Hypothyroidism is associated with higher hospitalization risk among patients with underlying cardiovascular disease, according to a recent study. Researchers examined the association of thyroid status, defined by serum thyrotropin (TSH), with hospitalization risk among patients who received care from a large university-based tertiary care center from 1990 to 2015. Thyroid status was categorized as hypothyroidism vs euthyroidism (TSH >4.7 vs 0.3-4.7mIU/L, respectively). They found:

• Among 52,856 patients who met eligibility criteria, 49,791 (94.2%) had euthyroidism and 3,065 (5.8%) had hypothyroidism.
• In analyses stratified by congestive heart failure (CHF) status, compared to euthyroidism, hypothyroidism was associated with higher risk of hospitalization in those with CHF but slightly lower risk in those without CHF.
• In sensitivity analyses accounting for death as a competing event, underlying coronary artery disease (CAD) modified the hypothyroidism-hospitalization relationship, such that stronger associations were observed among those with vs without CAD.
• In competing risk analyses, hypothyroidism was associated with higher vs lower risk of hospitalization among those with vs without cerebrovascular disease, respectively.