Serum glucose, also referred to as blood sugar, is the concentration of sugar in the blood. It comes from the breakdown of carbohydrates that you consume. It is the primary source of energy for the body's cells. If glucose levels are too high or too low, health problems may result. The most common illness related to blood sugar concentration is diabetes mellitus.
Normal Values
Many factors affect a person's blood sugar level. A body's homeostatic mechanism, when operating normally, restores the blood sugar level to a range of about 82 to 110 milligrams per deciliter, or mg/dL. According to NLM.nih.gov, blood sugar levels can vary among labs. In general, up to 100 mg/dL are considered normal. Those who have blood sugar levels between 100 and 126 mg/dL have impaired fasting glucose, and those with levels over 126 mg/dL have a diabetes diagnosis.
Procedure for Testing
Blood is drawn from a vein by a needle or by finger prick with a lancet. According to the Labtests Online website, the site is cleaned with alcohol. When drawing the blood from a vein, an elastic band is then placed around the upper arm to make the vein swell with blood. Next, the needle is inserted into the vein, and a collection tube is attached to the needle to collect the blood. The band and needle are then removed and a pressure dressing is applied to the site.
Test Preparation
Preparation for blood glucose testing depends on whether the test needs to be fasting. According to NLM.nih.gov, if a blood glucose needs to be fasting, then you can't eat for at least six hours before the test. Random tests do not have to be fasting and are not as reliable.
Serum Glucose Regulation
The amount of glucose in the bloodstream is regulated by hormones called insulin and glucagon, which are secreted by the pancreas. According to Endocrineweb.com, insulin transports glucose out of the bloodstream and into the body's cells, where it is either converted to energy or stored for later use. They are secreted in response to blood sugar levels but in an opposite manner. Insulin is secreted when blood glucose is high, and glucagon is secreted when blood glucose is low. Glucose levels in the bloodstream vary throughout the day, rising when sugar is ingested and dropping as insulin removes the sugar from the bloodstream.
Types of Diabetes
There are three types of diabetes, types I and II and gestational diabetes. According to Healthinsite.gov.au; type I, the pancreas produces little or no insulin; type II, the pancreas produces insulin, but the cells develop a resistance to insulin, and gestational diabetes is a carbohydrate intolerance that is diagnosed during pregnancy through an oral glucose tolerance test.
Type I usually has an onset at a young age and accounts for only 10 to 15 percent of all people with diabetes. Type II is much more common and usually develops with age and obesity. Gestational diabetes develops in about 5 percent of pregnant women.
