title: Frequency and determinants of intracranial atherosclerotic stroke in urban Pakistan.
abstract: BACKGROUND
  Intracranial atherosclerosis (ICAD) is a frequent underlying mechanism of ischemic stroke. There is little direct evidence on its frequency and determinants from regions of high prevalence. This study explores the conventional and socioeconomic risk factors of ICAD in a South Asian population.
  
  
  METHODS
  The Karachi Intracranial Stenosis Study is a case-control study of 313 cases of ischemic stroke secondary to ICAD and 331 controls enrolled from 4 major hospitals in Karachi, Pakistan. Stroke subtype was verified by a vascular neurologist using the Trial of Org 10172 in Acute Stroke Treatment classification. Relationships of conventional and socioeconomic risk factors with ICAD-related strokes are reported by calculating odds ratios (ORs) and their 95% confidence intervals (CIs).
  
  
  RESULTS
  ICAD was the cause of stroke in 81.1% cases with large-artery atherosclerosis and 19.5% of all stroke events. Along with risk factors like history of hypertension (OR, 3.33; CI, 2.31-4.78), history of diabetes (OR, 2.29; CI, 1.56-3.35), use of tobacco (OR, 1.49; CI, 1.03-2.16), waist-to-hip ratio (OR, 1.58; CI, 1.04-2.41), and family history of stroke (OR, 1.89; CI, 1.21-2.95), other significant social determinants of ICAD strokes were monthly income (OR, 1.59; CI, 1.01-2.51), unemployment (OR, 2.15; CI, 1.21-3.83), and chronic stress (OR, 3.67; CI, 2.13-6.34). These social determinants were independent predictors of the risk of ICAD, in addition to those described in other world populations.
  
  
  CONCLUSIONS
  ICAD accounted for one fifth of all strokes making it the most common ischemic stroke mechanism. In addition to aggressive risk factor control, data also indicated broader holistic efforts on ameliorating inequity, unemployment, and stress reduction to reduce stroke because of ICAD.
authors.affiliation: Stroke Service, Section of Neurology, Department of Medicine, Aga Khan University Hospital, Karachi, Pakistan. Electronic address: ayeesha.kamal@aku.edu.
authors.forename: Ayeesha K
authors.initials: AK
authors.lastname: Kamal
authors.affiliation: Research Section, Center for Non-Communicable Diseases, Khalid Mehmood Department of Medicine, Dow University of Health Sciences, Civil Hospital, Karachi, Pakistan.
authors.forename: Asif
authors.initials: A
authors.lastname: Rasheed
authors.affiliation: Dow University of Health Sciences, Civil Hospital, Karachi, Pakistan.
authors.forename: Khalid
authors.initials: K
authors.lastname: Mehmood
authors.affiliation: Medical College, Aga Khan University Hospital, Karachi, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Murtaza
authors.affiliation: Research Section, Center for Non-Communicable Diseases, Khalid Mehmood Department of Medicine, Dow University of Health Sciences, Civil Hospital, Karachi, Pakistan.
authors.forename: Moazzam
authors.initials: M
authors.lastname: Zaidi
authors.affiliation: Stroke Service, Section of Neurology, Department of Medicine, Aga Khan University Hospital, Karachi, Pakistan.
authors.forename: Maria
authors.initials: M
authors.lastname: Khan
authors.affiliation: Research Section, Center for Non-Communicable Diseases, Khalid Mehmood Department of Medicine, Dow University of Health Sciences, Civil Hospital, Karachi, Pakistan.
authors.forename: Nabi
authors.initials: N
authors.lastname: Shah
authors.affiliation: Research Section, Center for Non-Communicable Diseases, Khalid Mehmood Department of Medicine, Dow University of Health Sciences, Civil Hospital, Karachi, Pakistan.
authors.forename: Maria
authors.initials: M
authors.lastname: Samuel
authors.affiliation: Stroke Service, Section of Neurology, Department of Medicine, Aga Khan University Hospital, Karachi, Pakistan.
authors.forename: Bilal
authors.initials: B
authors.lastname: Ahmed
authors.affiliation: Medical College, Aga Khan University Hospital, Karachi, Pakistan.
authors.forename: Emmon
authors.initials: E
authors.lastname: Raza
authors.affiliation: Liaquat National Hospital, Karachi, Pakistan.
authors.forename: Naveeduddin
authors.initials: N
authors.lastname: Ahmed
authors.affiliation: Jinnah Postgraduate Medical Centre, Karachi, Pakistan.
authors.forename: Jamal
authors.initials: J
authors.lastname: Ara
authors.affiliation: Jinnah Postgraduate Medical Centre, Karachi, Pakistan.
authors.forename: Tasnim
authors.initials: T
authors.lastname: Ahsan
authors.affiliation: Jinnah Postgraduate Medical Centre, Karachi, Pakistan.
authors.forename: Syed M
authors.initials: SM
authors.lastname: Munir
authors.affiliation: Jinnah Postgraduate Medical Centre, Karachi, Pakistan.
authors.forename: Shoukat
authors.initials: S
authors.lastname: Ali
authors.affiliation: Dow University of Health Sciences, Civil Hospital, Karachi, Pakistan.
authors.forename: Karim U
authors.initials: KU
authors.lastname: Maki
authors.affiliation: Dow University of Health Sciences, Civil Hospital, Karachi, Pakistan.
authors.forename: Muhammad M
authors.initials: MM
authors.lastname: Ahmed
authors.affiliation: Dow University of Health Sciences, Civil Hospital, Karachi, Pakistan.
authors.forename: Abdul R
authors.initials: AR
authors.lastname: Memon
authors.affiliation: Research Section, Center for Non-Communicable Diseases, Khalid Mehmood Department of Medicine, Dow University of Health Sciences, Civil Hospital, Karachi, Pakistan; Department of Public Health and Primary Care, University of Cambridge, UK; Department of Medicine, University of Pennsylvania, Philadelphia.
authors.forename: Danish
authors.initials: D
authors.lastname: Saleheen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003920:Diabetes Mellitus / Q000453:epidemiology; D005190:Family; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D002537:Intracranial Arteriosclerosis / Q000150:complications* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010154:Pakistan / Q000453:epidemiology; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D012959:Socioeconomic Factors; D013315:Stress, Psychological / Q000150:complications*; D020521:Stroke / Q000209:etiology*; D014478:Unemployment; D049629:Waist-Hip Ratio
keywords: Intracranial stenosis; international; ischemic stroke; risk factors