The existence of diabetes has been noted throughout history, across a range of different civilisations. The first description of symptoms of the disease appeared over 3,000 years ago, in an ancient Egyptian text that described patients suffering from “too great emptying of the urine”. Around the same time, physicians in ancient India also noted symptoms of the disease, which they termed madhumeha or ‘honey urine’, referring to the excessive sugar levels in the urine of diabetics. Based on this, they developed a crude method of diagnosis: observing whether or not ants and flies were attracted to the urine of suspected sufferers. Attraction indicated high sugar levels, owing to it not being broken down or stored by the pancreas. Likewise, the ancient Greeks observed the condition in around 230BC, coining the term ‘diabetes’, meaning ‘to pass through’.
Despite ancient knowledge of the condition, it has, until relatively recently, been largely untreatable. While the ancients knew the symptoms and the mortal outcome of the disease, they were unaware of the cause of diabetes: a lack of insulin in the pancreas of the sufferer, creating an inability to process sugar.
Life for diabetics has become longer, more pleasant and less painful
As the ancient Greek physician Aretaeus of Cappadocia wrote in the second century AD: “Diabetes is a dreadful affliction.” For a diabetic, he noted in his work On the Causes and Indications of Acute and Chronic Diseases, “life is short, unpleasant and painful”, and “within a short time [sufferers] expire”. However, owing to a number of medical breakthroughs starting in the 20th century, life for diabetics has become longer, more pleasant and less painful.
The discovery of insulin, and the development of increasingly easy ways for sufferers to administer it themselves, allowed patients to self-perform the key function their own pancreases could not: use up or store sugars in the blood. Progress in the 21st century, however, continues apace and a number of new medical developments should mean further improvements to the lives of diabetes patients.
A significant breakthrough
To make treatment of diabetes possible, a clear understanding of its cause was needed. From the 19th century, scientists had started to understand that the sugar found within the urine of diabetics was glucose. However, without the discovery of insulin and the vital role it plays in the bodies of non-diabetics, treatments were generally restricted to recommending a restrictive diet. John Rollo, the surgeon-general of the Royal Artillery, developed a high-protein and low-carbohydrate diet for those believed to be suffering from the disease. Other methods included prescribing appetite suppressants such as opium. While these techniques often extended the lives of diabetics, they did not do so for very long; it was not uncommon for these diets – bereft of carbohydrates – to be so low in calories that patients would die of starvation.
It was not until the discovery of insulin by Fredrick Banting and Charest Best in 1921 that anything resembling a real breakthrough in treatment became possible. This occurred following the work of Oskar Minkowski and Joseph von Mering, who found in 1889 that removal of the pancreas of dogs caused them to suffer the same symptoms as those with diabetes. This discovery was expanded upon, with attempts to narrow down the chemical within the pancreas that was responsible for regulating glucose. In 1910, Edward Albert Sharpey-Shafer came to the conclusion that this regulator was a single chemical, which he called insulin.
By administering insulin to the diabetic dog, they were able to keep the dog alive for 70 days
Based on this previous research, Banting and Best successfully removed insulin from a dog’s pancreas in 1921. With this thick brown liquid, the two scientists treated another dog that was suffering from severe diabetes. By administering this insulin to the diabetic dog, they were able to keep the dog alive for 70 days, with the test animal only dying once they had run out of the insulin extract. The results seemed near conclusive: diabetes was caused by a lack of insulin, and could be treated by administering it from an outside source.
Alongside their colleagues, JB Collip and John Macleod developed a more refined form of insulin from cattle that, in 1922, was finally trialled on a human. A 14-year-old boy named Leonard Thompson was chosen. In hospital and facing certain death from the as-yet untreatable condition, Thompson was injected with the new refined insulin, resulting in his glucose levels falling to nearly normal levels. A successful means of treating diabetes in humans had been found. Soon, pharmaceutical firms started to produce insulin en masse, and eventually created both slow and fast-acting forms. With the cause and means of treating diabetes discovered, the task was now to develop the best technology to allow diabetics to administer this life-saving chemical.
Although responsible for extending the lives of untold millions, administering insulin was still fraught with a number of problems. Firstly, insulin was derived from animals such as cattle and pigs. This caused allergic reactions in certain patients, effectively excluding them from diabetes treatment. This led to the creation of synthetic ‘human’ insulin, derived from bacteria.
At the same time, the needles needed to administer insulin were terribly invasive. The first insulin injections required intramuscular injections of five to 18 millimetres. However, the 20th century saw gradual development, culminating in the current, small, relatively non-invasive needles used to dispense insulin. And progress did not stop there. Scientists around the world are still working on a plethora of other methods of allowing diabetics to get the life-saving insulin they need in easier and more efficient ways.
The first insulin injections required intramuscular injections of five to 18 millimetres
One of the latest and most promising methods is the insulin patch. Developed by researchers from MC10 alongside Dae-Hyeong Kim, an assistant professor at Seoul National University, the patch promises to do away with insulin injections (or the more invasive insulin pump) altogether. A small piece of graphene studded with gold particles, the patch is able to perform the dual task of monitoring blood glucose levels and administering insulin accordingly. It senses high glucose levels in the wearer, resulting in heaters in the patch dissolving a film that releases insulin.
The laborious task of measuring insulin levels and the slightly invasive injection needed to administer it may become relics of medical history. Of course, similar non-invasive methods of insulin administration have been tried before – from similar patches to the insulin inhaler – and have failed to deliver. But, if the history of insulin in the 20th century is anything to go by, insulin administration will become increasingly refined and perfected as time goes on.
The discovery and constant refinement of insulin has saved countless lives, and will continue to do so with increasing ease. As Michael Bliss wrote in his book The Discovery of Insulin: “[The discovery was] one of the most dramatic events in the history of the treatment of disease. Those who watched the first starved, sometimes comatose diabetics receive insulin and return to life saw one of the genuine miracles of modern medicine.” As instances of diabetes around the world grow, many more will be saved. However, the miracle of modern medicine will not end there, as further developments will make the administration of insulin an ever-easier process.