(HealthDay News) – Both subclinical hypothyroidism and hypothyroidism overall are associated with greater mortality risk in patients with congestive heart failure (CHF), according to a study published online May 29 in the Journal of Clinical Endocrinology & Metabolism.
Connie M. Rhee, MD, from Brigham and Women’s Hospital in Boston, and colleagues analyzed the association between all-cause mortality and subclinical hypothyroidism (thyrotropin [TSH] > assay upper limit normal [ULN]; total thyroxine [TT4] within reference) and hypothyroidism overall (TSH > ULN; TT4 < lower limit normal or within reference) among participants of the Third National Health and Nutrition Examination Survey.
The researchers note that there were 14,130 euthyroid controls (95%) and 749 participants with hypothyroidism (5%), 691 (4.6%) of whom had subclinical disease. There was an association between greater mortality and subclinical hypothyroidism compared to euthyroidism in those with CHF but not in those without (adjusted hazard ratio [aHR], 1.44 and 0.97, respectively [P for interaction = 0.03]). Hypothyroidism overall yielded similar findings. There was greater mortality in black participants with hypothyroidism overall compared to euthyroidism (aHR, 1.44) but not in non-blacks (aHR, 0.95) (P for interaction = 0.03).
“Among participants with CHF, subclinical hypothyroidism and hypothyroidism overall are associated with greater death risk,” the authors write.