Cardiovascular Risk and Mild Thyroid Hormone Deficiency: Are there some Differences in the Elderly?

Subclinical hypothyroidism (sHT) is a clinical condition defined as serum TSH concentration above the upper limit of the reference range in the face of normal free T4 (FT4) and free T3 (FT3) levels. Subclinical hypothyroidism, the prevalence of which increases with age, especially among women, up to almost 20%, encompasses several pathological entities, mainly represented by chronic autoimmune thyroiditis [1,2]. sHT is often associated to symptoms that resembles those of overt hypothyroidism, although to a lesser extent thus, the expression ‘mild thyroid impairment’ or ‘mild thyroid hormone deficiency’ would be more appropriate for defining such a condition [1]. Nonetheless, the term sHT is recognized worldwide and will be utilized in the present editorial. Since 90s, a relationship between sHT and increased cardio-vascular (CV) risk (both heart failure and coronary heart disease events) has been reported, although some experiences suggest that the risk may depend on the degree of TSH elevation [1,3-5]. Moreover, several reports from elderly population (>65 years old) showed that this relationship seems no longer evident in such individuals especially in the oldest old (>85 years old) [6-9].