Before knowing the major causes of diabetes, it is very important to know what happens in diabetes. Essentially, a diabetic patient's blood sugar levels remain high because the body either does not make sufficient levels of the hormone insulin (which regulates blood glucose levels), or the body cannot utilize the insulin present, or both.Well, there are two types of diabetes - type 1 and type 2. Type 1 diabetes happens when the cells that produce insulin, the beta cells of the pancreas, get destroyed and lead to the non-production of insulin. Type 2 diabetes occurs when the body is unable to produce sufficient amounts of insulin or utilize it properly. So, what creates such a condition in the body? What are the major causes of diabetes?
Causes of Diabetes Type 1:
Destruction of the insulin-producing beta cells of the pancreas takes place due to an autoimmune condition. The body's own immune cells start attacking the beta cells. This may go on for a few years before the first symptoms show up. The various causes for triggering this are as follows:
- Genetics - Certain genes make a person more susceptible to developing type 1 diabetes. These genes transcribe to form the human leukocyte antigen (HLA) proteins found in the white blood cells. The HLA proteins help in recognizing any cell as the body's or foreign. Certain HLA gene combinations make a person more susceptible to type 1 diabetes. The presence of certain other gene variants is also linked to the disease.
- Environment - Though the exact mechanism is yet unknown, certain foods and toxins can also trigger the autoimmune reaction in genetically susceptible people to destroy beta cells.
- Infection - Many studies have shown how viruses can damage beta cells or trigger an autoimmune response against the cells. Cases of type 1 diabetes also seem to rise in winter, coinciding with increased viral infections in that season. Viruses believed to be involved are rubella and mumps virus, adenovirus, cytomegalovirus, and coxsackievirus B.
- Infant feeding habit - Some studies link breastfed children and those receiving vitamin D supplements to a lowered incidence of type 1 diabetes.
Causes for Diabetes Type 2:
- Genetics - Certain genes have been found to influence insulin production in the body. For example, particular variants of the TCF7L2 gene increase the chances of type 2 diabetes, and more so if the person carries two copies of the same variant. Another theory suggests that genes that cause faster metabolism and storage of fat, leading to weight gain, can also promote obesity and type 2 diabetes.
- Sedentary lifestyle and obesity - This factor is strongly linked to type 2 diabetes. Both lack of physical activity and increased food consumption can cause insulin resistance and further diabetes.
- Insulin resistance - As explained above, obesity and inactivity can cause cells of the liver, fat, and muscle to stop responding to insulin. The pancreas begins to produce more insulin to counter this, but any form of beta cell abnormality can trigger diabetes.
- Excess glucose production by the Liver - In normal conditions, the pancreatic hormone glucagon (stimulates the liver to release glucose) level is low when blood levels are high, like after a meal. However, it is found to remain high in diabetics, causing even more glucose in the blood.