Diabetes is a chronic disease in which blood glucose rises to abnormal levels (hyperglycaemia) due to impaired assimilation, use and storage of sugar supplied by food.
It is thought that this auto-immune reaction is linked to a combination of predisposing genes and environmental factors. There are two types of diabetes – type 1 and 2.
There are over 3 million diabetics in France, which is almost 5% of the population. 10% of diabetes cases are type 1.
Type 1 diabetes is caused by the pancreas secreting insufficient insulin and gradually destroying beta cells in which the pancreatic islets synthesise insulin. Insulin is a hormone produced by certain pancreatic cells and is always present in the bloodstream. Its job is to keep blood sugar levels at around 1g/l when high levels of sugar are supplied. So after a meal, the pancreas produces more insulin to keep blood sugar levels within a normal range. In order to control blood sugar, insulin helps sugar enter the body's cells when they need it (e.g. muscle cells during exercise). If necessary, it allows sugar that has not been used by the body to be stored in the liver or fat cells.
This type of diabetes generally appears during childhood or adolescence before patients reach their 20th birthday. Besides genetic predisposition, excess weight and obesity are responsible for the steady rise of this disease.
In type 2 diabetes, blood sugar no longer responds to the insulin secreted by the pancreas. Therefore glucose is insufficiently used up by cells and blood sugar rises above normal levels. This form of diabetes generally appears in patients aged 40 and above, although it increasingly affects obese teenagers and young adults.
The disease is diagnosed by detecting autoantibodies in the bloodstream in individuals with high blood sugar levels. Using this diagnostic tool, it is possible to distinguish type 2 diabetes from other forms and adjust treatment accordingly. The only treatment currently offered is an insulin supplement administered either by injection or an insulin pump.
Insulin therapy is taxing and requires education – patients must measure their blood sugar levels several times a day by pricking their fingers and adapting the doses of insulin they inject. This education is essential, especially for limiting the risk of hypoglycaemia. Although treatment observance can quickly become a burden in everyday life, it is nevertheless crucial in order to avoid any complications. Since diabetics' observance rate is lower than 50%, tools have been developed to help them take their treatment properly. These include blood glucose diaries and blood glucose meters.
If blood sugar is not controlled in the long-term, serious complications may arise several years after the onset of this imbalance (often after 10 to 20 years). These complications mainly affect the heart and blood vessels which are the first organs to be damaged by a permanently excessive concentration of glucose in the bloodstream. Diabetes causes vascular lesions that increase the risk of atherosclerosis, heart attacks, strokes and lower limb arteritis. Diabetes also affects the kidneys, nerves in the lower limbs and retinas. It is therefore essential to monitor the disease regularly using various examinations such as those listed below:
Current research is mainly focused on preventing the disease in future years. In the meantime, despite the limitations of insulin therapy, diabetics have a similar life expectancy to everyone else.
There is no doubt that the main limitation facing diabetics is the need to inject themselves regularly with insulin. North American researchers have therefore designed and tested a microneedle skin patch loaded with insulin-filled vesicles. The patch (which measures 6 mm across) is composed of conical points topped by vesicles. These are 108 nm in diameter and therefore not much thicker than an eyelash. They are nevertheless strong enough to pierce the epidermis.
14 November, World Diabetes Day: knowledge, care and prevention
This date was chosen in memory of Frederick Banting who, assisted by Charles Best, first developed the theory that led to the discovery of insulin in 1922. World Diabetes Day is celebrated in 150 countries.
For further information, visit the website of the Fédération françaises des diabétiques: www.afd.asso.fr/