American Diabetes Association defines diabetes mellitus as a group of metabolic diseases characterized by hyperglycemia resulting due to the defects in insulin secretion, insulin action, or both. Prolonged diabetes is associated with dysfunction, and failure of various organs, especially the kidneys, heart, nerves, eyes and blood vessels. Acute, life-threatening consequences of uncontrolled diabetes are hyperglycemia with ketoacidosis or the nonketotic hyperosmolar syndrome.

Long-term complications of diabetes include retinopathy with potential loss of vision; nephropathy leading to renal failure; peripheral neuropathy with risk of foot ulcers, amputations, and Charcot joints; and autonomic neuropathy causing gastrointestinal, genitourinary, and cardiovascular symptoms and sexual dysfunction.

Among the two types of diabetes - insulin dependent diabetes mellitus (IIDM) called type 1 diabetes, and the insulin not dependent diabetes mellitus (NIIDM) called type 2 diabetes - NIIDM is prevalent among 90-95 percent of diabetic population. One of the major findings is that most of the patients suffering from type 2 diabetes are obese, which also causes insulin resistance to some level.

Researchers say people with variations in certain "obesity genes" tend to eat more meals and snacks, consume more calories per day and often choose the same types of high fat, and sugary foods. Recent studies suggest that specific areas of Hypothalamus may play a significant role in maintaining plasma glucose and insulin secretion. Researchers also discovered that individuals with BDNF variations consumed more servings from the dairy and the meat, eggs, nuts and beans food groups. They also consumed approximately 100 more calories per day. This indicates a connection of stimuli induced during growth of brain with diabetes. Brain is rich in poly unsaturated fatty acids (PUFAs) that constitute 30 percent to 50 percent of the total fatty acids in the brain.

Diabetes, obesity and neurological disturbances, most often show co-occurrence. Recent research published in Bioinformation indicated the role of Butyryl cholinesterase (BCHE) in diabetes, obesity and neurological disorders by performing a comparative analysis with Neuroligin (NLGN2), a protein belonging to the same family. BCHE also has its role in glucose regulation, lipid metabolism and nerve signaling.