There has been debate over the connection between blood glucose levels and severity of stroke, which is no surprise given the vast web of interconnecting inflammation in the body. Dr. Bruno, a stroke specialist at the Medical College of Georgia, is investigating the use of insulin injections to help alleviate post-stroke damage. Dr Bruno, who is also a clinical PI for the National Institute of Neurological Disorders and Stroke-funded study, believes that, upon admittance to the emergency room, every stroke patient should be given an insulin injection. Generally, simple finger-prick tests are administered to check for diabetes anyway, so he believes that an insulin injection should be a standard as well, whether or not the patient is diabetic. His rationale for this is that generally, stoke victims suffer more damage when blood glucose levels are high, so a quick dose of insulin should help lower glucose levels and therefore minimize damage. In addition, he explains that low blood glucose levels can mimic stroke symptoms, so an insulin injection may lead to less false-positives.
Does this theory sound promising? Possibly. Nearly 1400 physicians in the U.S. are claiming to subscribe to this easy treatments, but the exact method for success is not clear. It is believed that stroke triggers the release of stress hormones, and they may interfere with the ability of cells to uptake glucose, leading to higher levels in blood. So what causes the damage? Dr. Bruno hypothesizes that free radicals released during stroke amplify the damage. He is currently working a this trial, termed the SHINE Trial, in which stroke patients either receive insulin injections or, in tougher cases, IV insulin for three days. Three months later, the patients' health is assessed.
I thought this concept is interesting, and not too far-fetched. Insulin injection, at proper doses, should be safe, and it makes sense that you would see elevated blood glucose levels post-stroke due to wide-spread effects of inflammation. However, the article did not clarify how control over glucose levels would affect stroke damage, merely that there appears to be a connection. This news article also did not link a scientific paper or study, possibly because this group has not yet published on the topic. So the bottom line is: are elevated glucose levels partially responsible for more severe damage, or is this just an association? The answer to this question could provide the link necessary to truly treat strokes more effectively.
Study seeks to improve stroke outcomes by optimizing blood glucose control
Back when we read about obesity, we found that it was originally believed that inflammatory and stress hormones limited uptake of glucose so that it would be readily available to any of the cells working to fight off any bad guys in the body. We know that inflammation associated with stroke can be an issue, but if Dr. Bruno hypothesizes that it's the free radicals released during stroke that amplifies the damage, how does lowering the glucose in the blood help? And again, we come back to the questions of: will we cause other issues if we try to change the way our body is programmed to deal with something? The answer to the question you pose, if elevated glucose levels are partially responsible for more severe damage, will be interesting to find out, however, no doubt difficult to answer just because everything seems to be so interconnected!
ReplyDeleteI also would like to hear more about why Dr. Bruno thinks the increase in free radicals are primarily due to elevated blood glucose levels. Free radicals are a natural byproduct of metabolism but do their numbers increase drastically when blood glucose is slightly elevated? It seems that during stroke the brain is starved of oxygen and nutrients. I would think this starvation and cellular breakdown would lead to the creation of more free radicals than metabolism. It seems equally likely that the increase in free radicals is due to an inflammatory immune response. Also I would think finding a way to quickly reestablish blood flow and the delivery of nutrients would be beneficial. Would a reduction below normal glucose levels cause more extensive neuronal damage? I guess we will have to wait for the publication of his results to see if this therapy is effective.
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