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Metabolic surgery is a surgical approach whose primary aim extends beyond weight loss alone to influence metabolic parameters, particularly type 2 diabetes. Through planned reconfiguration of digestive system anatomy, it targets effects on intestinal hormones (GLP-1, PYY), insulin sensitivity and glycaemic control. It is considered in patients with BMI 30 or above with uncontrolled type 2 diabetes.
Metabolic surgery (commonly referred to as diabetes surgery) is a surgical approach whose primary goal is not weight loss, but the management of metabolic diseases — particularly type 2 diabetes. Through a planned reconstruction of the digestive system anatomy, it directly influences gut hormones (incretins), insulin sensitivity, and glycemic control (blood sugar regulation). For this reason, it cannot be categorized solely under obesity (bariatric) surgery; it is recognized as one of the evidence-based surgical treatment options for type 2 diabetes.
According to the World Health Organization, the global burden of diabetes has quadrupled over the past three decades, affecting more than 500 million adults [7]. A considerable proportion of patients fail to reach HbA1c targets despite oral antidiabetic medications and insulin therapy. Addressing this gap, the Diabetes Surgery Summit-II (DSS-II) consensus defined metabolic surgery in 2016 as a permanent component of the treatment algorithm for type 2 diabetes [1]. The American Diabetes Association (ADA) 2022 Standards of Care and the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) guidelines support this approach and recommend surgical evaluation for patients with uncontrolled type 2 diabetes at a BMI threshold of ≥ 30 kg/m² [2][5].
The most common questions about this treatment
No. Although the two share some common procedures (such as gastric bypass) in terms of technique, their goal, indication, and patient profile differ. The primary goal of bariatric surgery is obesity, and generally a BMI of ≥ 35–40 kg/m² is required. In metabolic surgery, the primary goal is controlling metabolic diseases — particularly type 2 diabetes — and a BMI of ≥ 30 kg/m² may be sufficient in the presence of uncontrolled diabetes. Weight loss is a result in metabolic surgery, not a goal.
One of the unique aspects of metabolic surgery is that its positive effect on blood glucose begins before weight loss. In the days following gastric bypass, insulin requirements decrease even before patients have lost meaningful weight. This is related to foregut and hindgut mechanisms and hormonal changes. However, weight loss and lifestyle discipline remain the determining factors for sustaining long-term remission. Early improvement is not dependent on weight; long-term persistence is largely related to weight and lifestyle.
DSS-II, ADA 2022, and IFSO guidelines recommend surgical evaluation for patients with uncontrolled type 2 diabetes at a BMI threshold of ≥ 30 kg/m². In patients with BMI 30–34.9 unable to reach HbA1c targets, metabolic surgery is an option that may be considered. In the BMI 25–29.9 range, although not a routine indication, an individual decision may be made in specific patient subgroups. Final eligibility is determined after examination and multidisciplinary evaluation.
This decision cannot be made based on a single criterion. Your age, BMI, duration of diabetes, medications used (oral antidiabetic or insulin), C-peptide level, accompanying diseases, and dietary habits are all evaluated together. Gastric bypass may come forward in short-duration diabetes with moderate BMI, while ileal interposition may be considered in resistant diabetes with lower BMI, and procedures such as SADI-S may be considered in severe metabolic syndrome with high BMI. The joint decision is made by the endocrinology and surgery team.
The standard clinical target is defined as HbA1c < 6.5%; the remission criterion is an HbA1c < 6.5% and a fasting glucose within the normal range for at least 1 year without the use of antidiabetic medications. Many patients reach this target within the first 6–12 months. However, complete remission cannot be expected in every patient; in those with long-standing diabetes or low C-peptide levels, the goal may be better-controlled diabetes rather than remission. Targets are personalized.
Insulin independence is achieved within the first month in a significant proportion of selected patients; this rate is higher in those using oral antidiabetics. However, how long and at what dose you have been using insulin, your C-peptide level, and your duration of diabetes are determining factors. In patients with long-standing insulin dependence, complete independence may not always be achieved; however, a significant reduction in insulin dose and improvement in HbA1c can still occur. Postoperative insulin adjustment is performed by endocrinology.
Yes; for this reason, the medical literature uses the term "remission" instead of "cure." If lifestyle habits are neglected, weight is regained, or beta cell reserve declines over time, diabetes may relapse. In the 10-year follow-up by Mingrone et al., both groups with sustained remission and those with relapse were identified; however, even in patients who relapsed, diabetes was more easily controlled compared to the medical therapy group [4]. Long-term follow-up and lifestyle discipline are therefore critical.
Reactive hypoglycemia (a drop in blood sugar 1–3 hours after meals) may occur, particularly after Roux-en-Y gastric bypass. This is related to rapid gastric emptying and an excessive GLP-1 / insulin response. It is largely managed by eating in frequent, small portions; avoiding simple carbohydrates; and increasing protein and fiber intake. In advanced cases, pharmacological intervention is considered. Rapid tapering of antidiabetic doses used in the early period also helps prevent hypoglycemia.
There is no strict age limit; the decision is made based on biological age and comorbidities. Guidelines generally accept the 18–65 age range as standard; however, patients over 65 with good general health may be evaluated, and application in individuals under 18 is limited to special indications. What matters is not age, but cardiopulmonary reserve, comorbidity burden, beta cell reserve, and surgical risk profile.
In Turkey, SGK may cover metabolic surgery for type 2 diabetes under certain conditions. Criteria such as BMI threshold, duration of diabetes, comorbidity status, and preliminary evaluation reports affect coverage decisions. As coverage conditions may change over time, the current status should be clarified in detail through the institution to be applied to and the center performing the operation. Private insurance coverage varies according to policy terms.
At metabolic surgery centers in Turkey, the process for international patients is carried out within the framework of international health tourism regulations. After sharing existing medical records (HbA1c, C-peptide, medications used, comorbidities, endoscopy reports), a remote video pre-evaluation can be conducted. For eligible patients, the Istanbul program is planned to include preoperative tests, surgery, hospital stay, and early discharge check. Long-term follow-up is continued through remote meetings in coordination with local endocrinology.
Long-term follow-up is planned to be lifelong. Outpatient check-ups are performed at months 3, 6, and 12 in the first year; at least one annual follow-up is recommended in the following years. These check-ups include HbA1c, lipid profile, liver enzymes, B12, iron, vitamin D, calcium, PTH, complete blood count, and weight-BMI monitoring. In patients who discontinue follow-up, both the risk of micronutrient deficiency and the risk of diabetes relapse increase significantly; for this reason, continuity of follow-up is an inseparable part of surgical success.
Explore other bariatric surgery options
Metabolic surgery refers to surgical procedures that reorganize the anatomy of the stomach and small intestine with the aim of controlling metabolic diseases such as type 2 diabetes, hypertension, dyslipidemia, and metabolic syndrome. Technically, some procedures overlap with bariatric surgery (such as Roux-en-Y gastric bypass and sleeve gastrectomy); however, the goal, indication, and patient profile differ. In metabolic surgery, success is measured not only by weight loss but by the reduction of HbA1c, decreased need for oral antidiabetics or insulin, improvement in the lipid profile, and normalization of metabolic parameters.
The scientific basis of this approach originated in the 1980s, when clinicians observed that blood sugar levels improved before meaningful weight loss in diabetic patients undergoing obesity surgery. In the following decades, randomized controlled trials (STAMPEDE, Mingrone et al.) demonstrated that surgery offers significant superiority over intensive medical therapy in glycemic control [3][4]. Today, metabolic surgery is a multidisciplinary field practiced at the intersection of endocrinology and surgery.
Bariatric surgery is primarily a treatment for obesity. The classical indication is BMI ≥ 40 kg/m² or BMI ≥ 35 kg/m² with accompanying comorbidity. The aim is significant and sustainable weight loss; metabolic improvements are considered secondary outcomes linked to weight loss.
In metabolic surgery, the equation is reversed. The primary indication is a metabolic disease — particularly type 2 diabetes that cannot be controlled with medical therapy. The BMI threshold is lower: DSS-II and ADA 2022 guidelines recommend surgery for patients with type 2 diabetes at a BMI ≥ 30 kg/m²; in selected cases, individual evaluation may even be considered in the BMI 25–29.9 range [1][2]. Weight loss here is a result, not a goal. The same operation (for example, gastric bypass) may be performed with a bariatric indication in one patient and a metabolic indication in another; although the surgical technique is similar, patient selection criteria, preparation, and follow-up parameters differ.
Additionally, some procedures (ileal interposition, transit bipartition, SADI-S, duodenal switch) are predominantly designed for metabolic purposes. These procedures maximize the incretin (gut hormone) response by enabling earlier contact between food and the distal small intestine.
The term "diabetes surgery" is widely used as an accessible patient-facing description of metabolic surgery, emphasizing its impact on blood sugar regulation in patients with type 2 diabetes. In the medical literature, the equivalent terms are "diabetes surgery" and "metabolic surgery." While the term may evoke exaggerated associations such as "getting rid of diabetes" in public discourse, the scientific framework uses a more measured definition: surgical control of type 2 diabetes, achievement of remission (regression of the disease), or significant reduction in the need for medical treatment.
Remission is defined as an HbA1c below 6.5% and fasting glucose within the normal range for at least one year without the use of antidiabetic medications. Although remission may appear to be a "cure," it can relapse if lifestyle habits deteriorate or beta cell reserve declines. For this reason, while "diabetes surgery" is a term commonly used by patients, the concepts of "metabolic surgery" and "remission" are more accurate throughout the clinical process.
The effect of metabolic surgery on diabetes cannot be explained solely by stomach volume reduction or weight loss. Within the first few days after surgery, measurable improvements in blood glucose levels are observed before any meaningful weight loss. This indicates that surgery directly creates hormonal and neuroendocrine changes along the gut-pancreas-brain axis. In the literature, these mechanisms are examined mainly under the foregut hypothesis and the hindgut hypothesis.
The foregut hypothesis suggests that the proximal small intestine (duodenum and proximal jejunum) is the source of "anti-incretin" signals that trigger insulin resistance. When this area contacts food, certain not-yet-fully-defined factors act in a direction that decreases insulin sensitivity. In procedures such as Roux-en-Y gastric bypass and duodenal switch, the proximal small intestine is excluded from food passage, reducing the effect of these signals.
The clinical reflection is as follows: within the first 48–72 hours after gastric bypass, a measurable reduction in insulin resistance is observed independent of caloric restriction. This explains the early glycemic benefit of surgery prior to weight loss.
The hindgut hypothesis states that the faster-than-normal arrival of nutrients into the distal ileum (the final part of the small intestine) increases the release of GLP-1 (glucagon-like peptide-1) and PYY (peptide YY). These two hormones stimulate glucose-dependent insulin secretion from the pancreas, suppress glucagon release, slow gastric emptying, and promote satiety. GLP-1 is the target of a current class of diabetes medications (GLP-1 analogs); surgery strengthens this system at the endogenous level.
The incretin effect refers to the post-meal insulin response stimulated by gut hormones being stronger than the response to the same amount of glucose delivered intravenously. This effect is diminished in patients with type 2 diabetes. Metabolic surgery — particularly ileal interposition and bypass-based procedures — significantly reactivates the incretin response. In ileal interposition, relocating a segment of the distal ileum to the proximal jejunum allows nutrients to contact GLP-1-secreting L-cells earlier.
A notable feature of metabolic surgery is that its effect on diabetes begins independently of weight loss. In the STAMPEDE study, HbA1c reduction was documented within the first week in some patients undergoing gastric bypass, with insulin requirements decreasing before weight loss reached a meaningful level [3]. The 10-year follow-up study by Mingrone et al. demonstrated that patients undergoing surgery maintained lower HbA1c levels compared to those receiving intensive medical therapy through mechanisms independent of weight loss [4].
This "weight-independent" effect is explained as the combined outcome of hormonal changes, bile acid signaling, gut microbiota remodeling, and central effects on hypothalamic energy balance. The multicomponent nature of the mechanism reveals the integrated effect of surgery, which cannot be replicated by a single medication.
There is no single "standard" procedure in metabolic surgery. Procedure selection is individualized based on the patient's BMI, duration of diabetes, C-peptide level (an indicator of beta cell reserve), accompanying diseases, and dietary habits. The decision is made jointly by a multidisciplinary team — endocrinology, surgery, nutrition, and, when necessary, psychiatry.
Roux-en-Y gastric bypass (RYGB) is the most frequently applied metabolic surgery procedure with the most extensive long-term data. It is performed by creating a small pouch from the stomach and anastomosing the small intestine to this pouch while bypassing a specific segment. RYGB simultaneously activates both the foregut (bypassed proximal intestine) and hindgut (earlier arrival of nutrients to the distal intestine) mechanisms.
In the STAMPEDE study, approximately 29% of patients with type 2 diabetes undergoing RYGB reached the HbA1c < 6% target at 5-year follow-up, compared to only 5% in the intensive medical therapy group [3]. In the 10-year follow-up by Mingrone et al., remission was maintained in a significant proportion of the gastric bypass group [4]. Younger patients with BMI 30–40, diabetes duration shorter than 10 years, and preserved C-peptide levels represent the profile that benefits most from RYGB.
Ileal interposition (ileal transposition) is a metabolic surgery technique performed by relocating a defined-length segment of the distal ileum to the proximal jejunum. It is generally combined with sleeve gastrectomy. The core aim is to maximize the incretin response by enabling GLP-1-secreting L-cells to contact nutrients immediately after a meal.
This procedure is a metabolic surgery option considered particularly for non-obese or mildly obese type 2 diabetes patients in the BMI 25–35 kg/m² range. Because it is technically more complex than RYGB, it is performed only in experienced metabolic surgery centers. It is not performed for classical bariatric indications; the primary indication is diabetes control. It may be considered as an alternative for patients with a lower BMI but long-standing diabetes resistant to medications and insulin.
SADI-S (Single Anastomosis Duodeno-Ileal bypass with Sleeve) combines sleeve gastrectomy with duodenal switch using a single anastomosis. After the stomach is shaped into a tube, the duodenum is divided and connected to the distal ileum. It provides restrictive (limiting stomach volume), malabsorptive (limiting absorption), and strong metabolic effects. It is an option that may be considered particularly in patients with high BMI (> 40) and severe metabolic syndrome. Due to its technical complexity and malabsorption risk, careful patient selection and long-term micronutrient follow-up are required.
Transit bipartition is a hybrid technique that combines sleeve gastrectomy with an anastomosis of the distal small intestine to the gastric antrum. Some nutrients follow the normal path while a portion reaches the distal ileum directly. This both strengthens the incretin response and partially preserves natural intestinal passage. It may be preferred to enhance the metabolic effect of sleeve gastrectomy in patients with moderate-to-high BMI and resistant type 2 diabetes.
Sleeve gastrectomy is a procedure in which approximately 80% of the stomach is removed vertically, reshaping it into a tube. Although primarily a bariatric operation, its metabolic effect cannot be disregarded. The removal of the fundus region, which secretes the appetite hormone ghrelin, accelerated gastric emptying, and the faster arrival of nutrients in the small intestine result in an increased GLP-1 response.
In terms of metabolic effect strength, sleeve gastrectomy is not as dominant as gastric bypass or SADI-S. However, in patients with BMI 35–45, short diabetes duration, and no established insulin dependency, it can provide adequate glycemic control. In the STAMPEDE study, the rate of reaching HbA1c < 6% at 5 years was reported at approximately 23% in the sleeve gastrectomy group — close to but slightly lower than RYGB [3]. Stronger metabolic procedures may be preferred in long-standing, insulin-dependent diabetes.
Candidate evaluation for metabolic surgery is performed based not on a single criterion but on the combined assessment of multiple parameters. DSS-II, ADA 2022, and IFSO guidelines provide a common framework [1][2][5]:
BMI ≥ 40 kg/m² with type 2 diabetes: surgery is strongly recommended.
BMI 35–39.9 kg/m²: surgery is recommended for patients with type 2 diabetes that cannot be controlled despite optimized lifestyle and medical therapy.
BMI 30–34.9 kg/m²: surgery should be considered for patients unable to reach HbA1c targets.
BMI 25–29.9 kg/m²: metabolic surgery (particularly ileal interposition) may be considered on an individual basis; it is not a routine indication.
Diabetes duration < 10 years: patients have a significantly higher likelihood of remission.
C-peptide > 1 ng/mL: indicates preserved beta cell reserve and predicts surgical response.
Type 1 diabetes: not an indication for metabolic surgery; insulin production capacity has been largely lost due to an autoimmune process.
Severe comorbidities (advanced heart failure, decompensated cirrhosis, active malignancy): surgical eligibility is determined through individual assessment.
Candidate evaluation is carried out jointly by a team of specialists from endocrinology, surgery, anesthesiology, nutrition, and, when necessary, psychiatry. In patients who are unlikely to adhere to lifestyle changes or long-term follow-up, the long-term success of surgery may be limited.
Metabolic surgery is conducted as a planned process. Preparation in the weeks before surgery, hospital stay, and the first postoperative week are all integral parts of the journey. All procedures are currently performed laparoscopically (closed method), which accelerates wound healing and shortens hospital stay.
Preoperative evaluation rests on four fundamental pillars:
Endocrinological examination: Duration of diabetes, medications used, insulin doses, HbA1c, fasting glucose, C-peptide level, thyroid function.
Surgical evaluation: Anesthesia consultation, upper gastrointestinal endoscopy, abdominal ultrasonography (particularly for fatty liver assessment).
Cardiopulmonary evaluation: ECG, echocardiography, and polysomnography for sleep apnea when needed.
Nutritional and psychological evaluation: Dietitian consultation, eating behavior assessment, clarification of motivation and expectations.
A 2–4 week "liver-shrinking" diet is typically implemented before surgery. This high-protein, low-carbohydrate diet reduces the amount of fat in the liver and increases the technical safety of the operation. Insulin and oral antidiabetic doses are gradually adjusted by endocrinology in the preoperative period.
Metabolic surgery procedures are performed under general anesthesia using a laparoscopic technique. Operation duration varies by procedure:
Sleeve gastrectomy: 60–90 minutes
Roux-en-Y gastric bypass: 90–120 minutes
Ileal interposition: 120–150 minutes
SADI-S and transit bipartition: 150 minutes and above
The first night after surgery is spent in intensive care or a close observation unit. Blood glucose is measured hourly; insulin doses are quickly readjusted — in most patients, insulin needs decrease significantly within the first 24 hours. Standard hospital stay is 3–4 days. Oral nutrition begins on the second day with clear liquids and gradually progresses to liquid and pureed forms.
The first week after discharge is a period in which strict adherence to the nutrition program and blood glucose monitoring come to the forefront. A liquid diet is followed for the first 1–2 weeks, then pureed food for 2 weeks, then soft food, and eventually a normal-consistency diet with small portions. A daily intake of at least 1.5–2 liters of fluid and approximately 60–80 g of protein is targeted.
Because blood glucose can change rapidly in the early weeks, the patient performs self-monitoring at least four times a day using a glucometer; medication doses are adjusted with the endocrinology team via phone or outpatient visits. Walking is recommended from the first day; it reduces thrombosis risk. Heavy physical activity and sports are gradually resumed 4–6 weeks later.
The effect of metabolic surgery on diabetes unfolds in layers over time. In the early period, hormonal mechanisms play a role; in the mid-term, insulin sensitivity linked to weight loss takes effect; and in the long term, continuity of lifestyle becomes the determining factor.
In the first 72 hours after procedures such as Roux-en-Y gastric bypass, a reduction in insulin resistance and a decrease in fasting glucose are observed even when caloric intake is restricted. This period represents the clinical reflection of the foregut hypothesis — the exclusion of the proximal small intestine eliminates anti-incretin signals. In many patients, insulin doses are significantly reduced within the first 48 hours; long-acting insulin may be discontinued in some. This early period requires careful glycemic monitoring, as excessive medication can increase the risk of hypoglycemia.
Between the first month and the first year after surgery, the insulin sensitivity gained from weight loss is added to the incretin-driven improvement. HbA1c levels gradually decrease as months pass. In selected patient groups, HbA1c typically falls by 2–3 points by the end of the first year, with a significant proportion of patients reaching normal ranges.
The DSS-II consensus report states that in selected cases, type 2 diabetes remission rates may approach 80% within one year with appropriate patient selection [1]. In the STAMPEDE study, the rate of reaching the HbA1c < 6% target at 1 year was significantly higher in surgery groups compared to the intensive medical therapy group [3]. During this period, oral antidiabetics are discontinued or reduced in many patients, and insulin independence is achieved within the first month in a considerable proportion of patients.
Long-term data indicate that while the effect of surgery somewhat attenuates over time, its superiority over medical therapy is maintained. In the 5-year results of the STAMPEDE study, approximately 29% and 23% of patients in the RYGB and sleeve gastrectomy groups reached the HbA1c < 6% target, respectively; this rate was only 5% in the intensive medical therapy arm [3].
The 10-year follow-up study by Mingrone et al. showed that remission was sustained in a significant portion of the surgical group, and that patients who experienced relapse had, on average, lower HbA1c and required fewer medications than the medical therapy group [4]. In other words, even when remission does not persist, diabetes control is more easily maintained compared to medical therapy. In the long term, regular follow-up, preservation of lifestyle, and nutritional discipline are key determinants of success.
Although its primary goal is diabetes, metabolic surgery also has significant effects on other components of metabolic syndrome. A substantial portion of excess weight is lost within approximately 1 year of follow-up, with outcomes varying by procedure. However, what matters in metabolic surgery is not weight loss alone, but the overall picture combined with improvements in comorbidities.
Hypertension: In a significant proportion of patients, blood pressure returns to normal ranges, and antihypertensive medication needs decrease or are discontinued. Dyslipidemia: Triglyceride levels decline rapidly, HDL increases; improvement in LDL is slower and statin therapy is evaluated individually. Sleep apnea: Particularly in high-BMI patients, CPAP device requirements may decrease; device pressure is retitrated with follow-up polysomnography. Non-alcoholic fatty liver disease (NAFLD) and NASH: Significant improvement is observed in fat infiltration of the liver, transaminase levels, and fibrosis scores.
Improvement in reproductive function in polycystic ovary syndrome and improvement in cardiovascular risk markers are also commonly documented benefits. The combined effect of these components requires metabolic surgery to be viewed as a treatment for metabolic syndrome as a whole — not just diabetes.
Procedure selection is based not on a single parameter but on the overall clinical profile of the patient. The profiling below is a framework frequently used in clinical practice; however, the final decision depends on multidisciplinary evaluation:
Young age, BMI 35–45, diabetes duration < 5 years, preserved C-peptide, oral antidiabetic use: Roux-en-Y gastric bypass is among the prominent options. It balances a strong metabolic effect with an acceptable surgical risk profile.
BMI 35–45, short diabetes duration, not insulin-dependent: Sleeve gastrectomy with close follow-up may be considered. Anatomical integrity is preserved.
BMI 25–34, resistant type 2 diabetes, preserved beta cell reserve: Ileal interposition (combined with sleeve) may be evaluated. It maximizes the hindgut mechanism.
BMI > 45, severe metabolic syndrome, advanced insulin-dependent diabetes: SADI-S or transit bipartition may be considered. A strong metabolic effect is provided together with significant weight loss.
Long-standing (> 15 years) diabetes, low C-peptide (< 0.5 ng/mL), insulin-dominant treatment: Expectations for full remission are low. Surgery can still be performed in these patients, but the goal is not remission — it is improved glycemic control, reduced medication burden, and improvement in comorbidities.
This profiling is approximate. Each patient is evaluated individually; gender, lifestyle, eating habits, previous surgeries, and psychosocial factors all contribute to the decision.
Despite its evidence-based effectiveness, metabolic surgery is a major surgical intervention and carries risks. When performed laparoscopically in experienced centers, mortality is reported in the range of 0.1–0.3% [1][5]. The most important surgical risks in the early period include anastomotic or stapler line leak, bleeding, thromboembolism, and infection. These complications occur at low rates in experienced hands.
Late-period risks specific to metabolic surgery include:
Reactive hypoglycemia: A drop in blood sugar 1–3 hours after meals, particularly after RYGB, due to an exaggerated insulin response. Managed through dietary adjustments.
Micronutrient deficiencies: Deficiencies of B12, iron, vitamin D, calcium, folate, and zinc. Lifelong supplementation and blood work at least once a year are required.
Dumping syndrome: Nausea, sweating, and palpitations due to rapid gastric emptying, particularly after bypass. Managed by avoiding high-glycemic-index foods.
Loss of bone density: Long-term DEXA monitoring is recommended; vitamin D and calcium supplementation are part of the standard protocol.
Incisional hernia and gallstone formation: Hernias at laparoscopic port sites occur at a low rate; during rapid weight loss, preventive treatments against gallstone formation may be considered.
Diabetes relapse: If lifestyle is not maintained, beta cell reserve declines, or weight is regained, remission may relapse. For this reason, the concept of being "in remission" — rather than "cured" — is essential.
The long-term follow-up protocol typically includes visits at 3, 6, and 12 months in the first year, followed by annual check-ups. HbA1c, lipid profile, liver enzymes, complete blood count, B12, iron, vitamin D, calcium, and PTH are routinely monitored. The risk of both micronutrient deficiency and diabetes relapse increases significantly in patients who discontinue follow-up.
Doç. Dr. Hasan Abuoğlu is a general surgeon who has been practicing in Istanbul for over 25 years, with a clinical focus on bariatric and metabolic surgery. His experience of more than 10,000 laparoscopic operations provides a significant clinical background for technically demanding metabolic procedures (ileal interposition, SADI-S, transit bipartition). He is a member of the Turkish Society of Bariatric and Metabolic Surgery (TBMCD) and the International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO).
The clinic's approach is grounded in the principle that metabolic surgery is not a standalone surgical intervention, but rather a long-term process involving endocrinology, nutrition, and, when necessary, psychiatry. Patient evaluation, procedure selection, and long-term follow-up are based on multidisciplinary decisions. Instead of "a single procedure fits all," the philosophy is "the most suitable procedure for this patient"; a young patient with diabetes at a BMI of 30 and a long-standing insulin-dependent patient at a BMI of 45 are directed toward different treatment algorithms rather than the same solution.
Clarity and evidence-based information sharing are the priorities in patient communication. Surgery is presented as an option that offers meaningful advantages over medical therapy in specific indications; patients are clearly informed that results may vary from person to person.
Disclaimer: Results in any surgical or interventional procedure may vary from person to person. Consulting your physician in detail before the procedure is recommended. This content is provided for informational purposes only and is not a substitute for medical diagnosis, treatment, or physician consultation. A personalized evaluation and treatment plan can be established only after a medical examination.
[1] Rubino F, Nathan DM, Eckel RH, et al. Metabolic Surgery in the Treatment Algorithm for Type 2 Diabetes: A Joint Statement by International Diabetes Organizations (DSS-II). Diabetes Care, 2016. — https://pubmed.ncbi.nlm.nih.gov/27222544/
[2] American Diabetes Association. Obesity and Weight Management for the Prevention and Treatment of Type 2 Diabetes: Standards of Medical Care in Diabetes — 2022. Diabetes Care, 2022. — https://diabetesjournals.org/care/issue/45/Supplement_1
[3] Schauer PR, Bhatt DL, Kirwan JP, et al. Bariatric Surgery versus Intensive Medical Therapy for Diabetes — 5-Year Outcomes (STAMPEDE Trial). NEJM, 2017. — https://www.nejm.org/doi/full/10.1056/NEJMoa1600869
[4] Mingrone G, Panunzi S, De Gaetano A, et al. Metabolic surgery versus conventional medical therapy in patients with type 2 diabetes: 10-year follow-up. The Lancet, 2021. — https://pubmed.ncbi.nlm.nih.gov/33485454/
[5] IFSO Global Registry Report 2023. International Federation for the Surgery of Obesity and Metabolic Disorders. — https://www.ifso.com/ifso-registry/
[6] Turkish Society of Bariatric and Metabolic Surgery (TBMCD). — https://www.tbmcd.org.tr/
[7] World Health Organization. Diabetes Fact Sheet. — https://www.who.int/news-room/fact-sheets/detail/diabetes
For detailed information about bariatric and metabolic surgery procedures, you may use the contact channels below. Initial consultations for international patients can be arranged remotely via video call or WhatsApp.

Assoc. Prof. Dr. Hasan Abuoğlu
Associate Professor of General Surgery