International Research Journal of Pharmacy and Pharmacology (ISSN 2251-0176) Vol. 2(12) pp. 306-310, December 2012 Available online http://www.interesjournals.org/IRJPP Copyright © 2012 International Research Journals Full length Research Paper Reverse dipper pattern of blood pressure as an indicator of sympathetic over activity in patients with systemic sclerosis and its relation with serum asymmetric dimethylarginine (ADMA) level Dr. Zuhal Ariturk 1* , Dr. Sevin Dag 2 , Dr. Remzi Cevik 2 , Dr. Hatice Yüksel 3 , Dr. Murat Yüksel 1 , Dr. Derya Uçmak 4 , Dr. Mustafa Oylumlu 1 , Dr. Ibrahim Batmaz 2 and Dr. M.Akif Sarıyıldız 2 1 Dicle University, Medicine Faculty, Department of Cardiology, Diyarbakir-Turkey 2 Dicle University, Medicine Faculty, Department of Physical Medicine and Rehabilitation, Diyarbakir-Turkey 3 Dicle University, Medicine Faculty, Department of Biochemistry, Diyarbakir-Turkey 4 Dicle University, Medicine Faculty, Department of Dermatology, Diyarbakir-Turkey Accepted October 15, 2012 Systemic sclerosis (SSc) is a multisystem disorder characterized by extensive vascular damage, with early generalized microangiopathy and fibrosis of the skin and internal organs. SSc is characterized by parasympathetic impairment and marked sympathetic over activity. The aim of this study was to investigate the potential relationship between serum asymmetric dimethylarginine (ADMA) levels and blood pressure pattern with sympathetic over activity in patients with SSc. Thirty patients with systemic sclerosis and thirty controls who had no cardiovascular risk factors were included in this study. All patients and the controls underwent a 24-hour holter recording and their plasma ADMA levels were measured. A total of 10 patients had dipper status (33.3%), 16 patients had non-dipper status (53.3%), 2 patients had reverse dipper status (6.7%) and 2 patients had extreme dipper status (6.7%). ADMA levels were higher in SSc patients when compared with control group and especially significantly higher in SSc patients with reverse dipper status. The relationship between elevated ADMA serum levels and reverse dipper blood pressure patterns in patients with SSC may be the result of sympathetic over activity. Keywords: 24-hour blood pressure monitoring, Systemic sclerosis, ADMA, reverse dipping status. INTRODUCTION Systemic sclerosis (SSc) is a multisystem disorder characterized by extensive vascular damage with early generalized microangiopathy and fibrosis of the skin and internal organs. Endothelial dysfunction and damage are primary events throughout the course of the disease, which result in vascular obliteration and diminished blood flow to the viscera. Endothelium injury is considered as one of the earliest key steps throughout the disease course. In SSc, microvascular involvement results in a transient vasospastic phenomenon and culminates in *Corresponding Author E-mail: zariturk@yahoo.com; Tel: 0090 5323338391; Fax:00904122488523 myointimal proliferation causing microvascular obliterations (Dimitroulas et al., 2008). Nitric oxide (NO) is a potent vasodilator synthesized by NO synthetase (Nos) isoforms and negatively regulated by Asymmetrical dimethylarginine (ADMA). ADMA levels are considered as the reflection of the endothelial dysfunction observed in several cardiovascular disorders. ADMA represents a novel risk factor for endothelial dysfunction. High ADMA levels predispose to acute coronary events, correlate with the severity of atherosclerotic disease and predict mortality of cardiovascular events in patients with end-stage renal disease (Valkonen et al 2001; Zoccali et al., 2001). It is also known that primary cardiac problems include pericarditis, heart failure; serious arrhythmias emerge in