Open Access

Low-density lipoprotein cholesterol estimation by the Anandaraja's formula – confirmation

Lipids in Health and Disease20065:18

DOI: 10.1186/1476-511X-5-18

Received: 03 May 2006

Accepted: 29 June 2006

Published: 29 June 2006

Abstract

The number of the indirect methods for LDL-C estimation is growing. Our result support the reliability of new Anandaraja's formula for low-density lipoprotein estimation from total cholesterol and triglycerides.

Gazi et al [1] presented results of evaluation the accuracy of various formulas for the calculation of low-density lipoprotein cholesterol (LDL-C) levels – indirect methods – in patients with the metabolic syndrome. LDL-C according Friedewald's formula showed significant differences from other formulas in the total cohort, as well as in patients with metabolic syndrome. Different plasma lipid and lipoprotein analytical techniques – direct methods, however, yield results, which are highly correlated, yet significantly different, too [2].

It is possible to supplement next calculation. Anandaraja et al [3] published new formula for LDL-C estimation from two other parameters, total cholesterol and triglycerides, as substitution to well known Friedewald's formula.

Our team recently compared two methods of estimation of low-density lipoprotein cholesterol, the direct Wako method versus Friedewald's formula [4]. We studied over 10 000 consecutive patients with different diseases, from mixed rural and urban Brazil population.

We re-counted our data with Anandaraja's formula. Main results are expressed in Table 1. Direct LDL-C and LDL-C calculated from Anandaraja's formula shows substantial better correlation in both total population (r = 0,969) and patients with triglyceride <350 mg/dl (r = 0,974) by comparison with calculated according to the Friedewald's formula (r = 0,924 and r = 0,935).
Table 1

Low-density lipoprotein cholesterol level

Particulars

Total population

Patients with triglycerides

<350 mg/dl (3,94 mmol/l)

Total sample number

10 324

10 102

Direct low-density lipoprotein cholesterol (mg/dl; mmol/l)

116 ± 22 (2,99 ± 0,57)

115 ± 22 (2,97 ± 0,57)

Calculated low-density lipoprotein cholesterol (mg/dl; mmol/l)*

120 ± 24 (3,10 ± 0,62)

119 ± 23 (3,08 ± 0,59)

Calculated low-density lipoprotein cholesterol (mg/dl; mmol/l)†

115 ± 23 (2,97 ± 0,59)

114 ± 21 (2,95 ± 0,54)

Difference between direct low-density lipoprotein cholesterol and calculated low-density lipoprotein cholesterol (mg/dl)*

- 4 ± 16

- 4 ± 14

Difference between direct low-density lipoprotein cholesterol and calculated low-density lipoprotein cholesterol (mg/dl) †

1 ± 14

1 ± 14

Correlation coefficient between direct low-density lipoprotein cholesterol and calculated low-density lipoprotein cholesterol*

0,924

0,935

Correlation coefficient between direct low-density lipoprotein cholesterol and calculated low-density lipoprotein cholesterol†

0,969

0,974

All measurements are expressed in mg/dl (mmol/l) and results are presented as mean ± S.D. Pearson's correlation coefficient used. Direct LDL-C measured with Wako method – for details see Ref. [4].

* Calculated low-density lipoprotein cholesterol from Friedewald's formula

† Calculated low-density lipoprotein cholesterol from new Anandaraja's equation

In each very low-density lipoprotein particle secreted from the liver, and therefore in each intermediate-density lipoprotein, low-density lipoprotein and lipoprotein (a) particles, a single molecule of apolipoprotein B (apo B) is present from the time of its assembly to its catabolism, which does not exchange between lipoproteins. More than 90% of apo B is in the low-density lipoprotein particles, and therefore, plasma total concentration of apo B can be considered as a measure of the number of atherogenic particles. New Anandaraja's equation takes into account only total cholesterol and triglycerides. Some authors recommend including apo B measurement as acomponent of the standard lipoprotein measurements performed to assess cardiovascular disease risk [5]. Contribution of LDL-C calculation with help of measured apo B is questionable. Apo B is real an independent risk factor.

In conclusion, LDL-C is the major indicator for initial classification of coronary heart disease risk status and lowering its level is a primary goal of therapy. The NCEP Working Group on Lipoprotein Measurement recommended the development of accurate direct low-density lipoprotein cholesterol methods. All available direct methods have yet limitations for general use. Our results support the reliability of Anandaraja's formula as indirect low-density lipoprotein cholesterol estimation – originally used in Indian population – in Brazil population, too.

Declarations

Acknowledgements

I would like to thank to the contributions Prof de Cordova, University of Blumenau, Blumenau, State Santa Catarina, Brazil.

Authors’ Affiliations

(1)
LABMED, a.s., clinical laboratory, University Hospital L. Pasteur

References

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Copyright

© Gasko; licensee BioMed Central Ltd. 2006

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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