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. 2017 Jan;13(1):65-69.
doi: 10.1016/j.soard.2016.03.003. Epub 2016 Apr 6.

Fat-free mass is not lower 24 months postbariatric surgery than nonoperated matched controls

Gladys Witt Strain  1 , Faith Ebel  2 , Jamie Honohan  2 , Michel Gagner  3 , Gregory F Dakin  2 , Alfons Pomp  2 , Dympna Gallagher  4
Affiliations

Fat-free mass is not lower 24 months postbariatric surgery than nonoperated matched controls

Gladys Witt Strain et al. Surg Obes Relat Dis. 2017 Jan.

Abstract

Objective: Concerns about an excessive loss of fat-free mass (FFM) after bariatric surgery prompted this comparison of operated versus matched nonoperated controls regarding FFM.

Setting: University Hospital and University Research Unit in an urban medical center.

Methods: Body composition with bioelectric impedance (Tanita 310, Tanita Corp, Arlington Heights, IL) was measured approximately 2 years after bariatric surgery in weight stable patients and nonoperated weight stable controls matched for body mass index (BMI), gender, and age. t tests provided comparisons. Analysis of variance was used to compare FFM changes for 4 procedures. Levene's test evaluated variance.

Results: Patients (n = 252; 24.7±15 mo after surgery) and nonoperated controls (n = 252) were matched for gender (71.8% female), age (44.5±11.0 yr), and BMI (32.8±7.0 kg/m2). Patients had different surgical procedures: 107 gastric bypasses (RYGBs), 62 biliopancreatic diversions with duodenal switch (BPD/DSs), 40 adjustable gastric bands (AGBs), and 43 sleeve gastrectomies (LSGs). FFM percentage was significantly higher in the operated patients than controls, 66% versus 62%, P<.0001. For 3 procedures, the FFM was significantly higher; however, AGBs changed only 7.3 BMI units and FFM was not significantly different from their matched controls, 59.8% versus 58.2%. Across surgical groups, FFM percentage differed, P<.0001 (RYGB 66.5±9.2%, BPD/DS 74.0±9.3%, AGB 59.8±7.0%, LSG 59.6±9.3%). Variance was not different (P = .17).

Conclusion: Weight-reduced bariatric surgery patients have greater FFM compared with nonoperated matched controls. These findings support surgically assisted weight loss as a physiologic process and in general patients do not suffer from excessive FFM depletion after bariatric procedures.

Keywords: Bariatric surgery; Body composition after bariatric surgery; Composition of weight loss; Fat-free mass; Obesity.

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Conflict of interest statement

Disclosures

The authors have no commercial associations that might be a conflict of interest in relation to this article.

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