INTRODUCTION TO HORMONES
Learning about and understanding hormones, and the vital role they play in your bodies functioning and health, is the cornerstone to achieving any of your goals. As you are well aware, hormones can make you well or make you ill. They do strange and wonderful things to your mind and your body.
They create your physique and they have the power to destroy your physique. Hormones can turn you into a testosterone driven focused, ambitious and strong success, or reduce you to a frightened quivering wreck. Hormones are the key to virtually every process in the human body and determine your success in achieving the body you desire. This being said you should have a firm understanding of the importance of this section alone.
SO JUST WHAT ARE HORMONES?
Well hormones are chemical messengers that coordinate the activities of different cells in multicellular organisms. The term hormone (derived from the Greek – ‘to spur on’) was first used in 1904 by William Bayliss and Ernest Starling to describe the action of secretin, a molecule secreted by the duodenum that stimulates the flow of pancreatic juice. Several very fruitful concepts emerged from their work. 1) Hormones are molecules synthesized by specific tissues (glands). 2) They are secreted directly into the blood, which carries them to their sites of action. 3)They specifically alter the activities of responsive tissues (target organs or target cells.)
Basically, hormones are messengers that tell the cells in your body to do things. They send messages that may tell the body to build up protein and hence build up muscle tissue. Or counter to that, they may tell the body to break down proteins, breakdown muscle. This is just one example of the many functions of the many hormones. As you will see, your hormones are generaly split into different groupings, and those groupings generally fall into two main categories – anabolic and catabolic. Anabolic hormones are involved in the creation and repair of cells, catabolic – the reverse, the breakdown.
WHICH IS THE BEST METHOD FOR TESTING HORMONES?
There is no single ideal method for assessment of hormones. Blood, saliva, and urine each have their advantages. Three testing methods can help you determine which method will provide you with the most useful information in a given clinical scenario.
Best used for:
- Female hormone balance
- Androgen balance
- Breast and prostate cancer risk factors
- Adrenal health
- Adrenal reserves
- Growth hormone
- 5α-reductase activity
- Monitoring bioidentical hormone therapy
In addition to being a non-invasive, patient-controlled collection, a 24-hour urine sample is most accurate because it provides a stable indicator of output not susceptible to the hour-to-hour fluctuations seen in serum or salivary measurements. Urine hormone testing is well-established in medical literature as a reliable method of assessing physiological hormone levels. Meridian Valley’s 24-hour urine profile reference ranges have been validated over many years of clinical testing and correlate well with patient symptoms and with therapeutic interventions.
Urinary evaluations also allow the measurement of many estrogen metabolites. These metabolites provide critical information about a person’s relative risk for estrogen related cancer. A recent concept in hormone-related cancer prevention is the measurement of the ratio of two estrone metabolites: 2-hydroxyestrone and 16α-hydroxyestrone. A decrease in the 2/16α ratio is associated with an increased risk of breast and cervical cancer. This ratio is available only in a urine collection.
Urinary estrogens can be a sensitive monitor of liver detoxification capability. Elevated urinary estrogens in normally-cycling women may indicate a history of exposure to compounds that stress the liver such as environmental chemicals. This phenomenon has also been observed in peri- or post-menopausal women who have previously taken conjugated equine estrogens. Interventions intended to improve liver function result in a gradual normalization of the abnormal estrogen levels. Thus measurement of urinary estrogens can give insight into other aspects of physiology.
Similarly, the broad array of glucocorticoid and mineralocorticoid metabolites measured in a 24-hour urine hormone profile take adrenal assessment beyond simple cortisol measurements. The 24-hour urine profiles provide a comprehensive picture of long-term adrenal health, short term stress response and cortisol/cortisone balance.
Best used for:
A blood (serum) test provides a direct assessment of circulating hormones. Most reported hormone values are “total”, including both free and bound hormones. Testosterone is the exception, being offered as “free” as well as total testosterone. Serum tests offer relatively accurate values with well-established reference ranges. However, reference ranges are often broad, reducing their clinical utility. Typically, serum estrogen measurements only include Estradiol (E2), although Estrone (E1) is also available. In serum, Estriol (E3) is usually available only as a measurement of unconjugated Estriol. This has limited usefulness as 90% of Estriol is conjugated. Free Estrone, free Estradiol, and free Progesterone are rarely measured. Serum measurements are a ‘snapshot’ look at sex hormones that may fluctuate greatly during day.
Meridian Valley Lab has pioneered clinical serum testing for 3β-Adiol, which holds great promise as a marker for the development of prostate cancer. Click here for more information about 3β-Adiol and the Testosterone Metabolite Test.
Best used for:
- Circadian cortisol pattern
- Menstrual cycle evaluation
Saliva testing for hormones is a method which has gained popularity in the recent years. This is due to the simplicity and noninvasive nature of sample collection. Saliva is beneficial for monitoring cortisol according to the AM/PM circadian rhythm. It can also be helpful to assess cyclical output of estrogen and progesterone throughout the month in a cycling or peri-menopausal woman.
Saliva tests results may be hindered in elderly patients with limited salivary output. Saliva testing can yield higher than physiological levels when using exogenous hormone replacement therapy; this can give a false impression of overdosing. Single point saliva tests also have the disadvantage of being a ‘snapshot’ look at hormones that ebb and flow throughout at 24-hour period.
100 Years of Hormones
Starling coined the term, derived from the Greek verb ‘ormao’ (to arouse or excite), during a Croonian Lecture at the Royal College of Physicians in London on the Chemical Control of the Functions of the Body. He defined hormones in terms of chemical messengers produced recurrently to answer the physiological needs of the organism and carried from the organ where they are produced to the organ which they affect by means of the bloodstream. He and his close colleague William Bayliss had a few years previously identified one of the first of these chemical messengers, secretin, during their experiments on digestion.
Since 1905, hormones, or rather the science that studies them, endocrinology, has increased our understanding of physiological processes in health and disease. From classical ‘gland’ based endocrinology of a few decades ago when only a handful of hormones were recognised, we now have insight into a highly complex array of literally hundreds of hormones that allow cells to communicate with their neighbours and also with cells far away in the body.
Clinical endocrinology working in parallel to laboratory based endocrine research has led to many important discoveries that have had significant impacts on many disease states including cancer, vascular disease (strokes and heart attacks), diabetes, osteoporosis, and obesity, to name but a few. Endocrine factors have not only been found to be responsible for producing or predisposing to some of these diseases, but manipulation of hormone systems has led to highly effective therapies, such as treatments for breast and prostate cancer.
New hormones continue to be discovered and characterised and although much is known about many hormones, the true complexity of interplay between these hormones in allowing effective cell communication is far from clear and will continue to tax endocrinologists well into the second century of hormones and endocrinology.