1 J Exp Clin Neurosci, 2017, 4(1): 1-4 Original Artcle Correlation of High Density Lipoproteins and Cerebral Vasomotor Reactivity in Healthy Individuals Mehdi Farhoudi a *, Mohammadali M. Shoja b , Naser Aslanabadi c , Laya Javanmanesh a , Saeed Sadigh-Eteghad a , Mohammad Moosavi a a Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran b Pediatric Neurosurgery, Children’s Hospital, Birmingham, Alabama, USA c Cardiovascular Research Center, Tabriz University of Medical Sciences, Tabriz, Iran Introduction Stroke is a common neurological disabling disorder that is the second cause of mortalities in developing countries and the ffth cause of mortality in the United States [1,2]. Some risk factors such as age, sex hypertension, diabetes, smoking, obesity, coronary artery disease, contraceptive drugs, alcohol and hyperlipidemia participate in stroke incidence. According to epidemiological studies, by increasing in age the incidence of the disease is increased while the occurrence in men is more than women [3]. Hyperlipidemia affects vessels endothelium and leads to atherosclerosis [4]. Cerebral vessels Vasomotor Reactivity (VMR) that has a direct relationship with cerebral vessels auto regulation is the main factor in cerebral infarction [5]. Hyperlipidemia is one of the important factors that affect VMR, so it seems that that to study the low-density level (LDL), high- density level (HDL) and atorvastatin on VMR is an important issue [6]. Several studies have been conducted on LDL and the effect of atorvastatin. However, there is no investigation about the effect of HDL on cerebral vessels vasomotor reactivity. Therefore, the present study was to point out HDL level effects in VMR of cerebral vessels in healthy individuals. Materials and Methods In this descriptive study, sixty healthy men under 45 years old without vessels risk factors like hypertension, diabetes, smoking, coronary and cerebral vessel disorder history from staff of Tabriz Imam Reza Hospital, northwest Iran and also medical students were studied. These individuals did not Correspondence Mehdi Farhoudi, Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran. Tel/Fax: +98-41-33340730, Email: Farhoudi_m@yahoo.com Received: 2016-11-14 Accepted: 2017-01-28 DOI: 10.13183/jecns.v4i1.60 Abstract Objectve: Cerebral Vasomotor Reactvity (VMR) which refects cerebrovascular autoregulaton is impaired in stroke patents. Some risk factors for stroke such as hyperlipidemia afects endothelial layer of vessels and by disturbing of VMR make an important role in the occurrence of stroke. The aim of this study is to evaluate High-Density Lipoproteins (HDL) efects on VMR of cerebral vessels. Materials and Methods: Sixty healthy male volunteers (<45 years old) without vascular risk factors history were evaluated in Tabriz Imam Reza Medical Center Northwest Iran, during a 12-month period. The partcipants were divided into three nearly equal groups with low HDL level (<40 mg/ml), normal HDL level (40-50mg/ml) and high HDL level (>40 mg/ml). The mean fow velocity of both middle cerebral arteries (MCA) was contnuously measured by Transcranial Doppler (TCD) and VMR of MCA was calculated by breath-holding index (BHI). Results: Mean BHI of lef MCA in persons with low, normal and high HDL levels were 1.32 ± 0.44 %/sec, 1.47 ± 0.65 %/sec and 1.18 ± 0.48 %/sec respectvely. Mean BHI of right MCA in low, normal and high HDL groups were 1.13 ± 0.35 %/sec, 1.39 ± 0.62 %/sec and 1.36 ± 0.55 %/sec, respectvely. There was no statstcally signifcant diference among these groups (p>0.05). Conclusion: The current study showed that there was no statstcally signifcant correlaton between serum HDL level and BHI in lef and right MCA of healthy persons. Keywords: HDL, Vasomotor reactvity, TCD, Breath-holding index ©2017 Swedish Science Pioneers, All rights reserved.