Obesity, bariatric surgery and a little about sleep apnea

Modern human civilization is threatened every year by various diseases, both long-known and new. Although medical science and knowledge do not stand still, there will always be a more common disease and the main cause of death. Obesity was known and reflected in human history from ancient times. It was even a sign of affluence for a while, but it was never a global problem.

Currently, more people in the world die from obesity than from cachexia or underweight. Overweight and obesity are no longer a sign of affluence, it is possessed by both the rich and the poor. Associated with cheap and unhealthy (a lot of easily digestible calories) food, availability of sweet and alcoholic drinks, sedentary lifestyle, constant work at home, sleep problems, use of various weight-influencing medications.

Obesity is a disease. It is included in the international classification of diseases (SSK 10 version E66). If it is a disease, it has different clinical manifestations and treatment options. Obesity is associated with chronic diseases such as sleep apnea, type 2 diabetes, cardiovascular diseases, non-alcoholic steatohepatosis, polycystic ovary syndrome, gallstone disease, depression, arthritis and other musculoskeletal diseases, colon tumor and other tumors. All these pathological conditions lead to disability, heart attacks, strokes and premature death. Overweight and obesity are associated with 2.8 million deaths per year worldwide

The fight against obesity is long-term and permanent for both the patient and the medical professional. As far as possible, the causes should be eliminated – lifestyle changes, diet changes, physical exercises. The next step may be weight loss medication. The mechanisms of action of the medication are reduction of fat absorption, reduction of the feeling of hunger, prolongation of the feeling of satiety. The goal for anti-obesity therapy is to lose 5-10% of total weight. Bariatric surgery helps not only to lose more than 10% of the total weight, but also to maintain this effect for a long time – for years.

It is considered that 10% of the total weight is sufficient to have a beneficial effect on reducing insulin resistance, reducing hypertension, reducing dyslipidemia. The weak side of conservative therapy is a person’s moral and physical abilities. As soon as you stop using diet, medication and exercise, the weight comes right back. It is related to the body’s tendency to keep everything in homeostasis.

Our internal metabolic processes, desires, cravings, and mood are regulated by hormones. The main task of appetite hormones, like other hormones, is to keep the body in homeostasis. Therefore, after a long unhealthy lifestyle and diet, it is difficult to suddenly follow a diet and physical activity. Our body does not want to adapt to new conditions so easily. Body weight is at a certain level and hormones do not allow it to decrease. Therefore, by reducing the amount of calories and the quality of food, energy consumption decreases, as the body tries to conserve resources. Appetite increases because hunger hormones are activated and the brain searches for food, thus the feeling of satiety decreases and does not increase after eating. A desire to find food appears, irritability and anxiety increase.

Hormones signal the brain to seek food, the brain tries to resist, which also changes our mood and perception. After stopping the diet, a person unnoticeably accumulates the previous weight faster and even more, because it is not known whether “starving times” will come again

Today, several (about 14) hormones and signaling molecules are known to influence the sensation of hunger and thirst. Most of it is excreted from the gastrointestinal tract. For example, ghrelin – the hunger hormone is released by the endocrine cells of the stomach, peptide YY from the small intestine. When food, together with bile and other digestive juices, enters the small intestine, the jejunum, hormones begin to be released that send satiety signals to the brain. In addition, satiety hormones have several other effects on the organs.

Modern understanding of the digestive process and energy consumption at the level of hormones appeared only in the 1990s. But bariatric surgery was started in the 80s with the aim of treating diabetes. Today, bariatric surgery is the only treatment method that promotes complete remission of diabetes.Modern bariatric surgery was created thanks to Theodore Billroth, who developed the methodology of gastrectomy and gastric resection at the end of the 19th century, and Cezer Roe (Theodore Kocher’s disciple), who improved Billroth’s method.

In the 20th century, in the 60s, 3 patients after gastrectomy and with diabetes mellitus are described, whose blood sugar condition significantly improves after the operation. The thought arose whether or not diabetes can be treated surgically. In the late eighties, a 6-year follow-up study was conducted in 400 patients with standardized gastric bypass or shunting according to the Roux method. About 150 patients had glucose level disorders, 90 of whom had diabetes. Only a few patients needed drug therapy after surgery. In addition, the normalization of sugar level and cancellation of insulin was observed even on the 10th day after the operation. The authors hypothesized a possible connection between the antrum of the stomach and the bypassed duodenum. It somehow affects the brain’s energy-regulating center in the hypothalamus.

Theories about appetite-regulating mechanisms and substances (neurotransmitters, hormones) existed since the first quarter of the 20th century. But only in 1994, Dr. Jeffrey Friedman discovered the appetite hormone – leptin, which is released from adipose tissue cells. Leptin regulates energy storage metabolism and suppresses appetite. Subsequently, many other hormones and signaling molecules were discovered that regulate appetite and metabolism.

Changes after bariatric surgery affect several appetite- and energy-regulating hormones. Many organ systems have a response reaction: a feeling of satiety occurs in the brain, hunger is less common, energy consumption increases, insulin secretion increases in the pancreas, insulin resistance decreases, the amount of urine excreted by the kidneys and natriuresis increases through angiotensin, the inotropic functions of the heart improve and adipose tissue in the heart decreases. the sense of taste also changes – you want sweet and fatty foods less.

The modern understanding of the mechanisms of action of bariatric surgery is hidden in the acronym BRAVE.

(Bile flow alteration; Reduction of gastric size; Anatomical gut rearrangement and altered flow of nutrients; Vagal manipulation; and Enteric gut hormone modulation)

B – Changes in biliary failure. Bile reaches the terminal parts of the ileum faster than food. The process of digestion begins distally – bile meets food in the distal part of the small intestine. It contributes to the early, stronger and long-lasting release of GLP-1 and PYY hormones, as well as the activation of other signaling molecules – the patient feels satiety faster, which lasts longer. These hormones also reduce insulin resistance.

R – Stomach reduction. With vertical resection of the stomach, a larger part of the stomach is removed, with gastric bypass, around 90% of the stomach is bypassed. Stomach is a bag in which food stays hydrochloric acid with pepsin – to disinfect and partially break down food. Humans and their ancestors hundreds of thousands of years ago did not have the opportunity to go to the store or find something tasty in the refrigerator. As soon as he caught or found a dead animal, he immediately tried to shove it inside him as much as possible. You never knew when you would be able to eat next. That’s why we used to overeat – eat so much until our stomachs are full. There are also endocrine cells in the stomach, especially in the fundus, which secrete the hormone ghrelin. They cause a feeling of hunger. So what is important is not how the stomach remains small, but how the amount of endocrine cells decreases and food does not stay in the stomach or a larger part of the stomach is bypassed.

A – Anatomical intestinal changes. It is especially important in gastric bypass surgery, because it runs through the greater part of the stomach, the duodenum, and part of the jejunum. Food enters the intestine about 1 meter behind the duodenum and begins to be digested 2.5 meters from the duodenum. They, in turn, change the release of satiety hormones.

V – stimulation of the vagus nerve with appetite hormones and possible partial redistribution of fibers of its tract during gastric resection. They, in turn, can change the motility of the stomach and the intestinal parasympathetic nervous system in general, as well as metabolic changes in the liver, pancreas and other organs.

E- The activation of gut hormones is a result of the changes mentioned above.

It should be noted that much of today’s knowledge is based on animal research models.

Bariatric surgery is developing and there are several associations and societies in the world. Guidelines have been developed to standardize the method. The first European guidelines for bariatric surgery were developed in 1991, the last ones were updated in 2020. The International Federation for Surgery for Obesity (IFSO – international federation for the surgery obesity) annually holds world congresses and collects data on bariatric surgery and patients from all over the world every 4 years. Indications and contraindications are determined, operative methods are standardized, preparation for surgery and post-operative observation are determined.

The recommended indications for operative therapy are patients with third-degree obesity or body mass index (BMI) above 40 kg/m2, second-degree obesity or BMI above 35 kg/m2 and the patient has a concomitant disease that can be resolved by surgery (type 2 diabetes, sleep apnea, arterial hypertension, musculoskeletal diseases and dyslipidemia or other) and patients over 30 kg/m2 whose diabetes is difficult to respond to conservative treatment.

Contraindications for bariatric surgery are: Severe heart failure, Unstable coronary artery disease, Severe respiratory disease, Existing oncological disease, Cirrhosis with portal hypertension, Uncontrolled drug and alcohol use, Crohn’s disease, Severe intellectual impairment, Planned pregnancy within the next yearThe most frequently performed operations in the world are gastric bypass after Roux (gastric bypass), gastric sleeve vertical resection (gastric sleeve), single-anastomosis gastric bypass (omega loop bypass). There are other surgeries that use combined approaches and more radical anatomical changes.

Gastric bypass has been researched for around 40 years, it is considered the gold standard. During the operation, the organs of the gastrointestinal tract are not removed, but rearranged. A small stomach (~60ml) is created, it is connected to the small intestine 1m from the ligament of Treitz. Then, another 1.5 meters from the stomach, a connection is made between the loops of the small intestine, where the digestion process begins. Food does not stay in the “small” stomach and reaches the small intestine faster, where the digestion process signals the brain to stop eating. This operation is considered reversible.

Known long-term results with stable weight loss and maintenance. The health benefit has been studied – for diabetes, blood pressure, sleep apnea, gastroesophageal reflux, dyslipidemia, polycystic ovary syndrome and other cases. Guidelines for post-operative patient care have been developed, as well as known actions for various types of complications.

After this type of surgery, B vitamins, vitamin D and calcium should be taken constantly. Less frequently, patients should use iron preparations.

Gastric sleeve appeared about 20 years ago, but is a more common operation in the world. During the operation, the outer, larger part of the stomach is removed along with a 1.33 cm wide gastric tube. Thus, a large part of the stomach’s endocrine cells, which produce the hunger hormone, have been removed. The stomach fills up faster – thus there is no “stomach hunger”. Food passes through the small intestine faster, it stimulates hunger hormones.

Compared to gastric bypass, this operation is technically simple, because there are no bowel and stomach connections. Fewer operations on the gastrointestinal tract means fewer early complications. In the first days after the operation, there is nausea and vomiting. There are studies that report worsening or recurrence of gastroesophageal reflux.On average, the operation takes less time than gastric bypass. However, the weight loss is comparable to gastric bypass surgery. Vitamins B and D should be used less often, calcium and iron preparations should be replaced.

Omega loop gastric bypass, or one-anastomosis reducing gastric bypass, or minibypass. This operation appeared about 15 years ago. It is technically easier to perform than the classical gastric bypass. The operations are both gastric resection as in gastric sleeve and bypass as in gastric bypass. A small stomach is created two to three times larger than with gastric bypass. A loop of jejunum 2 meters from the ligament of Treitz is taken and connected to the “small” stomach.

After the operation, the same good weight-reducing effect and metabolic effect can be observed, as with gastric bypass. You should also monitor and use vitamins D and B, calcium.

All described operations are comparable both in terms of weight loss and remission of comorbidities. Based on the patient’s weight, the surgeon recommends a certain type of surgery. The final decision is made by the patient.

Every 4 years, the International Federation of Bariatric Surgery gathers data from around the world on bariatric surgery. Data from 2018 on obesity-related diseases and their remission after surgery show a high effectiveness of bariatric surgery. Diabetes reduced by 60%, Hypertension by around 40%, depression by around 10%, sleep apnea similar to diabetes by around 60%, GERS by gastric bypass by 50%. Musculoskeletal problems in gastric bypass decreased by 58% in gastric resection by 47%, dyslipidemia decreased in 50% of patients. As you can see, many patients experience many other health improvements along with weight loss. (Schedule no..)

One of the more serious obesity-related diseases is sleep apnea. It affects around 60-80% of obese people. The mechanism of sleep apnea is reduced airflow through the airways. Air flow is reduced by anatomical features and the arrangement of fatty tissue in the oral cavity and throat. They, in turn, cause obstruction, which is manifested by loud snoring and breathing stops for about 10 seconds. The severity of sleep apnea is determined by the number of episodes of not breathing while sleeping (apnea-hypopnea index) – if there are more than 30 episodes per hour, then it is a severe form, from 15-30 moderate, from 5-15 mild, less than 5 episodes can be considered normal sleep .

Reduced air flow leads to hypoxia and disturbed sleep. In the morning, the patient feels tired, attention is reduced. Can’t concentrate at work while driving. Over time, they turn into anxiety or depression and even lead to fatal careless mistakes.

But there are still less obvious manifestations, internal and serious. Yes, a person does not try to do anything, chronic hypoxia occurs. It causes insulin resistance and heart ischemia, cardiac arrhythmia, as well as increases the activity of the sympathetic nervous system, all of which leads to hypertension, diabetes and other cardiovascular diseases.

The number of studies on pubmed.org with the keywords bariatric surgery and sleep apnea is increasing every year. It should be noted that most of them are prospective and retrospective cohort studies. A study with a higher quality of evidence – there was one randomized study in 2014 comparing conservative weight loss and gastric banding. Many studies are related to the perioperative care of sleep apnea patients. Of the studies that have observed a therapeutic effect after bariatric surgery, the statistical power is low, or the number of patients is small. In several observational studies after bariatric surgery, sleep apnea is not a primary target but a secondary and tertiary target. There are no standardized criteria in the initial evaluation of patients and interpretation of the results, for example, plethysmography is not performed everywhere or it is performed at home, oxygen saturation was not included in the measurement, different (non-unified) sleep quality scales were used, and the resolution of health problems caused by apnea was not reflected.

However, there are known results in favor of bariatric surgery. The truth is, with surgery, we cannot 100% help patients with sleep apnea, but we certainly reduce the severity of the apnea and the complications associated with it. Of the prospective studies, a relatively recent one with good methodology was conducted in Finland, which initially included around 500 patients who underwent gastric bypass surgery, as well as plethysmography, it was repeated after 1 year. However, at the end, 189 patients remained, of which 132 had overt sleep apnea, confirmed by sleep laboratories.

The initial BMI index was on average 43 kg/m2 after a year it decreased by an average of 10 kg/m2

Of 132 patients with sleep apnea, nearly half were in remission. Patients with mild apnea-hypopnea index (AHI) had a 29% reduction, a 53% reduction in moderate, and an 80% reduction in severe. It should be noted that patients who did not lie on their backs had better results.

What is more important – the level of glycolysed hemoglobin, blood pressure and dyslipidemia significantly improves in patients. Despite the overall positive results, many patients still have sleep apnea, albeit in a less severe condition. The development of sleep apnea, which was initially undetected, was observed in 8 patients

Schedule no. 2

Another available good quality study is the 2015 meta-analysis. There, 19 surgical and 20 non-surgical weight loss methods were compared, with a total of 525 patients in the surgical group and 825 in the non-surgical group. In these studies, sleep apnea was evaluated as an additional outcome.

Average initial BMI in surgical group 51kg/m2, in non-surgical group 38kg/m2. In the surgical group, BMI loss was 27% or 14kg/m2, while in the non-surgical group it was 8% or 3kg/m2. AHI decreased more after surgery. However, in proportion to the weight loss in the non-surgical group, there is also a significant reduction in the apnea-hypopnea index. This means that size is not as important in weight loss as weight loss as such.

Schedule 3

Previously mentioned results of randomized studies with gastric banding and conservative weight loss have similar results – the amount of weight loss did not play such a significant role in reducing the AHI index.

Bariatric surgery helps each patient improve their health status, quality of life and length of life. In a larger perspective, it allows to economize the state health budget funds and increase the number of working people in the country. For patients with obesity, the treatment of any health problem is long-term, requires more resources and the time of medical personnel. Globally, bariatric surgery is included in publicly funded care. The situation in the Baltic states is different. Estonia has developed state-funded bariatric surgical treatment and health programs for obese people, Lithuania has a partially paid state program and bariatric centers with world-renowned experts. Latvia mainly dealt with bariatrics in private clinics. In our country, 90% of bariatric surgeries have been performed on foreigners. There is no state funding, there are no state programs for anti-obesity, there is no state informative campaign, even though every 5 people in our country are obese, but after 50 years every 3 inhabitants of Latvia will be.

The patients we perform this type of surgery on average are 39 years old, mostly women with an average body mass index of 41 and one of the comorbidities of obesity. We performed all operations laparoscopically. On the first day after surgery, patients walk a lot and drink water, liquid yogurt. They are discharged home on the second day after the operation. From then on, the patient was observed by a family doctor, a dietician and an operating surgeon. Average excess weight loss after 3 months is around 40% and total weight loss around 17%. We perform around 300 bariatric surgeries a year with less than 1% of re-operations.