IGF-I linked to long-term stroke recovery

Åberg D. J Clin Endocrinol Metab. 2011;doi:10.1210/jc.2010-2802.

Issue: August 2011

High levels of insulin-like growth factor I were associated with better long-term recovery from stroke, according to data from researchers in Sweden.

“This study is interesting for two reasons. The first is that we show that a hormone is associated with improved long-term recovery, and thus, there is still the prospect of improvement — even 3 months after the stroke. The second is that levels of this hormone are known to be elevated in those who exercise often,” David Åberg, MD, PhD, associate professor at Sahlgrenska Academy, said in a press release. “It is, however, important to add that the levels of IGF-I are controlled also by other factors such as other growth hormones, heredity and nutrition.”

Using data from the Sahlgrenska Academy Study on Ischemic Stroke, Åberg and colleagues analyzed data for 407 patients with a mean age of 55 years and 40 randomly matched controls. Serum IGF-I was measured acutely at 1 to 10 days after stroke and 3 months after stroke. At 3 and 24 months after stroke, the modified Rankin Scale was used to evaluate recovery, and at the acute stage and 3 months after stroke, the Scandinavian Stroke Scale was used for assessment, according to the study abstract.

Serum levels of IGF-I were higher at the acute stage compared with 3 months after stroke (P<.001) and compared with controls (P<.001). Elderly patients had progressively lower serum IGF-I levels. According to the abstract, serum levels in the acute (P=.001; R=0.174) and 3-month post-stroke (P<.001; R=0.24) range were positively associated with improvement in the modified Rankin scores between 3 and 24 months.

“Our results may explain why patients who exercise more actively, with physiotherapy and physical exercise, demonstrate better recovery after a stroke. Unfortunately, we do not know how much our patients exercised after the stroke. This means that we need to carry out further studies in which we measure both the amount of physical activity and the levels of IGF-I to understand the exact relationships better,” Åberg said.

According to Åberg, treating with IGF-I or with GH are the two avenues open for exploration to determine whether drug treatments to raise IGF-I could improve long-term recovery from stroke.

“Of course, these possibilities must be tested in carefully constructed clinical trials, so that we discover any undesired effects that must be considered. This is particularly true during the acute phase of a stroke, while treatment during the recovery phase is probably easier and has greater benefit,” he said.

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