Introduction
The burden of stroke in china is very serious and the annual stroke
mortality rate is approximately 1.6 million, which has exceeded heart
disease to become the leading cause of death and adult disability (1).
Of all stroke types, ischemic stroke is the most prevalent accounting
for 69.6% (2). Currently, ischemic stroke severity and prediction of
functional outcome are assessed with standardized clinical criteria (3,
4). However, the prognostic value of these clinical parameters in
ischemic stroke is quite subjective and insufficient, such that
identification of new biomarkers may potentially improve the accuracy of
the current prognostic scales for functional outcome.
Recent studies suggest that serum concentrations of thyroid hormones are
altered in the acute phase of ischemic stroke and may have a potential
influence on functional outcome (5, 6). There are some evidences that
thyroid hormones play a neuroprotective role in the recovery of
post-ischemic stroke (7) and display a protective association between
subclinical hypothyroidism and better outcomes(8, 9) However, other
studies suggest that lower serum concentrations of T3 are associated
with poor outcome after ischemic stroke (6, 10).In addition, it is not
well recognized whether there are any associations between FT3, the
bioactive form of T3, and functional outcome of ischemic stroke. Studies
on the relationship between FT3 levels and functional outcomes after
ischemic stroke are controversial(10-16) .Thus, our study aimed to
investigate whether the serum concentrations of thyroid hormones on
admission, including thyroid stimulating hormone (TSH), free
triiodothyronine (FT3), and free thyroxine (FT4) were associated with
3-month functional outcome in acute ischemic stroke.