What is Bariatric Surgery?
Obesity Definition
Obesity means that body fat mass exceeds levels considered normal and is commonly defined by the Body Mass Index (BMI) measure (Table 1). BMI is calculated by dividing body weight in kilograms by the square of height in metres. While BMI values of 18.5-24.9 kg/m2 are considered healthy or normal, BMI values between 25-29.9 kg/m2 are considered overweight, and BMI > 30kg/m2 are considered obese. Those who are most at risk in terms of the consequences of obesity have a BMI > 40 kg/m2 and are in the group defined as morbidly obese.
Weight Category BMI (kg/m2)
Underweight <18.5
Normal 18.5-24.9
Overweight 25-29.9
Obese 30-34.9 Grade 1
35-39.9 Grade 2
≥ 40 3rd Degree (Morbidly obese)
Obesity is the most important health problem of our age in terms of both its frequency and its consequences. It is known that approximately 1/3 of adults living in developed and developing countries are overweight and 1/3 are obese. Obesity has begun to pose a very serious threat in terms of childhood diseases. Today, it has been determined that approximately 500 million adults and 50 million children in the world have serious health problems due to obesity.
Research shows that the prevalence of obesity is at similar levels in our country. Data from the Ministry of Health Nutrition Research and TURDEP-II study revealed that two out of every three adults in our country are overweight or obese. The prevalence of metabolic syndrome accompanied by central obesity, where the risk is particularly high, has been detected in 36.6% of our adult population.
In our country, approximately 3% of adults (approximately 2.5 million adults) are morbidly obese. Obesity itself is a significant disease that increases the risk of events and death from all-cause and cardiovascular causes. On the other hand, obesity is an important risk factor that increases the frequency of hypertension (HT), dyslipidemia, type 2 diabetes mellitus (T2DM), stroke, gallbladder diseases, osteoarthritis, sleep apnea syndrome and some types of cancer.
It is possible to say that obesity and the diseases it causes have significant effects on human and social life not only biologically, but also psychosocially and economically. It has been determined that obese people have 30% more doctor visits, 50% more hospitalizations, and 80% more medication costs compared to normal weight people.
It is reported that the annual amount of obesity-related health expenditures in the United States (US) is around 190 billion dollars. As a result, the prevention and treatment of obesity is not only a public health problem but also a socioeconomic problem. (Turkish Endocrinology and Metabolism Association)
Basic factors in obesity pathogenesis and treatment
There are many misconceptions about obesity and obese people. Chief among these is the idea that obesity is a cosmetic problem resulting from a personal lack of motivation or weakness of will. However, obesity is a multifactorial chronic disease that carries a strong genetic predisposition and is accompanied by an obesogenic environment and lifestyle. Decreasing physical activities and changing nutritional habits of modern people are among the most important causes of the obesity epidemic.
Due to the multiple etiological factors mentioned, diet and lifestyle changes used in obesity treatment may not be effective for every patient. In order to see long-term success, patients need to make permanent changes in their lifestyle. In recent years, many preparations have been approved and started to be used for the medical treatment of obesity. However, long-term safety information and effectiveness of these treatment agents are limited. For these reasons, surgical treatment of obesity is attracting increasing attention day by day. Today, it is generally accepted that bariatric surgery (BC) is the most effective and permanent method used in the treatment of obesity.
Indications for bariatric surgery
BMI ≥ 40 kg/m2
If BMI is ≥ 35 kg/m2, at least one obesity-related disease is present
These related conditions are:
Type 2 diabetes mellitus
Hypertension
Dyslipidemia
Sleep-apnea syndrome
Obesity-hypoventilation syndrome
Pickwick syndrome (combination of sleep-apnea syndrome and obesity-hypoventilation syndrome)
Non-alcoholic fatty liver disease or “non-alcoholic steatohepatitis (NASH)”
Pseudotumor cerebri
Gastro-esophageal reflux disease
Asthma
venous stasis disease
Severe urinary incontinence
Arthritis affecting daily life (Turkish Endocrinology and Metabolism Association)
In addition, although small studies have shown that BC is beneficial on glycemic control for type 2 diabetics with a BMI between 30-35 kg/m2, surgical treatment is not routinely recommended for this group because there is not enough evidence. However, BC may be considered in selected cases where adequate glycemic control cannot be achieved despite effective and intensive antidiabetic treatment. (Turkish Endocrinology and Metabolism Association)
Advantages of Bariatric Surgery (Metabolic Surgery)
In addition to weight control with bariatric surgery, obesity-related metabolic problems such as T2DM, HT, dyslipidemia and sleep apnea are also greatly improved. The improvement of these metabolic disorders is so rapid and significant that it is not possible to explain this effect with weight loss alone. For this reason, the tendency to use the expression metabolic surgery instead of BC is increasing nowadays.
Due to the rapid passage of food into the small intestine in the early period, there is a postprandial increase in the levels of glucagon-like peptide-1 (GLP1), peptide YY, and oxyntomodulin, while ghrelin secretion decreases. These hormonal changes cause decreased appetite and food intake.
Since calorie intake decreases in the early period after surgery, liver insulin sensitivity also increases significantly.
Bariatric surgery also causes positive effects on glycemia regulation by increasing the release of bile acids and affecting the configuration of the intestinal microbiota.