The effect of statin therapy on thyroid autoimmunity in patients with Hashimoto's thyroiditis: A pilot study.

BACKGROUND: Statins have been found to exert antiinflammatory and immunomodulatory properties. The aim of this study was to compare the effects of intensive and less aggressive statin treatment on thyroid autoimmunity and hypothalamic-pituitary-thyroid axis activity in patients with Hashimoto's thyroiditis.

METHODS: The study included 38 adult women with Hashimoto's thyroiditis, who required statin therapy and were allocated into one of two groups. Patients at very high cardiovascular risk (n=16) received intensive statin treatment (rosuvastatin 20-40mg daily), while patients at moderate or moderately high cardiovascular risk (n=22) were treated with simvastatin (20-40mg daily) for the following 6 months. Serum levels of thyrotropin, total and free thyroid hormones, and high-sensitivity C-reactive protein (hsCRP), as well as titers of thyroid peroxidase and thyroglobulin antibodies were measured at the beginning and at the end of the study.

RESULTS: Thirty-six individuals completed the study and were included in the final analyses. Apart from improving plasma lipids and reducing circulating levels of hsCRP, intensive, but not less aggressive, statin therapy reduced thyroid peroxidase and thyroglobulin antibody titers, as well as tended to reduce circulating levels of thyrotropin. The effect of intensive statin therapy on thyroid antibody titers was lipid-independent but correlated with treatment-induced changes in thyrotropin and hsCRP.

CONCLUSIONS: Although 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors are able to reduce thyroid autoimmunity in women with Hashimoto's thyroiditis, intensive statin therapy is required to produce this effect.