A reliable indicator of human growth hormone (HGH) level.
Low IGF-1 /HGH is associated with rapid aging, decreased
muscle and bone mass, poor response to exercise, and
IGF-1, also known as Somatomedin C, is a polypeptide hormone similar in structure to insulin and primarily produced in the liver. It is one of the main mediators of the actions of growth hormone in promoting muscular and skeletal growth. IGF-1 is itself a powerful anabolic hormone, and it also prevents premature cell death by inhibiting apoptosis. Because of its similarity to insulin, it also weakly activates the insulin receptor and therefore has insulin-like effects when present in large quantities.
Circulating IGF-1 is almost 100% bound to IGF binding proteins (IGFBP), the most abundant of these being IGFBP-3. These binding proteins stabilize IGF-1, prolonging its half-life in the bloodstream. Blood levels of IGF-1 are low in young children, peaking during the pubertal growth spurt and then declining steadily with age. IGF-1 is stable in whole blood dried on filter paper and therefore can be conveniently and accurately measured in dried blood spots .
Advantages of a Simple Dried Blood Spot Test
- A simple finger stick provides the few drops of blood required, which are collected on the filter paper provided
- Convenient sample collection at home – no phlebotomist required
- Easy shipment of samples by regular mail – samples are stable for up to a month at room temperature•Dried bloodspots carry minimal infection risk –infectious agents such as HIV are inactivated in dried blood
- Excellent correlation with serum/plasma IGF-1 levels
IGF-1 levels are an indicator of growth hormone secretion; low values imply growth hormone deficiency and high values are seen in acromegaly or gigantism. Low IGF-1 levels are seen in malnutrition or anorexia,and IGF-1 can be used as a sensitive indicator to monitor nutritional repletion. Dentists can use IGF-1 levels to assess cervical stage of patients, predict residual facial skeletal growth, and thus properly time orthodontic procedures. In growth hormone supplementation, IGF-1 levels should be kept within the physiological range to ensure safe dosing levels.