title: Diurnal variation in lipoprotein-associated phospholipase A(2) (Lp-PLA(2)).
abstract: OBJECTIVE
  The aim of our study was to determine the diurnal variation of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)), an arterial-specific inflammatory enzyme implicated in the formation of vulnerable, rupture-prone plaque that can identify individuals at high risk for cardiovascular disease. Presently, the diurnal variation of Lp-PLA(2) is not known.
  
  
  METHODS
  Ten men and 8 women (age range: 22-76 years) had a blood sample taken every 4 h over a 24-hour time period. Samples were analyzed for both Lp-PLA(2) mass and activity.
  
  
  RESULTS
  The mean coefficient of variation (CV) for Lp-PLA(2) mass was 5.9% (ranges from 2.5 to 9.4%) for the 18 subjects. Similarly, the mean CV for Lp-PLA(2) activity was 3.7% (ranges from 1.2 to 6.8%). There were no significant correlations between CV and any of the subject characteristics.
  
  
  CONCLUSIONS
  The diurnal variation of Lp-PLA(2) mass and activity is similar to that of well accepted lipoprotein risk factors. With the relatively low diurnal variability, there does not appear to be a need to make sure serial measurements of Lp-PLA(2) mass and activity are taken at the same time of the day.
authors.affiliation: Ball State University, Human Performance Laboratory, Clinical Exercise Physiology Program, Muncie, IN 47306, USA. kaminskyla@bsu.edu
authors.forename: Leonard A
authors.initials: LA
authors.lastname: Kaminsky
authors.forename: Cemal
authors.initials: C
authors.lastname: Ozemek
mesh_terms: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase / Q000097:blood*; D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000097:blood; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012307:Risk Factors; D013997:Time Factors
chemical_list: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase