Evaluation of an HPLC method for LDL-cholesterol determination in patients with various lipoprotein abnormalities in comparison with beta-quantification.
BACKGROUND
The main purpose of this study was to evaluate an HPLC method for LDL-cholesterol determination in the presence of abnormal lipoproteins.


METHODS
We compared LDL-cholesterol levels obtained by HPLC (HPLC-LDL), Friedewald (F-LDL), and beta-quantification (BQ-LDL) methods on 47 healthy volunteers and 50 outpatients with lipid disorders, including apolipoprotein E2/2 phenotype, cholesteryl ester transfer protein deficiency and lipoprotein lipase deficiency.


RESULTS
For the control group (n=50), the HPLC-LDL and the F-LDL correlated highly with the BQ-LDL (r=0.984 and 0.969, respectively), but the HPLC-LDL was lower than the BQ-LDL (mean bias: -4.0%, P<0.001). For the subjects with lipoprotein abnormalities, significant biases were found in HPLC-LDL for the hypertriglyceridemia (+25%, n=17, P<0.01), the hyper HDL (-15.2%, n=10, P<0.01) and the hyper lipoprotein(a) groups (-13.4%, n=12, P<0.001). The F-LDL was significantly higher than the BQ-LDL in the apolipoprotein E2/2 subjects (+92%, n=8, P<0.001), but not significantly different in other subjects with triglycerides <4000 mg/l.


CONCLUSIONS
There were several discrepancies in LDL-cholesterol levels determined by the HPLC and the BQ methods in samples with lipoprotein abnormalities. However, the HPLC method can be useful and informative for analysis of abnormal lipoproteins.
Okazaki
Mitsuyo
M
Tokyo Medical and Dental University, Ichikawa, Japan. okazaki.las@tmd.ac.jp
Usui
Shinichi
S
Nakamura
Masakazu
M
Yamashita
Shizuya
S
D008078:Cholesterol, LDL / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D050171:Dyslipidemias / Q000097:blood*; D006801:Humans; D008074:Lipoproteins / Q000097:blood*; D008297:Male; D015203:Reproducibility of Results; D014461:Ultracentrifugation / Q000379:methods
D008078:Cholesterol, LDL; D008074:Lipoproteins