The Gastric Sleeve, technically known as a Vertical Sleeve Gastrectomy (VSG), is a highly effective surgical procedure for treating severe obesity and related metabolic diseases. During this operation, a surgeon removes about 75 to 80 percent of the stomach, leaving behind a narrow, banana-shaped tube that functions as the new stomach. This reduction in size physically limits the amount of food a person can consume. The procedure has gained widespread recognition for its profound and rapid effects on metabolic health, especially for individuals managing Type 2 Diabetes.
Defining the Outcome: Remission vs. Cure
The question of whether a Gastric Sleeve “cures” Type 2 Diabetes requires a careful distinction between the terms “cure” and “remission.” Medical professionals generally avoid the word “cure” because diabetes is a chronic condition that can return if the underlying factors are not consistently managed. Instead, the term “remission” is used, which signifies that blood sugar levels have returned to normal without the need for diabetes medication.
Diabetes remission is specifically defined as achieving a non-diabetic A1C level—typically below 6.5%—while being off all glucose-lowering medications for a minimum of three months. This outcome is a major success for sleeve gastrectomy patients, with a significant percentage experiencing remission shortly after the operation. Studies show that between 56% and 59% of patients achieve remission within the first year following surgery.
The high rate of success is why the procedure is often referred to as metabolic surgery, not just weight loss surgery. Research indicates that approximately 42% of patients who initially achieve remission after a sleeve gastrectomy may see their diabetes return within five years. This recurrence is often associated with regaining a portion of the weight lost.
Physiological Changes That Impact Blood Sugar
The dramatic improvement in blood sugar levels following a sleeve gastrectomy is not solely due to weight loss; it also involves immediate and profound changes in gut hormones. These hormonal shifts begin almost instantly, often within days of the procedure and well before any significant weight reduction has occurred. The removal of the curved upper part of the stomach, called the fundus, is a key factor because this area is the primary site of production for the hormone ghrelin.
Ghrelin is widely known as the “hunger hormone” because it stimulates appetite. With a large portion of the ghrelin-producing tissue removed, patients experience a significant and long-term decrease in ghrelin levels, which helps to control hunger and reduce food intake.
More importantly for diabetes, the surgery alters the path of food through the digestive tract, causing undigested nutrients to reach the lower small intestine more quickly. This rapid delivery of nutrients stimulates the release of beneficial gut hormones, known as incretins, such as Glucagon-Like Peptide-1 (GLP-1) and Peptide YY (PYY).
GLP-1 is particularly important because it enhances the pancreas’s ability to secrete insulin in response to food and increases the body’s sensitivity to insulin. This process rapidly improves the body’s glucose metabolism, allowing blood sugar levels to normalize and often enabling patients to stop taking insulin and other diabetes medications very soon after surgery.
Maintaining Results and Long-Term Monitoring
Achieving diabetes remission through a sleeve gastrectomy is the first step, but maintaining that success requires a lifelong commitment to specific dietary and lifestyle protocols. Patients must adhere to a strict post-operative diet that prioritizes high protein and low sugar consumption to prevent weight regain and protect the new stomach pouch. Avoiding foods high in simple carbohydrates is important because the altered digestive tract can lead to a complication called reactive hypoglycemia, which is a rapid drop in blood sugar a few hours after eating.
Because the procedure involves no intestinal rerouting, the risk of malabsorption is less severe than with other bariatric procedures, but vitamin supplementation remains mandatory. Patients must take specific bariatric multivitamins, along with calcium and Vitamin B12, for the rest of their lives to prevent nutritional deficiencies. Failure to consistently adhere to these dietary and supplementation requirements significantly increases the risk of the diabetes returning.
Lifelong follow-up care with a metabolic surgeon and endocrinologist is necessary, even for those in complete remission. This monitoring includes regular blood tests to check blood sugar and A1C levels, as well as nutritional markers. Catching any subtle rise in A1C or the beginning of weight regain early allows for intervention before a full diabetes relapse occurs.