Morbid obesity or clinically severe obesity is a condition characterized by body mass index (BMI) over 40 kg/m2, and involves serious health consequences. Morbid obesity is associated with a number of comorbidities that enhance the risk of mortality.
Presentation
Weight problems with symptoms of associated complications are the major features of morbid obesity. Activity level of the patient and the diet history are major indicators of increased weight. Patient may present with any of the comorbidities including:
- Respiratory diseases: Sleep apnea, respiratory infections, bronchial asthma, and obesity hypoventilation syndrome
- Cardiovascular diseases: Essential hypertension, coronary artery disease, left ventricular hypertrophy, atherosclerosis, and pulmonary hypertension
- Central nervous system diseases: Idiopathic intracranial hypertension, stroke
- Gastrointestinal diseases: Fatty liver, gall bladder disease, reflux esophagitis
- Metabolic diseases: Diabetes mellitus, metabolic syndrome, dyslipidemia
Workup
Laboratory studies commonly used in the workup include fasting lipid profile, liver function studies, thyroid function tests, fasting glucose and HbA1c. Other tests are recommended based on the manifestations. Lipid profile is suggested to check for dyslipidemia characterized by increased levels of triglycerides in fasting, increased levels of LDL-C, and enhanced levels of total cholesterol. Liver tests are suggested to check for nonalcoholic steatohepatitis and fatty liver. Hypothyroidism may be detected using thyroid tests. Glucose levels and insulin studies are important as all patients with morbid obesity may have diabetes mellitus.
Degree of body fat is measured using waist circumference, waist to hip ratio, and BMI. Doctors may also recommend skin fold thickness measurement, radiographic absorptiometry, and ultrasonography. MRI may also be used in measuring visceral fat.
Treatment
Lifestyle management is the first step in the non-surgical treatment of morbid obesity. It includes diet control, increased physical activity, and behavior modification. Bariatric surgery is suggested as an adjunct to behavior modification for better results. Those who are not able to successfully lose and maintain the body weight may opt for weight loss medications. This medication is continued if the weight loss is effective and safe. Anti-diabetic medications with additional actions that help in weight loss may also be used. For control of hypertension, ACE inhibitors, calcium channel blockers and angiotensin receptor blockers are used.
Weight loss programs are scheduled in three phases, screening, weight-loss, and maintenance. Commercially available weight loss programs are also effective in bringing down the weight to an acceptable level. Bariatric surgery is the only surgical modality that aids in clinically significant weight loss. It also helps in reducing morbidities associated with obesity. The different types of bariatric procedures include gastric banding, gastric sleeve surgery, vertical sleeve gastrectomy, gastroplasty, duodenal switch procedures, and horizontal gastroplasty. Gastric restriction and gastric bypass are known to provide long-term effectiveness. Comorbidities are also carefully evaluated and treated. This is very important for the wellbeing of the patient and also to reduce the risk of morbidity and mortality.
Weight loss programs may sometime lead to complications like cardiac arrhythmia, electrolyte derangements, hyperuricemia, cholelithiasis, and psychological conditions like depression. A reasonable goal for weight loss is about 1-2 lb/week. But, weight loss program should be customized according to the requirement of each and based on the racial and ethnic background of the individual. For successfully maintaining the lost weight, diet, daily physical activity, monitoring of weight, and minimal sedentary time is very essential. For those who were on weight loss medication should have long-term strategies to prevent relapse of weight gain.
Prognosis
Studies show that obesity is associated with a considerable increase in morbidity and mortality due to comorbidities. It is reported that morbid obesity is associated with a higher risk of cardiovascular diseases that lead to morbidity and mortality [11]. The risk of mortality in a person increases considerably, and life expectancy is reduced by 20 years in men, and by about 5 years in women. This is more pronounced in a morbidly obese person who smoke.
Etiology
Against the general consensus that increased BMI is a result of imbalance in energy intake and output, morbid obesity is caused by multiple factors. Factors implicated in the development of this condition include:
- Dietary habits
- Metabolic factors
- Psychological factors
- Socioeconomic factors
- Genetic factors
- Racial factors
- Age and gender
- Pregnancy and menopause
- Ethnic factors
Studies show that genetic factors are very important in being obese [2]. These genetic factors when combined with appropriate environmental conditions favor increased BMI. Studies on twins and adopted children show that obesity may be inherited [3]. The increased incidence of obesity in the last few years coincides with the drastic changes in dietary habits, and this further supports the involvement of environmental factors in the development of the condition.
Epidemiology
Industrialized nations of the world are showing an increased prevalence of morbid obesity in the past few decades. In Europe, about 15% of men and 22% of women are found to be obese [4]. Many Middle Eastern countries including Bahrain, Saudi Arabia, Egypt and Jordan are showing about 40% obesity level among the population. Recently conducted UK government statistics show that about 1% of the obese people belong to the category of morbidly obese. In US, percentage of morbidly obese people have increased almost tenfold since 1986. This rate is continuing to increase but has slowed down in the past few years.
Prevalence of clinically severe form of obesity is 50% higher among women when compared to men [5]. Although obesity affects all races, some of the racial groups are more predisposed to higher BMI when compared to others. Non-Hispanic black people are found to be more predisposed to this condition when compared to Hispanic and non-Hispanic white people. Adolescents who are obese have an increased risk of becoming obese adults. Taller children are more obese than shorter ones [6].
Pathophysiology
Morbid obesity is characterized by hypercellular obesity in which there is a considerable increase in the number of adipocytes. Excessive storage of fats in the adipocytes may lead to enhanced lipolysis and thus release of fatty acids. Lipolysis is increased by enhanced sympathetic state that is characteristic of obesity. The free acids and their metabolites may lead to oxidant stress to the cellular organelles like mitochondria and endoplasmic reticulum. This results in lipotoxicity that affects many organs and leads to metabolic syndrome [7]. Free fatty acids may also inhibit lipogenesis leading to hypertriglyceridemia. Abnormality in the functioning of insulin receptors is one of the consequences of lipotoxicity due to free fatty acids. Hyperglycemia thus results from insulin-resistance. Hepatic gluconeogenesis sets in, increasing hyperglycemia. This may be further accentuated by decreased utilization of muscle glucose [8]. Pancreatic insulin secretion also decreases considerably due to lipotoxicity [9].
Secretion of inflammatory adipokines from white adipose tissues can cause dyslipidemia, hypertension, and atherogenesis, all of which are comorbid conditions with morbid obesity [10]. Fat deposits in different parts of the body like pancreas, mesentery, and gut, are enhanced with adipokine secretion. Inflammatory cytokines reduces the activity of lipase, increasing the serum triglyceride levels. Adipocytes are also known to secrete matrix metalloproteinases that promote atherosclerosis formation and progression. It may lead to intravascular thrombosis.
Prevention
Changing the lifestyle to a healthy one is the best possible method to deter morbid obesity. Change in eating habits, and improving physical activity goes a long way in controlling weight and also to prevent comorbidities, if one is on the higher side of the scale. Public health education programs in this effort are effective in reducing the incidence and prevalence of the condition. As the patient is trying to lose weight, effort must be on to prevent comorbidities and also the relapse of weight gain.
Summary
Morbid obesity or clinically severe obesity is a condition characterized by body mass index (BMI) over 40 kg/m2, and involves serious health consequences. Morbid obesity is associated with a number of comorbidities that enhance the risk of mortality. Many factors like onset of obesity, distribution of fat in the body, waist circumference, and intraabdominal pressure, are all associated with the development of comorbidities. Morbidity and mortality is high, particularly among smokers [1]. The prevalence of this clinically severe form of obesity is still increasing, although at a lesser rate in the recent years. Treatment may require a multi-system approach as many organs may be involved. For a given BMI, men are found to be at an increased risk of cardiovascular diseases when compared to women.
Patient Information
Morbid obesity refers to a condition in which the body weight is 50-100 percent above the ideal weight. The BMI of the person tends to be over 40 kg/m2. The body shows a slow and steady progression in the weight. A number of comorbid conditions are associated with morbid obesity. These include cardiovascular diseases, respiratory troubles, gastrointestinal problems, and central nervous system issues. It is the second most leading cause of death next only to smoking. Number of people having this condition has increased considerably since last few decades.
Morbidity is caused by multiple factors including dietary factors, metabolic factors, racial and gender factors. Presence of specific genes along with supporting environmental factors lead to increased body weight. Studies also show that obesity may be inherited. Drastic changes in our dietary habits and increased sedentary habits have also influenced addition of fat in the body. Increased prevalence of this condition is seen in industrialized nations. Morbid obesity occurs more commonly among women when compared to men. Some racial groups also have an increased incidence of this condition. Non-Hispanic black people are more predisposed to morbid obesity.
The life expectancy of a person with this disease is reduced by 20 years in men while it is reduced by 5 years in men. Increased body weight and associated complications are the major features of this condition. Patient may also present with respiratory diseases, cardiovascular diseases, metabolic diseases, gastrointestinal diseases, reduced mobility and presence of visceral fat. Laboratory studies and clinical manifestations are the major diagnostic indicators of morbid obesity. Lipid profile, glucose test, and liver tests are commonly used to test for comorbid conditions.
Lifestyle management is the first step in the non-surgical treatment for the disease. This includes diet, increased physical activity and behavior modification. Weight loss medications are suggested for some. The only surgical treatment available for the disease is bariatric surgery. Comorbid conditions must also be carefully evaluated and treated. Weight loss programs are customized according to the requirements. Changing the lifestyle of the individual is the best possible prevention method for morbid obesity.
References
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