Management of Obesity in Primary Care

Educational Objectives

The goal of this program is to improve management of obesity in the primary care setting and through bariatric sur­gery. After hearing and assimilating this program, the clinician will be better able to:

1.   Advise patients about evidence-based treatment of obesity.

2.   Recognize the comorbidities associated with obesity.

3.   Determine which patients are candidates for weight loss surgery.

4.   Recommend multifactorial weight management strategies for patients not considered candidates for surgery.

5.   Weigh the risks and benefits of surgical and nonsurgical treatment of obesity.

Faculty Disclosure

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the plan­ning committee to disclose relevant financial relationships within the past 12 months that might create any personal con­flicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, the faculty and planning committee reported nothing to disclose.

Acknowledgments

Dr. Baron was recorded at 37th Annual Advances in Internal Medicine, held May 18-22, 2009, in San Francisco, CA, and presented by the University of California, San Francisco, School of Medicine. Dr. Tichansky was recorded at 32nd Annual Eastern Shore Medical Symposium, held June 22-26, 2009, in Rehoboth Beach, DE, and presented by Jefferson Medical College and the University of Delaware, with promotional assistance provided by the Medical Society of Delaware. The Audio-Digest Foundation thanks the speakers and the sponsors for their cooperation in the production of this program.

Ten Myths About Obesity

Robert B. Baron, MD, Professor of Medicine, Associate Dean for Graduate and Continuing Medical Educa­tion, Vice-Chief, Division of General Internal Medicine, and Director, Weight Management Program, University of California, San Francisco, School of Medicine

Tobacco-related mortality: data from Centers for Disease Control and Prevention (CDC) showed that obesity-re­lated mortality growing at rate that would soon overtake tobacco-related mortality; methodology of data analysis criticized; findings refuted; tobacco remains leading cause of preventable death in United States (obesity second)

Childhood obesity: only partially true that epidemic slowing down; overweight in children defined as body mass in­dex (BMI) >85th percentile of average weight for age group, based on cohort from 1960s and 1970s (obese >95th percentile, severely obese >97th percentile); downward trend in childhood obesity among whites, but increase seen in black and Latino communities

Effect of weight on mortality: BMI  —  underweight <18.5; normal 18.5 to 25; overweight 25 to 30; obesity class I 30 to 35; obesity class II 35 to 40; obesity class III (extreme obesity) >40; National Health and Nutrition Examination Survey (NHANES) data  —  3 studies over 20 yr; slightly higher mortality of underweight category largely due to smoking (most smokers thinner); obesity (all classes) associated with excess mortality, but risk not dramatically higher (relative risk [RR] 1.8); overweight (BMI 25-30) not associated with excess mortality; in blacks, BMIs of 27 to 30 associated with normal outcomes, while in Asians, BMIs as low as 23 may be associated with excess mortal­ity; clinician’s role  —  determine whether patient has type of overweight associated with adverse outcomes; look for metabolic syndrome (measure waist circumference, blood pressure, lipids); take family history; current data  —  risk attributable to obesity decreasing over time, possibly because of better management of related conditions

Case: woman 40 yr of age with BMI 33; which abnormality best predicts her 10-yr mortality? waist circumference (36 in); fasting blood glucose (110 mg/dL); systolic blood pressure (BP; 140 mm Hg); triglycerides (185 mg/dL); exercise test (stopped after stage 2); answer  —  exercise test best predictor

Fit and fat: study confirmed earlier findings that sedentary lifestyle doubles risk for premature death over 14 yr; fit­ness more important than weight for measurement of health; study showed fat but fit subjects lived longer than thin but unfit subjects; findings not replicated in other studies, but fitness always shown to mitigate weight-related mor­bidities; urge patients to become as fit as possible, regardless of their weight

Exercise: not sufficient for weight loss; improves variety of metabolic factors (small dose-response effect) with or without weight loss; speaker recommends focusing initially on exercise duration and frequency rather than on in­tensity

Diet: necessary for weight loss; transtheoretical model’s stages of change applicable to prescribing diet and weight loss strategies; intervention should focus on stage of patient’s change; diet type less important than adherence to diet; similar effectiveness seen with various popular diets, including meal replacement (very low calorie), Atkins (low carbohydrate), Ornish (vegetarian); Zone (balanced macronutrient); mean intake 1400 calories/day on all di­ets; low-carbohydrate approach possibly slightly better; universal use of low-fat diet no longer evidence-based; pa­tient should have adequate social support and frequent visits with peer support, dietician, or physician

Rapid weight loss: very low calorie diet (VLCD)  —  »800 calories/day; preplanned meals with adequate vitamins, minerals, and proteins; meta-analysis showed patients on VLCD lose weight twice as quickly as those on tradi­tional low-calorie diet (LCD; 1200 to 1400 calories/day) in short term; LCD in clinical setting results in loss of 5% to 10% (average 7.5%) of patient’s original weight; VLCD 15% weight loss in short term; VLCD indicated in pa­tients who want to lose high volume of weight without surgery and in patients with need for rapid weight loss (eg, orthopedist recommends knee surgery, but requires that patient first lose 50 lb; patient too heavy for bariatric sur­gery table)

After weight loss: myth that after successful weight loss, patients can return to “sensible” (1800 calories/day) diet; patient must maintain 1400 calorie/day diet for rest of life or weight will be regained; supported by data from Na­tional Weight Control Registry; maintaining weight loss  —  high levels of physical activity (»1 hr of moderate-in­tensity exercise daily); low-fat or low-carbohydrate diet; regular self-monitoring of weight; “grazing” rather than binging; avoid fast foods; weekend diet and exercise regimen same as weekday regimen

Medications: speaker believes medicines not effective; phentermine  —  approved for 6 wk of use; weight usually re­turns upon termination of use; sibutramine – approved for 1 yr use; ineffective; orlistat  —  prescription-strength ap­proved for 2-yr use; topiramate  —  not approved for weight loss; exenatide  —  not approved for weight loss; speaker advises against use; drug vs placebo studies  —average loss »5% of original weight; study results unreliable because subjects placed on diet and exercise programs and behavioral therapy before start of medication trial; no data sug­gest >1-yr use of weight-loss medications reduces obesity-related morbidity and mortality; speaker posits drugs in­effective because multiple biologic systems (eg, central nervous system, endocrine system) affect appetite, and when one suppressed, others remain active or compensate

Surgery: gastric bypass twice as effective as best dietary intervention; risk for death within 30-day post-operative pe­riod 0.5% to 2.0%; factors affecting outcome include surgeon’s skill and patients’ preexisting comorbidities

Obesity Surgery 

David S. Tichansky, MD, Associate Professor of Surgery, and Director, Minimally Invasive and Bariatric Sur­gery Program, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pa

Background: obesity surgery differs from that of 7 to 10 yr ago; >50% of Americans overweight or obese; 1 in 25 Americans qualify for weight-loss surgery; 75% of obese children become morbidly obese adults; 1 in 3 children born after 2000 will develop type 2 diabetes; each year »112,000 people die prematurely of obesity-related condi­tions (more than deaths from breast cancer, prostate cancer, and colorectal cancer combined); society incorrectly views obesity as result of acquired self-destructive behavior, rather than as disease; obese individuals have lower rates of drug, tobacco, and alcohol use than national averages; problem  —  food highly efficient vehicle for disease; most smokers do not get lung cancer and few chronic alcohol abusers get cirrhosis, but everyone who consumes more calories than they burn will gain excess weight; candidates for weight-loss surgery  —  National Institutes of Health (NIH) criteria recommend weight-loss surgery for patients with BMI ³40, or BMI ³35 plus hypertension, heart disease, sleep apnea, or diabetes; nonsurgical weight-loss treatments have »95% long-term failure rate; bariat­ric surgery only scientifically proven method for long-term weight loss; improves or cures diabetes, hypertension, sleep apnea, and other weight-related morbidities

Laparoscopic surgery: now standard bariatric procedure; compared to open procedures, results in reduced incidence of wound infections, hernias, deep venous thrombosis, pulmonary embolism, and postoperative pneumonia as well as less pain and faster recovery; only 1% to 2% of patients undergoing laparoscopy develop wound infection, her­nia, or both (compared to 1 in 6 patients undergoing open procedures); recent improvements  —  standardized proce­dures; collaboration among surgeons nationally; improved patient selection; note  —  speaker advises procedure in patients <400 lb, preferably <300 lb; safer and more effective

Goals of surgery: gastric banding  —  restriction of caloric intake by restricting volume required for feeling of satia­tion; patients eat 3 4-oz meals daily; patients taught how to construct low-calorie meal; gastric bypass  —  restriction plus malabsorption

Gastric bypass: stomach stapled and cut to make new smaller stomach; intestine attached to new stomach; stomach still makes digestive secretions that mix with bile and pancreatic secretions; current procedures bypass only one-third of gastrointestinal (GI) tract; possible to achieve weight loss without predisposing patient to nutritional defi­ciencies

Adjustable gastric banding: band on outside of stomach causes narrowing; swallowed food fills and stretches nar­rowed upper stomach and sends signal to brain that entire stomach full; tubing connects to port placed subcutane­ously at midline, just off linea alba; band tightness adjusted in office by injecting saline into port

Sleeve gastrectomy: new procedure; excises »80% of stomach along greater curve; involves neither caloric restric­tion nor malabsorption; removes hormonal mediators of hunger (eg, ghrelin production virtually eliminated); pa­tients never hungry and have no desire to eat; avoids nearly all long-term complications of gastric bypass or implant, including nutritional deficiencies; preliminary results show efficacy higher than band and slightly lower than bypass; reduction in risk probably worth benefit

Benefits of weight loss surgery: much safer than in past (mortality rate 0.5%); about same as other major surgery (eg, vascular surgery)

Weight reduction: gastric band  —  European and Australian data show reduction of 50% to 60% of excess weight; data not replicated in United States; US data show 40% to 45% weight reduction at 3 yr; gastric bypass  —reduction of 65% to 75% of excess weight, mostly in first 18 mo

Diabetes: gastric band  —  type 2 diabetes improves in »70% of patients (complete resolution in some); gastric bypass  —  >90% improvement rate; majority cured (usually immediately after surgery; reason not clear)

Hypertension: gastric band  —  »55% improvement rate; possible cure; gastric bypass  —  »75% improvement rate; possible cure

Sleep apnea: cured in nearly all (98%-99%) patients by both procedures

Risks: intestinal leaking  —  can cause peritonitis; increases death rate from 1 in 200 to 1 in 15; most leaks success­fully managed; rarely occurs after banding; occurs in »1% of patients with bypass; pulmonary embolism  —  »1% for both procedures (recent reductions due to aggressive prophylaxis); death  —  nearly 0% with banding; »0.5% with bypass; reoperation rate  —  »4% in both procedures; major complications  —  »5% after banding; 5% to 8% af­ter bypass

Follow-up: because of high number of annual procedures, nearly every physician treats patients with history of bar­iatric surgery; nonabdominal or nonbariatric GI issues addressed as in patients without history of bariatric surgery; for upper GI complaints in patient with band, first deflate band; done by primary care physician or bariatric sur­geon; gastric cancer  —  uncommon, but likely to present at advanced stage (patient complaining of pain); biliary disease  —  endoscopic retrograde cholangiopancreatography (ERCP) difficult in patients with history of bariatric surgery; patient with biliary colic should be referred for gallbladder removal; liver  —  gastric bypass causes silent trauma, but improves or cures nonalcoholic steatohepatitis (NASH); gastric bypass not recommended for patients with active hepatitis B or C

Complications: early  —  patients with GI complications <60 days after surgery should be sent back to bariatric sur­geon; most problems surgically related; late complications  —after banding, most complications implant-related (eg, infection, breakage, erosion, slippage); nausea, reflux, or vomiting indicative of complications and should prompt emptying of band; obtain x-ray; after bypass, most commonly experienced complications include internal hernia, strictures, and ulcers; pain not normal after bypass; presence of pain suggestive of complications; intermit­tent cramping abdominal pain attributed to internal hernia (most serious long-term complication) until proven oth­erwise

Nutritional deficiencies: general malabsorption  —  food stream has shorter transit time and less absorptive area; spe­cific malabsorption  —  nutrient stream does not contact specific areas of absorption; iron  —  after gastric bypass, 50% of premenopausal women develop iron deficiency anemia if not taking supplements; calcium  —  two-thirds have altered calcium metabolism (likely vitamin D problem); thiamine – uncommon, but serious; may result in pe­ripheral neuropathy (usually irreversible); fat-soluble vitamins (A, D, E, K) – develop slowly; vitamin B₁₂  —laboratory testing shows £30% of bariatric procedure patients deficient in vitamin B₁₂; most asymptomatic; protein  —  not true malabsorptive deficiency; postoperatively, body’s use of fat and amino acids for energy wastes protein; recommendations  —  daily multivitamin usually sufficient to resolve or prevent vitamin deficiencies; speaker prescribes 2 chewable vitamins (18 mg of iron per tablet) and 1200 mg calcium with 400 IU vitamin D (eg, 2 Caltrate D tablets) daily; 70 to 80 g of protein per day by supplementation during acute weight loss phase; check serum levels frequently during rapid weight loss and annually thereafter; speaker recommends routinely checking calcium, vitamins A, B₁, B₉, B₁₂, D, E, and K, zinc, iron, and magnesium; start on multivitamin and thiamine (pend­ing test results)

Other primary care issues: stabbing pain (usually subxiphoid) likely ulcer; treat with proton pump inhibitor; serious cases may require liquid sucralfate (Carafate); severe pain surgical emergency; wide variability among patients, es­pecially those who underwent surgery >5 yr ago; speaker advises allowing surgeon’s office to handle insurance process; when referring for bariatric surgery, most important factors are surgeon’s experience and multidisciplinary team (especially dietician)

Suggested Reading

Barry D et al: Obesity and its relationship to addictions: is overeating a form of addictive behavior? Am J Addict 18:439, 2009; Batsis JA et al: Quality of life after bariatric surgery: a population-based cohort study. Am J Med 122:1055, 2009; Bray GA: Gastrointestinal hormones and weight management. Lancet Oct 22, 2009 [Epub ahead of print]; Colquitt JL et al: Surgery for obesity. Cochrane Database Syst Rev 2, 2009; Encinosa WE et al: Recent improvements in bariatric sur­gery outcomes. Med Care 47:531, 2009; Houston DK et al: Weighty concerns: the growing prevalence of obesity among older adults. J Am Diet Assoc 109:1886, 2009; Koepsell TD et al: Obesity, overweight, and weight control practices in U.S. veterans. Preventive Medicine 48:267, 2009; Laferrère B et al: Effect of weight loss by gastric bypass surgery versus hy­pocaloric diet on glucose and incretin levels in patients with type 2 diabetes. J Clin Endocr Metab 93:2479, 2008; Perry CD et al: Survival and changes in comorbidities after bariatric surgery. Ann Surg 247:21, 2008; Schweiger C et al: Nutri­tional deficiencies in bariatric surgery candidates. Obes Surg Oct 30, 2009 [Epub ahead of print]; Skinner AC et al: Using BMI to determine cardiovascular risk in childhood: How do the BMI cutoffs fare? Pediatrics 124:e905, 2009; Tice JA et al: Gastric banding or bypass? A systematic review comparing the two most popular bariatric procedures. Am J Med 121:885, 2008.