Abstract
Background The association of serum insulin-like growth factor I
(s-IGF-I) with favorable outcome after ischemic stroke (IS) beyond 2 years is
unknown. We investigated whether the levels of s-IGF-I 3 months post-stroke were
associated with functional recovery up to 7 years after IS, considering also
mortality and recurrent strokes.
Methods Patients (N=324; 65% males; mean age, 55 years)
with s-IGF-I levels assessed 3 months after the index IS were included from the
Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS). The modified Rankin
Scale (mRS) was used to evaluate outcomes at 3 months, 2 and 7 years after IS,
and recovery was defined as an improvement, no change, or deterioration in the
shifts of mRS score. Baseline stroke severity was determined using the National
Institutes of Health Stroke Scale (NIHSS).
Results The mRS score distributions were better in the above-median
s-IGF-I group (>146.7 ng/ml). The s-IGF-I level was not
associated with recurrent stroke (N=79) or death (N=44),
although it correlated with recovery (r=0.12, P=0.035). In the
regression analysis, s-IGF-I associated with recovery between 3 months and 7
years (but not between 2 and 7 years). The associations did not withstand
adjustment for age and sex. For comparison, the corresponding associations
between 3 months and 2 years withstood all adjustments.
Conclusion The association for s-IGF-I with long-term post-stroke
recovery persists after 7 years, which is also reflected in the mRS score
distributions at all time-points. The effects are however modest, and not driven
by mortality or recurrent stroke.
Altered levels of circulating insulin-like growth factor I (IGF-I) following ischemic stroke are associated with outcome - a prospective observational study