The effect of IGF-I bioactivity on functional outcome after acute ischemic stroke.

Rationale:

Stroke is the 3rd leading cause of death and the 1st cause of disability in developed countries and the need for effective and widely available therapies is highly evident.

There is evidence that insulin-like growth factor type I (IGF-I) plays a role in the outcome after stroke, by stimulating regeneration after ischemic stroke.

Most of IGF-I is bound to IGF binding proteins (IGFBP’s), which influences the IGF-I bioactivity. A recently developed IGF-I specific kinase receptor activation assay (KIRA) can determine this IGF-I bioactivity. Therefore, this test most likely gives more information than determining IGF-I levels alone.



Objective:

We aim to compare IGF-I bioactivity levels between patients with favorable and unfavorable functional outcome 3 months after acute ischemic stroke. Furthermore, we will compare the IGF-I bioactivity levels between patients with and without improvement in NIHSS-score at discharge and assess the association between IGF-I bioactivity and infarction size.



Study design:

Prospective, single center study.



Study population:

Patients who are 18 years or older with an acute ischemic stroke (<24 hours), who are not on insulin therapy.



Main study parameters/endpoints:

Modified Rankin Scale at 3 months, improvement in NIHSS-score at discharge, and infarction size on day 5.



Nature and extent of the burden and risks associated with participation, benefit and group relatedness:

Blood samples from 40 patients with acute ischemic stroke will be collected on admission, on day 2 and at 3 months (25mL each time). Plasma will be analyzed for IGF-I and IGF-I bioactivity, using the KIRA. A CT-scan will be performed on day 5 to determine infarction size. Studying the role of IGF-I bioactivity in the acute phase of ischemic stroke might be very interesting as it might be an important novel therapeutic agent.

We aim to compare IGF-I bioactivity levels between patients with favorable and unfavorable functional outcome 3 months after acute ischemic stroke. Furthermore, we will compare the IGF-I bioactivity levels between patients with and without improvement in NIHSS-score at discharge and assess the association between IGF-I bioactivity and infarction size.

3 months.

We will assess all patients at baseline, discharge and at 3 months. At baseline, data on clinical features of the ischemic stroke, demographic data, vascular risk factors and history, and use of medication will be obtained. Fasting glucose levels, 2-hour post-load glucose levels, body mass index, waist circumference, blood pressure and lipid profile will be assessed at baseline and at 3 months as part of standard procedure.
In all patients, we will collect blood samples (25mL) at inclusion into the study, 2 days after the admission and at 3 months for the assessment of total IGF-I and IGF-I bioactivity. Serum will be obtained by standard methods. After centrifugation, serum will be stored at -80ºC until analysis. On day 5, a CT-scan of the brain will be made to assess infarction size.