title: Inaccuracy of lipid measurements with the portable Cholestech L.D.X analyzer in patients with hypercholesterolemia.
abstract: BACKGROUND
  Although total cholesterol concentrations measured by portable lipid analyzers have acceptable bias and precision in young and middle-aged adults, clinically relevant differences in HDL-cholesterol (HDL-C) and triglyceride values have been described. Furthermore, the accuracy of portable lipid analyzers in older hyperlipidemic individuals, who have a high incidence of coronary heart disease, has not been validated. This study determined the biases and variability in portable lipid measurements in older patients with hypercholesterolemia and related them to National Cholesterol Education Program Adult Treatment Panel III guidelines.
  
  
  METHODS
  Participants were > or =70 years of age with fasting serum LDL-cholesterol (LDL-C) concentrations > 1.40 g/L. Fasting fingerstick samples were analyzed on a Cholestech L.D.X desktop analyzer. Antecubital venous samples were analyzed in a proficiency-certified clinical laboratory.
  
  
  RESULTS
  Portable measurements systematically overestimated triglycerides (0.296 g/L; P <0.001) and HDL-C (0.015 g/L; P = 0.026). LDL-C concentrations were underestimated (0.043 g/L; P = 0.046). Total and non-HDL cholesterol calculations based on the portable lipid device provided unbiased estimates, but wide variability was present. Significant variability in lipid determinations limited their clinical usefulness in individual patients, especially because 2 SD of the mean bias between the laboratory and the portable determinations of LDL-C and non-HDL cholesterol exceeded the 0.30 g/L cutoff that defines treatment targets in the current lipid guidelines.
  
  
  CONCLUSIONS
  Lipid values obtained from portable lipid analyzers may be useful for screening, but they should not be used to make clinical decisions regarding the diagnosis and management of dyslipidemia in individual patients.
authors.affiliation: University of Wisconsin Medical School, Madison, WI 53792, USA.
authors.forename: James H
authors.initials: JH
authors.lastname: Stein
authors.forename: Cynthia M
authors.initials: CM
authors.lastname: Carlsson
authors.forename: Kristi
authors.initials: K
authors.lastname: Papcke-Benson
authors.forename: Jean A
authors.initials: JA
authors.lastname: Einerson
authors.forename: Patrick E
authors.initials: PE
authors.lastname: McBride
authors.forename: Donald A
authors.initials: DA
authors.lastname: Wiebe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001774:Blood Chemical Analysis / Q000295:instrumentation; D001800:Blood Specimen Collection; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D005215:Fasting; D006801:Humans; D006937:Hypercholesterolemia / Q000097:blood / Q000175:diagnosis*; D008055:Lipids / Q000097:blood*; D008875:Middle Aged; D009313:National Health Programs; D017410:Practice Guidelines as Topic; D014280:Triglycerides / Q000097:blood; D014481:United States
chemical_list: D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D008055:Lipids; D014280:Triglycerides