Can Type 2 diabetes be reversed?

The good news is that Type 2 diabetes can be reversed; Dr Angela Murphy expands on the ways reversal can be achieved.

In short – yes, Type 2 diabetes can be reversed. However, it is neither easy nor possible for all patients. The word reversed somehow implies that diabetes will disappear never to be seen again. Most of my patients will ask this at some point, especially when the diagnosis is new, and I must emphasise that we do not have a cure for diabetes. It is possible to have remission of diabetes if certain criteria are met.

According to the American Diabetes Association these criteria are:

• Full diabetes remission – fasting blood glucose (FBG) < 5,56mmol/L and HbA1c < 6,0% on no diabetes treatment.
• Partial diabetes remission – FBG is 5,56-6,9mmol/L and HbA1c 6,0-6,5% on no diabetes treatment.

To consider whether it is possible to achieve remission, we need to take a step back and review what factors caused Type 2 diabetes to occur.

What factors caused the diabetes?

The human body requires an exquisite balance of systems to keep blood glucose in the normal range. Insulin produced by the beta-cells in the pancreas must be delivered throughout the body to do this. It is insulin that controls the amount of glucose produced by the liver when the body is in the fasting state, and insulin that regulates the uptake of glucose derived from food into the cells.

When a person gains excess weight, extra fat deposits in the liver and pancreas. This fat creates insulin resistance in the liver and so glucose production goes unchecked. In the pancreas, the fat interferes with normal beta-cell function. Eventually, the combination of increased insulin resistance and decreased insulin secretion causes diabetes. Although, there are always genetic influences, the main factor seems to be the excess fat.

Can the factor be removed?

Yes, most definitely with weight loss interventions. These are as follows:

Dietary

In 2011, the Counterpoint study showed that extreme calorie restriction could normalise blood glucose in a group of patients with Type 2 diabetes. The 11 study volunteers were given a liquid shake (Optifast – available in South Africa) and non-starchy vegetables totalling 600kcal per day. After the first week blood glucose levels dropped on average from 9,2mmol/L to 5,9mmol/L and remained there for the duration of the eight-week study. There was a significant improvement in insulin sensitivity in the liver and pancreas. This meant that the production of glucose in the liver decreased, and the pancreatic beta-cells could do their work again to control blood glucose. The average weight loss to achieve these changes was 15% of initial body weight.

The Counterbalance study, published in 2016, showed similar results in a larger group of patients with Type 2 diabetes who achieved normal blood glucose values for up to six months.

The DiRECT Trial, conducted in a general practice setting in the United Kingdom, showed diabetes remission in 46% of patients after a year and 36% of patients were still in remission after two years.  This showed that a calorie-controlled diet could induce diabetes remission. There is similar evidence for the use of a low carbohydrate diet as a dietary intervention to induce diabetes remission. There is still some debate whether it is the low carbohydrate intake per se or the associated overall drop in total calories that produces the benefit. In my experience, I like patients to follow diets they prefer as reducing calories is always hard work.

Surgery

Bariatric surgery has been used to treat obesity for many years. The sleeve gastrectomy, Roux-Y-gastric bypass and biliopancreatic diversion are the three main procedures.

The Swedish Obese Subject study followed several hundred patients with Type 2 diabetes who underwent bariatric surgery for over two decades. At the end of the second year, 72,3% of patients were in remission. This number decreased to 30,4% at 15-years post-surgery which is still significant.

We now talk about metabolic surgery which is defined as gastrointestinal surgery with the intent of treating diabetes and obesity. The improvement in glucose control post bariatric surgery occurs within days so it is not entirely dependent on actual weight loss. The significant drop in calories decreases the fat in the liver and pancreas restoring normal function in these organs. In addition, the levels of the gut hormone, GLP-1 (glucagon like peptide 1), increase which also increases insulin secretion from the pancreas. These changes lower insulin resistance and increase insulin production which decreases blood glucose. Many medical and scientific societies now endorse bariatric surgery as an effective treatment for Type 2 diabetes and a means to achieve diabetes remission.

What factors affect remission?

It has been shown that patients with longer diabetes duration, poor glucose control and low endogenous insulin production are less likely to achieve diabetes remission despite the above suggested interventions.

Patients choosing bariatric surgery will be assessed with one or other scoring method. The DiaRem score considers patient age, current HbA1c, the number of oral diabetic medications being used, whether the patient is on insulin and the duration of the diabetes. The higher the score, the less likely remission will occur, and this must be discussed with the patient prior to making any decision regarding surgery.

The type of bariatric surgery also affects the rates of diabetes remission with the more complex, malabsorption procedures (such as a biliopancreatic diversion) giving better results. The possibility of diabetes remission must be balanced against the possible risk of complications, especially long-term vitamin deficiencies.

Summary

The good news is that Type 2 diabetes can be reversed, and it is important that healthcare professionals discuss this possibility with patients. For many this will be information they can and will act on.

Bariatric surgery offers an excellent chance of diabetes reversal, but it is invasive and expensive. This makes it less accessible for most patients with Type 2 diabetes.

Lifestyle intervention should be a simpler option, but the calorie restriction is significant and for many people difficult to sustain. This is where newer medications, such as the GLP-1 receptor agonists (exenatide, liraglutide, dulaglutide and semaglutide) may help in the long-term use of very low-calorie diets.

It is vital to remember that good diabetes control decreases the risk of diabetes complications. It is much more beneficial to have good control with diabetic medications than fail at attempts to reverse diabetes and end up with poor control. To achieve diabetes remission is possible but not easy. To achieve diabetes control is possible and usually easier.

References:

1. Lim, E.L., Hollingsworth, K.G., Aribisala, B.S. et al. Reversal of type 2 diabetes: normalisation of beta cell function in association with decreased pancreas and liver triacylglycerol. Diabetologia 54, 2506–2514 (2011).
2. Steven S, et al. Very low-calorie diet and 6 months of weight stability in type 2 diabetes: pathophysiological changes in responders and nonresponders. Diabetes Care 2016; 39: 808– 15
3. Knowler WC, Barrett-Connor E, Fowler SE, Hamman RF, Lachin JM, Walker EA, et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med (2002) 346(6):393–403.

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