Body Composition Changes Following a Very Low Calorie Pre-Operative Diet in Patients Undergoing Bariatric Surgery

Transcription

1 Body Composition Changes Following a Very Low Calorie Pre-Operative Diet in Patients Undergoing Bariatric Surgery 03 September 2018 Jonathan Sivakumar, Lynn Chong, Salena Ward, Tom R Sutherland, Michael W Hii Department of Hepatobiliary and Upper GastroIntestinal Surgery St Vincent s Hospital Melbourne

2 Background Very Low Calorie Diet Liquid meal replacement to restrict daily energy intake to approximately kcal. Physiological purpose Liver shrinkage Improve intra-operative visualisation The primary objective is to compare FM, LBM, BMD before and after VLCD. Page 2

3 Methodology Prospective cohort study Population: Adults undergoing a bariatric surgical procedure Inclusion criteria Willingness to give written informed consent Over the age of 20 No history of a psychological illness Weight above 159 kg Dual-energy X-ray absorptiometry (DXA) Allows regional body composition assessment Differentiates between fat mass, lean body mass, and bone mineral content Low dose of radiation Page 3

4 Methodology Day 0 Body composition assessment Patients underwent initial DXA scan Day 1-14 VLCD Two week Optifast diet Day 15 Body composition assessment Patients underwent second DXA scan Footnote to go here Day/Month/Year Page 4

5 Results Kilograms Lost Following VLCD In patients undergoing bariatric surgery had, lean mass loss accounted for 67.4% of tissue mass loss. n = Weight (kg) BMI (kg/m2) FM (kg) LBM (kg) BMC (kg) p<0.001 p<0.001 p<0.001 p<0.001 p=0.422 Footnote to go here Day/Month/Year Page 5

6 Results Weight after VLCD is strongly associated with in BMI, and lean mass (r=0.643, p=0.002), but not with fat mass. Weight loss in Optifast program is due to loss of lean mass rather than fat mass. Association between body composition s (Pearson s correlation) Age Weight 0.202, p=0.408 BMI 0.218, p=0.371 Fat mass 0.368, p=0.121 Lean mass 0.155, p=0.526 BMC , p=0.252 Weight 0.907, p< , p= , p= , p=0.492 BMI 0.052, p= , p= , p=0.665 Fat mass , p= , p=0.103 Lean mass , p=0.010 In patients undergoing bariatric surgery had, lean mass loss accounted for 67.4% of tissue mass loss. Page 6

7 Results Weight after VLCD is strongly associated with in BMI, and lean mass (r=0.643, p=0.002), but not with fat mass. Weight loss in Optifast program is due to loss of lean mass rather than fat mass. Association between body composition s (Pearson s correlation) Age Weight 0.202, p=0.408 BMI 0.218, p=0.371 Fat mass 0.368, p=0.121 Lean mass 0.155, p=0.526 BMC , p=0.252 Weight 0.907, p< , p= , p= , p=0.492 BMI 0.052, p= , p= , p=0.665 Fat mass , p= , p=0.103 Lean mass , p=0.010 In patients undergoing bariatric surgery had, lean mass loss accounted for 67.4% of tissue mass loss. Page 7

8 VLCD & Muscle Loss Nutritional inadequacy Optifast g/day of protein VLCD vs LCD VLCD: LCD: Present study - LBM accounted for 67.4% of tissue mass loss kcal/day Chaston et al. (2007) - LBM accounted for 19-36% of tissue mass loss kcal/day Requirements are higher for bariatric patients Weight Age Non-alcoholic fatty liver disease Page 8

9 VLCD & Muscle Loss Future direction of our study Rate of weight loss High initial body weight vs Low initial body weight Nielsen et al. (2016): HIBW Greater LBM loss Physical exercise not accounted for in this study Page 9

10 Conclusion VLCD is used to reduce fat mass and improve access during the operation Our study demonstrates that VLCD is associated with much greater muscle loss than fat loss The relationship between VLCD and muscle mass warrants further assessment Future direction will explore the role of higher protein diets or preoperative exercise programs Page 10