 Normal blood glucose is ranging from mg/dl ( mmol/L).  This normal range is kept through the effect of pancreatic hormone insulin and it’s antagonists.

Insulin:  It is a peptide hormone produced by the beta cells of islets of langerhans of the pancreas.  This hormone is released after food ingestion and glucose absorption.  It tends to decrease blood glucose level through increasing entry of glucose into the tissues, such as muscles and adipose tissue.

Insulin antagonists include  Pancreatic hormone Glucagone, produced by the alpha cells of islets of langerhans.  It’s release is stimulated by hypoglycemia.  It acts through stimulation of phosphorylase enzyme ( a key enzyme in glycogen breakdown or glycogenolysis, and it stimulate gluconeogenesis).

 Anterior pituitary gland hormones  Growth hormone which increases the blood glucose through decreasing uptake of glucose into muscles and stimulation of glyconenolysis.  Glucosteroids: ACTH secreted by anterior pituitary increases gluconeogenesis.

 Thyroid gland: thyroxine which has controlling effect.  Hypothyroidism is associated with hyperglycemia (due to decrease utilization of glucose).  Hyperthyroidism is associated with a tendency to decrease blood glucose.

 Diabetes Mellitus (DM)  It is a clinical condition associated with increasing blood glucose level, usually above 120 mg/dl.  It could be due to deficient insulin production, and is called Type I DM (Juvenile DM).  It could be due to chronic pancreatitis, and is called Type II DM (secondary DM).

Diabetes mellitus is associated with: 1- hyperglycemia (increased blood glucose). 2- Glycosuria (appearance of glucose in urine). 3- polyuria, thirst.

 Cushing’s Syndrome:  Due to increased production of ACTH (anterior pituitary tumor).

 Acromegaly:  This is due to a tumor of the anterior pituitary, producing excessive growth hormone