Visceral fat and body composition changes in a female population after RYGBP: a two-year follow-up by DXA.

Background: Our aim was to monitor the impact of Roux-en-Y gastric bypass (RYGBP) on body composition over a 24-month period by dual-energy X-ray absorptiometry (DXA).

Methods: Forty-one women (40.6 ± 10.0 years old; 42.6 ± 6.6 kg/m(2)) entering a bariatric surgery programme were submitted to whole-body DXA (Lunar iDXA) before treatment and after 3, 6, 12 and 24 months. Fat mass (FM), non-bone lean mass (LM), bone mineral content (BMC) and density (BMD) were measured at whole body and regionally. Android visceral adipose tissue (VAT) was estimated by a recently validated software.

Results: Twenty-nine patients (44.3 ± 11.8 years old; BMI, 45.4 ± 8.9 kg/m(2)) concluded the study. Following surgery, the progressive decrease of BMI was associated with reduced whole-body and regional FM. LM showed a moderate decrease at 3 months and stabilized thereafter. A progressive decrease of total FM/LM and android FM/LM ratios were observed in the 3- to 6-month (-19.1 ± 8.4 % and -26.5 ± 10.9 %, respectively; p < 0.0001) and 6- to 12-month periods (-23.5 ± 16.8 % and -29.4 ± 23.9 %, respectively; p < 0.0001). VAT was the parameter showing the largest decrease (-65.6 ± 17.5 % at 12 months; p < 0.0001). Two years after the surgery, a slight but significant decrease of total and regional LM was observed, without any significant change in BMI.

Conclusions: Body composition significantly changes after RYGBP with a metabolically healthier redistribution of total and regional FM and a positive balance of FM/LM variation. DXA should be considered as a valid supplementary tool for the clinical assessment and follow-up in patients undergoing bariatric surgery.