Can you cure yourself of diabetes?

Listener Sam has this cure-ious question for physiologist, Sam Virtue.

Sam - Well the short answer is some people can and it's probably worth giving it a go. A lot of this research came from patients who were going to be undergoing bariatric surgery. And one of the things they aim to do before people have the surgery, because it’s quite hard to do surgery with lots and lots fat, is to try and get them to lose some weight. So they put them on very low calorie diets for several weeks ahead of the surgery. And they actually find these were pretty beneficial. Researchers led by a guy called Roy Taylor up in Newcastle have really been looking into this a lot and they, basically, put people on a diet which is about 600 calories, for eight weeks and we normally eat about 2000 calories, so that's a third of what we would normally eat. So this is pretty extreme. And when we looked at these subjects they lost about 14 kilos over the eight weeks and about 40 percent of them had recovered from having diabetes, and it wasn't just that they were more insulin sensitive. Their pancreas could make insulin again.

Chris - Should we point out that we're talking about type 2 diabetes, rather than type 1 diabetes where people are absolutely dependent on insulin to stay alive. Type 2 diabetes is the obesity associated diabetes that you would be working on.

Sam - Absolutely. And one of the things they found about the subjects who could basically reverse their diabetes is before they started the weight loss, these were the subjects who already had reasonable amounts of insulin. So if people had had diabetes for a long time, over 10 years, or they have very very low levels of insulin it was likely their pancreas was so badly damaged, just like a type 1 diabetic where the basal cells are destroyed by the immune system, that they couldn't recover. But subjects who had high blood glucose but high insulin, they just weren't making enough insulin for their body, they were the ones who were most likely to recover.

Chris - Do we know why, when a person does carry a bit too much weight, that the body's tissues essentially become deaf to their own insulin signals. So they can have paradoxically very high insulin levels but very high sugar levels. Do we understand that process?

Sam - That's exactly what I work on. There are several theories about it but the one we are interested in, is the idea that fat can accumulate in organs where it shouldn't. So fat can accumulate in liver, and the fat itself is what then poisons the cells and interferes with the signaling, essentially muffles the ability of the insulin to pass its signals down to do the things like say take up glucose.

Chris - And so when one loses weight to a profound degree you rob away some of that abnormally accumulated fat and therefore that muffled signal, the muffler is removed and now you can you can again see the insulin signal.

Sam - Indeed. And also fat can actually interfere with the production of insulin by the pancreas and one of the things they saw in the study, was in the subjects who particularly recovered well, they had much greater reductions in lipids within their pancreas. So yes that's very reasonable.