Pancreas is the organ which is responsible for development of diabetes. When there is dysfunction of pancreas, particularly beta-cells of pancreas which produce and secrete insulin, which is responsible for metabolism of glucose.

The diseases of pancreas include pancreatitis (infection/inflammation of pancreas which may be acute or chronic), diabetes mellitus, cystic fibrosis, cancer of pancreas etc.

Anatomy of Pancreas:

Pancreas is approximately six inches long, flat and narrow organ with a head, tail and middle section. The location of pancreas is between stomach and spine. Small ducts feed pancreatic juice to the pancreatic duct inside the pancreas, which connects to duodenum, through head section. The common bile duct also runs through the head section of the pancreas and carries bile from the liver and gall bladder into the small intestine.

Type-1 diabetes is immune (autoimmune) mediated and insulin dependent diabetes. The autoimmune process of development of type-1 diabetes starts several years before clinical features/symptoms of diabetes are seen or diagnosis made in routine blood sugar test. The autoimmune process is directed against the islets of Langerhans. Most, but not all, individuals have evidence of antibodies against of islets of Langerhans.

The pathogenesis of type-1 diabetes is the result of interactions between genetic, environmental, and immunologic factors that ultimately lead to the destruction of the pancreatic beta cells and insulin deficiency. There is high variation in the incidence of type-1 diabetes among different races and very high among Caucasians, low in Blacks and extremely low in Asians, which strongly suggest genetic influence in the causation of type-1 diabetes.

The development of type-1 diabetes occurs in series of stages which starts with genetic susceptibility and influenced by environmental and immunologic factors, which ultimately leads to destruction of beta cells of islets of Langerhans.

Type-2 diabetes is non-insulin dependent (insulin is not must for management), insulin resistance, abnormal insulin secretion and impaired pancreatic beta cell functions are central to the development of type-2 diabetes. Most studies suggest that insulin resistance precedes defect in insulin secretion, but diabetes develops only when insulin secretion becomes inadequate or insulin resistance becomes very high that the insulin secreted by beta cells become inadequate to maintain glucose level. Type-2 diabetes develops much later in life in compare to type-1 diabetes and generally seen only after 3^rd or 4^th decades of life.

Pathogenesis of type-2 diabetes is complex and involves a complex interaction between genetic and environmental factors. The genetic factor is much stronger in causation of type-2 diabetes, than type-1 diabetes and concordance of type-2 diabetes in identical twins is between 70 and 90%, in compare to 30% to 70% in type-1 diabetes. Many environmental factors are also implicated in the development of type-2 diabetes, such as sedentary lifestyle, excess food (calorie) intake which results in overweight and obesity (BMI of more than 30 is obesity).