Science - July 22, 2015

Pig is good model for diabetic patient

Albert Sikkema

Not all fat people are unhealthy, suggests Wageningen research on pigs. Pigs work well as a research model for determining the effect of diet on our wealth-related diseases.

The metabolism of humans and pigs is very similar, says researcher Sietse Jan Koopmans. Moreover, they are about as big and heavy and you can very well measure the effect of nutrition on obesity, diabetes and cardiovascular disease, in pigs. When Koopmans put a bunch of pigs on a diet with a lot of olives and fish oil, he got fat but healthy pigs. ‘Their arteries were spotless, their sugar level was low and the cholesterol levels healthy."

Koopmans, animal physiologist at Livestock Research, investigates the effect of nutrition on lifestyle diseases in pigs. In humans, you cannot measure the effects of unhealthy nutrition on for example, atherosclerosis or diabetes, in standardized tests, in pigs you can. Moreover, it can take up to 20 years with people before the effects of a diet manifest themselves as diabetes and cardiovascular diseases. In pigs, Koopmans can accelerate that process.

'Just like with men, the predisposition for obesity, arteriosclerosis and diabetes, varies a lot between pigs. If they get a high-sugar and high-fat diet for a very long time, the saturated fats will sit in the veins and the liver, but also in the pancreas, where insulin is made. This leads to more inflammation and malfunctioning of these organs, causing the metabolic syndrome to occur, the precursor of diabetes.’ With humans, this process can take 20 years. ‘We do not have that time as scientists, so we need a model system. In the pig, we can mimic this process in only 4 months, by placing the pigs on a fat and sugary diet.’

Subsequently it may take years before this metabolic syndrome becomes diabetes. This is because the pancreas produces much more insulin than the body needs. Due to ageing and poor eating habits the insulin production decreases, until there is a shortage of insulin. Koopmans can break off this insulin-buffer in pigs in a few weeks with the substance streptozotocin, he reports in the European Journal of Pharmacology. This makes him the first researcher who managed to develop a model of an obese pig with just / almost diabetes. He presents all sorts of meals to these pigs, to study the effect of diet on diabetes.