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Obesity surgery - health and diseases

Can bariatric surgery cure type 2 diabetes?

By 29 December, 2020No Comments

How and why can bariatric surgery cure type 2 diabetes?

In this blog post we will talk about how obesity surgery can cure type 2 diabetes for most patients. But what exactly is type 2 diabetes?

What is type 2 diabetes, what is insulin and how does it relate?

Type 2 diabetes is a chronic disease in which the affected person has a blood sugar level that is not regulated well enough due to partial or complete insulin resistance and excretion. That the disease is chronic means that it is long-lasting[1]. But what is insulin and how does it work?

Insulin is a hormone that plays a crucial role in the absorption of glucose (sugar). Simply explained, when we eat, the carbohydrates in food are converted into glucose which is absorbed into the bloodstream. However, glucose does little good in the bloodstream, we want the glucose into the body’s cells where it functions as fuel. Insulin acts as a key in the cells’ “keyholes” that are found in the surrounding membrane. Insulin (key) opens the door for the glucose do it can enter the cell[2].

If you have type 2 diabetes, as mentioned, you are less sensitive to insulin or maybe you do not secrete enough or no insulin at all. This causes the glucose to stay in the bloodstream and not enter the cells, which results in a too high blood sugar level. This can be measured with a blood glucose meter.

Having an elevated blood sugar level over a longer period of time increases the risk of various other diseases, which is why it is important to lower the blood sugar levels to a normal level.

What is the likelihood of my diabetes being cured?

First of all, we need to define what is meant by cured. When we talk about the patient being cured of type 2 diabetes (sometimes also called diabetes remission), it means that the patient has a normal blood sugar level and no longer needs to take any antidiabetic medication.

It is not possible to predict what the likelihood of diabetes remission is on an individual level before obesity surgery. There are several factors that affect the outcome. Bodies react differently to treatment, just as it does with other medical treatments.

However, it is of course possible to say something about it in general and talk about the average likelihood. Most studies show that 70-89% of patients who have type 2 diabetes prior to surgery are cured after undergoing obesity surgery[3],[4],[5],[6],[7].

In addition, you are more likely to experience complete remission of your diabetes if you have had the disease for a shorter period of time (under 5 years), have a milder degree of diabetes and have a large weight loss after surgery. For example, if you have had diabetes for less than 5 years there is a 95% probability of diabetes remission. Whereas if you have had the disease for 6-10 years, the probability is 75% and if you have had diabetes for more than 10 years, the probability of being cured is 54% [8].

Why can obesity surgery cure type 2 diabetes?

There are several factors that contribute to the fact that an obesity operation can cure type 2 diabetes, but there is not complete agreement on these mechanisms. One of the simple factors is weight loss itself, which increases insulin sensitivity. However, for example, gastric bypass surgery improves diabetes already within days after surgery and thus there are mechanisms other than weight loss that come into play[8].

For example, one hypothesized (the “Hindgut hypothesis”) explains that since food more quickly affects the distal (later) part of the intestines after surgery, there is an increased excretion of the hormones GLP-1 and peptide YY, which causes both increased insulin excretion and sensitivity[9].

Another hypothesis (“Foregut”) related to bypass is that the exclusion of the proximal (first) part of the small intestine on the food’s path through the intestinal system avoids the excretion of a suspected (and not yet clarified) signal that otherwise promotes insulin resistance[10].

In general, calorie restrictions (less than 1100 kcal/day) will result in increased liver insulin sensitivity within 2 days, as there is less insulin in the bloodstream and insulin-producing (beta) cells can rest because they therefore do not have to produce as much insulin [11],[12].

A very small Swedish study with 9 patients has shown that 90% of what affects the insulin mechanisms related to the hormorers GLP-1 and GIP are created by the dietary changes. They believe the same effect is experienced as if the patient had surgery, if the patient is on a powder diet and consumes less than 1000 kcal/day . However, the researchers behind the study find that weight loss is stronger and more permanent in surgery rather than on diet alone [13]. The results are very new and further research on the new findings must be conducted to support the theory.


In short, obesity surgery fixes the problems you have with insulin that cause elevated blood sugar when you are affected by type 2 diabetes through various mechanisms. These mechanisms are related to weight loss, increased insulin excretion and sensitivity and avoidance of insulin resistance.

Type 1 diabetes cannot be cured as this disease is caused by the destruction of the insulin-producing cells in the pancreas.


If you want to know more about overweight surgery, you can read about it here and here. Contact usif you consider that surgery could be beneficial for you!

But. till exempel.

[1] https://www.sundhed.dk/sundhedsfaglig/laegehaandbogen/endokrinologi/tilstande-og-sygdomme/diabetes-mellitus/type-2-diabetes/ But. till exempel.

[2] https://endocrinology.dk/nbv/diabetes-melitus/behandling-og-kontrol-af-type-2-diabetes/

[3] https://diabetes.dk/aktuelt/nyheder/nyhedsarkiv/2019/fedmekirurgi-faar-type-2-diabetes-til-at-forsvinde-hos-3-af-4.aspx But. till exempel.

[4] https://pubmed.ncbi.nlm.nih.gov/19272486/

[5] https://pubmed.ncbi.nlm.nih.gov/15479938/ But. till exempel.

[6] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1234815/

[7] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1360104/

[8] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3102524/

[9] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2936261/

[10] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1856597/ But. till exempel.

[11] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4202361/

[12] https://www.gastrojournal.org/article/S0016-5085(09)00150-4/pdf

[13] https://www.medicin.lu.se/article/strang-diet-forklarar-fetmakirurgins-magi-0