One of the top stories on EndocrineToday.com last week emphasizes an association between low levels of thyroid-stimulating hormone and risk of fracture. This is not surprising since the effect of thyroid hormones on the skeleton is very similar to that of parathyroid hormone.

I wonder whether this association with a low TSH might explain the reports of an increased incidence of atrial fibrillation in patients on bisphosphonates. Let me quickly add that this possible side effect is by no means well documented to date.

What is missing from the EndocrineToday.com article is a strong warning to consider a low TSH particularly in patients taking exogenous thyroxine. Patients with endogenous hyperthyroidism are usually unwell and are likely to present for medical care relatively early in the disease. In contrast, patients with hypothyroidism treated chronically with thyroid replacement can have mildly suppressed TSH for extended periods of time without any overt clinical manifestations. This chronic mild “hyperthyroid” is more likely to have a long-term adverse effect on the skeleton. Checking TSH and free T4 should be routine in the initial evaluation of patients found for the first time to have low bone density.

A problem arises when a patient on thyroid replacement is found to be a little over-suppressed. I have found it quite difficult to reduce the dose because the patient simply doesn’t feel as well on a lower dose of T4. The change in self-rated health is unquestionably real and one cannot blame any patient who balks at this change in well-being.

The solution? I’m not sure I have one, but I have been measuring markers of bone resorption and formation to see if they are elevated or not. If they are, I push a little harder to reduce the T4 dose. If not, I tend to back off and recommend treatment for osteoporosis independent of the thyroid state. This brings me right back to the potential link between bisphosphonates and atrial fibrillation. Always keep in mind that hyperthyroidism has adverse health effects that extend beyond the skeleton.

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A few years ago I was given access to a medical claims database that included 250,000 women aged 50 years and older. I tracked claims for fracture over a three-year period and the traditional osteoporosis-related fractures — wrist, vertebra, hip — were reported with increasing frequency with increasing age. The wrist fracture increase was reported in the first 10 years post-menopause. Spine fractures began to increase some five to 10 years later while the hip fracture increase was not noted until after age 70 years.

Surprisingly, the most common fracture was “foot and ankle,” but equally surprisingly, the incidence did not track with age. Most authorities in the field of osteoporosis do not accept these fractures as being related to osteoporosis and there is a “confirming” publication from a large Australian study pointing out that ankle fractures were not predictive of future fragility fractures in women. Just to cloud the issue further, these fractures were important predictors of future fracture in men.

So how should I have handled the 70-year-old woman who limped into my clinic the other day having sustained her third ankle fracture following a simple twisting accident? “I have floppy ankle joints and so does my son but he hasn’t fractured yet,” she reported.

This woman deserves a DEXA study as do all women aged 65 years and older, according to the United States Preventive Services Task Force. While I am waiting for the result of the DEXA, I turned to FRAX, the new World Health Organization tool for calculating future fracture risk that I have written about before. That instrument asks about previous fracture as a Yes/No question without regard to the circumstance of the fracture or the site of fracture.

With a T-score of –1.0 and “no” fracture, this patient’s 10-year probability of a future major osteoporosis fracture was 14%. If I checked the box that said “yes” for fracture, the risk increased 23%. For a T-score of –2.5 the risk without previous fracture was 22%, rising to 34% if I checked the “yes” box for previous fracture.

Still confused about the ankle fracture being osteoporosis? Do not get hung up on the diagnostic label, focus instead on management. If the DEXA T-score does not suggest to you that the patient needs pharmacologic therapy, please turn to the FRAX website before making your final decision.

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At age 20 years, my patient was diagnosed as having bulimia — less common in men than in women. His parents were wonderful and made certain that he went for therapy and a good result was achieved.

Unfortunately too good! When I saw him at age 40 years, he weighed in at 467 lbs. and he left the clinic only after I had made a referral to a very reputable weight loss program and he had scheduled an appointment. I have little doubt that he will keep that appointment. He specifically did not want to be considered for bariatric surgery but was convinced that with the right coaching he could lose the weight just as he had overcome bulimia. I am confident that he will, but just hope that he does not go too far in the other direction as he did before.

He was referred to me not for an eating disorder but because of low testosterone levels — not at all a surprising observation in the massively obese. He had been on testosterone replacement in the past but had stopped on his own accord despite the seemingly obvious benefits he derived. His major problem was a re-awakening of libido while he found himself in a situation where, because of his weight, there was not much he could do about it. After discussion he elected to forego testosterone replacement for now. That will make it a bit harder for him to convert fat to muscle but, even knowing that, it was his choice.

Why bring up this clinical anecdote? This is a highly educated, intelligent gentleman with a very responsible academic position. Yet he could not overcome his weight problems at either extreme of the spectrum despite interaction with skilled and reputable practitioners. Ongoing success for this patient will require almost lifelong intense care. “Cure” can be achieved in patients with eating disorders but it requires an understanding and expertise way beyond my skills — these patients must be referred to the appropriate colleagues!

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