不同代謝性手術對肥胖患者之身體組成與脂肪分布的影響

Influences of Different Metabolic Surgeries on Body Composition and Fat Distribution in Obese Individuals

背景：代謝性手術主要為限制型及吸收不良型兩類，雖都可減輕體重，但兩種類型手術對於身體組成變化的影響卻尚未明確探討。
方法：蒐集自2008年至2013年於成大醫院接受代謝性手術個案共47人，其中限制型手術21人(男/女=9/12，平均年齡34.1±10.1歲，平均身體質量指數42.3±6.6 kg/m2)，吸收不良型手術26人(男/女=14/12，平均年齡36.8±10.5歲，平均BMI 41.7±7.0 kg/m2)為研究對象。所有個案於術前及術後6個月均以生物電阻抗分析法(BC-418, Tanita Corp., Tokyo, Japan)測量脂肪及去脂肪質量。同時量取腰圍及臀圍，並計算腰臀圍比值表示脂肪分布狀態。
結果：全體個案手術後6個月平均BMI平均下降22.6±7.5%，平均脂肪質量下降43.0±15.1%，平均體脂率下降27.1±14.2%，平均腰臀圍比值下降4.6±5.3%，均達顯著差異。於6個月時吸收不良型之脂肪質量與體脂率之下降幅度大於限制型手術（p值分別為0.020及0.018)，其餘身體組成與體脂分布的變化程度均未達統計顯著差異。於6個月時不同性別之身體組成與體脂分布的變化程度皆未達統計上顯著差異。
結論：接受兩種不同代謝性手術術後6個月時其減重幅度相近且均超過術前體重之20%以上。吸收不良型手術對肥胖患者之脂肪質量與體脂率下降幅度大於限制型手術，其餘身體組成及脂肪分布的下降幅度於兩種手術類型之間並無顯著差異。

Background: Two major types of metabolic surgeries – restrictive and malabsorptive – are both effective in treating obesity. However, whether the type of metabolic surgery exerts different influences on body composition and fat distribution remains an understudied issue. Method: During 2008 to 2013, a total of 47 subjects undergoing metabolic surgeries were enrolled, including 21 restrictive type (male/female = 9/12, mean age = 34.1±10.1 years-old, body mass index (BMI) = 42.3±6.6 kg/m2) and 26 malabsorptive type (male/female = 14/12, mean age =36.8±10.5 years-old, BMI = 41.7±7.0 kg/m2). Body composition assessment was performed before and six months after the surgery using a bioelectric impedance analyzer (BC-418, Tanita Corp., Tokyo, Japan) measuring fat mass (FM) and fat free mass (FFM). The waist circumference (WC) and hip circumference (HC) of each subject were also measured to obtain a waist-to-hip ratio (WHR) as the basis for estimating body fat distribution.
Results: Six months after the surgery, statistically significant changes were observed in mean BMI (down by 22.6±7.5%), mean FM (down by 43.0±15.1%), mean percent body fat (PBF, down by 27.1±14.2%) and mean WHR (down by 4.6±5.3%). Compared to its restrictive type counterpart, malabsorptive metabolic surgery achieved significantly greater reduction in both FM (p=0.020) and PBF (p=0.018). Otherwise, there was no significant difference in other body composition indicators and fat distribution between the two types of metabolic surgeries or between subjects of different genders at six months after the surgery.
Conclusion: Both types of metabolic surgeries produced similar results in weight loss as indicated by the over 20% reduction in weight at six months after the surgery. Except for the greater mean FM and PBF reduction in the malabsorptive type, there was no significant difference in the changes of body composition and fat distribution between two types of metabolic surgeries in obese people.