medical treatment of obesity 2016

Treatment of Obesity

Magnitude of problem 50% of US population is

overweight (BMI > 25) 22% are obese (BMI >

30) Second most common

cause of death in US 60 Billion a year is

spent on diet programs and supplements (2012 figure)

Obesity in America

Everything you know about calories is wrong

Kcal (food calorie)- amount of energy required to heat 1 kg of water by 1 C. Fats- 9 kcal/gram Carbohydrates and proteins-

4 kcal/gram Calculation are from a 19th

century lab experiment

Dunn, R. Scientific American, Sept ‘13


In reality it depends on- If the food evolved to survive

digestion How cooking affects its structure and

chemistry How much energy the body expends

to break down the food The extent to which the GI flora aids

digestion or steals calories


Has the food evolved to survive digestion? How durable are the cell walls? Baby

spinach vs. adult spinach. When cell walls hold strong- foods

preserve their calories and pass through our body intact

People who eat almonds received only 128 calories, instead of the 170 that was estimated


How cooking affects the structure and chemistry Cooking helps to break

down food- making it more easily digestible.

Studies in mice show greater weight gain in mice feed cooked instead of raw sweet potatoes and meat


How much energy does the body expend to break down the food? Whole wheat bread requires 2x more

energy to digest and only gives 90% of the calories

The extent to which the GI flora aids digestion or steals calories Lactase is the classic example- high

calorie latte or low calorie diarrhea?

Morbid Conditions Related to Obesity

Venous stasis Atherosclerosis Diabetes Dysmenorrhea Reflux Hirsutism Hypertension

Osteoarthritis Sleep apnea Restrictive lung

disease Depression Cancer (endometrial,

colon, prostate, and breast)

Clinical Evaluation of Obese Adults

Eckel R. Nonsurgical Management of Obesity in Adults. NEJM. 2008;358:1941-50.

Treatment options

1. Diet and exercise

2. Medical3. Surgery

Guidelines from National Heart, Lung, and Blood Institute

Effectiveness of diet 29% of US men

and 44% of women report trying to lose weight.

Only 20% of those people report decreasing calories

Nonpharmacologic weight loss

Adding exercise to caloric restriction minimally improves initial weight loss. But is the component that most likely

contributes to long-term maintenance of decreased weight

Exercise is one the most evidence-based intervention that people can do to improve their health.

Which “diet” is best? Low-Fat Diet

Ornish diet (<7% fat) has been shown to decrease progression of atherosclerosis

Low-Carbohydrate Diet Significant better weight loss at 6 months More effective for weight loss and cardiovascular risk reduction

Mediterranean Diet 25% reduction in death from cancer and heart disease, also

decreases dementia. Vegan Diet

Improves glycemic control and LDL

Weight loss companies

LA Weight loss Jenny Craig Nutrisystem Weight

Watchers Dr. Gann’s Diet

of Hope

Electronic programs to help weight loss Cochrane Review 2012

Meta-analysis of 14 weight loss studies with 2537 people

People who used on-line programs lost 1.5 kg more than the control group

However, those enrolled in face-to-face programs lost 2.1 kg more

Feedback is important

Electronic programs Lose It! 40-30-30 Calorie Tracker iMapMyRun BuddySlim.com FatSecret.com MyFoodDiary.com

Obesity: Medical Therapy Three mechanisms of obesity medication.

1. Decrease food intake by reducing appetite or increasing satiety.

2. Decrease absorption3. Increase energy expenditure

– No medications in US approved that act by this method (e.g. ephedrine).

Obesity: Medical therapy Xenical/orlistat/Alli Belviq/locaserin Contrave/

bupropion-naltrexone

Qsymia/phentermine-topiramate

Saxenda/liraglutide

Appetite-suppressant medications

Noradrenergic agents Phentermine: approved for short-term weight loss

(<12 weeks)Monotherapy has not been

associated with valvular disease (compared to combination therapy with Fenfluramine)

Phenylpropanolamine: was approved for OTC appetite suppressant, but was withdrawn due to risk of hemorrhagic stroke

Appetite-suppressant Medications

Lorcaserin- Selective serotonin 2C receptor agonist (Belviq)

Increases weight loss from 2.2 kg to 5.8 kg compared with placebo

Weight returned to baseline after medication was stopped.

Approved by FDA July ‘12

Locaserin effectiveness

Smith et. al. in NEJM 2010;363:245-56.

Medication that reduces absorption

Orlistat (Xenical): binds GI lipases preventing hydrolysis of dietary fats. Excrete in the stool about 1/3 of fat calories Pt’s lose 9% of body weight, compared to 5% with

placebo Associated with decreased blood pressure and

fasting insulin level Pt’s should take daily vitamins Once medication is stopped, weight is regained. ½ strength dose available OTC as Alli

Phentermine/topiramate (Qsymia)

Combination medicine approved July 2012 Phentermine- reduces appetite and decreases

oral intake Topiramate- appetite suppressant and satiety

enhancement Given daily in the morning due to insomnia

Start 3.75/23mg daily for 14 days, than titrate to 7.5/46mg daily and evaluate in 12 weeks

If less than 3% weight loss – either stop of increase dose to 11.25/69 for 14 days, than 15/92mg daily

Recheck in 12 weeks and if less than 5% weight loss- stop drug

Phentermine/topiramate


Significant improvement with treatment Blood pressure, lipid

concentration, and blood glucose levels

Risks include Nephrolithiasis,

hypokalemia, dry mouth, paresthesia, constipation and insomnia

Bupriopion/Naltrexone (Contrave)

Combination medicine approved Sept 10th 2014 Initially rejected in 2011 due to concern of cardiac problems Approved for adults with BMI > 30 or >27 and one weight-

related condition In conjunction with weight loss program

Evaluate at 12 weeks and drug should be stopped if there is not >5% weight loss

Patients lose 4% more of bodyweight with medicine compared to placebo (9% compared to 5%).

Nausea in 34% of patients- patients should be warned about suicide risk

May raise blood pressure

Saxenda/Liraglutide Better known as

Victoza 3.0 mg dose-

compared to 1.2 or 1.8 for diabetes

Patients lost 8% of body weight compared to 2.6% with placebo.

Saxenda/liraglutide

HCG First suggested as treatment for obesity in 1954 Lancet

paper Obtained from the urine of pregnant women Popular in 1970’s Multiple clinical trials show no benefit Current popularity due in part to Kevin Trudeau’s 2007

book “The weight loss cure they don’t want you to know about.” “Miracle weight loss breakthrough” FTC ordered Trudeau to pay $37 million

HCG American Society of Bariatric Physicians (2009)

Numerous clinical trials have shown HCG to be ineffectual in producing weight loss. HCG injections can induce a slight increase in muscle mass in androgen-deficient males. The diet used in the Simeons method provides a lower protein intake than is advisable in view of current knowledge and practice. There are few medical literature reports favorable to the Simeons method; the overwhelming majority of medical reports are critical of it. Physicians employing either the HCG or the diet recommended by Simeons may expose themselves to criticism from other physicians, from insurers, or from government bodies.

Bariatric Surgery: types Gastric

restriction Gastric

resection with bypass

Gastric resection with malabsorption

Other

Gastric restriction (AKA gastroplasty)

Decreases stomach capacity

Food distends pouch causing satiety

Several main methodsBoth decrease

stomach contests to 10-20 cc

Vertical-banded gastroplasty

Gastric restriction: adjustable gastric banding

Most common bariatric procedure in Australia and Europe

Adjustable banding is associated with a decreased rate of weight loss compared to vertical-banded.

Gastric restriction with bypass Used to be the most

common bariatric procedure in US

Length of Roux limb varies between 75-150 cm Longer for more

weight loss Results in more

weight loss then gastric restriction

Gastric resection with malabsorption Two types of surgery Original procedure

Hemigastrectomy Biliopancreatic limb of the

bypass is attached to ilium 50cm from ileocecal valve

High incidence of malnutrition and vitamin deficiencies.

Gastric resection with malabsorption

Modification of bypass- biliopancreatic bypass with duodenal switch Increases common loop to

100cm Less side effects Calcium deficiency still occurs

AspireAssist A modified 6 mm PEG

tube Allows patients to remove

up to 30% of stomach contents after a very well masticated meal

Costs about $10,000 Device stops working

after 6 weeks, tube must be shortened as people lose weight

AspireAssist

Coolsculpting FDA approved fat-

reduction treatment Cold can cause fat cells

to undergo apoptosis without damaging other tissue AKA cryolipolysis

Best for people who has lost weight already

Coolsculpting

Complications of Surgery

Complications: Dumping In gastric bypass,

patients are unable to tolerated food high in fat and sugar

Postprandial diaphoresis, weakness and malaise

Symptoms usually improve

Complications: Nutritional deficiencies ALL surgery pt’s

are at risk 2/3 of patients have

hyperhomocystemia Risk of deficiency

depends on operation Roux: iron, vitamin

B12 or calcium Bypass: calorie and

fat soluble vitamin

Iron deficient anemia

One of most frequent deficiencies after surgery Incidence after VBG is about 1/3 Incidence after bypass is about ½ Absorption of iron

Ferric ion must be reduced to ferrous state to be absorbed by stomach acid.

Production of stomach acid is significantly decreased after surgery

Other vitamins

Vitamin B12: requires intrinsic factor to be absorbed Because a large amount of B12 is stored in the

liver, usually takes 1-9 years for patients to show def.

Thiamine: absorbed in the entire duodenum Calcium/Vit D: calcium is mainly absorbed in

duodenum and proximal jejunum

Complications: Reflux Seen in vertical banding

gastroplasty 5-fold increase in reflux

Can be treated with gastric bypass

Complications: Osteoporosis Decreased density

observed Unclear mechanism,

not due to hyperparathyroidism At risk for calcium

and vit D deficiency Clinical significance

not established.Intern R2 R3

Complications: Gallstones Rapid reduction of

weight is associated with gallstones

27% of bariatric surgery pt’s require cholecystectomy in 3 years Prophylactic

cholecystectomy? Ursodilol 600 mg daily

Other complications

Gastrogastric fistula Ulcer/stricture Excess skin

Most surgeons will wait to remove skin until 1 year at a stable weight

Bariatric surgery: How well does it work?

Sjostrom et al. Lifestyle, Diabetes, and Cardiovascular Risk Factors 10 years after Bariatric Surgery. NEJM. 2004;351:2683-2693.

Swedish Obese Subjects (SOS) Study

Prospective, cohort trial involving 4047 obese pt’s.

Surgery pt’s were matched 5 months before surgery with control Considered 18 variables when matching

Treatment was surgery or usual care Surgeries: Fixed or variable banding, vertical

banding, or gastric bypass

Sjostrom L et al. N Engl J Med 2007;357:741-752

Results

Sjostrom L et al. N Engl J Med 2007;357:741-752

SOS adverse events

0.25% died post-op 13% had post-op complications

6.1% pulmonary 2.1% deep infections 1.5% wound complication 0.8% PE/DVT 0.5% bleeding complications

Health care use during 20 years following surgery Followed SOS subjects- 2010 adults who

underwent surgery and 2037 matched controls Compared to controls

Bariatric surgery patients used more inpatient and nonprimary outpatient care during the first 6 year period, but not thereafter

Drug costs from years 7-20 were lower for surgery patients than controls

Neovius et. al. JAMA. 2012;308(11):1132-1141

Obesity: the future Pharmaceutical

companies are investing significant resources into treating obesity

Lesson from schizophrenia, GERD and most other diseases

Is obesity an addiction?

Studies in obese rats show similar behavior to drug addicted rats- behavior persists despite negative consequences.

Endorphin blocking drugs decrease overeating as well as heroin, alcohol and cocaine use

Lorcaserin stimulates serotonin receptor which also reduces the desire to consume nicotine in lab rats

medical treatment of obesity 2016

Health & Medicine