Human growth hormone (HGH), also known as somatotropin, is a vital hormone produced by the pituitary gland. It plays a crucial role in growth for children and helps maintain body structure and metabolism in adults.
What is Human Growth Hormone (HGH)?
HGH is a naturally occurring hormone produced and released by the pituitary gland. In children, it promotes growth, particularly by acting on bones and cartilage. Once the growth plates in the bones have fused, HGH no longer increases height but continues to play a significant role in maintaining body structure and regulating metabolism throughout adulthood.
Hormones are chemical messengers that travel through the bloodstream, coordinating various bodily functions by signaling organs, muscles, and tissues. The body produces over 50 hormones, which interact in a complex web to regulate numerous processes.
The pituitary gland, a small, pea-sized gland located at the base of the brain, consists of an anterior (front) and posterior (back) lobe. The anterior lobe is responsible for producing HGH. Communication between the pituitary gland and the hypothalamus, a brain region controlling functions such as blood pressure, heart rate, body temperature, and digestion, is facilitated through a network called the pituitary stalk. The hypothalamus releases growth hormone-releasing hormone (GHRH) to stimulate HGH release and somatostatin to inhibit it.
Synthetic HGH, also known as recombinant HGH, is used to treat specific medical conditions, such as growth hormone deficiency. It should only be taken under the guidance of a healthcare provider.
What Triggers HGH Release?
HGH is released in short bursts throughout the day. The hypothalamus controls this release through GHRH, which stimulates HGH production, and somatostatin, which inhibits it. Other hormones, including insulin-like growth factor 1 (IGF-1), also regulate HGH. IGF-1, produced by the liver in response to HGH, provides feedback to inhibit further HGH release.
Factors like sleep, stress, exercise, low blood sugar (hypoglycemia), and amino acids can stimulate HGH release, while high blood sugar (hyperglycemia) inhibits it.
Functions of HGH
HGH has two primary functions: promoting growth and regulating metabolism.
Growth: HGH stimulates growth in almost all tissues and organs, especially bones and cartilage during adolescence. After the growth plates fuse, HGH continues to help maintain normal body structure.
Metabolism: HGH influences metabolism by increasing the production of IGF-1, which has insulin-like effects, helping to regulate blood sugar levels. Insulin, produced by the pancreas, lowers blood glucose levels, while HGH can increase glucose levels when necessary. However, excessive HGH can lead to elevated blood glucose levels by counteracting insulin.
Can HGH Make You Taller?
HGH can increase height in children before their growth plates fuse. After fusion, HGH cannot make you taller but continues to help maintain body structure and metabolic functions.
Normal HGH Levels
HGH levels vary based on age, sex, and time of day. Because HGH is released in pulses, random measurements are not typically useful. Instead, healthcare providers use stimulation or suppression tests to evaluate HGH levels. Normal ranges are:
– Adults assigned male at birth: 0.4 to 10 ng/mL (18 to 44 pmol/L)
– Adults assigned female at birth: 1 to 14 ng/mL (44 to 616 pmol/L)
– Children: 10 to 50 ng/mL (440 to 2200 pmol/L)
Low HGH Levels
Low HGH levels, known as growth hormone deficiency, can result from issues with the pituitary gland. In adults, this can lead to increased body fat, heart disease risk, and weakened muscles and bones. In children, it causes slow growth, delayed puberty, and a younger appearance for their age. Causes can be genetic, idiopathic, or due to injury.
High HGH Levels
Excess HGH can cause acromegaly in adults, leading to enlarged hands, feet, and facial features, and increased risk of heart disease and diabetes. In children, it can cause gigantism, resulting in excessive height and delayed puberty. Most cases are due to pituitary adenomas.
Measuring HGH Levels
HGH levels are typically measured through stimulation and suppression tests rather than single blood tests due to the hormone’s pulsatile release pattern. IGF-1 levels are also measured to assess HGH activity.
HGH as Medication
Synthetic HGH, approved by the FDA, is used to treat conditions like growth hormone deficiency, Turner syndrome, and muscle loss from HIV. It is administered via injection and should only be used under medical supervision due to potential side effects such as carpal tunnel syndrome, insulin resistance, and increased cancer risk.
When to See a Healthcare Provider
If you or your child experience symptoms of HGH deficiency or excess, consult a healthcare provider. Regular monitoring is essential if you are undergoing HGH treatment to ensure its effectiveness.
HGH is essential for growth and metabolism, and imbalances can significantly impact health. If you have concerns about HGH levels, seek guidance from a healthcare professional.
