INTRODUCTION Insulin is a hormone that is important for metabolism and utilization of energy from the ingested nutrients - especially glucose. Insulin is produced in the islets of Langerhans in the pancreas. The name insulin comes from the Latin insula for "island" from the cells that produce the hormone in the pancreas. Insulins structure varies slightly between species of animal. Both porcine (from pigs) and bovine (from cows) insulin are similar to human insulin but porcine insulin resembles human insulin more closely.
Dr. Nicolae Paulescu , Romanian scientist invented Insulin in 1916. On January 11, 1922 Leonard Thomson a 14 year old boy who was dyeing of Diabetes , was given the first experimental dose of insulin and his life saved. In 1923 , Banting and Macleod were awarded the noble prize for their work on discovering insulin.
WHAT DOES INSULIN DO ? It causes the cells in the liver, muscle, and fat tissue to take up glucose from blood and convert it to glycogen that can be stored in the liver and muscles. Insulin also prevents the utilization of fat as an energy source. In absence of insulin or in conditions where insulin is low glucose is not taken up by body cells, and the body begins to use fat as an energy source. Insulin also controls other body systems and regulates the amino acid uptake by body cells. It has several other anabolic effects throughout the body as well.
INDICATIONS OF INSULIN THERAPYAt onset : Fasting > 250 mg /dl Post prandial > 300mg/dl HbA1c > 9.0%OHA Failure Fasting >150mg/dl Random or Post prandial > 200mg/dl HbA1c >8.5%Co-morbid conditions Severe systemic infection or sepsis Acute Myocardial Infarction / Unstable Angina Diabetic Ketoacidosis/Hyperosmolar state Diabetic Kidney Disease Pre - gestational / Gestational Diabetes
INSULIN DOSING REGIMENS Degree of glycaemic control. Severity of underlying insulin deficiency. Patient’s lifestyle. His/Her ability to adjust the insulin dose.(SMBG)
TYPE OF INSULIN FOR INSULIN INITIATION Insulin initiation could be done with premixed insulins which control effectively both fasting and post prandial hyperglycemia. Premixed formulations are generally available as 30/70, 25/75 or 50,50 combinations of rapid acting and intermediate acting insulins. The gold standard for insulin regimen is basal bolus therapy combining one or two doses of basal insulins and three doses of rapid acting insulins to cover the post prandial peaks following three major meals.
SIDE EFFECTS OF INSULIN THERAPY Hypoglycaemia (<63mg/dl) Weight gain Peripheral oedema( salt and water retention) Insulin antibodies Local allergy ( rare ) Lipodystrophy at injection sites.
CONCLUSIONThere is evidence demonstrating that fasting plasma glucose(FPG) should be the key focus in initial management of patients with poor glycaemic control,while postprandial glycaemia should be targeted in patients with lower HbA1c.Controlling glycaemia is an important part of this integrated multifactorial approach and maintaining glycaemic levels as close to the non-diabetic range as possible and is essential in preventing microvascular as well as macrovascular complications.The gold standard for insulin regimen is basal bolus therapy combining one or two doses of insulins and three doses of rapid acting insulins to cover the postprandial peaks following three rapid meals.