Bariatric surgery is increasingly recognised as a viable approach to effective weight-loss management. In part one of a new series the authors discuss the different types of bariatric surgery
Nicola Maguire, Milind Rao, Bussa Rao Gopinath The University hospital of North Tees, Stockton- on-Tees
The World Health Organisation defines overweight and obesity as an abnormal or disproportionate accumulation of body fat which may be harmful to health. 1 The incidence of overweight or obese adults in England in 2013 was 62.1% (67.1% of men and 57.2% of women). 2 This presents a significant public health challenge. Those classified as overweight or obese are at risk of developing major health problems associated with a reduction in life expectancy. A BMI of 30-35 carries with it a 2-4 years reduction in life expectancy, a BMI >40 is associated with an 8-10 year reduction. 3 Significant morbidity in combination with substantial social consequences of obesity such as discrimination, social isolation and potential reduction or loss of earnings negatively impacts on the wider UK economy. 4 NHS costs attributable to overweight or obese patients are estimated to be £4.2 billion and indirect costs to the wider economy of £15.8 billion, with this set to rise with the increasing rates of overweight and obese adults and children in the UK. 5 Worldwide, bariatric surgery is being increasingly utilised to treat obesity and its complications as studies have shown it to be the only method for achieving long term weight loss in the morbidly obese. 6 In the UK, more than 18,283 bariatric operations have been carried out between 2010 and 2013. 7
Classiﬁcation and prevalence
Obesity is most commonly classified using BMI which is calculated by the weight in kilograms divided by height in metres squared (kg/m 2). Although BMI does not directly measure adiposity and must be interpreted with caution in certain populations (for example pregnancy and children), a BMI of over 30 kg/m 2 is classified as obesity.8 The prevalence of obesity (BMI >30 kg/m 2) in England is calculated to be 24.4% in men and 25.1% in women with similar figures throughout the UK. 2,9–11 The highest prevalence of obesity worldwide occurs in the United States of America. If current trends continue it is estimated that by 2025 UK obesity could have increased to 47% and 36% in men and women respectively.5
Sequelae of obesity
Overweight and obese patients are at increased risk of developing a number of medical conditions including type 2 diabetes mellitus, hypertension, dyslipidaemia, cardiovascular disease, sleep apnoea, osteoarthritis and certain cancers, mainly oesophageal, endometrial, colorectal and breast (in post-menopausal women).12 With the development of these serious health conditions comes a reduction in life expectancy and the WHO estimate 3.4 million adults die each year as a result of being overweight or obese.1 Obesity also impacts upon reproductive health and fertility,13,14 psychological health and has wider social and economic implications.4 Obesity is now recognised as a disease by the WHO and has been incorporated into the ‘Global Action Plan for the prevention and control of non-communicable diseases 2013-2020’ with the aim of stopping the growth of global obesity and therefore reduce its impact on mortality worldwide.1
Current treatment modalities
The management of obesity is multifactorial and National Institute for Health and Care Excellence (NICE) recommend a tier based approach (Figure 1). 15 The starting tier is dependent on increasing BMI with or without associated obesity related comorbidities or unsuccessful progress at lower tiers. Tier 1 approach focuses on primary care and community advice to support weight management with guidance on reduction in calorie intake, healthy eating and physical exercise. The second tier of obesity management focuses on community interventions managed by the general practitioner and the community team including exercise prescription. Pharmacotherapy (Table 1) is a further treatment modality which may be considered when patients have not achieved their target weight with the help of diet, exercise and behavioural alterations or are struggling to maintain their weight loss. Tier 3 involves referral to a multi-disciplinary specialist weight management service in the community and progression to Tier 4 signifies involvement of secondary care and bariatric surgeons.
Orlistat, a selective lipase inhibitor, is currently the only anti-obesity medication approved in the UK by NICE. Orlistat selectively binds to gastric and pancreatic lipase in the gastrointestinal tract. This partially inhibits the hydrolysis of dietary triglycerides to their substrates, thereby limiting their absorption. The fat which is not absorbed (approximately 30% of intake) is excreted, which can make stools pale and loose. 16 NICE guidelines suggest it may be prescribed in patients of BMI >30kg/m 2 or BMI >28kg/m 2 with associated risk factors when diet and exercise is failing. Orlistat may be continued after three months if the patient loses at least 5% of their body weight. Cases should be reviewed on an individual bases after a year. 8
Adjustable gastric band
Biliary pancreatic diversion (BPD) (+/- duodenal switch)
Bariatric surgery and diabetes
2. Health and social care information centre. Statistics on Obesity, Physical activity and diet: England. 2014.
3. Prospective Studies Collaberation. Body-mass index and cause-specific mortality in 900 000 adults: collaborative analyses of 57 prospective studies. Lancet . 2009;373(9669):1083–96.
4. Morgan E, Dent M. The economic burden of obesity Oxford: National Obesity Observatory. 2010.
5. MacPherson K, Marsh T, Brown M. Tackling Obesities : Future Choices – Modelling Future Trends in Obesity and the Impact on Health 2nd Edition. Foresight Programme of the Government Office for Science. London; 2007.
6. Maggard M, Shugarman L, Suttorp M, Maglione M, Sugerman H, Livingston E, et al. Ann Intern Med . 2005;142:547–59.
7. National bariatric surgery data committee. The United Kingdom National Bariatric Surgery Registry: Second Registry Report. 2014.
8. NICE. Obesity : Identification , assessment and management of overweight and obesity in children , young people and adults. 2014. p. 1–70.
9. The Scottish Government. The Scottish Health Survery . 2012.
10. The Welsh Government. The Welsh Health Survey . 2012.
11. Organisation for Economic Co-operation and Development. Health at a Glance . 2013. 12. Picot J, Jones J, Colquitt J, Gospodarevskaya E, Loveman E, Baxter L, et al. Heal Technol Assess . 2009;13:1–190, 215–357, iii – iv.
13. Motta A. Curr Pharm Des . 2012;18(17):2482–91.
14. Vrebosch L, Bel S, Vansant G, Guelinckx I, Devlieger R. Obes Surg . 2012 Oct;22(10):1568–79.
15. NICE. Managing overweight and obesity in adults – lifestyle weight management services. 2014.
16. Guerciolini R. Int J Obes Relat Metab Disord . 1997;21(Suppl 3):S12–23.
17. Bray GA. Best Pract Res Clin Gastroenterol . Elsevier Ltd; 2014 Aug;28(4):665–84.
19. Miyazaki Y, Takiguchi S, Seki Y, Kasama K, Takahashi T, Kurokawa Y, et al. World J Surg . 2013 Dec;37(12):2883–90.
20. Buchwald H, Oien DM. Obes Surg . 2013 Apr;23(4):427–36.
21. Baldry EL, Leeder PC II. Obes Surg . 2014;24(3):416–21.
22. Zerrweck C, Maunoury V, Caiazzo R, Branche J, Dezfoulian G, et al. Obes Surg . 2012;22(5):777–82.
23. Genco A, López-Nava G, Wahlen C, Maselli R, Cipriano M, et al. Obes Surg . 2013;23(4):515–21.
24. Brown W, Korin A, Burton P. Aust Fam Physician . 2009;38(12):972–6.
25. O’Brien PE, MacDonald L, Anderson M, Brennan L, Brown W. Ann Surg . 2013;257(1):87–94.
26. Brown JJS, Boyle M, Mahawar K, Balupuri S, Small PK. Br J Surg . 2013;100:1614–8.
28. Frezza E. Surg Today . 2007;37:275–81.
29. Gumbs A, Gagner M, Dakin G, Al E. Obes Surg. 2007;17:962–9.
30. Arterburn DE, Courcoulas AP. BMJ [Internet]. 2014;349:g3961
31. Dixon JB, Brien PEO, Playfair J, Chapman L, Schachter LM, Skinner S, et al. JAMA . 2008;299(3):316–23.
32. Vest AR, Heneghan HM, Agarwal S, Schauer PR, Young JB. Heart . 2012 Dec;98(24):1763–77.
33. Schauer PR, Bhatt DL, Kirwan JP, Wolski K, Brethauer S a, Navaneethan SD, et al. N Engl J Med . 2014;370(21):2002–13.
34. Sjöström L. J Intern Med . 2013;273(3):219–34.