By J.L.G., M.D.
Endocrinology is the medical specialty that deals with the endocrine glands and the hormones they secrete. Hormones are the chemical messengers that travel through our blood and carry out a multitude of functions. Hormones regulate our metabolism, reproduction, energy, strength, development and growth. The major endocrine glands in the body include the pituitary (often referred to as the master gland), the thyroid, adrenal, pancreas, testes and ovaries.
Since hormones act on virtually every organ and cell type in the body, diseases in endocrine glands can present themselves in innumerable ways. Fatigue, weight changes, hair loss, low libido, menstrual irregularity, increased urination, and low or high blood pressure are just a few presentations of endocrine disease that we see.
Endocrine disease may have an abrupt onset when caused by medications, trauma or radiation exposure. Oftentimes they are caused by a combination of factors in one’s lifestyle (i.e. poor diet and lack of exercise) with background genetic predisposition. Alternatively, some endocrine diseases may have a long latency period often referred to as a pre-clinical phase, which can be exacerbated and unmasked with stress, illness or medications.
The Chicken or the Egg?
Hormonal abnormalities may also result from other non-endocrine diseases. In such cases, it may be difficult to discern which came first. That’s where I come in. Endocrinology is detective work. When a patient presents to my office with a suspicion for an endocrine disorder, I take a thorough history and physical examination. I look for clues in the family history, work or environmental exposures and medication use.
I examine the family history of an endocrine disease in a close relative (first-degree relative) such as a parent or sibling. This commonly occurs in diabetes and hypothyroidism.
Common medications that can cause endocrine disorders include steroids (prescribed or illicit), which can cause or worsen diabetes or hypogonadism (low testosterone). Also, I look for cardiac medications such as Amiodarone which can cause hypothyroidism or hyperthyroidism. Lithium can cause hyperparathyroidism and hypothyroidism. Seroquel can cause diabetes, anti-depressants can cause osteoporosis. Hydrochlorothiazide (a diuretic) can cause hypercalcemia (elevated calcium) or other electrolyte disorders.
I scour their old medical records for any signs or subtle abnormalities that may have, in retrospect, hinted at an evolving endocrine disease. For example, if they had elevated blood sugars before they were diagnosed with diabetes, or if their thyroid levels were trending down over the years. I also look for electrolyte abnormalities that were missed or ignored and not followed-up, as well as if they had unexplained or early-onset, atypical diabetes, osteoporosis, or hypogonadism.
For example, cases I have seen include a woman with ignored stomach pains and diabetes who had evolving pancreatic cancer; a young man with very low testosterone, obesity and a femoral fracture who had a pituitary tumor undiagnosed for many years; a young man with family history of kidney stones and fractures who had early-onset osteoporosis; a woman with dramatic weight gain, severe weakness, fatigue, osteoporosis and elevated calcium who had multiple endocrine neoplasia (a genetic disorder of tumors in multiple endocrine glands).
I narrow down to a list of possible causes and run complex tests measuring hormones in the blood and urine. The hormones I look for include testosterone, estrogen, LH, FSH, prolactin, cortisol, ACTH, aldosterone, parathyroid hormone, thyroid hormone, thyroid stimulating hormone, urine cortisol, urine calcium, as well as 24-hour urine metanephrines and normetanephrines.
Endocrine Testing: Snapshot or Video?
Evaluating the endocrine system is not nearly as simple as other systems. Hormones tend to follow diurnal rhythms where they are higher in the mornings and lower during the day. Measuring the right hormone at the wrong time of day can give a false-positive result. Moreover, hormones are present in very minute quantities in the blood and it is critical to have the right lab that has validated, sensitive assays to run these tests. Sometimes, we want to know the profile of a hormone over an entire 24-hour period rather than just in a single blood test at that moment. Think of this as the difference between a video and a snapshot. In such cases, patients may need to be hospitalized for continuous blood draws, or do home collections of urine or saliva for subsequent analysis.
In endocrinology, when we suspect a hormone is too low, we may try to stimulate it with injections or infusions of a medication. Alternatively, when a hormone is suspected of being too high, we will try and suppress it as a diagnostic test. There are detailed protocols we must follow for such dynamic testing and oftentimes a test needs to be run more than once before we can make a final determination.
Common Endocrine Diseases
The following are the most common diseases or issues I encounter as a medical consultant and some key points you should know about each:
• Diabetes When I was in medical school, my professor said, “to know diabetes is to know medicine” and now I understand what he meant. It’s not an overstatement to say we are living in an epidemic of diabetes (current estimates are 1 in 3 will have it over the next 20 years). Moreover, we now know that the pre-diabetic state may be just as serious. The most common cause of death in diabetics is coronary artery disease but along the way, unchecked diabetes leads to blindness, kidney failure, neuropathy, immune dysfunction and more. Diabetes often flares up after an injury, decreased physical activity, medications or emotional stress.
• Autoimmune Thyroid Disease Hypothyroidism and hyperthyroidism are two extremes of thyroid diseases. Think of hyperthyroidism as the gas pedal (fast heart rate, anxious, unintended weight loss, anxiety, and palpitations) and hypothyroidism as the break (fatigue, weight gain, high cholesterol, hair loss and infertility). Too often I see patients who were told they were just anxious or needed to eat healthier, when in fact they had a serious thyroid imbalance. Extreme thyroid dysfunction can even cause cardiac arrhythmias, coma and death. Chemical exposures, radiation, medications and genetics are all common identifiable causes of thyroid dysfunction. Thyroid tests can be complex and are incorrectly ordered or interpreted. It takes a keen eye to know whether the problem is from the patient or the test
• Thyroid cancer In 2013, it is estimated that there will be 60,220 new cases of thyroid cancer and an estimated 1,850 people will die of this disease. Thyroid cancer is more common in women than men and among those with a family history of thyroid disease. Over the last decade, rates for new thyroid cancer cases have been rising an average 6.4% per year. Death rates have been rising on average 0.9% each year over the same period. Thyroid cancer can be easily screened for with an inexpensive thyroid ultrasound to look for nodules in the gland. These nodules are typically comprised of small clusters of cells and can be easily biopsied in the office. When detected early, the long-term survival rate of thyroid cancer is nearly 100%. Unfortunately, when not detected early or properly treated, thyroid cancer can take a very different course, leading to local invasion into lymph nodes, the throat and trachea and distant metastases to the lungs, bones and brain.
• Osteoporosis This is not just your grandmother’s disease and despite popular belief, it is never normal to fracture a hip or spine from a standing height fall. Hormones regulate bone health and osteoporosis is a complex metabolic disease that can occur at any age. It robs your bones of their architecture and strength, dramatically increasing the risk of fractures. Secondary causes of osteoporosis may occur in 2/3 of patients, yet many people are never even evaluated. Gastrointestinal, kidney and parathyroid diseases, medications, vitamin D deficiency and inflammatory conditions are just a few of the common secondary causes of osteoporosis that I see in my practice. Osteoporosis can have significant health consequences such as chronic pain, poor pulmonary function, immobility weight loss and death. In fact, the risk of death in a 50-year-old woman with a hip fracture is equivalent to her risk of death from breast cancer and 4 times higher than that from endometrial cancer. Up to 20% of patients die in the first year following hip fractures and less than half those who survive regain their previous level of function. A simple screening x-ray called a bone density exam or DEXA can detect osteoporosis before a fracture occurs.
• Hypogonadism You can’t open a men’s health magazine and or go online these days without hearing about “low T”. The doping clinics and anti-aging centers are so fixated on the cosmetic effects of low testosterone that it’s easy to lose sight of the fact that this can be a serious medical condition. Low testosterone (aka hypogonadism) can come from a testicular problem (primary hypogonadism) or a pituitary or hypothalamic problem in the brain (secondary hypogonadism). Too often, I encounter men who have been put on testosterone without undergoing any evaluation for why it is low. A pituitary tumor, breast disease, testicular disease, stress, medications, head trauma or testicular abnormalities are common (and sometimes reversible) causes. Low testosterone causes erectile dysfunction, fatigue, weight loss, muscle loss and osteoporosis. Men with diabetes are twice as likely to have low testosterone as men without diabetes and there is emerging evidence that treatment of low testosterone can improve diabetic control.
Too much testosterone is also unhealthy and I have seen many young men who are juicing with testosterone to improve their strength or appearance. When a young man takes testosterone, it’s true he will likely have increased energy, sex drive and muscle mass, but his testicles will shrink, his hair may fall out and he will become infertile. Other side effects include polycythemia (thickening of the blood), which can cause headache and stroke, worsening sleep apnea, (cessation of breathing during sleep) and increased PSA levels and risk of prostate cancer.
The Bottom Line
Endocrinology is a highly complex field that affects each and every one of us. Endocrine diseases are often discovered after an injury or illness and the effects can range from cosmetic to life threatening. Patients with symptoms suggestive of a hormone imbalance deserve a thorough, evidence-based evaluation to determine whether they truly have a hormone disorder and what has caused it.