Diabetes, Metabolic Syndrome and Obesity (Oct 2018)

Influence of gastric bypass surgery on resting energy expenditure, body composition, physical activity, and thyroid hormones in morbidly obese patients

  • Mirahmadian M,
  • Hasani M,
  • Taheri E,
  • Qorbani M,
  • Hosseini S

Journal volume & issue
Vol. Volume 11
pp. 667 – 672

Abstract

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Mehri Mirahmadian,1 Motahareh Hasani,2 Ehsaneh Taheri,3 Mostafa Qorbani,4 Saeed Hosseini5 1Department of Nutrition and Biochemistry, School of Nutrition Sciences and Dietetics, Tehran University of Medical Sciences, 2School of Public Health, Iran University of Medical Sciences, 3Endocrinology and Metabolism Molecular and Cellular Sciences Institute, Tehran University of Medical Sciences, 4Noncommunicable Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, 5School of Nutrition, Tehran University of Medical Sciences, Tehran, Iran Introduction: One way to lose weight is bariatric surgery. Various studies have shown that after Roux-en-Y gastric bypass (RYGB), resting energy expenditure (REE) decreased may be a result of changes in fat-free mass (FFM) and thyroid-stimulating hormone levels. The aim of our study was to assess changes in body composition, REE, and thyroid hormones in patients undergoing RYGB.Methods: A total of 42 patients participated (21 undergoing RYGB and 21 age- and weight-matched subjects as controls) in our study. Weight, body-mass index, body composition, resting metabolic rate, physical activity, and thyroid hormones were measured at baseline in cases and 3 months after surgery in case and control groups.Results: At 3 months after surgery, patients lost an average of 21.7±1.4 kg weight, and fat mass, FFM, and REE decreased significantly. REE was higher in cases compared to controls. T4, T3, and thyroid-stimulating hormone at 3 months after RYGB decreased, but the decrease was significant only in T4 compared to controls. FFM was higher and fat mass lower in cases compared to controls.Conclusion: We detected a meaningful difference in REE before and after surgery, but we did not detect any meaningful difference in REE between controls and cases. Keywords: gastric bypass surgery, resting energy expenditure, body composition

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