title: Apolipoprotein-containing lipoprotein subclasses and subclinical atherosclerosis in systemic lupus erythematosus.
abstract: OBJECTIVE
  Traditional classification of hyperlipidemia using high-density lipoprotein, low-density lipoprotein (LDL), and very low-density lipoprotein does not provide information on lipoprotein function. Apolipoproteins (Apos), which are protein components of plasma lipoproteins (including A, B, C, D, E) with their different composition, metabolic, and atherogenic properties, provide insight on lipoprotein functioning. In particular, the Apo B/A-I ratio is associated with atherogenic LDL and development of cardiovascular disease. We explored the baseline association between these nontraditional risk factors with subclinical measures of atherosclerosis (coronary artery calcification [CAC] and carotid intima-media thickness [IMT]) in systemic lupus erythematosus (SLE).
  
  
  METHODS
  A total of 58 SLE patients (97% women, 58% white, 40% African American, and 2% other, mean ± SD age 44 ± 11 years) had measurement of Apo and lipoproteins by immunoturbidimetric procedures, electroimmunoassays, and immunoprecipitation. CAC was measured by helical computed tomography and carotid IMT by carotid duplex. This study was based on the baseline assessment of subclinical atherosclerosis in the Lupus Atherosclerosis Prevention Study. The measurement of the lipoproteins was made on sera collected at the same time.
  
  
  RESULTS
  There was no association between cardioprotective Apos (Apo A-I, LpA-I, LpA-I:A-II) and CAC (P < 0.15, P < 0.41, and P < 0.39, respectively) or carotid IMT (P < 0.97, P < 0.53, and P < 0.76, respectively). CAC and carotid IMT did not associate with atherogenic Apos either, including LpB:E+LpB:C:E, Apo B, LpB, LpB:C, Apo C-III, Apo C-III-HS, Apo C-III-HP, Apo C-III-R, LpA-II:B:C:D:E, and Apo B/Apo A-I. Measures of disease activity, including physician's global assessment and Systemic Lupus Erythematosus Disease Activity Index, were not associated with CAC or carotid IMT.
  
  
  CONCLUSIONS
  Neither cardioprotective nor atherogenic lipoproteins were associated with measures of subclinical atherosclerosis in this series of SLE patients. Further studies with a larger sample size are warranted to confirm our findings.
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Adnan N
authors.initials: AN
authors.lastname: Kiani
authors.forename: Hong
authors.initials: H
authors.lastname: Fang
authors.forename: Ehtisham
authors.initials: E
authors.lastname: Akhter
authors.forename: Carmen
authors.initials: C
authors.lastname: Quiroga
authors.forename: Nancy
authors.initials: N
authors.lastname: Simpson
authors.forename: Petar
authors.initials: P
authors.lastname: Alaupovic
authors.forename: Laurence S
authors.initials: LS
authors.lastname: Magder
authors.forename: Michelle
authors.initials: M
authors.lastname: Petri
mesh_terms: D000328:Adult; D001053:Apolipoproteins / Q000097:blood*; D058070:Asymptomatic Diseases; D050197:Atherosclerosis / Q000097:blood* / Q000175:diagnosis / Q000209:etiology; D015415:Biomarkers / Q000097:blood; D002340:Carotid Artery Diseases / Q000097:blood / Q000175:diagnosis / Q000209:etiology; D059168:Carotid Intima-Media Thickness; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000097:blood / Q000175:diagnosis / Q000209:etiology; D050171:Dyslipidemias / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012307:Risk Factors; D036542:Tomography, Spiral Computed; D018616:Ultrasonography, Doppler, Duplex; D061205:Vascular Calcification / Q000097:blood / Q000175:diagnosis / Q000209:etiology
chemical_list: D001053:Apolipoproteins; D015415:Biomarkers