1. 1. University of Sulaimani Faculty of medical sciences School of Medicine Department of Family and Community Medicine Report title: Obesity Prepared by: Aram A. Shah Ayyub Qadir Soma Dler Baxan Swara Treefa Omar Supervisor: Ms Goshan Mohamed Karadaghi
2. 2. Obesity: Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have a negative effect on health, leading to reduced life expectancy and/or increased health problems. 1 For thousands of years obesity was rarely seen.2 It was not until the 20th century that it became common -- so much so that in 1997 the World Health Organization (WHO) formally recognized obesity as a global epidemic.3 In June of 2013 the American Medical Association classified obesity as a disease with much controversy.4 Although during history overweight was sometimes linked with disease and shorter life span, in general, extra fat was related to wealth, health, and attractiveness. Low weight and thinness were associated with poverty, malnutrition, and wasting diseases such as tuberculosis. Scarcity of food throughout most of history meant that most people did not have the opportunity to become obese.5 Epidemiology: Overall, about 13% of the worlds adult population (11% of men and 15% of women) were obese in 2014.The worldwide prevalence of obesity more than doubled between 1980 and 2014. Most of the world's population live in countries where overweight and obesity kill more people than underweight (this includes all high-income and most middle-income countries).6 Obesity is a leading preventable cause of death worldwide, with increasing rates in adults and children. Authorities view it as one of the most serious public health problems of the 21st century.7 Worldwide, at least 2.8 million people die each year as a result of being overweight or obese.8 While less than 2.7 million deaths have been reported due to AIDS by the WHO in 2001 and less than 1 million for cancer.9 The United States has the highest obesity rates in the developed world.10 And the United Kingdom now has the highest rate of obesity in Europe.11 There are two types of obesity: 1. Android obesity: male pattern or abdominal obesity.1 2. Gynoid obesity: female pattern or gluteal obesity.1 Predominant age: obesity can occur at any age. 12 Predominant sex: According to WHO, females are more commonly affected than males.12 Etiology : Body weight is ultimately determined by the interaction of genetic, environmental and psychosocial factors acting through the physiological mediators of energy intake and expenditure.13 Like many other medical conditions, obesity is the result of an interplay between genetic and environmental factors.13
3. 3. Genetic: Polymorphisms in various genes controlling appetite and metabolism predispose to obesity when sufficient food energy is present.14 A few rare single gene disorders have been identified which lead to severe childhood obesit. People with two copies of the FTO gene (fat mass and obesity associated gene) have been found on average to weigh 34 kg more and have a 1.67-fold greater risk of obesity compared with those without the risk allele.15 The influence genetics have on BMI varies from 6% to 85% depending on the population examined.16 Obesity is a major feature in several syndromes, such as PraderWilli syndrome, Bardet Biedl syndrome, Cohen syndrome, and MOMO syndrome: Macrosomia (excessive birth weight), Obesity, Macrocephaly (excessive head size) and Ocular abnormalities.17 Some reasons for the increasing prevalence of obesity (obesogenic environment): Diet: Total food energy consumption has been found to be related to obesity.18 Most of this extra food energy is from an increase in carbohydrate consumption rather than fat consumption.19 The primary sources of these extra carbohydrates are sweetened beverages, which now account for almost 25 percent of daily food energy in young adults in America, and potato chips. Consumption of sweetened drinks such as soft drinks, fruit drinks, iced tea, and energy and vitamin water drinks is believed to be contributing to the rising rates of obesity.20 Increasing energy intake: Increased portion sizes, increased Snacking and loss of regular meals, increased Energy- dense food (mainly fat), and increased affluence (Richness). These conditions make the energy intake more than the expenditure which leads to storing the excess energy as fat in the body.21 Sedentary lifestyle (decreased energy expenditure): Currently at least 30% of the world's population gets insufficient exercise.22 Increased car ownership, decreased walking to school/work, increased Automation; decreased manual labour.23 Decreased sports in schools.24 Increased time spent on computer games and watching TV.25
4. 4. Potentially reversible causes of weight gain: Endocrine factors leading to obesity: Hypothyroidism, which is a condition in which the thyroid gland does not produce enough thyroid hormones which have important role in regulating metabolism and energy expenditure, is one of the conditions leading to obesity. Cushings syndrome is another condition causing obesity, in this disorder therell be excessive production of the hormone Cortisol by the adrenal gland or exogenous cortisol is taken as medication leading to change in the fat metabolism. Another condition leading to obesity is growth hormone deficiency, which is caused by damage to pituitary gland which normally produces growth hormone, or congenital deficiency of the hormone. Growth hormone has many metabolic functions including fat metabolism, deficiency of this hormone leads to obesity.26 Drugs causing obesity: These include insulin, sulfonylureas, thiazolidinediones, atypical antipsychotics, antidepressants, steroids,certain anticonvulsants (phenytoin and valproate), pizotifen, and some forms of hormonal contraception.1 Infetious agents causing obesity: An association between viruses and obesity has been found in humans and several different animal species. The amount that these associations may have contributed to the rising rate of obesity is yet to be determined. 27 Pathophysiology: There are many possible pathophysiological mechanisms involved in the development and maintenance of obesity. This field of research had been almost unapproached until the leptin gene was discovered in 1994.28 Leptin and ghrelin are considered to be complementary in their influence on appetite, with ghrelin produced by the stomach modulating short-term appetitive control (i.e. to eat when the stomach is empty and to stop when the stomach is stretched). Leptin is produced by adipose tissue to signal fat storage reserves in the body, and mediates long-term appetitive controls (i.e. to eat more when fat storages are low and less when fat storages are high). Although administration of leptin may be effective in a small subset of obese individuals who are leptin deficient, most obese individuals are thought to be leptin resistant and have been found to have high levels of leptin.29 This resistance is thought to explain in part why administration of leptin has not been shown to be effective in suppressing appetite in most obese people. While leptin and ghrelin are produced peripherally, they control appetite through their actions on the central nervous system. In particular, they and other appetite-related hormones act on the hypothalamus, a region of the brain central to the regulation of food intake and energy expenditure. 30 Complications: Cardiological and Endocrine: Obesity is associated with cardiovascular diseases including angina and myocardial infarction.31 It increases one's risk of venous thromboembolism by (2.3) folds.32 Having a BMI greater than 30 doubles one's risk of congestive heart failure. More than 85% of those with hypertension have a BMI greater
5. 5. than 25. Increased LDL cholesterol (bad cholesterol) and lowered HDL cholesterol (good cholesterol). One of the strongest links between obesity and disease is that with type 2 diabetes, these two conditions are so strongly linked that researchers in the 1970s started calling it diabesity. 1 Reproductive system: Polycystic ovarian syndrome (PCOS), Infertility, Complications of pregnancy, Birth defects, Intrauterine fetal death.33 Oncological: A study from the United Kingdom found that approximately 5% of cancer is due to excess weight.34 These cancers include: breast, ovarian, esophageal, colorectal, liver, pancreatic, gallbladder, stomach, endometrial, cervical, prostate, kidney, non-Hodgkin's lymphoma, multiple myeloma. In addition to to Other Dermatological, gastro-intestinal (including gastroesophageal reflux disease; GERD), neurological, psychiatric, respirological, rheumatological, urological and nephrological complications. Figure1:http://www.homeopathicdoctor.co.in/obesity-causes-complications- prevention/ Investigation: Usually these investigations are required to exclude underlying disease or to determine risk factors. 1. Thyroid function test, to exclude underlying thyroid disorder. 2. Serum cholesterol and triglyceride for cardiac risk factor. 3. Blood glucose, to exclude diabetes and for cardiac risk factor. Special tests: 1. Severity of obesity can be quantified using the BMI (Body mass index), which is a measure of relative size based on the mass and height of an individual. Table: BMI Underweight Below 18.5 Normal 18.524.9 Overweight 2529.9 Obesity: 30.0 and Above Class1(moderate) 30-34.9 Class2(severe) 35-39.9 Class3(very severe) 40.0 and Above
6. 6. 2. Fat distribution: a waist circumference of > 102 cm in men or > 88 cm in women indicates that the risk of metabolic and cardiovascular complications of obesity is high.35 Management: A. general measures: The doctor should assess the degree of health risk from BMI and waist circumference, and Assessment of motivation to lose weight.36 B. diet restriction: Diet restriction is an important method for obesity management. The diet should be of low fat, high complex carbohydrates and high fiber quality. Diets to promote weight loss are generally divided into four categories: low-fat, low-carbohydrate, low-calorie, and very low calorie. A meta-analysis of six randomized controlled trials found no difference between three of the main diet types (low calorie, low carbohydrate, and low fat), with a 24 kilogram weight loss in all studies. The composition of the diet should ensure a minimum of 50 g of protein each day for men and 40 g for women to minimize muscle degradation. Side-effects are a problem in the early stages and include orthostatic hypotension, headache, diarrhea and nausea. 36 C. Exercise: improves long term results of weight loss treatment. With use, muscles consume energy derived from both fat and glycogen. Due to the large size of leg muscles, walking, running, and cycling are the most effective means of exercise to reduce body fat. D. medications: Orlistat: Inhibits pancreatic lipase, and thereby decreases the hydrolysis of ingested triglycerides, reducing dietary fat absorption by 30%.37 The drug is not absorbed and adverse side-effects relate to the effect of the resultant fat malabsorption on the gut, namely: loose stools, oily spotting, fecal urgency, flatus and the potential for malabsorption of fat-soluble vitamins.38 Orlistat is taken with each of the three main meals of the day and the dose can be adjusted (60120 mg) to minimize side-effects.39 Starch blockers( e.g. Sure Slim): These new products are extracts of white kidney bean (Phaseolus vulgaris) which inhibit the pancreatic Alpha-amylase enzyme in small intestine and prevent it from digesting complex carbohydrates(e.g. starches). These pass undigested into the stool, thus lowering the calorie intake from meals up to 60% of carb calories. Dosage: 1 capsule thrice daily, just 15 minutes before meals.40
7. 7. Sibutramine : Is a neurotransmitter reuptake inhibitor that reduces the reuptake of serotonin , norepinephrine, and dopamine, thereby increasing the levels of these substances in synaptic clefts and helping enhance satiety; the serotonergic action, in particular, is thought to influence appetite.41 Therefore, it reduces food intake through receptor agonist activity in the central nervous system. But this drug is a withdrawn medication due to cardiovascular side effects.42 E. Surgery: Bariatric surgery to reduce the size of the stomach is by far the most effective long-term treatment for obesity.43 Bariatric surgery is an operation on the stomach and/or intestines that help morbidly obese patients lose substantial amounts of weight. While some surgeries restrict the amount of food that the stomach can hold, others affect the way that food is metabolized; both result in the outcome of significant weight loss. Various types of bariatric surgery are performed, such as Laparoscopic sleeve gastrectomy in which a part of the stomach alongside the great curvature is removed, gastric bypass in which the esophagus will be continuous with the small intestine bypassing the stomach. The latter is done in case of severe ulceration of stomach. Another type of surgery is putting a band around the neck of the stomach to minimize food intake. 44 Figure2: http://www.mdlingo.com/article/bariatric-surgery-a-means-to-lose-diabetes-along-with-weight
8. 8. Prevention: Different policy approaches may be needed to achieve improvements in food and physical activity environments, such as choosing healthier foods (whole grains, fruits and vegetables, healthy fats and protein sources) and beverages, limiting unhealthy foods (refined grains and sweets, potatoes, red meat, processed meat) and beverages (sugary drinks), increasing physical activity, limiting television time, screen time, and other sit time, improving sleep, reducing stress. The latter two have role in hormonal regulation of the body associated with fat storage and weight.45 Conclusion Obesity is a medical condition in which excessive fat will be stored in the body and lead to other health problems and diseases. It has become very common in the last two centuries so much that it was recognized as a disease. Obesity is a leading cause of mortality globally causing death of people by millions annually more than AIDS and cancer. It affects both male and female and it increasingly affects both adults and children. Obesity is caused by many interacting factors including genetics, diets with high energy intake and low energy expenditure, endocrine factors such as in Cushings syndrome, drugs such as steroids, and could be caused by some viral infections. The body regulates appetite and satiety by many mechanisms including the hormone Leptin which is released by adipose tissue. It suppresses appetite and stimulates fat burning by the body for energy. Obesity leads to many diseases, the most important ones are type 2 Diabetes Mellitus, cancers, and the cardiovascular diseases including Myocardial Infarction, hypertension, heart failure, and deep vein thrombosis. Obesity is mostly measured by BMI, which is the body weight (in kilograms) over squared height (in meters). BMI more than 25 indicates overweight, and more than 30 indicates obesity. Obesity can be managed by many ways including proper diet, exercise, medications, and bariatric surgery. It can be prevented by choosing good, healthy foods and beverages and staying away from bad, unhealthy ones, regular exercise, staying away from sedentary lifestyle, improving sleep, and reducing stress in your life.
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