Diabetes is a disease caused by glucose homeostasis not functioning properly. There are two forms:

• Type I: this is insulin-dependent diabetes in which there’s a large deficiency of insulin due to the ?-cells being killed off, by a virus for example. It’s also known as early-onset diabetes and usually appears during childhood.
• Type II: this is non insulin-dependent diabetes in which insulin is produced but the insulin receptors located in the target cells don’t function. It’s also known as late-onset diabetes and usually appears around the age of 40 in people who are overweight. In the industrialised world 90% of diabetes sufferer have Type II diabetes.

In both types of diabetes the glucose level in the body is much too high after eating. As the kidney is unable to reabsorb so much into the blood a lot of glucose has to be excreted with urine. This is where the name diabetes mellitus comes from: ‘sweet fountain’.

The symptoms of diabetes include:

• being very thirsty because a lot of water is leaving the cells and entering the blood by osmosis
• urinating a lot due to more water in the blood
• bad vision because the water is lost from the eye lens by osmosis
• fatigue because glucose can’t be take up properly by the liver and muscle cells which means the body contains no stores of glycogen and a lot is lost in the urine
• the muscles start to waste away as the rate of gluconeogenesis increase with the high level of glucagon

It’s possible for diabetes to be controlled with insulin injections and a strict diet. Insulin can be taken from pig and cattle pancreas tissue or produced by genetically engineered bacteria in fermenters. There are also a variety of ways it can be administered including injection pens, oral preparations and infusion pumps. There have even been developments towards islets of Langerhans transplants.