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Editor's Correspondence
Oct 22, 2012

Subclinical Hypothyroidism and Cardiovascular Disease

Author Affiliations

Author Affiliations: Department of Geriatrics and Metabolic Diseases, Second University of Naples, Naples, Italy.

Arch Intern Med. 2012;172(19):1523-1524. doi:10.1001/archinternmed.2012.4409

We thank Razvi et al1 for their informative article on subclinical thyroid disease. The study by Razvi et al1 provides useful information regarding the importance of recognizing subclinical hypothyroidism (SCH) in anticipation of decreasing cardiac risks, although definitive long-term prospective controlled studies proving the benefits of treatment in various age groups have not been performed. In this context, we observed that innate immune overactivity is associated with an unstable phenotype of atherosclerotic plaques in patients with SCH enlisted to undergo endoarterectomy for high-grade (>70%) carotid artery stenosis.2 In particular, macrophages were significantly more abundant in SCH atherosclerotic lesions compared with control lesions, and it was associated with higher nuclear-factor–κB, tumor necrosis factor, and matrix-metalloproteinase-9 levels, along with less interstitial collagen content. All of this might increase the risk of acute ischemic events precipitated by inflammatory-dependent rupture of atherosclerotic plaques.3