Body Mass Index (BMI) Bariatric Surgery 19/6/2013 BMI 體重指標. Obesity Co-morbidities 肥胖相關疾病. Mortality increases with BMI 死亡率與體重指數成正比

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1 Mortality Ratio 死亡比率 19/6/2013 Med 5 Refresher Course Body Mass Index (BMI) BMI 體重指標 = Body Weight 體重 (kg 公斤 ) Height 身高 x Height 身高 (metre² 米 ²) Hon. Consultant Surgeon, 名譽外科顧問醫生 Department of Surgery, Pamela Youde Nethersole Eastern Hospital 尤德夫人東區醫院 Consultant Surgeon, 外科顧問醫生 Department of Surgery, Prince of Wales Hospital 威爾斯親王醫院 Clinical Associate Prof. (Hon.) Department of Surgery, The Chinese University of Hong Kong Obesity Co-morbidities 肥胖相關疾病 Non-Alcoholic Liver Disease (NAFLD) Stroke 中風 Mortality increases with BMI 死亡率與體重指數成正比 American Cancer Society Study of 750,000 Men and Women Gall bladder disease 膽囊疾病 Hormonal abnormalities 荷爾蒙分泌不正常 Osteoarthritis 骨性關節炎 Venous insufficiency 靜脈血液供血不足 Hyperuricaemia & gout 高尿酸血症及痛風 Heart disease 心臟病 Diabetes 糖尿病 Cardiovascular risk factors 心血管風險要素 Cancer 癌症 Respiratory disease 呼吸系統疾病 Digestive and Pulmonary Disease Men Women Moderate Very Low Low Cardiovascular and Gallbladder Disease Diabetes Mellitus Moderate BMI 體重指數 Reprinted from Gray. Med Clin North Am. 1989;73(1):1-13, based on statistical information from Lew et al. J Chron Dis. 1979;32: High Very High BMI > % Female Male Overall 25.0% 26.7% 29.8% 25.7% 20.0% 15.0% 10.0% 16.9% 21.6% 22.0% 14.9% 13.0% 18.8% BMI >30 5.0% 0.0% 5.0% 4.6% 3.5% 4.1% 3.8% 3.5% 2.6% 3.4% 2.3%

2 BMI >25 WC, male >90cm, female >80cm Male Female Female Male Ko GT et al. Eur J Clin Nutri 2010 後果 Definition by International Diabetes Federation (IDF) Central Obesity (Asia) 中央肥胖 90cm men, 80cm women + Any Two HDL 好膽固醇 men < 1 mmol/l, female <1.3 mmol/l Triglyceride 三酸甘油脂 1.7 mmol/l High blood pressure 血壓提高 130/85 mmhg DM or 高血糖 FBG 5.6 mmol/l HT DM 心血管併發症 IHD, CAD, CVA PVD, Renal Failure etc Lipid 1st International Symposium on MES and Prediabetes, Berlin, May WHO criteria for obesity In Asia Pan WH et al. Asia Pac J Clin Nutr 2008;17(S1):

3 Body weight 19/6/ kg/m 2 : lifestyle modification (diet / exercise) Consider drug if risk factors (DM/HT/CHD/HL) >25-30 kg/m 2 : significant obesity More action needed on lifestyle Advise from doctor Drug Rx 30 kg/m 2 : severe obesity Multidisciplinary counseling May need specialist opinion Early intervention (VLCD / drug therapy) Invasive therapy should be consider Surgery to loss weight (Weight Reduction / ) Behavioral Surgery eating less eating slow eating healthy Diet and exercise Behavior modifications Weight Loss Orilstat Sibutramine Rimonabant = 2.9kg = 4.2kg = 4.7kg 2 nd weight reduction attempt 1 st weight reduction attempt Time Weight C Weight B Weight A Weight loss programs Drugs Xenical Reductil VLCD meal replacement 3

4 Homeostasis of body weight Basal metabolic rate Energy Consumption (appetite) Energy Expenditure (activity) Appetite & Metabolism Central Control Swedish Obesity Subjects (SOS) Interventional Study +1.6% Medical -16.1% Leptin Surgery 10 years FU Adipose cells GI tract Sjostrom LL et al. N Eng J Med 2004 NIH Consensus Conference (USA) 1 st Line treatment Non-surgical Therapy Who need surgery? For patients with Morbid Obesity No drug therapy useful for prolong weight loss Max wt. Loss with non-surgical Rx 10kg No role in long term behavioral modification Surgery offer only proven long term weight control NIH Consensus Conference (1991) 4

5 Indications Indication (Caucasian) BMI > 40 or BMI > 35 + severe co-morbidities NIH Consensus Conference (1991) Indication (Asian-Pacific) BMI > 35 or BMI > 30 + DM & central obesity or + 2 severe co-morbidities Age # Contra-indications Contraindication Endocrine disease causing obesity Psychiatric disorder (schizo/borderline P.D/major depression) Active substances abuse Non-compliance with previous medical care Asia Consensus Meeting of Metabolic Surgery 2008 India NIH Consensus Conference (1991) Selection Mechanism of Restriction Bypass/ Diversion Combined Gastric Volume Reduction Meal size Calories restriction Reduce Absorption Alter small bowel transit time Macro/Micro Nutrients Absorption Restriction & limited mal-absorption Mechanism of Restrictive surgery No mal-absorption problem No restriction to liquid / semi-solid Mal-absorption surgery Effective weight loss Life-long nutrition supplement (Ca, Fe, Vit B12 etc ) Dumping Surgical Treatment Historical Ileojejunal bypass Jaw wiring Horizontal Gastroplasty Manson s Vertical banded gastroplasty (VBG) Silicone Ring Vertical gastroplasty Mason s gastric bypass Roux-en-Y gastric bypass (RYGB) Biliopancreatic diversion (BPD) BPD with Duodenal Switch (BPD-DS) Adjustable gastric banding (AGB) Sleeve Gastrectomy (SG) 5

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7 Gastric Banding Sleeve Gasterctomy Lap Gastric Bypass BPD Major Cx Malnutrition Weight loss 40~50% EBW 50~70% EBW 60-70% EBW 65~80% EBW Excessive Body Weight = current BW ideal BW (at BMI 25) Mechanism of Vagal afferent after Restriction Gastric Volume Reduction Meal size Calories restriction Bypass/ Diversion Reduce Absorption Alter small bowel transit time Macro/Micro Nutrients availability Neuro-Endocrine Effect Vagal Stimulation Gut hormone manipulation Satiety 80% of Vagal Nerve fibre are Afferent Schwartz MW. Central nervous system control of food intake. Nature 2000; 404: Gut Hormone after Results? Increased PYY Reduced Ghrelin Increased GLP-1 CCK Korner J, Leibe RL. To eat or not to eat How the gut talks to the brain. N Eng J Med 2003; 7

8 Mean %EWL, % 19/6/2013 Swedish Obesity Subjects (SOS) Study Long Term 15 years follow up Fu time, month Sjostrom LL et al. N Eng J Med 2007 Improve survival Swedish Obesity Subjects (SOS) Interventional Study 10 years FU Preop DM / HT / Gout SOS Sweden study H.R (p=0.04) 40% reduction risk of death (H.R 0.60 p<0.001) CAD DM Cancer 56% 92% 60% Resolution of NIDDM / HT / Gout (Surgery can treat DM / MetS) Sjostrom LL et al. N Eng J Med 2007 Adams TD et al. N Eng J Med 2007 Sjostrom LL et al. N Eng J Med 2004 Restrictive Gastric bypass BPD Excessive Weight loss % 61.8% 70.1% DM resolve % 83.7% 98.9% HT resolve % 75.4% 81.3% OSA resolve % 86.6% 95.2% Buchwald H et al. Systemic Analysis. JAMA RCT/ 28 NRCT/ 101 case series (n=22094) RCT on T2DM patients BMI>35, DM>5y, HbA1c>7.0% (Rome) Medical Rx(20) Vs Surgery gastric bypass 20 / BPD-DS 20 Primary Outcome: DM remission at 2y No medicine FBG <5.6mmol/l + HbA1c<6.5% RCT on T2DM patients BMI>27, HbA1c>7.0% (Boston) Medical Rx(50) Vs Surgery gastric bypass 50 / LSG 50 Primary Outcome: HbA1c <6% at 1y With or without Dm medication Mingrone G et al.. NEJM 2012 Schauer PR et al.. NEJM

9 DM Remission Rate HbA1c <6% 95% 42% p< % p= % 0% Medical Rx Gastric Bypass BPD 12% Medical Rx Gastric Bypass Sleeve Bring down BMI Reduce body weight May associate with improve DM Metabolic Surgery Bring down HbA1c Reduce medication use May associate with weight loss Mingrone G et al.. NEJM 2012 Schauer PR et al.. NEJM 2012 Which patients with type 2 diabetes should be considered for bariatric surgery? Mechanism of Metabolic Surgery IDF Position statement 2011 Surgery should be included In the algorithm of DM Management Caucasian Asian BMI > 35 >32.5 Prioritized: Eligible: BMI > 30 >27.5 HbA1c > 7.5 despite fully optimised conventional therapy *Referral to bariatric expertise with multi-disciplinary team Caucasian Asian Prioritized: BMI > 40 >37.5 Eligible: BMI > 35 >32.5 Mechanical Effect Restriction Weight loss Reduce Insulin resistance Hormonal Effect Improve beta cell function Improve Incretin / Insulin effect The Hindgut Theory Risk of Surgery? 手術的風險? The rapid & early delivery of undigested nutrients to the distal bowel upregulates the production of L-cell derivatives like GLP-1, PYY Mason E. Obes Surg ,

10 Risks Anesthesia Co-morbidities ( HT / DM / cardiac / respiratory) Difficult intubations, Delay extubation Postoperative complication DVT / PE Atelectasis / chest infection Wound infection / dehiscence Anastomotic leakage (1-2%) Impaired normal pathology Co-existing disease Difficult Airway Difficult IV access Monitoring Position of patient Maintenance of anaesthesia Waking/Extubation Analgesia Avoiding DVT, PE, Atelectasis, FFA Mobilisation Avoiding infection postop Dominguez-Cherit et al World J Surg Open vs Laparoscopic Annals of Internal Medicine 2005 Education Health & Reality Obesity Risk Yo-Yo phenomena Treatment target Expectation Surgical options & risk analysis Restrictive Vs Malabsorptive Reversible Vs Irreversibility Permanent Vs Temporary Degree & rate of wt loss Operative risk & side effect 10

11 Co-morbidity Screen Look for Undiagnosed co-morbidities DM / HT (baseline BP / FBG / HBA1c) OSA (snoring / headache / sleepiness) PCOS (menstrual disturbance) Arthropathy (joint pain) GERD / ulcer (symptomatic dyspepsia / OGD) Eating disorder (binge eating habit / bulimia nervosa) Depression (unstable mood / insomnia / unexplained cry) Avoid Unfavorable Patient Look for contra-indication Endocrine Cause of Obesity Indication of poor compliance Major Psychiatric Disease (Schizophrenia / personality disorder) Substance abuse (alcoholic / drugs) Medical history of frequent default treatment 11

12 Surgery for Obesity DM patient Surgery for Obesity DM patient 12