Dr. Sylvia Weiner in an expert interview on diabetes surgery

Dr. Sylvia Weiner, M.D., is an expert in the field of bariatric and metabolic surgery. With nearly two decades of experience, she has established herself as a leading specialist in the treatment of obesity and its consequences and has served as the director of the Clinic for Bariatric and Metabolic Surgery at Sana Klinikum Offenbach since October 2022. Dr. Weiner is also the driving force behind the Obesity Academy, an innovative institution in the Frankfurt-Rhine-Main metropolitan region dedicated entirely to the treatment and management of obesity. Together with Dr. Anne Freund, she offers a unique, interdisciplinary program there that provides patients with holistic support for weight loss and improving their quality of life.

Dr. Weiner completed her medical studies at the University of Würzburg and her residency training at renowned institutions such as Mount Sinai Hospital in New York City and Justus Liebig University in Giessen. Her extensive training and years of experience as department head at Sachsenhausen Hospital and the German Bariatric Center, as well as her role as head of the Department of Bariatric and Metabolic Surgery at Krankenhaus Nordwest in Frankfurt am Main, have not only provided her with extensive expertise but have also established her as a leading figure in the field.

With more than 100 scientific publications to her name, she actively contributes to the advancement of bariatric and metabolic surgery. Her broad range of treatments includes both conservative and surgical approaches. Dr. Weiner places particular emphasis on providing individualized care for each patient, relying on a combination of nutritional counseling, exercise therapy, medication, and behavioral therapy to achieve sustainable weight loss.

Dr. Weiner takes an interdisciplinary approach and works closely with physicians, dietitians, physical therapists, and psychologists to develop a customized treatment plan for each patient. Her Obesity Academy also offers comprehensive training courses and workshops for healthcare professionals to further improve the treatment of obesity across the entire medical community. Of particular note is Dr. Weiner’s commitment to research and the development of new treatment methods.

The editorial team at Leading Medicine Guide spoke with Dr. Weiner about diabetes surgery and learned more about this option for people with diabetes, which, unfortunately, is still not widely known

Diabetes surgery is an emerging field of medicine that focuses on surgical procedures for the treatment of diabetes mellitus, particularly in patients with type 2 diabetes who are unable to achieve adequate control of their blood sugar levels despite intensive medical treatment. These surgical procedures—which primarily include bariatric surgeries such as gastric bypass and sleeve gastrectomy—have proven to be promising treatment options for sustainably improving the metabolic disorders associated with diabetes or, in some cases, even inducing remission of the disease. This field of medicine aims not only to reduce body weight but also to increase insulin sensitivity, normalize insulin production, and reduce the risk of complications such as cardiovascular disease, kidney failure, or blindness. Given the rising number of people with diabetes worldwide, diabetes surgery is becoming increasingly important as a key treatment option for this complex condition.

In Germany, approximately 11 million people currently live with diabetes, including about 8.7 million with diagnosed type 2 diabetes—which accounts for 95 percent of all cases—and 372,000 with type 1 diabetes. (Source: Dt. Diabetes Hilfe, https://www.diabetesde.org/ueber_diabetes/was_ist_diabetes_/diabetes_in_zahlen)

In addition, it is estimated that two million people have the disease but remain undiagnosed. More than half a million new cases are diagnosed each year, which corresponds to about 1,600 per day. The average age at diagnosis for type 2 diabetes is 61 for men and 63 for women, although those affected have often been living with the disease undetected for as long as eight years. Approximately 340,000 adults and 32,000 children and adolescents under the age of 18 have type 1 diabetes. Each year, there are about 3,100 new cases among children and adolescents and about 4,150 among adults. The number of type 1 diabetes cases is rising by three to five percent annually. According to projections, the total number of diabetes cases in Germany will rise to about 12.3 million by 2040.

“Diabetes is a manifestation of obesity. Of course, the sugar content in various foods also contributes to the significant rise in diabetes cases, as do the additives in industrially processed foods or ‘light’ products. These have a significant impact on our gut microbiome and our metabolism, as they cause a marked alteration in the functioning of signaling pathways. The body enters a state of alarm because it detects the arrival of substances that are difficult to metabolize. It tries to conserve energy and slows down the metabolism. This leads to more sugar being stored in adipose tissue and the liver producing additional sugar—in an effort to defend itself against this nonspecific attack. This process unfolds over many years and is not caused solely by the occasional consumption of low-calorie products or sugar. In the long term, the body reacts to what is regularly fed to it—and unfortunately, that’s often not very good for it. It’s not just about sugar consumption, but about everything that permanently alters the metabolism. “Ultimately, the metabolism always tries to protect us from starvation,” as Dr. Weiner explains, adding a key point regarding resistance to diabetes:

“Natural childbirth and breastfeeding, for example, can reduce the risk of diabetes in both mother and child from the very beginning of life. This is because during a natural birth, the baby comes into contact with the mother’s vaginal flora, which promotes the development of a healthy microbiome. This plays an important role in metabolism and provides long-term protection against type 2 diabetes. Breastfeeding further supports the child’s gut flora, provides important nutrients and hormones, and reduces the risk of obesity and diabetes. For the mother, breastfeeding helps stabilize blood sugar levels, lose weight, and improve insulin sensitivity, which also reduces the risk of diabetes.”

Surgical treatment for type 2 diabetes has established itself in recent years as a promising therapeutic option, particularly for obese patients in whom conservative treatments such as diet and medication are not sufficiently effective. 

Among the most commonly used procedures are gastric bypass and sleeve gastrectomy, which can lead to a significant improvement in blood sugar control. “Gastric bypass is considered an effective, proven procedure and is also recommended as a surgical therapy in international guidelines, as the surgery involves bypassing the first part of the small intestine. We know that certain signaling molecules are produced in this area that have a positive effect on the pancreas. In principle, all procedures that lead to weight loss should be viewed positively. This is because weight loss has an indirect positive effect by reducing body fat content, which in turn leads to a secondary improvement in insulin resistance,” explains Dr. Weiner.

In bypass surgery, the stomach is divided into two parts: a small gastric pouch, which serves as a new, greatly reduced stomach, and the remaining, larger portion of the stomach, which is largely bypassed in the digestive process. The small intestine is rerouted so that the first part of the small intestine (duodenum) and a portion of the middle small intestine are bypassed. This reduces the surface area available for the absorption of nutrients and calories (malabsorption). This bypass effect leads to several positive outcomes: First, the reduction in stomach size significantly limits the amount of food that can be consumed. Second, bypassing the first section of the small intestine has specific hormonal effects. Studies show that this leads to increased release of hormones such as GLP-1 (glucagon-like peptide-1). These hormones regulate feelings of hunger and insulin action, thereby not only contributing to weight loss but also potentially improving type 2 diabetes in the long term or even bringing it into remission. Bypassing the first part of the small intestine thus plays a central role, as this section is normally crucial for the absorption of calories and nutrients, particularly fats and carbohydrates. 

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As an alternative to surgery, there is GLP-1 analog therapy.

This therapy uses medications that mimic the hormone GLP-1 (glucagon-like peptide-1). This hormone is released in the gut after eating and regulates blood sugar and feelings of hunger. GLP-1 analogs are primarily used to treat type 2 diabetes and, in some cases, for weight loss. They work by promoting insulin release when blood sugar is high, while simultaneously reducing the release of glucagon—a hormone that raises blood sugar. This helps keep blood sugar stable. They also slow gastric emptying, which prolongs the feeling of fullness, and act directly on the brain to reduce appetite. These medications are usually administered by injection, often once daily or weekly, and have proven to be an effective and safe treatment for both blood sugar control and weight loss. Side effects such as nausea are more common at the start of treatment but often subside over time.

“However, GP1 analog therapy only works as long as it is being used!” emphasizes Dr. Weiner.

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The sleeve gastrectomy is a slightly less complex procedure in which a large portion of the stomach is removed, leaving only a tube-shaped remnant. This surgery significantly reduces food intake while also decreasing the production of ghrelin, the so-called hunger hormone. Less ghrelin means that the patient feels less hungry, which leads to spontaneous weight loss. In addition to this mechanical effect, the procedure also has positive effects on insulin sensitivity and blood sugar levels. 

“When it comes to deciding on a treatment method, there is always a primary medical recommendation. Ultimately, however, the patient decides for themselves whether they want surgery at all, since this is still considered an elective procedure. Unfortunately, we often fail to gain the understanding of the patient and/or the primary care physician regarding surgery, even though diabetes is no longer detectable after such a procedure and insulin therapy can be suspended for a period of about 5 to 15 years. Patients also benefit in terms of long-term survival, as the delay in the progression of diabetic disease can significantly prevent the later onset of long-term complications,” explains Dr. Weiner.

With regard to insulin use, it is often the case that patients experience a significant reduction or even an immediate and complete discontinuation of insulin therapy following successful diabetes surgery. 

“The shorter the patient has had diabetes, the greater the effect of the surgery. So anyone who has been injecting insulin for 20 years or longer should not expect such dramatic results. However, there are patients who required 200–300 units of insulin before surgery and no longer needed insulin immediately afterward—a state that often persists for many years. Weight loss then occurs gradually, and the patient loses about 80% of their excess weight in the first six months,” explains Dr. Weiner, elaborating on why more patients do not opt for diabetes surgery:

“This therapy isn’t entirely new. It has been included in the international guidelines of diabetes professional societies for nearly ten years. However, this knowledge is not sufficiently disseminated among primary care physicians. Unfortunately, patients are only sporadically made aware of the benefits of surgery, which is why there hasn’t yet been a large influx of patients. Education is urgently needed here, because ultimately, surgery in these cases is far less dangerous than continuous insulin use—especially with regard to secondary cardiovascular diseases such as heart attacks or strokes. These “secondary complications” typically do not arise until after 20 years of insulin use. Patients are often unaware that, in the worst-case scenario, they are losing years of life.”

Lifestyle changes and postoperative follow-up care play a crucial role in the long-term success of surgical procedures for treating type 2 diabetes. 

“A key factor for long-term success is bypassing the duodenum through traditional bypass surgery, which facilitates approximately 15 years of insulin-free treatment. However, it must also be anticipated that diabetes may return in some cases. After surgery, patients go through a transition phase of about one to three months during which their diet is gradually reintroduced, as they must adjust to new eating and lifestyle habits. “As a general rule, patients should take multivitamins for the rest of their lives because the reduced stomach can no longer absorb enough vitamins. Long-term blood sugar monitoring is also advisable,” Dr. Weiner clarifies.

Sustained weight loss, especially in the first few months after surgery, contributes significantly to improved insulin sensitivity and blood sugar regulation. Patients must therefore make long-term changes to their eating habits by being more mindful of calories, eating a balanced diet, and consulting a nutritionist or dietitian if necessary. Exercise is another important part of a healthy lifestyle that has a positive effect on blood sugar control. Regular physical activity increases insulin sensitivity, improves metabolism, and helps patients lose or maintain a healthy weight. 

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Diabetes surgery is available to patients with all health insurance plans, provided the condition is recognized as such, and is included among the so-called standard benefits covered by health insurance plans.

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Insulin-Free Through the Obesity Academy

Surgical interventions for type 2 diabetes offer significant long-term economic benefits. By improving blood sugar control and potentially inducing remission, the need for expensive diabetes medications and insulin is reduced. In addition, complications such as cardiovascular disease or kidney failure are reduced, which lowers healthcare costs and absenteeism. The savings on medication and treatment costs often exceed the initial investment in the surgery, making it a cost-effective therapy.

“Approximately 30% of our patients undergo diabetes surgery, mostly in the 40-year-old age group, though there is no fixed age limit. For example, we recently had a 76-year-old patient who also benefited, simply through the improvement in his quality of life in everyday life, since he no longer has to constantly manage insulin and monitor his blood sugar levels. That doesn’t get any easier with age. Older patients also benefit in terms of life expectancy, since long-term insulin use increases the risk of becoming a dialysis patient,” Dr. Weiner explains at the conclusion of the interview.