Glucose is important as the primary energy source for most body cells and critical for brain functioning. The body requires a steady supply of glucose at all times. The normal source of glucose is through digestion of carbohydrates that are broken down into glucose and absorbed in the small bowl to circulate in the blood stream. The utilization of glucose for energy production depends on a hormone called insulin that is responsible for facilitating transport of glucose into the body cells and storing excess energy as glycogen and as triglycerides in fat cells.
Blood glucose usually rises after a meal followed by insulin secretion and subsequent movement of glucose to the body cells. The blood glucose level drops as the glucose is metabolized and the pancreas produces less insulin. When the blood glucose level drops too low, glucose is released from glycogen storage by the hormone glucagon.
Diabetes is a disease that disrupt the balance between glucose and the pancreatic hormones and can result in high and low blood glucose levels. Diabetes is associated with insufficient insulin production by the pancreas (Diabetes mellitus Type1) and/or a resistance to the effects of insulin (Diabetes mellitus Type 2).
Fasting glucose determine the amount of glucose in the blood after an 8 hour fast (thus not affected by food). Glucose testing is usually performed to establish if your blood glucose level is within the normal range, to screen and confirm diabetes and monitor for high (hyperglycaemia)and low (hypoglycaemia) blood glucose.
Fasting glucose may be ordered during general health screens or when diagnosis of diabetes is suspected including:
Signs or symptoms of hyperglycemia (high blood glucose levels)
General risk factors for developing diabetes
Testing intervals-Annually as part of general health screening or individuals at risk