Predictors of fat-free mass loss 1 year after laparoscopic sleeve gastrectomy.

PURPOSE: Laparoscopic sleeve gastrectomy (LSG) is one of the most frequently performed bariatric surgery interventions because of its safety and efficacy. Nevertheless, concerns have been raised on its detrimental effect on patient nutritional state that can ultimately lead to the loss of fat-free mass (FFM). There is interest in identifying predictors for the early identification of patients at risk of this highly unwanted adverse because they could benefit of nutritional preventive interventions. Therefore, we investigated whether anthropometric parameters, body composition or resting energy expenditure (REE) measured before surgery could predict FFM loss 1 year after LSG. METHODS: Study design was retrospective observational. We retrieved data on body weight, BMI, body composition and REE before and 1 year after LSG from the medical files of 36 patients operated on by LSG at our institutions. Simple regression, the Oldham's method and multilevel analysis were used to identify predictors of FFM loss. RESULTS: Averaged percentage FFM loss 1 year after LSG was 17.0 ± 7.7% with significant differences between sexes (20.8 ± 6.6 in males and 12.2 ± 6.1% in females, p < 0.001). FFM loss was strongly predicted by pre-surgery FFM and this effect persisted also after correcting for the contribution of sex. CONCLUSIONS: High FFM values before surgery predict a more severe FFM loss after LSG. This factor could also account for the higher FFM loss in men than in women. Our finding could help in the early identification of patient requiring a nutritional support after LSG.

Short-Term Changes in Body Composition and Response to Micronutrient Supplementation After Laparoscopic Sleeve Gastrectomy.

BACKGROUND: We evaluated dietary intakes, body composition, micronutrient deficiency, and response to micronutrient supplementation in 47 patients before and for 6 months after laparoscopic sleeve gastrectomy (LSG). METHODS: Before, 3, and 6 months after LSG, we measured dietary intakes with food-frequency questionnaires, body composition with bioimpedance analysis (BIA) and bioelectrical vector analysis (BIVA), and plasma concentrations of iron, Zn, water-, and lipo-soluble vitamins. RESULTS: After LSG, energy intake significantly decreased and patients lost weight, fat mass, and free-fat mass. BIVA showed a substantial loss of soft tissue body cell mass (BCM) with no change in hydration. Before surgery, 15 % of patients were iron deficient, 30 % had low levels of zinc and/or water-soluble vitamins, and 32 % of vitamin 25(OH)-D3. We treated iron deficiency with ferrous sulfate, isolated folate deficiency with N5-methyiltetrahydrofolate-Ca-pentahydrate, and deficiencies in vitamin B1, B12, or Zn, with or without concomitant folate deficiency, with multivitamin. No supplementation was given to vitamin 25(OH)-D3 deficient patients. At first follow-up, 7 % of patients developed new deficiencies in iron, 7 % in folic acid (n = 3), and 36 % in water-soluble vitamins and/or zinc whereas no new deficit in vitamin 25(OH)-D3 occurred. At final follow-up, deficiencies were corrected in all patients treated with either iron or folate but only in 32 % of those receiving multivitamin. Vitamin 25(OH)-D3 deficiency was corrected in 73 % of patients even though these patients were not supplemented. CONCLUSION: LSG-induced weight loss is accompanied by a decrease in BCM with no body fluid alterations. Deficiencies in water-soluble vitamins and Zn respond poorly to multivitamin supplementation.