Laboratory Evaluation of Hormonal or Endocrine Status

Your endocrine, or hormonal, system represents a complex and dynamic interplay of various hormones and hormone-like compounds. Together, they orchestrate normal metabolic function within your body. There are many checks and balances involved in normal endocrine balance. Thus, interdependence is created which requires adequate or normal levels of various types of hormones in your body for the creation of optimal health.

For that reason, we may order one or more types of hormone panels to evaluate your own individual medical condition based on symptom presentation. In this overview, I have tried to clarify the rationale for ordering the various types of hormone tests and their clinical relevance for an individual. Based on your previous history, clinical presentation and symptom complex, we may order one or more of these tests to gain a better understanding of your own, unique biochemistry.
Thyroid. The thyroid gland is located about mid-line in the neck area. It is a small organ that secretes active and inactive thyroid hormones. The thyroid gland secretes T3 and T4, with T3 being the main, metabolically active hormone. T4, in general, represents a reservoir from which the body can convert T4 to the more active form of T3. TSH, or thyroid-stimulating hormone, is a hormone released by the pituitary gland. It stimulates the thyroid to make more thyroid hormone. This complex interplay depends on a negative feedback system. For example, if, on your laboratory test, your TSH is elevated, it is an indication that your pituitary gland is attempting to encourage your thyroid gland to make more thyroid hormone. This is suggestive of a low thyroid state.

Some individuals have normal thyroid hormone levels, but, in actuality, have true low-functioning thyroid activity. These individuals are often considered to be functioning at sub clinically low thyroid levels (sub clinical hypothyroidism). Because of the complex interplay of hormones, it is often necessary to order a complete panel when evaluating adequate thyroid function, including T3, T4 and TSH. In some situations, other thyroid tests are required, to provide a better understanding of the overall function of the person\'s thyroid gland. Those who have low thyroid function tend to feel fatigued, cold most of the time, depressed, with low energy, poor sleep, poor exercise tolerance, easy increase in weight and difficulty losing weight. Women tend to have PMS symptoms and heavy or irregular periods. Fluid retention is also common, as is decreased libido. Gathering information on thyroid hormone levels through clinical tests is, therefore, relevant and helpful as we seek to understand your specific clinical symptoms.

Testosterone. Testosterone is an active anabolic hormone that is manufactured, in the male, in the testes and, in the female, in the ovaries. Both sexes also make some amount of testosterone in the adrenal glands, which sit on top of the kidneys.

Testosterone is generally looked at as being a \"male\" hormone, secondary to the fact that men tend to have about 10 times as much testosterone as women. We know, however, that testosterone also plays a significantly active role in the overall health of the female gender. For both sexes, it regulates libido, or sexual desire. In addition, it is associated with lipid status, such as cholesterol and triglyceride abnormalities, normal cardiovascular and circulatory function, normal neurologic function, wound healing, muscle, bone and connective tissue strength, overall health and many other functions.

Cortisol and aldosterone. Cortisol and aldosterone are adrenal hormones that are generally evaluated by a 24-hour urine test. The reason for using a 24-hour urine test is that these hormones are released in a pulsatile, secretory fashion, which makes them difficult to evaluate with random blood draws. Symptomatic low adrenal function is a relatively common, and often overlooked, diagnosis. It is often accompanied by significant fatigue, poor stress tolerance, low blood pressure, a tendency to be anergic or allergy-prone or sensitive to multiple foods and chemicals. In addition, poor exercise tolerance and an easy susceptibility to various infections and difficulty in clearing those infections are commonplace. If your adrenal function is found to be low, there are certain herbal preparations, such as licorice, that can be used to modulate and improve overall function. As a person\'s general health begins to improve, adrenal function will often improve as well. Improvement can be followed clinically (secondary to improvement in clinical symptoms) and adjunctively (through clinical laboratory assessment).

DHEA and Pregnenolone. Both DHEA and pregnenolone are adrenal hormones that, of late, have received considerable media attention as potential life-extension medicines. Indeed, in animal models, they seem to improve the duration and quality of the animal\'s lifespan. Clinical trials of life extension medicines with human beings have not yet been conducted since, of course, it would take a very long time to study such a possibility. However, these hormones are also integrally important in immune regulation, maintenance of normal neurologic, cardiovascular, and circulatory function and in the stabilization of the body\'s endocrine system. Please see the individual handouts on pregnenolone and DHEA for further specific information.

Melatonin. This is a salivary test, in which free fractions of melatonin are measured from saliva samples. Melatonin is, of course, a pineal hormone that assists with normal sleep regulation. In addition, it is involved in the interplay of the body\'s other hormonal systems. It also has an immune-regulating effect. In some clinical studies, it has been used as a specific immune stimulant in the treatment of various types of cancer, including breast cancer.

FSH. FSH stands for follicle-stimulating hormone. This is a general screen used to determine the adequacy of estrogen production. If the FSH hormone is elevated, it tends to imply that a woman\'s estrogen level is depleted. FSH is secreted from the pituitary gland and is a stimulant for the ovarian system to produce more estrogen. This screen is helpful in assessing the overall menopausal status of women in that age group.

IgF-1 (indirect measure of growth hormone). Growth hormone\'s popularity as an anti-aging medicine is discussed with greater and greater interest in the media these days. Growth hormone is a pituitary hormone that is present in high amounts when we are young and declines rather precipitously with age. It seems to be involved in almost all of those parameters we generally associate with feeling young -- such things as better skin tone, less body fat, greater muscle strength, and more muscle tissue. Normal hair health and density and a tendency not to gray are associated with higher levels of growth hormone and IgF-1.

It seems that much of the biological effect of growth hormone is mediated through a group of hormones called somatomedins. Somatomedins are composed of a group of hormones called insulin-like growth factors. As a general screen, we usually check a level of IgF-1 (insulin-like growth factor, Type 1) for an assessment of the adequacy of a person\'s growth hormone status. This is done because accurately measuring growth hormone itself, given its rather short lifespan in the human circulatory system, is difficult.

In times past, therapy with growth hormone injections as an anti-aging medicine has been relegated to the lifestyles of the rich and famous, secondary to its lofty price tag of nearly $30,000 per year. In recent years, because of increased pharmaceutical competition, wider availability of growth hormone preparations and FDA approval for growth hormone treatment of adults with clinically documented growth hormone deficiencies; the price has become more reasonable. It is currently in the realm of $300 a month for growth hormone injections. However, many insurance plans cover this type of hormone augmentation, when clinically indicated.

For more information on growth hormone therapy, I would suggest that you read the book, Growing Young with HGH, by Ronald Klatz, M.D.

If you are truly growth hormone deficient, it may be reasonable to discuss growth hormone augmentation with your doctor. The laboratory results will be reviewed in your follow-up appointments and a decision can be made at that time.

Dale Guyer, M.D.