an overview of obesity and weight loss surgery · an overview of obesity and weight loss surgery...

F E A T U R E A R T I C L E

An Overview of Obesity and Weight Loss SurgeryThomas L. O’Connell, MD

Obesity is a nutritional disorderthat spans all ages and ethnici-ties and affects both sexes. In

2000, the World Health Organization(WHO) convened an international con-sultation on obesity to review epidemio-logical data worldwide. It concluded thatobesity is a rapidly growing epidemicand at the same time acknowledged itsstatus as a disease. Projections for thenext decade were felt to be so concern-ing that urgent public health actionswere recommended.1

The United States has not beenspared from the epidemic of obesity.More than half of the U.S. population isoverweight or obese. Body mass index(BMI) is a ratio of a person’s weight inkilograms divided by their height inmeters squared. The WHO definesweight status based on this ratio (Table1). Based on the WHO classification,61% of the U.S. population (> 120 mil-lion people) are overweight or obese.Thirty-four percent are overweight, witha BMI of 25–29.9 kg/m2, and 27% areobese, with a BMI ≥ 30 kg/m2.2

In spite of the growing medicalawareness and growth of diet and exer-cise programs, the prevalence of obesityhas increased by more than 75% since1980.3 Even our children and adoles-cents are affected, with just over 10% of2- to 5-year-olds now being overweight.More than 15% of both 6- to 11-year-olds and 12- to 19-year-olds are alsooverweight.4

COMPLICATIONS AND RISKSASSOCIATED WITH OBESITYObesity has been linked to increasedrates of many other chronic disease

115CLINICAL DIABETES • Volume 22, Number 3, 2004

states. The dramatic increase in obesityin the past decade has been associatedwith a 25% increase in the prevalence oftype 2 diabetes.5 Among those in whomtype 2 diabetes has been diagnosed,67% have a BMI of at least 27 kg/m2,and 46% have a BMI of at least 30kg/m2.6 Development of insulin resist-ance and diabetes seems to be particu-larly sensitive to the development of vis-ceral adiposity.

Hypertension, dyslipidemia, coro-nary heart disease (CHD), and strokehave also been linked to obesity. Thelink between CHD and obesity classi-

cally has been thought to be related tothe impact of obesity on risk factorsincluding hypertension, dyslipidemia,and impaired glucose metabolism. Atleast two long-term observational stud-ies, however, have shown that beingoverweight is a predictor of cardiovas-cular atherosclerosis independent of itseffects on traditional risk factors.7,8

Other complications, such as obstruc-tive sleep apnea, cholelithiasis, liverdisease, musculoskeletal disease, anddisorders of reproduction, have all beenassociated with obesity andoverweight.9–13 Even certain cancers,including colon cancer,14 endometrialcancer,15 and postmenopausal breastcancer,16 have been associated withincreasing body weight.

Most studies clearly show anincrease in mortality rate associated withBMI (Figure 1). Individuals with a BMIof at least 30 kg/m2 have a 50–100%increased risk for death from all causes,compared with individuals at a BMI of20–25 kg/m2. Most of this increase isbecause of cardiovascular disease.17

Clearly, obesity and overweight are asso-ciated with a significant amount ofexcess morbidity and mortality in thiscountry.

Obesity has become an epidemic inthe United States, with more than60% of the population now eitheroverweight or obese. Lifestyle modi-fications and weight loss medicationshave failed to provide significant,lasting weight loss in the majority ofpeople who are overweight. Weightloss surgery has proven to be a safeand effective means of losing signifi-cant and lasting weight and shouldbe considered in those who are mor-bidly obese.

IN BRIEF

Table 1. WHO Classification of Overweight and Obesity

Class BMI (kg/m2) Risk of ComorbidityUnderweight < 18.5 LowNormal range 18.5–24.9 AverageOverweight (grade 1 obesity) 25.0–29.9 Mild increaseObese (grade 2 obesity) 30.0–39.9 Moderate/severeMorbid/severe obesity (grade 3) ≥ 40.0 Very severe

Adapted from Ref. 1.

of calories to 500–1,000 calories lessthan the amount required for weightmaintenance.20 More severe caloricrestriction with the use of very-low-calorie diets increases the rapidity ofweight loss but not the rate of long-termsuccess in maintaining a lower weight.19

Although adding exercise to calorierestriction only modestly increasesweight loss, it appears to be the mosteffective component of treatment inweight maintenance once weight islost.21 Behavioral therapy helps obesepeople develop adaptive eating, thinking,and exercise habits that enable them todecrease their weight and avoid regain-ing weight.20 People who combinecaloric restriction and exercise withbehavioral therapy may expect to lose5–10% of their weight over 4–6 months.

Even this modest weight loss hasbeen shown to improve many obesity-related conditions.22 Unfortunately, for thevast majority of people, weight loss is fol-lowed by slow, progressive weight gain topre-diet body weight or even higher.23

MedicationsPharmacological therapy may be addedto diet, exercise, and behavioral therapy


COSTS OF OBESITYObesity and its complications are costlyto society. An estimated $52 billion indirect medical costs each year is spenttreating obesity-related disease (Table2). Another $50 billion each year isspent on weight loss attempts.18 Half ofthis is spent on diet foods, and the rest isspent on various weight loss programs,supplements, and medications. Alltogether, more than $100 billion is spenteach year combating obesity and its con-sequences. This figure can only beexpected to rise as the prevalence ofobesity continues to increase.

NONSURGICAL THERAPY

LifestyleThe National Institutes of Health (NIH)guidelines recommend weight loss forobese people with a BMI of ≥ 30 kg/m2

and for people who are overweight(BMI 25–29.9 kg/m2) with two or moreobesity-related comorbidities.19 Lifestylemodifications are generally the recom-mended first approach to weight loss.

Many studies have shown that over-weight individuals can lose about 0.5 kgper week by reducing their daily intake

Volume 22, Number 3, 2004 • CLINICAL DIABETES116

to assist with weight loss. Medicationsare an adjunct to lifestyle modifications,however, and not a replacement.

Expected weight loss with any of thecurrently available weight loss medica-tions is usually less than 10% of thepatients’ pre-intervention weight. Afterinitial weight loss, a regain of at leastpart of the lost weight can be expected.Most studies, however, show less regainin the treatment groups compared withthose taking placebo.

Weintraub24 suggested in the early1990s that obesity needs to be treatedmore as a chronic condition that mayneed prolonged use of medications forappropriate control. Unfortunately, thesafety and efficacy of weight loss med-ications beyond 2 years has not beenestablished, and discontinuation of med-ication usually results in regain to pre-treatment weight or higher. Improve-ments in obesity-related disease are notsustained if weight is regained. There-fore, it is prudent to consider more sus-tainable options for weight loss to beadded to lifestyle modifications.

WEIGHT LOSS SURGERYThe idea of weight loss surgery wasconceived after surgeons noticed thatpatients undergoing resection of portionsof the stomach and small intestine forother reasons lost weight.25 Surgery formorbid obesity was first described in acase report by Kremen et al. in 1954.26

Figure 1. Relation between mortality and BMI. At a BMI below 20 kg/m2 andabove 25 kg/m2, there is an increase in relative mortality for men and women.Data from Lew EA: Mortality and weight: insured lives and the AmericanCancer Society studies. Ann Intern Med 103:1024–1029, 1985. Reprinted withpermission from the author of Ref. 46.

Table 2. Cost of Obesity in theUnited States

Disease Direct Cost ($U.S. billions)

Diabetes mellitus 32.4CHD 7.0Osteoarthritis 4.3Hypertension 3.2Gallbladder disease 2.6Colon cancer 1.0Breast cancer 0.84Endometrial cancer 0.29Total 51.6

Adapted from Ref. 18.

MenWomen

20 25 30 35 40Body Mass Index, kg/m2

VeryLow Low Moderate High

VeryHigh

0

1.0

1.5

2.0

2.5

Mor

talit

y ra

tio

gastric banding, and vertical banded gas-troplasty. They work by reducing gastricvolume, slowing gastric emptying, andcreating early satiety. Restrictive proce-dures lead to significant weight loss inalmost all patients, although it is possi-ble to “eat through” the procedure andregain some of the lost weight.25 This ismore of a problem with the verticalbanded gastroplasty than with theRNYGB and gastric banding.

The gold standard and most commonsurgical procedure for weight loss in theUnited States is the RNYGB. This pro-cedure has proven long-term weight loss,excellent patient tolerance, and accept-able short- and long-term complicationrates.32 RNYGB is accomplished by cre-ating a small (15–30 ml) gastric pouchby placing staples across the proximalstomach and dividing it. The jejunum isdivided about 30 cm beyond the liga-ment of Treitz. The distal limb is broughtup, and a proximal end-to-side gastroje-junostomy is performed with the gastricpouch. The proximal limb of thejejunum is anastomosed to the distaljejunum forming a jejunojejunostomyapproximately 75–100 cm distal to thegastrojejunostomy25 (Figure 2).

Table 3 is adapted from Schauer etal.’s article32 and lists outcomes forRNYGP performed by many of the sur-geons who have contributed significantlyto the field of bariatric surgery in thepast two decades.33–43 Mortality amongpatients receiving RNYGB in these trialsranged from 0 to 7.7%. Overall, there


They published a report of an end-to-end jejunoileostomy performed specifi-cally for weight reduction. Payne theninitiated the first clinical program ofintestinal bypass for morbid obesity in1956.26 Gastric bypass for the treatmentof severe obesity was first described byMason and Ito in 1967.27 It consisted ofa loop gastrojejunostomy and a stapledpouch of ~10% of the gastric volume.28

Some of the early procedures wereassociated with unacceptable sequelae,including diarrhea, malabsorption, elec-trolytic disturbances, hepatic failure,vitamin deficiencies, and even death.27–30

The severity of these complications mayexplain some of the negative attitudesthat arose towards the surgical treatmentof obesity. Over the past 30 years,numerous modifications were made tothe earliest procedures, eventually pro-ducing safer and more lasting options forweight loss surgery.

Appropriate Candidates for SurgeryThe 1991 NIH consensus conference onobesity surgery released guidelines tohelp determine which patients are appro-priate for weight loss surgery. They sug-gested that all people with a BMI > 40kg/m2 and those with a BMI > 35 kg/m2

who also have serious comorbiditiesshould be considered for surgery.31

Patients must have failed conventionalmethods for weight loss. Also, patientsmust be good candidates from a psycho-logical standpoint. Serious psychologi-cal disease, including some personalitydisorders and substance abuse, areabsolute contraindications. Somepatients who are not initially candidatesfrom a psychological standpoint maybecome acceptable with treatment oftheir disorder. Surgical candidates mustalso be committed to maintaininglifestyle changes and continuing long-term follow-up after the surgery.25

Current ProceduresSurgical procedures promote weight lossvia gastric restriction or malabsorption.Gastric restrictive procedures includeRoux-en-Y gastric bypass (RNYGB),


were 22 deaths among 3,434 proceduresperformed, for a 0.64% risk of deathrelated to the surgery. If the 1969 seriesby Mason and Ito33 is excluded, then themortality rates range from 0 to 1.5%,and overall mortality is reduced to0.58%. Complication rates generallydecline as the surgical team gains experi-ence, with many series researchers com-menting that a disproportionate numberof complications occur early in thecohort. In the long term, patients under-going this procedure maintain significantweight loss.

In the series by Pories et al.,40 aver-age follow-up was 14 years. Patients lost~70% of their excess weight in the first6–12 months and kept off ~50% of theirexcess weight at the time of reporting.To put this in perspective, a 5'10" malewho weighs 350 lb and has a BMI of 50kg/m2 can expect to reach a nadir inweight of ~220 lb at 1 year and weigh258 lb with a BMI of 36 kg/m2 or less 10years after the procedure.

The adjustable gastric banding pro-cedure has recently gained recognitionas a surgical option and offers some sig-nificant advantages. Unlike the verticalbanded gastroplasty and RNYGB, theadjustable gastric band (Figure 3)involves no stapling of the stomach wall,no cutting or opening of the stomach,and no alteration of the gastrointestinaltract.44 Should it become medically nec-essary, the band can be removed andnormal stomach anatomy restored. Also,the degree of restriction created by theband can be adjusted by injecting orwithdrawing saline through a port underthe skin. This allows the size of thestoma (opening between the upper andlower stomach) to be changed to fit eachpatient’s nutritional and weight lossneeds.

Malabsorptive procedures combinegastric restriction with reduced calorieand nutrient absorption. Malabsorptiveprocedures of preference are the bil-iopancreatic diversion and the duodenalswitch. Neither procedure is widely usedbecause of the high incidence of nutri-tional deficiencies. The RNYGB is con-Figure 2. Roux-en-Y gastric bypass.

patients whose surgeries were performedwith a laparoscope had a shorter lengthof hospital stay, earlier return to work,and equal or better rates of short-termcomplications compared with patientswho had open procedures. There wasone death (0.4%) related to a pulmonaryembolus. Similar long-term outcomes inrelation to weight lost and improve-ment/resolution of comorbidities werealso seen. Most centers now perform


sidered a purely restrictive procedurebecause not enough small intestine isbypassed to cause malabsorption. How-ever, several investigators are looking atplacing the jejunojejunostomy fartherdown the jejunum to induce an elementof malabsorption. This may prove tohave added benefit when operating onthe super obese (BMI > 50 kg/m2).

Laparoscopic ApproachSince laparoscopic cholecystectomy wasintroduced in the late 1980s, the positiveimpact of laparoscopic surgery on reduc-ing perioperative complications has beenrepeatedly demonstrated.32 Morbidlyobese patients generally have significantcomorbidities, which increase their risksfor postoperative cardiopulmonary andwound-related complications. It there-fore makes sense that a laparoscopicapproach might benefit them even morethan it would nonobese people.

In 2000, Schauer et al.32 publishedtheir series of 275 consecutive laparo-scopic RNYGBs to compare short-termand long-term complications and out-comes to published outcomes of openprocedures. The conversion rate to anopen procedure was only 1%. Those


weight loss surgery (either RNYGB oradjustable gastric banding) laparoscopi-cally unless other confounding factorsprohibit this approach.

IMPROVEMENT IN COMORBIDITIES WITH SURGICAL WEIGHT LOSSIt is generally accepted that most, ifnot all, obesity-related diseasesimprove with significant weight loss.

Figure 3. The lap band.

Table 3. Outcomes of RNYGB

Study n BMI (kg/m2), Early Mortality PE Leak Hernia Follow- Weight weight (kg), Complication (%) Rate Rate (%) up Lossor % IBW Rate (%) (%) (%) (months)

Mason 196933 42 42 kg/m2 19 7.7 3.4 0 11.5 12 43 kg Griffin 198134 402 134 kg 4.2 0.75 0.25 5.47 3.5 6 35 kg Linner 198235 174 126 kg 10.4 (all) 0.57 0 0.57 0 24 64% EWL Sugerman 198936 182 213% — 1 0 1.6 18 12 67% EBW Hall 199037 99 198% 20 0 3 0 2 36 67% lost

> 50% EBW Brolin 199138 90 62 kg/m2 5 0 1.1 0 6.6 43 64% EWL MacLean 199339 106 50 kg/m2 — 0 — 5.6 — 33 58% lost

> 50% EBW Pories 199540 608 50 kg/m2 25.5 1.5 — — 23.9 168 49% EWL Capella 199641 560 52 kg/m2 1 0 0 0 — 60 62% EWL Fobi 199842 944 46 kg/m2 2.7 0.4 0.6 3.1 4.7 24 80% EWL MacLean 200043 243 49 kg/m2 — 0.41 — — 16 66 BMI 44 to

> 29

EBW, excess body weight; EWL, excess weight loss; IBW, ideal body weight; PE, pulmonary embolism; —, not reportedTable adapted from Ref. 32.

tions. The remaining 17% did not nor-malize, but did have significant improve-ment in glycemic parameters while onless medication.45

Improvements in patient outcomesare not limited to physical disorders.When Schauer’s patients were surveyedfor quality of life changes, 58% said theirquality of life was “greatly improved,”37% said it was “improved,” and 5% saidthat there was no change in quality oflife. No patient undergoing surgeryreported a diminished quality of life.45

CONCLUSIONSObesity is a growing epidemic affect-ing a large proportion of the U.S. pop-ulation. Currently, more than 60% ofthe U.S. population is either over-weight or obese. Projections suggestthat this percentage will continue toincrease. This trend is even affectingchildren and adolescents, with a grow-ing number of them developing weightproblems at earlier ages. Unfortunately,lifestyle modifications and medicaltherapies for weight loss have notproven to provide significant, sustainedweight loss.

Bariatric surgery has been shown toinduce durable weight loss, with mostseries reporting 50% or greater excessweight loss in the long term. Along with


Table 4, adapted from Schauer et al.,32

shows typical improvements in obesity-related disease that can be expectedfrom RNYGB. Metabolic complica-tions classically associated with mor-tality in obese patients essentially allimprove, if not resolve. These include:• dyslipidemia: improvement in 96%,

resolution in 63%• hypertension: improvement in 88%,

resolution in 70%• diabetes: improvement in 100%,

return to normoglycemia withoutmedications in 82%

• sleep apnea: improvement in 93%,resolution in 74%

Schauer et al.’s original series32

included only 275 patients and only 18with diabetes. They published anotherseries 3 years later to report on outcomesin a larger number of patients with dia-betes.45 In the second series, 240 of1,160 patients undergoing laparoscopicRNYGB over 5 years had type 2 dia-betes or impaired fasting glucose.Patients went from a mean preoperativeweight and BMI of 308 lb and 50.1kg/m2 to a mean of 211 lb and 34kg/m2—a mean weight loss of 97 lb andmean excess weight loss of 60%. Fastingplasma glucose and hemoglobin A1c

results improved in all patients, with83% returning to normal on no medica-


this weight loss comes improvement orresolution of most, if not all, obesity-related diseases.

Surgical candidates should be select-ed based on currently accepted guide-lines and should also comprehend therisks inherent to the procedure. Onemust balance the ~0.5% risk of deathassociated with the procedure with theimprovement in health status, reductionin comorbidities, and decreased mortali-ty associated with a decreased BMI. TheNIH consensus conference concludedthat in those with a BMI > 40 kg/m2 andthose with BMI > 35 kg/m2 and comor-bidities, the benefits of the procedureoutweigh the risks.

Therefore, weight loss surgeryshould at least be discussed with allpatients meeting the NIH criteria. Forthose who are willing to undergo theprocedure and who do not have anymajor contraindications, weight loss sur-gery is a low-risk option with significantbenefits.

ACKNOWLEDGMENT

Special thanks go to Dr. John Grant,director of the Duke University WeightLoss Surgery Center, for overall reviewand, in particular, assistance with thesurgical section.

Table 4. Change in Obesity-Related Comorbidity

Comorbidity Total Patients Aggravated (%) Unchanged (%) Improved (%) Resolved (%)

OA/DJD 64 2 10 47 41 Hyperlipidemia 62 0 4 33 63 GERD 58 0 4 24 72 Hypertension 57 0 12 18 70 Sleep apnea 44 2 5 19 74 Depression 36 8 37 47 8 Peripheral edema 31 0 4 55 41 Urinary incontinence 18 0 11 39 44 Asthma 18 6 12 69 13 Diabetes 18 0 0 18 82 Anxiety 7 0 50 17 33 Venous insufficiency 7 0 71 29 0 Gout 7 0 14 14 72

Adapted from Ref. 32. DJD, degenerative joint disease; GERD, gastro-esophogeal reflux disease; OA, osteoarthritis.

16Huang Z, Hankinson SE, Colditz GA,Stampfer MJ, Hunter RJ, Manson JE, HennekensCH, Rosner B, Speizer FE, Willett WC: Dualeffects of weight and weight gain on breast can-cer risk. JAMA 278:1407–1411, 1997

17Troiano RP, Frongillo EA Jr, Sobal J, Levit-sky DA: The relationship between body weightand mortality: a quantitative analysis of com-bined information from existing studies. Int JObes Relat Metab Disord 20:63–75, 1996

18Wolf AM, Colditz GA: Current estimates ofthe economic cost of obesity in the United States.Obes Res 6:97–106, 1998

19National Institutes of Health: Clinical guide-lines on the identification, evaluation, and treat-ment of overweight and obesity in adults: theEvidence Report. Obes Res 6 (Suppl.2):51S–209S, 1998

20Wadden TA, Foster GD: Behavioral treat-ment of obesity. Med Clin North Am 84:441–461,2000

21McGuire MT, Wing RR, Klem ML, Hill JO:Behavioral strategies of individuals who havemaintained long-term weight losses. Obes Res7:334–341, 1999

22Blackburn G: Effect of degree of weightloss on health benefits. Obes Res 3 (Suppl.2):211S–216S, 1995

23Technology Assessment Conference Panel:Methods for voluntary weight loss and control.Ann Intern Med 119:764–770, 1993

24Weintraub M: Long-term weight controlstudy: conclusions. Clin Pharmacol Ther51:642–646, 1992

25Barrow CJ: Roux-en-Y gastric bypass formorbid obesity. AORN J 76:590, 593–604, 2002

26MacDonald KG: Overview of the epidemi-ology of obesity and the early history of proce-dures to remedy morbid obesity. Arch Surg138:357–360, 2003

27Kral JG: Overview of surgical techniquesfor treating obesity. Am J Clin Nutr 55 (Suppl.):552S–555S, 1992

28Mason EE, Ito C: Gastric bypass in obesity.Surg Clin North Am 47:1345–1351, 1967

29Mason EE, Doherty C: Surgery. In Obesity,Theory and Therapy. 2nd ed. Stunkard AJ, Wad-den TA, Eds. New York, Raven, 1993, p. 313–325

30Shikora SA, Benotti PN, Forse RA: Surgicaltreatment of obesity. In Obesity, Pathophysiology,Psychology and Treatment. Blackburn GL, Kan-ders BS, Eds. New York, Chapman & Hall, 1994,p. 264–282

31NIH Conference Development ConferencePanel: Gastrointestinal surgery for severe obesity.Ann Intern Med 115:956–961, 1991

32Schauer PR, Ikramuddin S, Gourash W,Ramanathan R, Luketich J: Outcomes afterlaparoscopic Roux-en-Y gastric bypass for mor-bid obesity. Ann Surg 232:515–529, 2000


REFERENCES

1World Health Organization: Obesity: pre-venting and managing the global epidemic: reportof a WHO consultation. World Health Org TechRep Ser 894:I–xii,1–253, 2000

2National Center for Health Statistics: Preva-lence of overweight and obesity among adults:United States, 1999. Available online atwww.cdc.gov/nchs/products/pubs/pubd/hestats/hestats.htm

3Flegal KM, Carroll MD, Kuczmarski RJ,Johnson CL: Overweight and obesity in the Unit-ed States: prevalence and trends, 1960–1994. IntJ Obes Relat Metab Disord 22:39–47, 1998

4Ogden CL, Flegal KM, Carroll MD, JohnsonCL: Prevalence and trends in overweight amongU.S. children and adolescents, 1999–2000. JAMA288:1728–1732, 2002

5Harris ML, Flegal KM, Cowie CC, Eber-hardt MS, Goldstein DE, Little RR, WiedmeyerHM, Byrd-Holt DD: Prevalence of diabetes,impaired fasting glucose, and impaired glucosetolerance in U.S. adults: the Third NationalHealth and Nutrition Examination Survey,1988–94. Diabetes Care 21:518–524, 1998

6National Task Force on the Prevention andTreatment of Obesity: Overweight, obesity, andhealth risk. Arch Intern Med 160:898–904, 2000

7Manson JE, Willett WC, Stampfer MJ,Colditz GA, Hunter DJ, Hankinson SE, Hen-nekens CH, Speizer FE: Body weight and mortal-ity among women. N Engl J Med 333:677–685,1995

8Garrison RJ, Castelli WP: Weight and 30-year mortality of men in the Framingham Study.Ann Intern Med 103:1006–1009, 1985

9Strohl KP, Strobel RJ, Parisi RA: Obesityand pulmonary function. In Handbook of Obesity.Bray GA, Bouchard C, James WPT, Eds. NewYork, Marcel Dekker Inc., 1998, p. 725–739

10Khare M, Everhart JE, Maurer KR, HillMC: Association of ethnicity and body massindex (BMI) with gallstone disease in the UnitedStates (Abstract). Am J Epidemiol 141(Suppl.):S69, 1995

11Sheth SG, Gordon FD, Chopra S: Nonalco-holic steatohepatitis. Ann Intern Med126:137–145, 1997

12Anderson JJ, Felson DT: Factors associatedwith osteoarthritis of the knee in the first NationalHealth and Nutrition Examination Survey(NHANES I): evidence for an association withoverweight, race, and physical demands of work.Am J Epidemiol 128:179–189, 1988

13Grodstein F, Goldman MB, Cramer DW:Body mass index and ovulatory infertility. Epi-demiology 5:247–250, 1994

14Lee IM, Paffenbarger RS: Quetelet’s indexand risk of colon cancer in college alumni. J NatlCancer Inst 84:1326–1331, 1992

15Garfinkel L: Overweight and cancer. AnnIntern Med 103:1034–1036, 1985


33Mason EE, Ito C: Gastric bypass. Ann Surg170:329–339, 1969

34Griffen WO, Bivins BA, Bell RM, JacksonKA: Gastric bypass for morbid obesity. World JSurg 5:817–822, 1981

35Linner JH: Comparative effectiveness ofgastric bypass and gastroplasty. Arch Surg117:695–700, 1982

36Sugerman HJ, Londrey GL, Kellum JM,Wolf L, Liszka T, Engle KM, Birkenhauer R,Starkey JV: Weight loss with vertical banded gas-troplasty and Roux-en Y gastric bypass for mor-bid obesity with selection vs random assignment.Am J Surg 157:93–102, 1989

37Hall JC, Watts JM, O’Brien PE, DunstanRE, Walsh JF, Slavotinek AH, Elmslie RG: Gas-tric surgery for morbid obesity: the AdelaideStudy. Ann Surg 211:419–427, 1990

38Brolin RE, Kenler HA, Gorman JH, CodyR: Long-limb gastric bypass in the superobese: aprospective randomized trial. Ann Surg215:387–395, 1991

39MacLean LD, Rhode BM, Sampalis J, ForseRA: Results of the surgical treatment of obesity.Am J Surg 165:155–162, 1993

40Pories WL, Swanson MS, MacDonald KG,Long SB, Morris PG, Brown BM, Barakat HA,deRamon RA, Israel G, Dolezal JM: Who wouldhave thought it? An operation proves to be themost effective therapy of adult onset of diabetesmellitus. Ann Surg 222:339–352, 1995

41Capella JF, Capella RF: The weight reduc-tion operation of choice: vertical banded gastro-plasty or gastric bypass. Am J Surg 171:74–79,1996

42Fobi MA, Lee H, Holness R, Cabinda D:Gastric bypass operation for obesity. World JSurg 22:925–935, 1998

43MacLean LD, Rhode B, Nohr CW: Lateoutcome of isolated gastric bypass. Ann Surg231:524–528, 2000

44Ferraro D: Laparoscopic adjustable gastricbanding for morbid obesity. AORN J 77:924–940,2003

45Schauer PR, Burguera B, Ikramuddin S,Cottam D, Gourach W, Hamad G, Eid G, MattarS, Ramanthon R, Barinas-Mitchel E, Harsha R,Kuller L, Kelley D: Effect of laparoscopic Roux-en Y gastric bypass on type 2 diabetes mellitus.Ann Surg 238:467–483, 2003

46Bray GA: Obesity: overview of therapy forobesity. UpToDate [serial on CD-ROM] 2000;8(1). Wellesley, Mass., UpToDate, 2000

Thomas L. O’Connell, MD, is an assis-tant clinical professor in the Division ofEndocrinology, Department of Medicineat Duke University Medical Center, inDurham, N.C.

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