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Laporan Kasus

J Indon Med Assoc, Volum: 62, Nomor: 3, Maret 2012 107

Mortality and Morbidity Benefit of Bariatric Surgery Among Obese Patients:

an Evidence Based Report

Alvin Nursalim,* Wismandari Wisnu**

*Faculty of Medicine Universitas Indonesia, Jakarta**Department of Internal Medicine Metabolic Endocrine Division,

Faculty of Medicine Universitas Indonesia-Cipto Mangunkusumo Hospital, Jakarta

Abstract Introduction : Bariatric surgery is a surgical procedure resulting in weight loss. Weight lossafter surgery is well documented, but the favorable effect on mortality and morbidity need to be

further elucidated. Aim: To determine whether bariatric surgery possess mortality and morbidity benefit. Method : After structured literature searching, all studies are critically appraised and presented as evidence based case report.

Result : All five studies are considered to have good validity and relevance. Sjostorm et al and Adams et al confirmed reduction of mortality in surgery group. Relative risk reduction (RRR):

21% and 31%, absolute risk reduction (ARR): 1.3% and 1.4%, number needed to treat (NTT):77 and 72. Incidence of diabetes, hypertryglyceride and hyperuricemia were significantly lower in surgery group after 10 years (RRR 6-20%, ARR 5-10% and NNT 10- 20).Conclusion : Bariatric surgery for severe obesity is associated with decreased mortality and morbidity. J Indon Med Assoc. 2012;62:107-12 .

Keywords : Obesity, bariatric surgery, mortality, morbidity

Korespondensi : Alvin Nursalim, Email: [email protected]

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Operasi Bariatrik dalam Menurunkan Mortalitas dan Morbiditas padaPasien Obes: Laporan Berbasis Bukti

Alvin Nursalim*, Wismandari Wisnu**

*Fakultas Kedokteran Universitas Indonesia, Jakarta**Departemen Ilmu Penyakit Dalam Divisi Metabolik Endokrin Fakultas Kedokteran Universitas Indonesia/

Rumah Saki t Cipto Mangunkusuno, Jakarta

Abstrak Pendahuluan : Operasi bariatrik adalah prosedur yang bertujuan untuk menurunkan berat badan. Penurunan berat badan setelah prosedur ini banyak didokumentasikan, namun keuntunganbedah bariatrik terhadap mortalitas dan morbiditas masih perlu dipelajari lebih lanjut.Tujuan: Untuk mengetahui efek operasi bariatrik terhadap mortalitas dan morbiditas padaindividu obes.

Metode : Setelah dilakukan pencarian literatur secara terstruktur, studi yang didapat ditelaahkritis dan disajikan dalam bentuk laporan berbasis bukti.

Hasil : Ditemukan lima studi dengan validitas dan relevansi yang baik. Sjostorm et al dan Adamset al memaparkan penurunan angka mortalitas pada kelompok operasi bariatrik. Hal ini terlihat dari relative risk reduction (RRR) 21% dan 31%, absolute risk reduction (ARR) 1,3% dan 1,4%,serta number needed to treat (NTT) 77 dan 72. Operasi bariatrik menyebabkan penurunaninsiden diabetes, hipertrigliserida dan hiperurisemia setelah 10 tahun (RRR: 6-20%, ARR:5-10% dan NNT:10-20).

Kesimpulan : Operasi bariatrik pada individu obes berhubungan dengan menurunnya mortalitasdan morbiditas. J Indon Med Assoc. 2012;62:107-12 .

Kata Kunci : Obesitas, operasi bariatrik, mortalitas, morbiditas.

Introduction

Obesity is defined by a body mass index (BMI) of 30 ormore. The BMI cut-off for obesity varied among region, BMIabove 25.0 is considered obese for Asia Pacific population. 1,2

The amount of obesity cases around the world is stagger-ing. There are approximately 250 million people with BMI>30 kg/m 2 worldwide. This number represents 7% of adultpopulation. 2 According to Riset Kesehatan Dasar 2010,the prevalence of obesity for individual above 18 years oldis 21.7%. This number is higher as compared to obesity preva-lence in 2007 (19.1%). We can expect an even higher obesitycases in the upcoming years. As obesity cases increase, thecomplications would eventually rise as well. 3 The increasingnumber of obesity is very much influenced by theobesogenic environment that promote sedentary lifestyleand attractive calorie-riched food (usulally called as junk food). 4

Obesity is strongly linked to the increasing amount of cardiovascular complication. Obesity increases triglyceridelevel, which has a detrimental effect on cardiac health. Onthe other hand, obesity reduce the amount of cardiac-pro-tective lipid, high density lipoprotein (HDL). 5 As obesity caseincrease, the amount of hypertension case would also in-crease accordingly. Obesity is also associated with other

numerous comorbidities, such as diabetes mellitus, left ven-tricular hypertrophy, certain cancers, and sleep apnea orsleep-disordered breathing. 6

Weight loss is known to be associated with improve-ment of risk factors for many diseases, including diabetes,hypertension, and dyslipidemia; therefore, lifestyle changesand medication need to be applied to those obese popula-tion. Despite intensive lifestyle changes and maximum medi-cation regimens, some people failed to achieve the targetideal weight. In this case, more aggressive measure need tobe done, especially in those population with BMI >35 kg/m 2

with comorbid or BMI >40 kg/m 2. Bariatric surgery might bethe only hope for those markly obese population who unre-sponsive to other treatment. 4

Bariatric surgery is a surgical procedures designed toproduce substantial weight loss. There are various bariatricprocedures, such as: laparoscopic adjustable gastric bandsand vertical banded gastroplasty; a restrictive but alsomalabsorptive concept such as roux-en Y gastric bypass andsleeve gastrectomy. 4 Since bariatric surgery is the lastmeassure for obesity and rarely performed, especially in In-donesia, not many clinician are aware of this procedure. Al-

though bariatric surgery is not as popular in Indonesia as it

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J Indon Med Assoc, Volum: 62, Nomor: 3, Maret 2012 10 9

is in western countries, but as more evidence support theefficacy of this surgery for severe obese population, it isnoteworthy for clinician to know about the surgery. Hope-

fully, this report could give a new insight on bariatric sur-gery for obesity management in Indonesia.Weight loss after the surgery is well documented, but

information regarding the favorable effect of the surgery onlife span and morbidity is lacking; therefore whether bariatricsurgery possess benefit in terms of mortality and morbidityneed to be investigated.

Clinical Question

Does bariatric surgery provide benefit on mortality andmorbidity for obese population who underwent the proce-dure?

According to International Diabetes Federation, therecommended BMI for bariatric surgery is BMI >35 kg/m 2

with comorbid or BMI >40 kg/m 2. However, to expand ourdiscussion later on and to give further recommendation, wedid not limit our search to a certain grade of obesity. 1 So, if any, even first grade obesity (defined by BMI >30 kg/m 2 andBMI >27.5 kg/m 2 for asian) would be included in the ap-praisal.

From the clinical question above, the intervention isany bariatric surgery procedure, while the comparison is anylifestyle and medication intervention (excluding any surgeryintervention) that usually performed among obese popula-tion. Mortality benefit is defined by any death reductionfrom any cause during follow-up period, which benefit mostlikely to occur in long term (although we are not excludingany immediate mortality benefit, if there is any at all). Mor-bidity is defined the state of being unhealthy. There are nu-merous parameters for morbidity, such as disease remission(good blood glucose control on diabetes, dyslipidemia) andquality of life.Method

PubMed and Google search was performed onMarch 7 th 2012, using the keywords obese, bariatric,mortality, and morbidity along with its synonyms and

related terms (Table 1). Search strategy, results, the inclusionand exclusion criterias are shown in a flowchart (Figure 1).Bariatric surgery is a relatively new procedure to treat obe-sity; therefore, we deliberately limit our search to any stud-ies published from 2001 to early 2012. In this review we onlyappraise individual study or randomized controlled trial (RCT)with relevant topic with the clinical question. After the selec-tion, critical appraisal was performed using several aspectsbased on Center of Evidence-based Medicine, University of Oxford for therapy study (Table 2). 8

Table 1. Search Strategy used in PubMed and Google (Conducted on March 7 th 2012)

Database Search terms Results

Pubmed ((bariatric surgery[MeSH Terms] OR 44(7 th March 2012) (bariatric [All Fields] AND surgery

[All Fields]) OR bariatric surgery[All Fields]) AND (gastric bypass[MeSH Terms] OR (gastric[All Fields] AND bypass[All Fields])OR gastric bypass[All Fields])AND (mortality[Subheading] OR mortality[All Fields] OR mortality[MeSH Terms]) AND (obesity[MeSHTerms] OR obesity[All Fields] OR obese[All Fields])) AND (2007/01/16[PDat] : 2012/01/14[PDat])

Google Bariatric, obese, gastric bypass, mortality, 5(7 th March 2012) morbidity

Figure 1 Flow Chart of Search Strategy

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J Indon Med Assoc, Volum: 62, Nomor: 3, Maret 2012110

Result

From the selection and filtration, five articles qualifiedfor further assessment. These articles were appraised andconsidered to have a good validity and relevance. Most of these studies are large scale studies with adequate followup period and all of them are written in english. We did notfind any articles written in other language beside englishthat would be otherwise relevant to our clinical question.

Sjostrom et al studied the long term benefit of bariatricsurgery in swedish obese population. The study involved4047 obese subjects, which comprised of two groups, 2010subjects in the surgery group, and 2037 subjects in the con-trol group who only receive conventional treatment (lifestylechanges) for obesity. Of the 2010 subjects in the surgerygroup, 376 underwent nonadjustable banding, 1369 under-went vertical banded gastroplasty, and 265 underwent gas-tric bypass. The average BMI for the surgery group was42.44.5 and for the control group was 40.14.7. 9

The mortality hazard ratio for subject who underwentthe surgery as compared with the control group was 0.76(95% confidence interval, 0.59 to 0.99; P=0.04). During thefollow-up period, 129 subjects in the control group died, ascompared with 101 in the surgery group. The Control Event

Sjostrom L et al 9 + 4047 - + + + + + + + A 2B

Adams TD et al 10 -**** 9949 - + ? + + + + + B 2B

Dixon JB et al 11 + 60 + + ? + + + + + C 1B

Sjostrom L et al 12 + 4047 - + ? + + + + + D 2B

Dixon JB et al 13 + 459 ? + ? + + + + + E 1B

S t u d y

d e s i g n

N u m

b e r o f p a

t i e n

t s

R a n

d o m

i z a t

i o n *

S i m i l a r

i t y

t r e a

t m e n

t

a n d c o n t r o

l

B l i n d

i n g *

*

C o m p a r a

b l e

t r e a

t m e n

t

I n t e n t

i o n

t o t r e a

t

D o m a i n

D e t e r m

i n a n

t

M e a s s u r e m e n

t o f

o u t c o m e

Articles Validity Relevance Resul t Levels of evidence***

Table 2 Critical Appraisal of the 5 useful articles based on criterias by Centre of Evidence Medicine University of Oxford 8

Legend:+ stated clearly in the article- not being done? not stated clearly

*Since the intervention is surgical procedure, randomization is not performed in most studies.**We define blinding for outcome assessor and this blinding need to be clearly stated in the study.***Levels of evidence based on The Oxford Centre of Evidence-based Medicine**** The study performed by Adams TD et al was a retrospective cohort studyA: After 10 years, there were 129 deaths in the control group and 101 deaths in the surgery group. The hazard ratio was 0.76 in the surgery

group (95% confidence interval, 0.59 to 0.99; P = 0.04)B: During a mean follow-up of 7.1 years, long-term mortality from any cause in the surgery group decreased by 40%, as compared with

that in the control group (37.6 vs. 57.1 deaths per 10,000 person-years, P

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111

levels

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risk of complication post-operative, high cost of the surgeryand the high NNT as showed above, made it absurd to applythis surgery for general obese population; therefor, this sur-

gery required meticulous candidate selection to assure thesafety and long term benefit of the procedure. Limited ac-cess to multidisciplinary facilities in some Indonesian re-gion, might also compromise the benefit of this surgery. Thewide variety of bariatric surgery procedures require furtherinvestigation as to determine which one is the best proce-dure in terms of clinical and cost efficacy.

All these studies are not without limitations. Since theintervention is an invasive surgical procedure, it would beunethical to perform randomization. The lack of randomiza-tion made most of these clinical trials fall into a lesser level of evidence. Other limitation of this appraisal is the small num-ber of articles found. We only found one relevant articleswith good level of evidence (1b). Nonetheless, all of thesearticles reported similar findings in terms of mortality andmorbidity benefit of bariatric surgery. One important thing tobe further studied is the long term safety profile of this pro-cedure. Although, most studies showed favourable effect of bariatric surgery, clinical experience with this type of sur-gery is still limited (especially in Indonesia) and there mightbe other side effects yet to be discovered. Therefore, theconclusion of these studies need to be applied with caution.

Conclusion

These evidence provides reliable proof of the benefit of

bariatric surgery in terms of hard end point (mortality) andmorbidity for extremely obese patient. From our extensivesearching, there was still limited high-quality studies uponthis matter. So, further studies are required to give clinicianmore high-quality evidence (RCT) to back up their clinicaldecision. For now, this invasive procedure need to be ap-plied with caution, require each patients characteristicassestment and thorough consideration.

Recommendation for clinical use

These evidences can be applied into clinical practise.For example, this case is presented to us. A 55 years old

woman came to a private hospital for a regular check-up. Shecame from a good socio-economic background. She had beendiagnosed of diabetes, hypertension and dyslipidemia since2 years ago. The doctor concerned about her body weight.Her weight was 89 kg, while her height was 1.57 m. Her BMIwas 36 kg/m 2. Her body weight used to be 94 kg and herbody weight remained the same despite maximum diet andintensive lifestyle changes for the last 8 months. She alsocomplained of depression and lack of confidence due to herphysical appearance. The doctor considered a bariatric sur-

gery as the last meassure. According to the evidences found,bariatric surgery is proven to have beneficial effect in termsof diabetes remission and reduced overall mortality. Bariatric

surgery can be carried out for this case. We emphazise onthe long term multidisciplinary approach pre and post opera-tive. Patient physical and mental condition need to be sup-ported throughout the procedure.

References1. WHO/IOTF/IASO. The Asia-Pacific perspective: Redefining

Obesity and its treatment. [cited 2011 December 24]. Availablefrom: http://www.wpro.who.int/nutrition/documents/Redefining_obesity/en/index.html

2. Sugondo S. Obesitas. In: Sudoyo AW, Setiyohadi B, Alwi I,Simadibrata M, Setiati S, editors. Buku ajar ilmu penyakit dalamedisi V. Jakarta: Interna Publishing; 2009. p. 1973-83.

3. Riset Kesehatan Dasar 2010. [cited 2012 July 5]. Available from:

http://www.litbang.depkes.go.id/sites/download/buku_laporan/ lapnas_riskesdas2010/Laporan_riskesdas_2010.pdf 4. International Diabetes Federation. Bariatric surgical and proce-

dural interventions in the treatment of obese patients with type2 diabetes: a position statement from the International DiabetesFederation Taskforce on Epidemiology and Prevention. [cited2012 July 5]. Available from: http://www.diabetes.org.br/anexo/ idf-position-statement-bariatric-surgery.pdf

5. Lavie CJ, Milani RV. Obesity and cardiovascular disease: theHippocrates paradox? J Am Coll Cardiol. 2003;42:677-9.

6. Artham SM, Lavie CJ, Milani RV, Ventura HO. Obesity and hy-pertension, heart failure and coronary heart disase- risk factor,paradox, and recommendations for weight loss. The OchsnerJournal. 2009;9:124-32.

7. Renard E. Bariatric surgery in patients with late stage type 2diabetes; expected beneficial effects on risk ratio and outcomes.Diabetes Metab. 2009;35:564-8.

8. Centre for Evidence Based Medicine. Oxford Centre for Evi-dence-based Medicine- Level of Evidence. CEBM March 2009.[cited 2012 January 20]. Available from: http://www.cebm.net/ index.aspx?o=5513.

9. Sjostorm L, Narbro K, Sjostrom D, Karason K, Larsson B, WedelH, et al. Effects of bariatric surgery on mortality in swedish obesesubjects. N Eng J Med. 2007; 357:741-52.

10. Adams TD, Gress RE, Smith SC, Halverson RC, Simper SC,Rosamond WD, et al. Long term mortality after gastric bypasssurgery. N Eng J Med. 2007;357:753-61.

11. Dixon JB, OBrien PE, Playfair J, Chapman L, Schacter LM,Skinner S, et al. Adjustable gastric banding and conventionaltherapy for type 2 diabetes. JAMA. 2008;299:316-23.

12 . Sjostrom L, Lindroos AK, Peltonen M, Torgerson J, Bouchard C,

Carlsson B, et al. Lifestyle, diabetes, and cardiovascular risk fac-tors 10 years after bariatric surgery. N Eng J Med. 2004;351:2683-93 .

13 . Dixon JB, Dixon ME, OBrien PE. Quality of life after lap-bandplacement: influence of time, weight loss and comorbidities. ObesRes. 2001; 9:713-21.

14 . Hoerger TJ, Zhang P, Segel JE, Kahn HS, Barker LE, Couper S.Cost-effectiveness of bariatric surgery for severely obese adultswith diabetes. Diabetes Care. 2010;33:1933-9.

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