Does weight loss surgery prevent diabetes complications?

This study looked at the effect of bariatric surgery (BS; weight loss surgery) on complications of type 2 diabetes (T2D). It found that patients who had BS had fewer vision, foot, and kidney complications.

Diabetes is a long-lasting health condition that involves high levels of sugar in the blood. Over time, high blood sugar can damage small blood vessels and delicate tissues. Diabetes is a leading cause of kidney failure and of nerve damage. Diabetes can also damage the retina (light-sensitive tissue in the back of the eye) of the eyes, which worsens vision. Additionally, diabetes can damage the nerves, leading to loss of sensation and slow-to-heal foot wounds.

Type 2 diabetes (T2D) is closely related to obesity. There are medications and lifestyle adjustments which can manage T2D. Managing bodyweight is an important aspect of treating T2D. BS is one of the most effective treatments for obesity, and it can lead to improvement or even remission of T2D. Whether BS can also improve diabetes complications of the small blood vessels is still unknown.

This study used a database of ongoing medical records. It included 1,126 patients with obesity and T2D who were undergoing BS. The types of surgery included gastric band surgery and sleeve gastrectomy. Each patient was matched to two other patients who were not having surgery but had similar weights and lengths of T2D. There were 3,345 patients total, and they were followed for an average of 3.9 years.

Over 2.8 years, patients who had BS lost more weight (21.6% vs. 4.6% of body weight) compared to the non-surgical group. The BS patients also had improved blood sugar control (HbA1c reduction of 1.3%), while the non-surgical group had a 0.2% increase. These weight and blood glucose improvements were significant for all types of BS.

Overall, patients in the BS group had a 47% lower risk of developing small blood vessel complications compared to the non-surgical group over 2.2 years. Patients who had surgery had a 39% lower risk of diabetic foot disease. They also had a 42% lower risk of retinal eye damage and 37% lower risk of kidney disease.

This study found that patients with T2D have fewer complications of the small blood vessels following weight loss surgery.

This study had a relatively large number of patients. Also, other studies have had similar findings. Both of these facts increase the certainty that these findings are reliable.