Link between Chronic Isolated Lightheadedness and Abnormal Blood Phospholipids

Abstract

Background: To evaluate whether Chronic Isolated Light-headedness (CIL) commonly manifested in elderly patients with Suspected Chronic Cerebral Circulation Insufficiency (SCCCI) is related with a certain abnormality in circulation. Methods: In this case-control study, 462 patients (aged 40-83 years) with CIL and 238 clinical data matched controls were enrolled consecutively from January 2011 to September 2014. The plasma level of phospholipids with solubility similar to that of lysophosphatidic acid (PSS-LPA), a surrogate marker for cerebral oxidative stress, was determined in all subjects to compare the occurrence and severity of CIL with the values of PSS-LPA. Findings: Patients with CIL had significantly higher plasma levels of PSS-LPA than controls, χ2 = 448, odds ratio (95% CI) = 140 (72-260), P<0*001; the mean plasma levels were 0*573 vs. 0*290 mmol/L respectively (P<0*001). Regardless of having or having not psychogenic abnormalities, patients with CIL had significantly higher level of PSS-LPA than those patients without light-headedness. Receiver operator characteristic (ROC) analyses showed plasma PSS-LPA was both sensitive and specific for CIL. The area under ROC curve (AUC) was as high as 0*953 (0*938-0*968). The changes in severity of CIL between two separate assays of one month apart were correlated closely with the changes in plasma levels of PSS-LPA for the same patients, correlation coefficient (Spearman) = 0*90, p<0*001. Interpretation: CIL is a manifestation of abnormal blood phospholipids. This new finding initially revealed a possible mechanism of CIL. PSS-LPA can at least be used in excluding the psychogenic lightheadedness. Funding: Grant of the 304 Hospital, China. Declaration of Interests: The authors declare no conflict of interest. Ethics Approval: This study was conducted according to the Helsinki II Declaration and approved by the ethics committee of the 304 Hospital, Chinese Army.