First, because the word metabolism is involved with virtually everything in our bodies, it helps to know exactly what we’re talking about. “Metabolism” means the sum total of all the chemical processes going on inside you that are necessary to keep you alive. When your metabolic rate is normal you feel pretty good. If it’s too high, you’re hyper, wired, and shaky, with a heart that may feel like its beating too fast.
Being hypometabolic means your metabolic rate is low and slow, “sluggish” being the operative word, but as you’ll soon see there can be a lot more going on.
Your metabolic rate is similar to the amount of pressure you put on the gas pedal when your car is in neutral:
- Press the pedal to the floor and everything speeds up, your car vibrating with too much energy. That’s hypermetabolism.
- Take your foot off the pedal, and if your idle is set too low the engine s-l-o-w-s way down, sometimes even quitting on you. This is hypometabolism. It doesn’t take much to grasp that when you die, your metabolic rate is zero (and vice versa).
Being hypometabolic, even mildly, can produce a tsunami of seemingly unrelated symptoms, often with no positive test results. Brace yourself for what’s coming next at the website of Gina S. Honeyman, DC. This list of hypometabolic symptoms is long. Go ahead and print it out if you like, placing a check next to any symptoms you have.
I wanted to use Dr. Honeyman’s list because back in 2003 she and her then husband, the late Dr. John C. Lowe, wrote a very useful (but unfortunately out of print) book entitled Your Guide to Metabolic Health. Medical doctors really should read it, but never will because of the Honeyman/Lowe professional credentials. They’re chiropractors and thus to most MDs beyond the pale in terms of academia. I’m confident that if Jesus Christ himself were a DC (Doctor of Chiropractic), he’d never be able to get an article entitled “Let Me Explain My Healing Techniques Once and For All” accepted into the Journal of the AMA.
If you ponder Dr. Honeyman’s symptom list, your first thought might be, “These sound like the symptoms of an underactive thyroid and I’ve got a lot of those symptoms, but my doctor tested my thyroid and told me my tests were normal. He said there must be something else going on and sent me to see some specialists,” and off you go, waving a sheath of scheduled appointment slips.
Hypometabolic and hypothyroid sound as if they’re interchangeable terms, but that’s not exactly the case. Hypothyroidism (low thyroid) is indeed the main cause of hypometabolism (slow metabolism), but the source of mischief can also include other glands like your adrenals, sex glands, and pituitary. Poor eating habits and nutritional deficiencies can affect your metabolism as well.
So let’s expand on this.
Here’s Thyroid 101
Your thyroid is an endocrine gland, meaning it secretes its hormone into your bloodstream, as opposed to exocrine—outside–glands, like sweat glands. Your thyroid releases two hormones, thyroxine (T4) and triiodothyronine (T3). The T4 is inactive and needs to be converted by your body to the active T3 in order to regulate your metabolism.
Your thyroid is controlled by your pituitary, the master gland tucked beneath your brain. Sensing you might need thyroid hormone, your pituitary releases TSH (thyroid-stimulating hormone) to increase your T4/T3 levels. Doctors measure the TSH levels in your blood to determine if your thyroid is underfunctioning (in which case your TSH will be high as your pituitary struggles to get the thyroid going) or overfunctioning (sensing high levels of thyroid hormone, your pituitary lowers its TSH production to nearly zero).
Using TSH to test thyroid status is conventional medicine’s Thyroid Mistake Number One. If you think about it, TSH measurement assumes your pituitary is functioning normally. TSH fails as a useful test if your low thyroid level is occurring because your pituitary isn’t working properly. This situation is called secondary hypothyroidism.
• Primary hypothyroidism: Low T3, Low T4, High TSH
• Secondary hypothyroidism: Low T3, Low T4, Low TSH
These are the two major causes of hypometabolism.
Another problem with measuring TSH is that endocrinologists can’t decide where Normal stops and a diagnosis of Hypothyroid (low thyroid) begins. When the test was first invented, any TSH above 7.0 was considered to indicate low thyroid. Then it was dropped to 5.0, and more recently to 2.5. All this fussing over TSH completely overlooks secondary hypothyroidism. With the secondary type, you have all the symptoms of low thyroid, but your TSH hovers around 1.0 because the real problem lies with your pituitary, even though—and this is key–primary and secondary hypothyroidism are treated the same way.
But this simply emphasizes the uselessness of the TSH test. If you have secondary hypothyroidism (hypometabolic symptoms, normal TSH), you won’t receive a prescription for your desperately needed thyroid replacement hormone. You’ll simply be told everything is normal. If your doctor would only follow a rule learned in medical school—“treat the patient, don’t treat the lab test”–you’d get your prescription and start feeling better in days.
When your TSH reaches whatever number your personal physician defines as signaling low thyroid, you’ll likely be prescribed Synthroid (Levoxyl), the synthetic form of T4.
Using Synthroid is Thyroid Mistake Number Two. Conventional physicians adore Synthroid because they fell completely for the advertising campaign Abbott Labs used decades ago when it introduced Synthroid and (falsely) promoted the new product as biologically superior to natural desiccated thyroid (NDT). NDT is pig thyroid sold under names like Armour and Nature-Throid, the form that was used by physicians for decades. Abbott later retracted its claim, but not before brainwashing two generations of physicians.
With Synthroid being T4, you’re receiving an inactive form of thyroid hormone, which most people (but not everyone) can convert to the active T3. Pig thyroid hormone is a much better physiologic mixture of T4 and T3, covering all the bases in case you have a problem converting. Some doctors skip the conversion issue altogether and prescribe Cytomel, which is pure T3. Many patients report feeling just fine using Synthroid, and that’s great. But many do not, sensing that something’s missing. Maybe you’ve read about NDT, maybe asked your doctor for a prescription. Know this: whatever excuses you heard if your doctor refused to prescribe it are a result of Abbott’s successful ad campaign.
The most significant problem with Synthroid is that while it will lower your TSH (so that on paper it looks as if you’re improving), because of its sluggish conversion to T3 you may not feel all that much better. Hence, patients on Synthroid frequently hear their docs say, “Well, I know you think you’re still hypothyroid based on your symptoms, but look how low your TSH is now. In fact, on paper you’re almost hyperthyroid. I just can’t safely increase your dose further.” And you (sluggishly) drag yourself out the door.
Thyroid Mistake Number Three is a situation frequently overlooked when treating underactive thyroid. With some thyroid patients, no matter what form of thyroid hormone the doctor prescribes, there’s not much clinical improvement, despite ever-increasing doses. What occurs is a condition called “partial peripheral resistance to thyroid hormone.” This means the cells normally responsive to thyroid hormone have set up barriers to block its effect. You’re taking your hormone, but nothing seems to be happening, or not enough is happening, a situation that can only be overcome by gradually increasing T3 (under medical supervision, of course).
This resistance occurs more frequently in women and according to Dr. Lowe’s research (his lifework actually, in the immense Metabolic Treatment of Fibromyalgia) may be at the heart of fibromyalgia and chronic fatigue. Read more about peripheral resistance here.
There’s more to hypometabolism than low levels of thyroid hormones
As mentioned earlier, you’ve got more endocrine glands, including a pair of adrenal glands (one atop each kidney) and also your paired sex glands (ovaries/testicles). We’ll discuss those next week.
Let me conclude on this note. Please once more flip back to Dr. Honeyman’s list of symptoms linked with being hypometabolic. Choose any diagnosis from the list–infertility, for example. Now think about the amount of time and egregious amounts of money you’d waste getting involved in a complete infertility work-up and treatment if the entire problem were nothing more than needing a small dose of thyroid hormone.
How about another diagnosis, say hypercholesterolemia (very high levels of cholesterol). Imagine all those years of statins avoided had your hypothyroidism been treated first. Constipation? Those laxatives, colonoscopies. Get the drift? If you think you’ve got thyroid issues, link up to Janie Bowthorpe’s marvelous website Stop The Thyroid Madness.
And be a pro-active patient.
Hang in there and be well,
David Edelberg, MD