Serum Levels of Myo-inositol Predicts Clinical Outcome 1 Year After Aneurysmal Subarachnoid Hemorrhage

Abstract

BACKGROUND:Early prognostication of long-term outcome in patients suffering from spontaneous subarachnoid hemorrhage (SAH) remains a challenge. No biomarkers are routinely used for prognostication. A previous study has indicated that the metabolite myo-inositol (MI) may be used to predict long-term outcome.OBJECTIVE:To investigate if MI measured in serum correlates with long-term clinical outcome in patients suffering from SAH.METHODS:We conducted an observational cohort study including 88 patients treated for SAH at Umeå University Hospital. Serum samples were collected in the hospital, and a gas chromatography/mass spectroscopy method was used to quantitatively measure MI. Patients were assessed after 1 year using the Glasgow Outcome Scale Extended and dichotomized to favorable or unfavorable outcome. Differences in MI levels between the 2 groups were analyzed.RESULTS:There was no difference in MI levels between the groups upon admission. Myo-inositol levels decreased over time in the entire study population. The decrease was significantly larger in the unfavorable outcome group. A receiver operating characteristics analysis yielded an area under the curve of 0.903 (CI 0.8-1.0, P < .001) for the MI value on day 7 to predict favorable outcome after 1 year.CONCLUSION:Myo-inositol measured in serum may aid prognostication of outcome in patients with SAH. The mechanism behind this remains unclear, although it can be theorized to reflect processes leading to delayed cerebral ischemia, which affects long-term outcome. This is the first study to quantitively measure MI in serum for prognostication of outcome in patients with SAH.

Commentary: Serum Levels of Myo-inositol Predicts Clinical Outcome 1 Year After Aneurysmal Subarachnoid Hemorrhage

“…Although some papers have looked at specific metabolite levels in the cerebrospinal fluid (CSF) and serum, this study did not. 6 Further studies would aim to correlate serum and CSF levels of MI and other metabolites involved in aSAH. This would improve the utility of any marker given that serum values are more easily and readily obtained than CSF.…”

“…MI levels at day 7 were correlated with outcomes at 1 year. 6 The authors chose to focus on vasospasm and DCI because these are some of the main factors that affect mortality and morbidity in aSAH. 8…”

“…MI levels at day 7 were correlated with outcomes at 1 year. 6 The authors chose to focus on vasospasm and DCI because these are some of the main factors that affect mortality and morbidity in aSAH. 8 Although this paper presents a novel biomarker for prognostication after aSAH, the paper is not without flaws, which the authors themselves point out.…”

“…Blood was drawn from participants only when convenient for nursing staff which led to discrepancies in both the number of patients with MI levels on a given day and varying timing of those draws. 6 Further work should address this issue to better elucidate the relationship between MI and complications.…”

“…4,5 We may quickly diagnose, stabilize, and treat patients with aSAH, but no quantitative tool exists for long-term prognostication. In this article, 6 the authors sought to increase our understanding in how to rapidly and effectively predict long-term complications of SAH to better guide treatment strategies. Better understanding of these mechanisms may contribute to novel treatments for aSAH.…”