Should I refer my obese patient for bariatric surgery? Dr. Khalid Azzam Assistant Professor of Medicine HHS Bariatric Medical Clinic 4 th McMaster University.

Should I refer my obese patient for bariatric surgery?

Dr. Khalid AzzamAssistant Professor of Medicine

HHS Bariatric Medical Clinic

4th McMaster University Review Course in

INTERNAL MEDICINE

Dr. Khalid Azzam has NO potential for conflict of interest with this presentation

4th McMaster University Review Course in

INTERNAL MEDICINE

Component of Statistics Canada Catalogue no. 82-625-XHealth Fact Sheets. www.statcan.gc.ca/chms.

One in Four Adult-Canadians is Obese

Obesity Etiology

• Majority of obese subjects are affected by common obesity of multifactorial origin

What Causes Common Obesity?

accumulation of body fat over time

as a result of energy imbalance

Due to a state where calorie intake is more than calorie expenditure.

Obesity Etiology is Complex

• Obesity is directly Caused by increased food intake and decreased physical activity in genetically predisposed individuals, this process is complex and does not operate in a vacuum.

• A wide range of factors influence obesity; – Lifestyle– Social– Psychological– Financial– Cultural an– Environmental

Complications, comorbidities and barriers to obesity management

Sharma AM. Obesity Reviews (2010) 11, 808–809

Obesity Management

ClinicallySignificant

Weight Loss vs

CosmeticallyAcceptable

Clinically Significant Weight Loss

• Modest weight loss; 5 – 10 % of initial body weight;– A realistic goal to achieve– Improves well-being– Improve many of the medical complications– Prevent the development of new obesity-related

illnesses

Impact of Weight Loss on Risk Factors~5%

Weight Loss5%-10%

Weight Loss

HbA1c

Blood Pressure

Total Cholesterol

HDL Cholesterol

Triglycerides

1. Wing RR et al. Arch Intern Med. 1987;147:1749-1753.2. Mertens IL, Van Gaal LF. Obes Res. 2000;8:270-278.3. Blackburn G. Obes Res. 1995;3 (Suppl 2):211S-216S.4. Ditschunheit HH et al. Eur J Clin Nutr. 2002;56:264-270.

1

2

3

3

1

2

3

3

4

Modified from slide librarywww.obesityonline.com

Armamentarium for Obesity Treatment

• Bariatric Surgery

• Anti-obesity Drugs

• Behavioral Modification– Diet & physical activity

Comprehensive Approach to Obesity Management

• Should not focus on food and calorie only

Behavior Modification for Prevention and Treatment

of ObesityLifestyle Changes,

Diet & Physical Activity

Cardinal Behaviors of Successful Long-term Weight Management

• Self-monitoring:– Daily food records– Limit certain foods or food quantity– Weight: check body weight >1 x/wk

• Low-calorie, low-fat diet:– Total energy intake: 1300-1400 kcal/d– Energy intake from fat: 20%-25%

• Eat breakfast daily

• Regular physical activity: 2500-3000 kcal/wk (eg, walk 4 miles/d)Klem et al. Am J Clin Nutr 1997;66:239.

McGuire et al.Int J Obes Relat Metab Disord 1998;22:572.

Diet Principles

• Diet selection depends on the subjects' preferences and comorbidities;

• Diets with defined number of calories may be beneficial– Portion-controlled foods– Shakes– food bars

Samaha et al, N Engl J Med 348:2074-2081, 2003Jeffery et al. J Consult Clin Psychol 1993;61:1038

What is the Evidence for Lifestyle Interventions?

Look AHEAD (Action for Health in Diabetes)

• Multicenter randomized clinical trial

Intensive lifestyle intervention (ILI) vs

Diabetes support and education (DSE; the control group)

• Outcome: Incidence of major CVD events

• 5145 overweight or obese individuals with T2DM(59.5% female; mean age, 58.7 years)

• > 93% of participants provided outcomes data at each annual assessment.

Arch Intern Med. 2010;170(17):1566-1575

At each session, participants were weighed, self-monitoring records were reviewed, and a new lesson was presented.

Arch Intern Med. 2010;170(17):1566-1575

Intensive Lifestyle Intervention (ILI) Diabetes Support and Education (DSE)

Diet:• Calorie goal (1200-1800 kcal/d)• < 30% of calories fat (10% saturated fat)• Minimum of 15% of calories from

protein• Portion-controlled diet (liquid meal

replacements) was used to increase dietary adherence

Exercise: • At least 175 min of physical activity / wk• Activities intensity similar to brisk

walking.Behavioral strategies:• Self-monitoring, Goal setting and

Problem solving

• Invited to 3 group sessions each year.

• Sessions used a standardized protocol and focused on:

– Diet– physical activity– social support

• Information on behavioral strategies was not presented

• Participants were not weighed at these sessions.

Arch Intern Med. 2010;170(17):1566-1575

Look AHEAD

Arch Intern Med. 2010;170(17):1566-1575

Average effect is the difference between ILI and DSE averaged across the 4 years

Arch Intern Med. 2010;170(17):1566-1575

Weight Management Programs

Total Meal Replacement Programs

• 26 weekly sessions– 12 Weeks of low calorie meal replacement

• 4 high protein shakes (Optifast®) per day total 900 kcals– Followed by

• Progressive re-introduction of food

• Ongoing Behavioral Modification and Psychosocial Assessment and Support

The Louisiana Obese Subjects Study (LOSS)

• intensive medical intervention (IMI) (n=200) – 900-kcal liquid diet for 12 weeks or less– Group behavioral counseling– Structured diet– Choice of pharmacotherapy months 3 to 7 – Maintenance strategies for months 8 to 24

OR • Usual care condition (UCC) (n=190).

– Internet weight management program.

Rayan D, et. al, Arch Intern Med. 2010;170(2):146-154

Rayan D, et. al, Arch Intern Med. 2010;170(2):146-154

The Louisiana Obese Subjects Study (LOSS)

Rayan D, et. al, Arch Intern Med. 2010;170(2):146-154

Percentage of the participants in the LOSS who met weight loss or gain categories at year 2

Medications

Orlistat

• Pancreatic lipase inhibitor

• Works non-systemically to block the absorption of dietary fat

• minimally (<1%) absorbed from the gastrointestinal tract

-12

-9

-6

-3

0

Effect of Long-term Orlistat Therapy on Body Weight and Diabetes

0Weeks

52

(XENDOS) Torgenson et al. Diabetes Care 2004;27:155

Cha

nge

in W

eigh

t (kg

)

104 156 208

P<0.001 vs placebo

-4.1 kg

-6.9 kg

Placebo

Orlistat

Modified from slide librarywww.obesityonline.com

37% reduction in the cumulative incidence of new-onset T2DM

- 11%

-6%

Gastrointestinal Side Effects of Orlistat TherapyYear 1 Year 2

Placebo Orlistat Placebo Orlistat

Fatty/oily stool 5 31 1 8

Increased defecation 7 20 2 2

Liquid stools 10 13 5 8

Fecal urgency 3 10 2 3

Flatulence 3 7 2 3

Flatus with discharge 0 7 0 1

Fecal incontinence 0 7 0 2

Oily evacuation 1 6 0 5

Low plasma vitamin conc:

Vitamin A 0.6 0.3 0.8 0

Vitamin D 0.6 5.1 0.8 3.1

Vitamin E 0.9 4.6 0 1.6

Sjostrom et al. Lancet 1998;352:167.Values are percentage of subjects.

Recommended by FDA Panel.. Approval Pending

Bariatric Surgery

NIH Consensus Development Panel Recommendations

• Patients seeking therapy for severe obesity for the first time should be considered for treatment in a nonsurgical program that integrates a dietary regimen, appropriate exercise, behavior modification, and psychological support

• Gastric restrictive or bypass procedures could be considered for well-informed and motivated patients in whom the operative risks were acceptable

• Patients who are candidates for surgical procedures should be selected carefully after evaluation by a multidisciplinary team with medical, surgical, psychiatric, and nutritional expertise

• Patients should undergo lifelong medical surveillance after surgery.

NIH Consensus Development Panel. Ann Intern Med 1991;115:956.

The Evidence

• Currently, there are no randomized, long-term studies in existence.

Swedish Obese Subjects (SOS) Study

• Prospective, non-randomized matched cohort study

• The largest and longest comparison of bariatric surgery and medical management.

• 4047 obese subjects. – Surgery group: 2010 bariatric surgery– Matched Control group: 2037 “conventionally

treated” Sjöström et al, N Engl J Med 2004;351:2683-93.

Mortality in SOS

• Mortality benefit after an average of 10.9 years follow up.

• NNT is 77 to save one life after 10 years in SOS subjects.

Sjöström et al, N Engl J Med 2007;357:741-52

Limitations of SOS

• Non-randomized

• Potential treatment bias: The medical management of the controls varied from no treatment to intensive medical therapy.

• Potential selection bias: patients undergoing surgery healthier.

• The impact of more modern medical management might narrow the SOS morbidity and mortality– 13% of the entire SOS cohort had either DM or previous MI or stroke – < 2% of the cohort was on a statin.

Sjöström et al, N Engl J Med 2004;351:2683-93.

Cons of Surgery

• Nutrients Malabsorptions• Medications side-effects• No reductions for cost of mediation.. Post op• Mental health issues and addictions• Increase VTE, • Increased Hospitalization

Medications & Nutrients Absorption• Effect of Gastric Bypass procedures:

• Decreased Drug solubility• Decreased surface area for absorption• Unpredictable site of absorption• Change in gastric PH

– Nutrient deficiency– Need for lifelong supplements– Decreased absorption and medication efficacy

Increases Risk for Medication Adverse Events

• Reduced size of the stomach increases risk for adverse events associated with– NSAIDS– ASA– Oral bisphosphonates.

Medication Costs

• SOS • Surgery did not result in decreased medication

costs as • decreased diabetes and cardiovascular

medications were offset by increased GI tract, NSAIDs, pain, anemia and vitamin deficiency medications.

Narbro K, et al. Arch Intern Med 2002; 162:2061-9.

Longitudinal Assessment of Bariatric Surgery 1 (LABS-1) trial

• Prospective, multicenter, observational Study

• 4776 consecutive patients undergoing bariatric surgical

• Within 30 days of surgery, 5% of patient has VTE; reintervention; or failure to be discharged

Flum et al. NEJM 2009;361:445-54

Complications of Bariatric SurgeryAll procedures

• Deep vein thrombosis & Pulmonary embolism

• Intractable vomiting

• Nutritional Deficiencies– Kwashiorkor (Protein malnutrition)– B1 deficiency (Berberi)

Procedure specific ComplicationsGastric banding

procedureGastric bypass Biliopancreatic

diversionBand slippage Anastomotic leak with

peritonitisAnastomotic leak with peritonitis

Band erosion Stomal stenosis Protein-calorie malnutrition

Esophageal dilatation Marginal ulcers

Band or port infections Staple line disruption DehydrationPort disconnection Nutrient deficiencies

(iron, calcium, folic acid, vitamin B12)

Nutrient deficienciesCalcium, iron, folic acid, Fat soluble vitamin (A,D,E,K) deficiencies

Port displacement Dumping syndrome SteatorrheaSmall bowel obstruction Small bowel obstructionInternal hernia Internal hernia

Adhesions Adhesions

Other Factors Influencing Mortality

• Age > 65; 30 day mortality 4.8 %

• Surgeons and Hospitals performing < 100 procedures a year– OR 2.5 and 2.3 compared to high volume centers

JAMA 2005 Oct 19;294(15):1903-8

Surgery. 2008 Nov;144(5):736-43. Epub 2008 Jul 21

Increased Hospitalization• Retrospective study of administrative data for patients

undergoing Roux-en-Y gastric bypass in California from 1995 to 2004 .

• 60,077 patients• 3-year post-operative follow up data was available for 24,678

patients• Results:

– Pre-procedure hospitalizations occurred in 8.4%– First post-operative year occurred in 20.2% (NNH=9)– Second post-operative year 18.4% (NNH=10)– Third post-operative 14.9% (NNH=16)

Zingmond DS, et al. JAMA 2005; 294:1918-1924.

Post Operative Mortality

• 16,155 Medicare beneficiaries underwent bariatric procedures between 1997-2002.– 1-year mortality – Overall 4.6% (NNH=22)– Men 7.5% (NNH=14)– Women 3.7% (NNH=27) and– Aged 65 years and older 11.1% (NNH=9).

Flum DR ,JAMA 2005; 294:1903-1908

Failure to Lose Weight & Weight Regain

• Regain of lost weight occurs in up to 20% in 2nd and 3rd year post-op

– Noncompliant eating and other behavioral– Gradual enlargement of the gastric pouch– Dilation of the gastrojejunal anastomosis

Obes Surg 2002 Apr;12(2):270-5

Am J Surg 1984 Sep;148(3):331-6

Psychosocial Impacts

• Surgery may increase risk for substance misuse and addictions. – Neurochemical void caused by restricted food

ingestion– Substitute other substances or behaviors to boost

dopamine to get the feel-good effect– Change in alcohol absorption and metabolism

after Gastric Bypass

Med Clin N Am 91 (2007) 451–469

After bariatric surgery, there is higher than expected;– Suicide– Depressions– Eating disorders

Med Clin N Am 91 (2007) 451–469

• Patients with history of psychiatric disorders should have appropriate care before and after bariatric surgery.

• We are not able to fully predict which surgical patients will have suboptimal weight loss or suffer from clinically significant psychosocial complications.

• Patients with active psychiatric illnesses, suicidal ideation and substance abuse should not undergo surgery.

The Bottom Line

More Evidence is Needed!

• There is need for good-quality, long-term RCTs comparing different operative techniques and non-surgical treatment for obesity.

• Theses future studies should include an assessment of – patient quality of life– psychosocial consequences of surgery and– impact on mortality in the context of current treatment trends for

cardiovascular diseases and diabetes.

• Results from ongoing, well-designed studies using intensive medical therapy in patients with obesity are awaited.

Managing all the modifiable factors contributing to obesity

long-lasting benefits

Lifestyle Social

Psychological

Environmental

CulturalFinancial

• Patients with severe obesity should be treated initially in a medical program that focus on – Diet– Activity– Lifestyle changes– Behavior modification,

and – Specialized psychosocial

assessment and support

• Bariatric Surgery is a useful tool in the management of obesity for carefully selected individuals and is not a quick fix

• Surgery should be offered ONLY to candidates who the benefits of surgery outweigh the expected medical, psychosocial and financial harms.

• Failure to adhere to behavior modification and addressing the psychosocial determinants of obesity cannot be fixed by bariatric surgery

• Physicians should be knowledgeable of pros and cons of bariatric surgery and the availability of alternative treatment strategies.

Lets Talk Numbers

• 2008-2009 total 2385 procedures in Canada

• Ontario Bariatric Network planned to provide 2000 surgeries per year

• 5.8 % of Canadian has BMI that qualifies for Surgery App = 1.9 Million

• Assuming that 10% will request Surgery (190,000)

• Requires about 20,000 procedure per year over 10 year

NoYes