Obesity is a multifactorial disease which has become a public health problem with increasing frequency, especially in recent years. Obesity causes many health problems with its negative effects on organs, systems, and psychosocial status. It is a serious risk factor for many diseases and also causes a significant increase in morbidity and mortality in these diseases.

Although dietary treatments and medical treatment options are frequently used, surgical options are still the most effective treatment. Bariatric and metabolic surgical techniques are frequently applied, especially in patients with advanced obesity and obesity-related comorbidities. The most commonly applied bariatric metabolic surgical techniques, as in our clinic, are laparoscopic sleeve gastrectomy (LSG) and Roux-en-y gastric bypass procedures.

The role of adipokines, secreted from adipose tissue and thought to play a role in the development of obesity, is quite important in the obesity mechanism, as they are effective not only in energy processes but also in metabolic processes. These adipokines secreted by adipose tissue play an active role in many mechanisms in the body, including vasoactivity, oxidative processes, immunity, lipid and glucose metabolism. Adipokines function actively in many target organs such as the pancreas, liver, and brain.

Isthmin, a relatively new adipokine expressed from brown and white adipocytes, also affects many systems like other adipokines. Studies have shown that Isthmin plays an active role in glucose and lipid metabolism, and it has been reported to play a role in many metabolic processes, from insulin resistance to hepatic steatosis.

The aim of this study is to investigate whether isthmin levels change before and after surgery in patients undergoing LSG for severe obesity, given that isthmin is thought to be associated with obesity and insulin resistance, particularly by affecting the appetite center in metabolism.

Obesity is a multifactorial disease caused by genetic, environmental, and psychiatric factors. Having existed for hundreds of years, obesity has become a public health problem with increasing frequency, especially in recent years. According to WHO data, in 2016 there were 1.9 billion overweight and 650 million obese patients worldwide, and in 2022, there were 2.5 billion overweight and 890 million obese patients. This massive increase in obesity incidence in such a short time highlights that obesity is a very serious problem worldwide. According to this data, approximately 43% of the adult population over 18 years of age is overweight. This data reiterates the fact that obesity is a widespread problem with a rapidly increasing trend globally.

Obesity causes many health problems with its negative effects on organs, systems, and psychosocial status. It is a serious risk factor for many diseases and also causes a significant increase in morbidity and mortality in these diseases. Studies estimate that approximately 5 million people die worldwide due to non-communicable diseases such as cardiovascular diseases, diabetes, cancer, neurological disorders, chronic respiratory diseases, and digestive disorders related to obesity.

Today, many treatment methods are available for obesity. Although dietary treatments and medical treatment options are frequently used, surgical options are still the most effective treatment. Bariatric and metabolic surgical techniques are frequently applied, especially in patients with advanced obesity and obesity-related comorbidities. For this purpose, numerous bariatric metabolic surgical techniques have been developed. Currently, the most commonly applied bariatric metabolic surgical techniques, as in our clinic, are laparoscopic sleeve gastrectomy (LSG) and Roux-en-y gastric bypass procedures.

The role of adipokines, secreted from adipose tissue and thought to play a role in the development of obesity, is quite important in the obesity mechanism, as they are effective not only in energy processes but also in metabolic processes. These adipokines secreted by adipose tissue play an active role in many mechanisms in the body, including vasoactivity, oxidative processes, immunity, lipid and glucose metabolism. They exert their effects through paracrine and autocrine pathways. Adipokines function actively in many target organs such as the pancreas, liver, and brain.

Isthmin, a relatively new adipokine expressed from brown and white adipocytes, also affects many systems like other adipokines. Studies have shown that Isthmin plays an active role in glucose and lipid metabolism, and it has been reported to play a role in many metabolic processes, from insulin resistance to hepatic steatosis.

The aim of this study is to investigate whether isthmin levels change before and after surgery in patients undergoing LSG for severe obesity, given that isthmin is thought to be associated with obesity and insulin resistance, particularly by affecting the appetite center in metabolism.

Inclusion Criteria:

• Being over 18 years of age
• Being diagnosed with severe obesity
• Patients who do not wish to participate in the study

Exclusion Criteria:

• Patients under 18 years of age
• Overweight patients with a Body Mass Index <40 kg/m2 and no comorbidities
• Patients with rheumatological diseases (rheumatoid arthritis, SLE, etc.)
• Patients with chronic kidney and liver failure
• Patients diagnosed with Diabetes Mellitus
• Patients with malignancy
• Patients who do not wish to participate in the study

BMI > 40 kg/m2 without comorbidity who are planned for Laparoscopic Sleeve Gastrectomy