Comparing calculated LDL-C with directly measured LDL-C in healthy and in dyslipidemic children.
BACKGROUND
LDL-C is one of the strongest markers for atherosclerosis and therapeutic decisions in children are based on its levels. Friedewald formula (FF) which is usually used for the calculation of LDL-C (cLDL-C); and Anandaraja's formula (AF) may under- or overestimate actual levels.


OBJECTIVE
To compare cLDL-C with directly measured LDL-C (dLDL-C) as a screening tool and to evaluate dyslipidemic children.


METHODS
The study population consisted of 1005 children, 2-18years, 688 of whom underwent lipid screening in a regular check-up (group A); and 317 were dyslipidemic (LDL-C ≥130mg/dl) (group B). A fasting serum lipid profile was assessed. LDL-C was measured using a homogenous assay and was calculated using FF and AF.


RESULTS
Each method of calculating LDL-C was highly correlated to dLDL-C. Using FF, cLDL-C was lower than dLDL-C in 75.6% (group A) and in 77.3% (group B) of children; the mean difference was significant in dyslipidemic group. Moreover, in group B, 25% of children with boundary high and 12% with high dLDL-C would be misclassified. Using AF, LDL-C was higher than dLDL-C; the mean difference was significant in group A. Based on cLDL-C, 52% of group A with borderline dLDL-C and 27.5% of group B children with boundary high dLDL-C would be considered as dyslipidemic and eligible for medication respectively.


CONCLUSIONS
Comparing two methods of calculated LDL-C with directly measured LDL-C. FF was more accurate as a screening tool while AF was more accurate in the evaluation and follow-up of the dyslipidemic group.
Second Department of Pediatrics, National and Kapodistrian University of Athens, Medical School, "P & A Kyriakou" Children's Hospital, Athens, Attica, Greece.
Anastasia
A
Garoufi
Biochemistry Laboratory, "P & A Kyriakou" Children's Hospital, Athens, Attica, Greece.
Antonis
A
Drakatos
Laboratory of Clinical Biochemistry - Molecular Diagnostics, Second Department of Pediatrics, National and Kapodistrian University of Athens, Medical School, "P & A Kyriakou" Children's Hospital, Athens, Attica, Greece.
Charalampos
C
Tsentidis
Second Department of Pediatrics, National and Kapodistrian University of Athens, Medical School, "P & A Kyriakou" Children's Hospital, Athens, Attica, Greece.
Eleni
E
Klinaki
Department of Clinical Microbiology, "P & A Kyriakou" Children's Hospital, Athens, Attica, Greece.
Irene
I
Paraskakis
Laboratory of Clinical Biochemistry - Molecular Diagnostics, Second Department of Pediatrics, National and Kapodistrian University of Athens, Medical School, "P & A Kyriakou" Children's Hospital, Athens, Attica, Greece.
Antonios
A
Marmarinos
Laboratory of Clinical Biochemistry - Molecular Diagnostics, Second Department of Pediatrics, National and Kapodistrian University of Athens, Medical School, "P & A Kyriakou" Children's Hospital, Athens, Attica, Greece. Electronic address: dgourg@med.uoa.gr.
Dimitrios
D
Gourgiotis
D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D050171:Dyslipidemias / Q000097:blood*; D005260:Female; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood*; D008297:Male
D008077:Lipoproteins, LDL
Anandaraja's formula; Children; Direct measurement; Dyslipidemia; Friedewald equation; LDL-C; Overestimation; Underestimation