LSTDXAwere 0.677,0.69,and 0.847 before and 3 and 6 months after surgery,respectively（P<0.001）.The correlation coefficients r between v BMD and a BMD were 0.523,0.701,and 0.509 before and 3 and 6 months after surgery,respectively（P<0.01）。Conclusion1.The early decline of BMI after bariatric surgery is the loss of fat,accompanied by drastic reduction of lean soft mass（skeletal muscle）content.2.BMD started to decrease 6 months after surgery,later than changes in body composition component.3.Despite that both imaging tests can reflect changes of BMD and body composition component,QCT can not only accurately reflect distribution of body composition component,but also better detect changes of general metabolic function after bariatric surgery in an early phase,which can thus be used as the preferred tool for follow-up after bariatric surgery.Figure 5 Table 3 Reference 86... |
PDF Full Text Request