Advanced Health Tune Up

Type 1 Diabetes mellitus is a chronic metabolic disorder caused by an absolute or relative deficiency of insulin. Insulin, an anabolic hormone is produced by the beta cells of the islets of Langerhans located in the pancreas. The absence, destruction, or other loss of these cells results in type 1 or insulin-dependent diabetes mellitus (IDDM). Most children with diabetes have IDDM and a lifetime dependence on exogenous insulin.

Type 1 diabetes results from the autoimmune destruction of the beta cells, possibly triggered by a viral infection (e.g., Coxsackie virus or other enteric virus) or by toxic exposure in a genetically susceptible individual. The progressive destruction takes place, in part, from T cell release of cytokines, which attack the beta cells. By the time a patient with type 1 diabetes presents with symptoms, the pancreatic beta cells are 80% to 90% destroyed.

Insulin is essential to process carbohydrates, fat, and protein. Insulin reduces blood glucose levels by allowing glucose to enter muscle cells and by stimulating the conversion of glucose to glycogen as a carbohydrate store (glycogenesis). Insulin also inhibits the release of stored glucose from liver glycogen (glycogenolysis) and slows the breakdown of fat to triglycerides, free fatty acids, and ketones. It also stimulates fat storage. Additionally, insulin inhibits the breakdown of protein and fat for glucose production (gluconeogenesis) in both liver and kidneys.

Hyperglycaemia (i.e., random blood glucose concentration more than 11 mmol/L) results when insulin deficiency leads to uninhibited gluconeogenesis and prevents the use and storage of circulating glucose. The kidneys cannot reabsorb the excess glucose load, causing glycosuria, osmotic diuresis, thirst, and dehydration. Increased fat and protein breakdown leads to ketone production and weight loss. Without insulin, a child with IDDM wastes away and eventually dies from diabetic ketoacidosis (DKA).

Aetiology / Risk Factors

Family history of type 1 diabetes
Mother who had preeclampsia during pregnancy
Family history of immune diseases including Hashimoto's thyroiditis, Graves' disease, myasthenia gravis, Addison's disease, or pernicious anaemia

Illness during early infancy

Child of an older mother

Northern European or Mediterranean descent

Cow's milk consumption in infancy (controversial): one study found that children exposed to cow's milk during the first 8 days of life had two times the risk of developing type 1 diabetes compared to newborns receiving breast milk alone.

Symptoms & Signs

While destruction of beta cells occurs gradually, the following symptoms generally appear quite abruptly once 80% to 90% of the pancreatic beta cells are destroyed: