Definition of terms
Glucose : A simple sugar obtained through hydrolysis scission of carbohydrates ingested with food; it is the body’s resource for obtaining quick energy after meals.
Glycemia : The concentration of glucose in the blood. It is the most important value the diabetic patient must control. Maintaining normal glycemia levels is the purpose of glycemic self-monitoring and is the best way for the diabetic patient to avoid complications.
Liver : The largest gland of the human body that plays a major role in metabolism and has a number of functions in the body, including glycogen storage, plasma protein synthesis, and detoxification. It also produces bile which aids in digestion.
Glycogen : The form in which glucose is stored in the liver and muscles. Glycogen is the main energy reserve immediately available to the body.
Pancreas : Large gland located horizontally behind the stomach. It produces an external secretion containing numerous digestive enzymes and two internal secretions: insulin and glucagon, respectively secreted by the beta and alpha cells of the islets of Langerhans.
Insulin : A hormone secreted by the beta cells of the islets of Langerhans in the pancreas at an average of 0.6 U/Kg/24h. It signals the liver to block glucose production. By reaching peripheral tissues through the blood, it helps glucose to penetrate the cells where it is then transformed into energy.
Glucagon : A hormone secreted by the alpha cells of the islets of Langerhans in the pancreas. It signals the liver to free glucose in the blood. Artificial glucagon is used to combat severe hypoglycemia.
Diabetes mellitus : Medical term for diabetes. Of ancient Greek origin, “mellitus” means sweet and derives from the fact that the urine of diabetes patients has a sweet taste given the high concentrations of blood glucose passed into the urine.
Hyperglycemia : Excessive increase of sugar in the blood. If not correctly treated, in the long-term it can cause permanent damage to organs such as the eye, kidneys, and to the limbs (circulation).
Glycosuria : The presence of glucose in the urine. It is sign of an abnormal condition given that glucose should not be present in urine. It “overflows” from the blood to the urine only if it reaches a certain level in the blood (180mg/dl), otherwise known as the renal threshold.
Complications : classified as acute and chronic:
- Acute complications:
Hypoglycemia – low concentration of glucose in the blood under “normal” levels (80mg/dl). There are three levels of hypoglycemia: mild (80-50mg/dl), moderate (50-40mg/dl) and severe (‹ 40mg/dl).
Ketoacidosis – increased concentration of ketone bodies (chemical by-products the body produces when cells burn fat instead of sugar) in all body liquids. Being metabolic acids, they alter the physiologic pH level with consequences such as coma and death.
Hyperosmolar coma – state of extreme confusion or stupor corresponding to severe dehydration; caused by the lack of insulin and the presence of high blood glucose levels yet without ketoacidosis. Hyperosmolar coma derives from severe dehydration in diabetes type II patients, and usually in the elderly, more than from the poor control of blood glucose levels.
- Chronic complications:
the various diseases a diabetic patient risks developing due to the persistence of hyperglycemia in the blood over long periods of time. Several organs can be affected: eyes (retinopathy), kidneys (nephropathy), nerves (neuropathy), and the circulatory apparatus. In some cases these are typical diseases of the diabetic patient and in others they are diseases or conditions that can also affect non-diabetic subjects (i.e. cardiovascular problems, obesity). Recent studies confirm that the risk of complication is notably reduced by maintaining stable glucose levels in the blood.
Diabetes type I : a chronic condition in which the pancreas produces little or no insulin due to the destruction of pancreas beta cells by a faulty immunology process (autoimmune disease). The body is no longer able to use glucose (sugar in the blood) to produce energy. Unfortunately the symptoms of diabetes type I usually appear when the destruction of beta cells has practically been completed. The symptoms are: increase of frequency and quantity of urine, weight loss, hunger, thirst. In order to successfully control diabetes, the patient must administer several insulin injections daily, follow a strict diet and exercise as much as possible. The patient must also frequently control glycemia levels in the blood. Usually the onset of the disease occurs in childhood and rarely after 40 years of age. For this reason it is also known as “juvenile diabetes.”
Diabetes type II : the most common form of diabetes mellitus. It is estimated that about 90-95% of people affected with diabetes have the type II kind. Contrary to insulin-dependent diabetes where the pancreas does not produce insulin, those affected with non-insulin dependent diabetes mellitus are able to produce insulin in the pancreas. Nevertheless, their body does not produce a sufficient quantity and their cells have a certain resistance to insulin action. People with non-insulin dependent diabetes mellitus often are able to control their condition by simply losing weight, following an adequate diet and exercising regularly. If this is not enough, they must use oral hypoglycemic drugs together with diet and exercise. In some cases it is also necessary to administer insulin externally. Generally non-insulin dependent diabetes mellitus strikes those over 40 years of age and is called “adult diabetes.” Most of these patients are overweight.
OGTT (oral glucose tolerance test): an oral test to measure glucose metabolization in the bloodstream. It determines the presence or tendency towards diabetes. Performed at the medical office, a blood sample is taken on an empty stomach. The patient is then given a glucose solution to drink and other blood samples later are taken at fixed intervals. The concentration of sugar (glycemia) is measured in each blood sample. The resulting curve informs us how the patient responds to glucose assumption.
Self-monitoring : measurement of the concentration of glucose in the blood, done by the patient at home using capillary blood. Self-monitoring is performed by pricking the fingertip (there are less nerve endings near the edges so pricking hurts less) to obtain a small amount of blood. The sample is placed on a disposable “strip” and the glucose in the blood triggers a chemical reaction that is read and translated by an instrument called the “glucometer.”
Glucometer : also called “glycemia reader” or “reflectometer,” is an instrument that measures the glucose level in the blood through the use of a strip upon which a small drop of blood is placed or absorbed. The instrument measures the quantity of glucose present in the blood, evaluating the variation of color created by the chemical reaction set off by the glucose on the strip (reflectometer) or by measuring the variation of the electrical current provoked by the glucose (with potentiometric technology).