Glossary

Beta cells (β-cells): Beta cells (β-cells) are a type of pancreatic cell that produce isnulin and are contained within the islets of Langerhans. The primary function of a beta cell is to produce, store and release insulin, an hormone involved in the absorption of glucose in the body. Type 1 diabetes results from the destruction of insulin-producing cells by a β cell-specific autoimmune process and it is characterized by a complete insuline deficiency. Type 2 diabetes is a metabolic disorder that is characterized by an insulin resistance and relative insulin deficiency.

Glucagon: Glucagon is a peptide-hormone secreted by the α cells of the pancreas when blood glucose level is low; its effect is opposite that of insulin. Glucagon’s action stimulates liver to release stored glucose from its cells into the blood.  Glucagon also stimulates the production of glucose by the liver obtained from other nutrients. Both, glucagon and insulin, are part of a feedback system that keeps glucose at a stable level in the blood.

Glucose: Glucose is the most common carbohydrate and classified as a monosaccharide, an aldose, a hexose, and is a reducing sugar. Glucose is an important molecule in biology, because it is the primary source of energy and a metabolic intermediate in the cells. Normally it circulates in the blood at a concentration of 65-110 mg/dL (or 65-110 mg/100 ml) of blood. Insulin plays a key role in the assimilation of glucose in the cells.

Glycated hemoglobin or glycosylated hemoglobin (or HbAic): HbAic is a form of hemoglobin that is covalently bond with glucose. It is formed in a non-enzymatic glycation reaction by hemoglobin’s exposure to plasma glucose. A standard amount of glycated hemoglobin is usually produced in normal people. When the average amount of plasma glucose increases, also the fraction of glycated hemoglobin increases proportionally. Glycated hemoglobin can be used as a marker to identify the increasing plasma glucose concentration over long-term periods of time in diabetic patients.

Glycemia: Glycemia is the concentration of glucose in the blood. It is usually expressed in milligrams per deciliter (mg/dl) but it may also be expressed in millimol per decilitre (mmol/dl). A normal glycemia range is up to 126 mg/dl fasting and 200 mg/dl after meal.

Hemoglobin: Hemoglobin is an iron-containing oxygen-transport metalloprotein in red blood cells. Hemoglobin in the blood carries oxygen from lungs to tissues in the rest of the body, where it is released. Oxigen is reqired by the cells to burn nutrients that provide energy for the body functions.

Hyperglycemia: Hyperglycemia indicates a condition in which an excessive amount of glucose circulates in the blood plasma. Generally levels over 126 mg/dl fasting and 200 mg/dl after meal are considered predictive of diabetes.

Hypoglycemia: Hypoglycemia is characterized by a critical reduction in plasma glucose concentration to a level that may induce a variety of symptoms caused by an inadequate supply of glucose to the brain. This condition causes neuroglycopenia, coma and (rarely) permanent brain damage or death. The most common reasons of hypoglycemia in patients with diabetes are skipping a meal or overdosing insulin.

Insulin: Insulin is an important hormone that allows glucose (blood sugar) to get into the cells when it binds specific insuline receptors on the cell membranes. In diabetes, insulin production, release and action are compromised. Without insulin, the glucose accumulates into the blood stream, producing a condition of hyperglycemia (high glucose concentration in the blood), that is the main trait of diabetes. Hyperglycemya causes complications in multiple organs, as kidneys, eyes, nerves, skin, heart and blood vessels.