Background
Obesity has truly become a worldwide problem, affecting countries rich and poor. One of the most recent and careful global estimates finds that roughly 500 million adults are obese (defined as a body mass index, or BMI, of 30 or higher).(1) Nearly 1.5 billion adults were overweight or obese (defined as a BMI of 25 or higher). National survey on diabetes mellitus and risk factors for Non-communicable Diseases (NCDs) in Myanmar was performed in 2014 which included 8757 adults aged 25 to 64 years. According to that survey, prevalence of obesity and overweight was 5.5% and 22.4% respectively.(6)
Pathophysiology
Controlling energy intake and energy expenditure are the main mechanisms by which energy balance is achieved. However, energy regulation is complex and a widely held view is that obesity results from an interaction between environment/lifestyle and genetic susceptibility. Secondary causes (hypothyroidism, Cushing’ syndrome, hypothalamic lesions, polycystic ovarian syndrome and some drugs) are other uncommon causes of obesity.(5)
Measurements of obesity
Obesity represents a state of excess storage of body fat. Body Mass Index (BMI), also known as the Quetelet index, is defined as weight in kilograms divided by height in meters squared. Other indices used to estimate the degree and distribution of obesity include the four standard skin thicknesses (i.e., subscapular, triceps, biceps, suprailiac) and various anthropometric measures, of which waist and hip circumferences are the most important. Skin fold measurements are the least accurate means by which to assess obesity.(3)
Classification of Obesity (2)
Note: Asians do use lower thresholds for overweight (> 23 kg/m2) and obesity (> 25 kg/m2).
Consequences of Obesity (5)
Management
(a) Assessment
For overweight and obese patient, standard assessment includes: medical history, medical conditions and medications that could be contributing to weight gain, sleep apnea, history of weight gain, family history of obesity, dietary and physical activity habits, environmental and cultural factors impacting weight, pattern of weight changes over the years, and history of weight loss attempts. The following should also be included: physical examination, blood pressure assessment, and fasting glucose, lipid measures and endocrine functions.
(b) Lifestyle intervention
Lifestyle modification is recommended as the cornerstone of obesity management. To successfully achieve clinically meaningful weight loss of 5– 10%of original weight (maximum weekly weight loss of 0.5 -1 kg), a comprehensive, intense lifestyle intervention is needed that includes at least fourteen in-person sessions within 6 six months.
Effective weight loss interventions should focus on long-term lifestyle changes rather than a short-term, quick-fix approach, which includes being multi component, addressing both diet and activity, and offering a variety of approaches, using a balanced, healthy-eating approach, recommending regular physical activity and behavioral strategies to foster adherence to dietary and physical activity recommendations. These can be delivered via individual or group sessions, with both approaches being effective at promoting weight loss.
People who are overweight or obese, and their families and/or carers, should be given relevant information on the distinction between losing weight and maintaining weight loss, and the importance of developing skills for both; the change from losing weight to maintenance typically happens after 6 – 9 months of treatment.(2, 4)
(c) Pharmacotherapy
Pharmacotherapy should be a consideration for patients with a BMI of ≥ 30 kg/m2 and BMI of ≥ 27 kg/m2with weight-related comorbidities such as T2D, and is the next logical therapeutic approach for patients who have historically failed to benefit from lifestyle modification approaches and for those with difficulty maintaining weight loss over the long term.(2)
Four medications—phentermine, diethylpropion, phendimetrazine, and benzphetamine—all structurally related to amphetamine, and approved for short-term use only, have been available for well over 50 years in the United States. Five medications currently approved in the United States for long-term weight management are Orlistat (intestinal pancreatic lipase inhibitor), Lorcaserin (5 HT2c agonist), Liraglutide (GLP-1 agonist), Qnexa (combination of Phentermine and Topiramate), and Contrave (combination of Naltrexone and Bupropion).Clinicians should consider continuing the medication as long as benefit outweighs risk and discontinue drug therapy if 5% weight loss is not achieved after three to four months.(2,5)
(d) Medical devices
Six FDA-approved medical devices including a laparoscopic adjustable gastric band (LAGB), are available for obesity management. Three intra-gastric balloons (Orbera, Re Shape Duo, Obalon) are approved for use up to six months to assist weight loss among patients with BMI of 30 – 40 kg/m2.The Maestro Rechargeable System is a form of vagal nerve blockade and is approved for long-term use in patients with BMI 35 – 45 kg/m2. For long-term use in patients with BMI 35 – 55 kg/m2, gastric emptying systems (Aspire Assist) is approved. Each device has its own benefit and risk.(2)
(e) Bariatric surgery
It is indicated for patients with BMI ≥ 40 kg/m2and ≥ 35 kg/m2 in the presence of weight-related comorbidities such as T2D, with lower BMI cutoffs for LAGB. Common surgical procedures are sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), LAGB and biliopancreatic diversion with duodenal switch. LAGB is the least invasive of the four procedures and has the least complications and is also reversible. Sleeve gastrectomy has gained popularity in the past decade due to procedural ease, less frequency of serious complications and significant weight loss. It is now endorsed by leading diabetes organizations as an effective intervention for T2D and is recommended for patients with class III obesity and for those with class II obesity whose hyperglycemia is inadequately controlled by lifestyle and medical therapy.(2)
Conclusion
Obesity, besides impairing quality of life, is associated with numerous chronic diseases. Although global obesity prevalence has not decreased, more therapeutic options are available today, thus improving management of patients with obesity and related comorbidities.
References
- Finucane, M. M., Stevens, G. A., Cowan, M. J., et al (2011) National, regional, and global trends in body-mass index since 1980: systematic analysis of health examination surveys and epidemiological studies with 960 country-years and 9.1 million participants. Lancet. 377, pp: 557- 67.
- Gadde, K. M., Martin, C. K., Berthoud, H. R., et al (2018) Obesity: Pathophysiology and Management. Journal of the American College of Cardiology. 71(1). pp: 79 – 84.
- Hamdy, O. (2017) Obesity: Practice Essentials. Medscape Medical News.
- NICE clinical guideline 43 (2006) Obesity: guidance on the prevention, identification, assessment and management of overweight and obesity in adults and children. www.nice.org.uk/CG043 (Accessed on 13.3.2019)
- Oxford Handbook of Endocrinology and Diabetes. 3rd edition. India: oxford University Press, pp: 847 – 865.
- Tint-SweLatt, Ko-KoZaw, Ko-Ko., et al (2014) National Survey on Diabetes Mellitus and Risk Factors for Noncommunicable Diseases (NCDs) in Myanmar.
Cho Mar1, Moe Wint Aung2, Khin Saw Than3
1 Lecturer, Department of Endocrinology, University of Medicine 1, Yangon
2 Professor, Department of Endocrinology, University of Medicine 1, Yangon
3 Professor/Head, Department of Diabetes and Endocrinology, Yangon General Hospital
