Comparison of modified Friedewald’s formula with direct measurement of low-density lipoprotein cholesterol in Bangladeshi population

Abstract

A modification of Friedewald’s formula to estimate serum low-density lipoprotein cholesterol (LDLC) up to serum triglyceride (TG) level of 11.3 mmol/L in Bangladeshi population has recently been published. The aim of this study was to compare the modified formula with direct measurement of LDLC in Bangladeshi population in a different setting. One thousand and fifty two specimens from adult subjects were analyzed. Serum total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), LDLC and TG were measured by standard methods. The modified Friedewald’s formula was applied to estimate LDL cholesterol concentration. Results were expressed as mean ± SD and calculated LDLC was compared with measured LDLC by two-tailed paired t test, Bland-Altman plot for absolute bias, Pearson’s correlation coefficients of calculated LDLC with measured LDLC and Passing & Bablok regression equation of calculated LDLC against measured LDLC. The mean ± SD of measured LDLC was 2.98±0.82 mmol/L. LDLC calculated by modified Friedewald’s formula was 2.77±0.86 mmol/L. The mean absolute bias was –0.20±0.32 mmol/L, Pearson’s correlation coefficient (r) was 0.9293 (P<0.0001) and Passing & Bablok regression equation was y= – 0.3856+1.0597x for modified formula up to serum TG?11.3 mmol/L. Compared to original Friedewald’s formula, performance of the modified Friedewald’s formula was better up to serum TG?4.52 mmol/L. The study reveals that the modified Friedewald’s formula may be used to calculate LDLC approximately in Bangladeshi population. DOI: http://dx.doi.org/10.3329/bmrcb.v39i3.20312 Bangladesh Med Res Counc Bull 2013; 39: 120-123

Evaluation of the Novel Method and the Regression Equation for Calculation of Low-Density Lipoprotein Cholesterol

“…The underestimation of LDL-chol calculated by FF is also common in Bangladeshi population [17][18][19][20][21][22][23] and there is no evidence of systematic overestimation of LDLchol by FF in this population. [17][18][19][20][21][22][23] Till now only one regression equation (RE) has been developed and validated externally in our population.…”

“…The underestimation of LDL-chol calculated by FF is also common in Bangladeshi population [17][18][19][20][21][22][23] and there is no evidence of systematic overestimation of LDLchol by FF in this population. [17][18][19][20][21][22][23] Till now only one regression equation (RE) has been developed and validated externally in our population. 23 Recently, a novel method 24 has been developed using continuously adjustable ratio of TG/VLDL-cholesterol rather than a fixed factor as in Friedewald formula 6 , DeLong modification 25 or other formulas [26][27][28][29][30] Fig.…”

Derivación y validación de una ecuación para estimar el colesterol ligado a lipoproteínas de baja densidad en una población de Lima, Perú

“…En el total de sujetos del estudio, la fórmula de Friedewald y la nueva ecuación infraestimaron el LDLc, obtenién-dose sesgos absolutos de 14,01 mg/dL y 5,52 mg/dL, respectivamente, resultados que coinciden con otros estudios que también utilizaron el análisis de regresión múltiple para derivar su ecuación, pero validado en otra población (22,23) .…”

“…En nuestro estudio, de las 2 508 determinaciones de LDLc, 52,8% y 25,5% de las estimaciones por la fórmula de Friedewald y la nueva ecuación, respectivamente, presentaron una diferencia porcentual mayor a ±12% con respecto al método directo, lo que evidencia un menor error de estimación de la nueva ecuación a comparación de la fórmula de Friedewald para estimar el LDLc, resultados que concuerdan con los estudios realizados por Saiedullah y Chowdhury en una población de Bangladesh (23,28) .…”

Evaluation of Recently Developed Regression Equation with Direct Measurement of Low-density Lipoprotein Cholesterol in a Bangladeshi Population

“…Like the underestimation reported in different population, the underestimation of LDL cholesterol calculated by FF is also common in Bangladeshi population [18][19][20][21][22][23][24][25] and there is no evidence of systematic overestimation of LDL cholesterol by FF in this population. [18][19][20][21][22][23][24] In 2014 Saiedullah et al published a regression equation by analyzing lipid profiles of 531 adult Bangladeshi subjects which was validated externally using lipid profiles of 952 Bangladeshi subjects using linear regression. 24 Subsequently it has been evaluated using another set of lipid profiles collected from the setting of external validation group of the previous study.…”