Diabetes is a disease characterised by hyperglycaemia (high blood sugar levels), resulting from inadequate secretion of the hormone insulin, an inadequate response to insulin production, or a combination of these two factors.
The three most common forms of diabetes are Type I, Type II and Gestational diabetes.
In Type 1 diabetes there is a loss of insulin-producing beta cells in the ‘Islets of Langerhans' (insulin producing factors) in the pancreas. Without insulin, ketosis can develop (an abnormality of the metabolic process, resulting in an increase of ketones in the blood, increasing the risk of developing kidney stones - ketoacidosis).
This type of diabetes can affect both children and adults, but is generally known as Juvenile diabetes.
In Type 2 diabetes there is a combination of faulty insulin secretion and reduced insulin sensitivity. This results in elevated levels of insulin in the blood.
Type 2 diabetes is more common in adults, comprising 90% or more of cases of adult-onset diabetes. There is a strong association with obesity.
Type 2 diabetes may go unnoticed for years in a patient before diagnosis, since the symptoms are typically milder and can be sporadic.
In Gestational diabetes there is inadequate insulin secretion and responsiveness, as in Type 2 diabetes which develops during pregnancy (around 40% of women with Gestational diabetes go on to develop Type 2 diabetes).
The main risks diabetes pose to health are its heavily associated long-term complications (cardiovascular disease, chronic renal failure, retinal damage leading to blindness, nerve damage, erectile dysfunction (impotence) and risks of amputation of toes, feet, and even legs).
Other health problems may accelerate the effects of diabetes and glucose metabolism (elevated cholesterol levels, high blood pressure and lack of regular exercise).
Diabetes symptoms include polyuria (frequent urination), polydipsia (increased thirst, and consequent increased fluid intake) and blurred vision. There may also be weight loss, increased appetite, and fatigue.
(Other severe complications may include: hypoglycemia and diabetic coma.)
Causes
The most common cause of beta cell loss leading to Type 1 diabetes is autoimmune destruction (i.e. antibodies directed against insulin and islet cell proteins).
Insulin resistance may be genetically-related, related to hormonal defects, or chemical or drug exposure.
Food allergies are a common feature in Type 2 diabetes, e.g. from peanuts, corn, gluten, or dairy products (dairy products can allow abnormal proteins and hormones to enter the blood stream and cause autoimmune reactions).
Some cases of Type 1 diabetes are caused by viruses (where the virus attacks beta cells).
Vaccines can also contribute if a person is allergic to the base of the vaccine, triggering the auto-immune system into reaction.
Inadequate minerals are also an important factor. For example, if some of the key molecules that form insulin are not available the beta cells simply cannot manufacture insulin. The most common culprit is chromium deficiency.
Heavy metals such as mercury can inhibit the ability of the pancreas to produce insulin due its toxicity.