People with type 2 diabetes mellitus (T2DM) are frequently obese. Type 2 diabetes mellitus works together with obesity to enhance insulin resistance. Insulin resistance is a condition whereby the target organs fail to respond to insulin being produced by the pancreas. Dropping the extra pounds improves insulin sensitivity and the blood sugar levels and reduces the risk of complications in diabetics. Having that said, if you are a diabetic, managing obesity can be challenging. This is because some anti-diabetic medications can end up causing more weight gain. Besides, medications that treat both diabetes and obesity are limited. Fortunately, surgical procedures, collectively termed as bariatric surgeries are available today and can be considered as the most effective treatment for diabetic individuals who are obese.
What are the Different Methods of Bariatric Surgery?
A variety of surgical methods can be performed to achieve the desired weight loss. These are as follows:
- Reducing the size of the stomach with a gastric band
- Removing a portion of the stomach (sleeve gastrectomy)
- Resecting and re-routing the small bowel to a small stomach pouch (gastric bypass)
How is Bariatric Surgery Superior to Anti-Diabetic Medications?
Various trials have been conducted that compare the effectiveness of bariatric surgery to medical therapy.
In one of the latest trials, diabetic obese patients were randomized to three groups: intensive medical therapy plus either gastric bypass or sleeve gastrectomy. This trial that extended for over 1 and 3 years after randomization, revealed that both gastric bypass and sleeve gastrectomy were superior to intensive medical therapy alone. In the group with gastric bypass and sleeve gastrectomy, the glycated hemoglobin (HbA1c) levels ( a test which tells you your average level of blood sugar over the past 2 to 3 months ) were ≤6.0% that suggested excellent blood glucose control. Moreover, the surgery groups demonstrated a substantial reduction in body mass index (a measure of body weight) and the cardiovascular risk along with an improvement in the quality of life, and a reduced need for anti-diabetic medications.1
Additional Parameters that Indicate the Usefulness of Bariatric Surgery in Diabetes
In diabetes, bariatric surgery significantly lowers the number of medications required to treat blood lipid derangements (hyperlipidemia) and high blood pressure (hypertension). This reduction indicates optimal control of both the blood pressure and lipid abnormalities. Both hyperlipidemia and hypertension are important co-exisiting cardiovascular risk factors in diabetes.
Sleeve gastrectomy drastically lowers the albumin-to-creatinine ratio (ACR) in urine. ACR is a ratio that compares the amount of albumin (a protein which when excreted in larger amounts suggests kidney disease) excreted in urine to the amount of creatinine excretion. A higher ratio is linked with a higher risk of developing progressive kidney disease or diabetic nephropathy depending upon the ACR value. A drop in the ACR implies positive effects of bariatric surgery on the kidneys (one of the organs frequently affected with long-standing diabetes.1
Furthermore, although bowel-related adverse events are noted after bariatric surgery, significant weight gain and an increase in kidney-associated complications are greater with medical therapy.1 Hence, your physician will assess the risk-benefit ratio before considering bariatric surgery.
How do Bariatric Procedures Lower Blood Glucose Levels?
Gastric bypass alone markedly enhances insulin sensitivity that lowers the blood glucose levels. The beneficial effects of bariatric surgery on glucose metabolism are observed before the improvements in weight and BMI. Both gastric bypass and sleeve gastrectomy greatly stimulate incretins, remarkably GLP-1 (glucagon-like peptide-1). Incretins are hormones that trigger the release of insulin from the beta cells of the pancreas after meals.2,3
Additionally, calorie restriction following gastric bypass by itself considerably accelerates weight loss. This subsequently causes a drop in the fasting blood glucose levels.
Bariatric surgery offers a dual advantage in diabetes. Being a weight loss procedure, it vastly benefits diabetic individuals who are obese. The glucose-lowering effect of bariatric surgery is also superior to conventional antidiabetic therapy and frequently occurs within days following surgery. If you are an obese diabetic, talk to your doctor if bariatric surgery is the right option for you.
- PR Schauer et al. Bariatric Surgery Versus Intensive Medical Therapy for Diabetes - 5-Year Outcomes. N Engl J Med. 2017;376 (7), 641-651. doi: 10.1056/NEJMoa1600869.
- Kashyap SR, Bhatt DL, Wolski K, et al. Metabolic Effects of Bariatric Surgery in Patients With Moderate Obesity and Type 2 Diabetes: Analysis of a randomized control trial comparing surgery with intensive medical treatment. Diabetes Care. 2013;36(8):2175-2182. doi:10.2337/dc12-1596.
- Xiong S-W, Cao J, Liu X-M, Deng X-M, Liu Z, Zhang F-T. Effect of Modified Roux-en-Y Gastric Bypass Surgery on GLP-1, GIP in Patients with Type 2 Diabetes Mellitus. Gastroenterology Research and Practice. 2015;2015:625196. doi:10.1155/2015/625196.