title: Lipoprotein (a) level, apolipoprotein (a) size, and risk of unexplained ischemic stroke in young and middle-aged adults.
abstract: Circulating lipoprotein (a) [Lp(a)] level relates inversely to apolipoprotein (a) [apo(a)] size. Both smaller apo(a) isoforms and higher Lp(a) levels have been linked to coronary heart disease and stroke, but their independent contributions are less well defined. We examined the role of Lp(a) in younger adults with cryptogenic stroke.
  
  
  
  Lp(a) and apo(a) isoforms were evaluated in a prospectively designed case-control study of patients with unexplained ischemic stroke and stroke-free controls, ages 18 to 64. Serum Lp(a) was measured among 255 cases and 390 controls with both apo(a)-size independent and dependent assays. Apo(a) size was determined by agarose gel electrophoresis.
  
  
  
  Cases and controls were similar in socio-demographic characteristics, but cases had more hypertension, diabetes, smoking, and migraine with aura. In race-specific analyses, Lp(a) levels showed positive associations with cryptogenic stroke in whites, but not in the smaller subgroups of blacks and Hispanics. After full adjustment, comparison of the highest versus lowest quartile in whites was significant for apo(a)-size-independent (OR = 2.10 [95% CI = 1.04, 4.27], p = 0.040), and near-significant for apo(a)-size-dependent Lp(a) (OR = 1.81 [95% CI = 0.95, 3.47], p = 0.073). Apo(a) size was not associated with cryptogenic stroke in any race-ethnic subgroup.
  
  
  
  This study underscores the importance of Lp(a) level, but not apo(a) size, as an independent risk factor for unexplained ischemic stroke in young and middle-aged white adults. Given the emergence of effective Lp(a)-lowering therapies, these findings support routine testing for Lp(a) in this setting, along with further research to assess the extent to which such therapies improve outcomes in this population.
authors: Department of Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, USA.
authors: Azadeh
authors: A
authors: Beheshtian
authors: Department of Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, USA.
authors: Sanyog G
authors: SG
authors: Shitole
authors: Department of Neurology, Weill Cornell Medicine, New York, NY, USA.
authors: Alan Z
authors: AZ
authors: Segal
authors: Department of Neurology, Weill Cornell Medicine, New York, NY, USA.
authors: Dana
authors: D
authors: Leifer
authors: Department of Pathology and Laboratory Medicine, University of Vermont College of Medicine, Burlington, VT, USA.
authors: Russell P
authors: RP
authors: Tracy
authors: Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
authors: Daniel J
authors: DJ
authors: Rader
authors: Department of Medicine, Weill Cornell Medicine, New York, NY, USA.
authors: Richard B
authors: RB
authors: Devereux
authors: Department of Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, USA; Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, USA. Electronic address: jorge.kizer@einstein.yu.edu.
authors: Jorge R
authors: JR
authors: Kizer
mesh_terms: D000293:Adolescent; D000328:Adult; D053241:Apoprotein(a) / Q000737:chemistry*; D015992:Body Mass Index; D016022:Case-Control Studies; D003327:Coronary Disease / Q000097:blood* / Q000453:epidemiology; D005006:Ethnicity; D005260:Female; D006801:Humans; D017270:Lipoprotein(a) / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000097:blood* / Q000453:epidemiology; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D017270:Lipoprotein(a); D053241:Apoprotein(a)
keywords: Case control study; Lipoprotein (a); Stroke