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Measuring Low Density Lipoprotein Cholesterol: Comparison of Direct Measurement by HiSens Reagents and Friedewald Estimation.

Lee SY, Hahm SK, Park JA, Choi SK, Yoon JY, Choi SH, Jeon KS - Korean J Fam Med (2015)

Bottom Line: For more than 10 mg/dL of their absolute differences, the DLDLC was typically lower than the CLDLC.Unlike other studies, DLDLC was significantly lower than CLDLC and the large differences in LDLC concentrations were not dependent on TG concentration.Our work suggests that verification of DLDLC accuracy is needed and differences in LDLC measurements should be accounted for in making clinical decisions.

View Article: PubMed Central - PubMed

Affiliation: Department of Family Medicine, The KEPCO Medical Center, Seoul, Korea.

ABSTRACT

Background: Directly measured low density lipoprotein cholesterol (DLDLC) has been reported to be more accurate than calculated low density lipoprotein cholesterol (CLDLC) using the Friedewald equation. However, some limitations of DLDLC have been reported. In this study, we evaluated differences between CLDLC and DLDLC measured using HiSens reagents.

Methods: Data were collected from 582 persons undergoing routine physical examinations at a general hospital. LDLC measurements were made directly or estimated using the Friedewald formula, and were classified according to the National Cholesterol Education Program's Adult Treatment Panel III guidelines. The relationship between these differences and other clinically relevant factors, such as triglyceride (TG) levels, were examined using multiple logistic regression analysis.

Results: The DLDLC and CLDLC were strongly correlated according to simple linear regression analysis (r=0.917, P<0.001) but the mean difference between measurements was -11.0±15.3 (-62 to 90.5) mg/dL (P<0.001). For more than 10 mg/dL of their absolute differences, the DLDLC was typically lower than the CLDLC. The highest discrepancies in LDLC measurements occurred when LDLC was more than 160 mg/dL and less than 190 mg/dL. Differences in LDLC measurements were prone to striking negative and positive biases dependent on CLDLC and TG concentrations, respectively (all r>0.5).

Conclusion: Unlike other studies, DLDLC was significantly lower than CLDLC and the large differences in LDLC concentrations were not dependent on TG concentration. Our work suggests that verification of DLDLC accuracy is needed and differences in LDLC measurements should be accounted for in making clinical decisions.

No MeSH data available.


Related in: MedlinePlus

Correlation of DLDLC values measured using the HiSens reagent and DLDLC values measured using the Beckman Coulter 5821 analyzer and dedicated reagent. Y=0.962X+1.175, r=0.996, r2=0.992, P<0.001 for simple linear regression (solid line). Dotted line: 95% confidence interval. DLDLC, direct low density lipoprotein cholesterol.
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Figure 4: Correlation of DLDLC values measured using the HiSens reagent and DLDLC values measured using the Beckman Coulter 5821 analyzer and dedicated reagent. Y=0.962X+1.175, r=0.996, r2=0.992, P<0.001 for simple linear regression (solid line). Dotted line: 95% confidence interval. DLDLC, direct low density lipoprotein cholesterol.

Mentions: Among other factors, TC and HDLC were negatively correlated with the difference in LDLC measurements, while glucose was slightly positively correlated (simple linear regression) (Figure 3). The multiple logistic regression analysis showed that high glucose, glomerular filtration rate, and high CLDLC were significantly associated with high LDL differences (Table 3). Lipid lowering medications were also associated with high differences in LDL measurements, but the statistical significance was slightly low (P=0.054). Additionally, current smoking, coronary calcium score, high TC, and high TG were significantly associated with very high LDL differences, but the goodness of fit for the logistic regression was slightly low (P=0.047, estimated by the Hosmer-Lemeshow test). The HiSens DLDLC concentrations were strongly correlated the with Beckman Coulter DLDLC measurements (simple linear regression, r≥0.975) (Figure 4).


Measuring Low Density Lipoprotein Cholesterol: Comparison of Direct Measurement by HiSens Reagents and Friedewald Estimation.

Lee SY, Hahm SK, Park JA, Choi SK, Yoon JY, Choi SH, Jeon KS - Korean J Fam Med (2015)

Correlation of DLDLC values measured using the HiSens reagent and DLDLC values measured using the Beckman Coulter 5821 analyzer and dedicated reagent. Y=0.962X+1.175, r=0.996, r2=0.992, P<0.001 for simple linear regression (solid line). Dotted line: 95% confidence interval. DLDLC, direct low density lipoprotein cholesterol.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4515509&req=5

Figure 4: Correlation of DLDLC values measured using the HiSens reagent and DLDLC values measured using the Beckman Coulter 5821 analyzer and dedicated reagent. Y=0.962X+1.175, r=0.996, r2=0.992, P<0.001 for simple linear regression (solid line). Dotted line: 95% confidence interval. DLDLC, direct low density lipoprotein cholesterol.
Mentions: Among other factors, TC and HDLC were negatively correlated with the difference in LDLC measurements, while glucose was slightly positively correlated (simple linear regression) (Figure 3). The multiple logistic regression analysis showed that high glucose, glomerular filtration rate, and high CLDLC were significantly associated with high LDL differences (Table 3). Lipid lowering medications were also associated with high differences in LDL measurements, but the statistical significance was slightly low (P=0.054). Additionally, current smoking, coronary calcium score, high TC, and high TG were significantly associated with very high LDL differences, but the goodness of fit for the logistic regression was slightly low (P=0.047, estimated by the Hosmer-Lemeshow test). The HiSens DLDLC concentrations were strongly correlated the with Beckman Coulter DLDLC measurements (simple linear regression, r≥0.975) (Figure 4).

Bottom Line: For more than 10 mg/dL of their absolute differences, the DLDLC was typically lower than the CLDLC.Unlike other studies, DLDLC was significantly lower than CLDLC and the large differences in LDLC concentrations were not dependent on TG concentration.Our work suggests that verification of DLDLC accuracy is needed and differences in LDLC measurements should be accounted for in making clinical decisions.

View Article: PubMed Central - PubMed

Affiliation: Department of Family Medicine, The KEPCO Medical Center, Seoul, Korea.

ABSTRACT

Background: Directly measured low density lipoprotein cholesterol (DLDLC) has been reported to be more accurate than calculated low density lipoprotein cholesterol (CLDLC) using the Friedewald equation. However, some limitations of DLDLC have been reported. In this study, we evaluated differences between CLDLC and DLDLC measured using HiSens reagents.

Methods: Data were collected from 582 persons undergoing routine physical examinations at a general hospital. LDLC measurements were made directly or estimated using the Friedewald formula, and were classified according to the National Cholesterol Education Program's Adult Treatment Panel III guidelines. The relationship between these differences and other clinically relevant factors, such as triglyceride (TG) levels, were examined using multiple logistic regression analysis.

Results: The DLDLC and CLDLC were strongly correlated according to simple linear regression analysis (r=0.917, P<0.001) but the mean difference between measurements was -11.0±15.3 (-62 to 90.5) mg/dL (P<0.001). For more than 10 mg/dL of their absolute differences, the DLDLC was typically lower than the CLDLC. The highest discrepancies in LDLC measurements occurred when LDLC was more than 160 mg/dL and less than 190 mg/dL. Differences in LDLC measurements were prone to striking negative and positive biases dependent on CLDLC and TG concentrations, respectively (all r>0.5).

Conclusion: Unlike other studies, DLDLC was significantly lower than CLDLC and the large differences in LDLC concentrations were not dependent on TG concentration. Our work suggests that verification of DLDLC accuracy is needed and differences in LDLC measurements should be accounted for in making clinical decisions.

No MeSH data available.


Related in: MedlinePlus