Role of Insulin in Managing Blood Sugar
Diabetes is a debilitating illness that requires lifelong treatment. The American Diabetes Association has recommended insulin therapy only when medical and/or nutritional therapy fails to maintain the blood glucose levels.^1,2 

Role of insulin in normal cases
Insulin plays a vital role in regulation of glucose metabolism. Principal function of insulin is to control the uptake and utilization of glucose in peripheral tissues through the glucose transport. Insulin regulates sugar in blood stream after meals. Sugar is the primary source of energy required in the body. The carbohydrates obtained from the diet are broken into sugar molecules that enter the bloodstream in the form of glucose. The pancreas produces the hormone known as insulin that allows glucose to enter into the cells and tissues for the production of energy. Excess glucose is stored in the liver as glycogen. When the blood glucose levels are low, liver releases glycogen to form glucose and this keeps the blood glucose level at optimal range. If the blood glucose levels are high, the liver stops the release of glycogen while the insulin production in the pancreas is increased.^1-3

Abnormalities of insulin in diabetics
Severity of diabetes leads to decreased insulin secretion, increased insulin resistance and loss of cells that produce insulin (known as beta cells) in the pancreas. Increased blood glucose level causes several complications in diabetic patients that include loss of vision, high blood pressure, kidney failure, leg ulcers and other nerve disorders.^{1, 3}

Role of insulin in the treatment of diabetes
Despite many improvements, insulin is the oldest and best treatment for diabetes mellitus. Studies have shown that the early use of insulin mimic the body’s physiological secretion of insulin. Use of insulin is associated with weight gain, yet tight control in the glycemic level is very much important to avoid the complications.² Insulin used for the treatment of diabetes are of different types: conventional (human) insulin, rapid-acting insulin analogs, basal insulin analogs, and insulin analog premixes.⁴

Type 1 diabetes
In a type 1 diabetic patient, the pancreas produce very less insulin or does not produce insulin at all.¹Type 1 diabetes mellitus patients thus require daily injections of insulin to control the blood glucose levels.

Type 2 diabetes
Type 2 diabetes is mostly caused due to sedentary lifestyle and obesity. Type 2 diabetes is associated with insulin resistance or abnormal insulin secretion. Although diet and exercise can help in the control of blood glucose levels in type 2 diabetic patients, the administration of medications to control the blood glucose levels becomes necessary in certain situations. The oral hypoglycemic agents which help in the reduction of the blood glucose levels are first line of treatment. Failure to control blood glucose levels with diet, exercise and/or oral medications advocates the need for insulin therapy in type 2 diabetes.^{2, 4}

Gestational Diabetes Mellitus
Gestational Diabetes Mellitus (GDM) refers to the diabetes mellitus noted for the first time during pregnancy. GDM is caused due to insufficient insulin secretion and/or decreased insulin sensitivity. Inadequate beta cell function is the potential cause for gestational diabetes. During gestational diabetes insulin produced in the mother’s body is inadequate to meet tissue demands in both the mother and growing baby.⁵ Insulin therapy is recommended if the blood glucose level exceeds in two or more occasions at an interval of 1 or 2 weeks. Decreased maternal insulin sensitivity in gestational diabetes leads to increased nutritional availability to the fetus, which possibly accounts for the increased risk of fetal overgrowth. Increased insulin resistance leads to low birth weight during delivery.⁷ Insulin is the drug of choice for the treatment of gestational diabetes as the studies show that insulin preparations do not cross the placenta.⁶

Conclusion
Insulin improves blood glucose control in diabetic patients and results in improvement in the quality of life, retention at employment, greater productivity and less absenteeism. Greater economic benefits are considered not only to the individual patient but also as a whole to the society.

Written by: Healthplus24 team
Date last updated: October 27,2009