Heart Disease, Thyroid Disease, and Statins: New Links, New Solutions

It should be no secret that heart disease is inextricably linked to thyroid disease, especially hypothyroidism caused by such maladies as Hashimoto's Thyroiditis (a condition I suffer from).

A recent study of 25,000 people recently published in the Archives of Internal Medicine has confirmed that sub-clinical hypothyroidism (those with supposedly normal TSH test results) is positively linked to fatal heart disease in women. However, there were not enough cardiac deaths to extend this conclusion to men (note that this DOES NOT mean men are not affected, it simply means there were not enough events to prove it statistically within the 95% confidence interval established for the study). This study confirms the findings of a smaller study published in the Archives last year.

The message these studies provide is clear. Persons with TSH test results even in the intermediate range of "normal" (1.14-2.52 mIU/L) may be at heightened risk for cardiac death. The practical result is that patients should no longer rely on supposedly "normal" TSH test results to rule out hypothyroidism.

Now come two new studies that suggest statins may help to control your heart and thyroid disease - even if you test normal for both cholesterol and thyroid levels.

The JUPITER study was recently terminated a year early because of overwhelming evidence that even individuals with LDL cholesterol well below established guidelines benefited from taking a statin if they had elevated C-reactive-protein (CRP) levels (CRP is a measure of inflammation - more on that later).  Investigators showed that 20mg daily of rosuvastatin significantly reduced nonfatal MI (heart attack), nonfatal stroke, hospitalization for unstable angina, revascularization, and confirmed death from cardiovascular causes by 44% compared with individuals treated with placebo.  Of course, we must take the study with a grain of salt since it was sponsored by the company that makes rosuvastatin but the results are impressive.  The key here is that statins appear to also have powerful anti-infalmmatory effects.

Another study involved hyperthyroid patients taking various statins.  The conlcusion reached was that "Statins may falsely lower the serum TSH without altering thyroid function ("pseudohyperthyroidism") or, alternatively, statins may improve thyroid function in patients with hyperthyroidism.  An earlier hypothyroidism study looking at simvastatin noted, "An increase in serum free tri-iodothyronine (T3) and free thyroxine (T4) levels and a decrease in TSH levels were observed (P < 0.05) with Simvastatin treatment.  Similar to the JUPITER study, the effect suggested that, "Simvastatin is an immune modulatory agent and improves thyroid function in patients with HT" (Hashimoto's Thyroiditis, a form of hypothyroidism) and in all likelihood the effect is, "not confined to Simvastatin since Mevastatin, Pravastatin and Cerivastatin also induced apoptosis in lymphocytes."