| Abstract | Korištenje Friedewaldove jednadžbe za procjenu vrijednosti LDL kolesterola (LDL-K)
ne zahtjeva dodatni financijski trošak zbog čega se u laboratorijima diljem svijeta, pa
tako i u Republici Hrvatskoj, ona koristi više nego direktne metode za određivanje
vrijednosti LDL-K. Zbog svojih ograničenja, a i sukladno preporukama Europskog
društva za kardiologiju (ESC) iz 2021. godine potrebno ju je zamijeniti
Martin/Hopkinsovom ili Sampsonovom jednadžbom. Obzirom na razlike u procjeni
LDL-K korištenjem različitih jednadžbi i sukladno dobroj laboratorijskoj praksi
potrebno je provesti usporedbu metoda, što do sada još nije provedeno u Hrvatskoj.
Cilj istraživanja:
Ovim istraživanjem provesti će se usporedba vrijednosti LDL-K procijenjenih
Friedewaldovom, Martin/Hopkinsovom i Sampsonovom jednadžbom. Prema
dobivenim vrijednostima LDL-K utvrditi će se stupanj slaganja klasifikacije
bolesnika u skupine kardiovaskularnog rizika.
Ispitanici i metode:
Provedeno je retrospektivno istraživanje u Odjelu laboratorijske dijagnostike
Specijalne bolnice za medicinsku rehabilitaciju Varaždinske Toplice. Za potrebe ovog
istraživanja koristili su se isključivo rezultati ukupnog kolesterola, triglicerida, HDL-K i
LDL-K koji su zatraženi i dobiveni tijekom rutinske laboratorijske obrade bolesnika u
razdoblju od 01.01.2021. do 30.11.2023. i koji su dostupni u laboratorijskom
informacijskom sustavu (LIS). Ispitanici kojima je koncentracija triglicerida veća od
4,5 mmol/L isključeni su iz daljnjeg istraživanja (N=21). U ispitivanje je uključeno 655
ispitanika oba spola (291 muškaraca i 364 žena). Vrijednost LDL-K se procijenila
korištenjem Friedewaldove, Martin/Hopkinsove i Sampsonove jednadžbe.
Rezultati:
Usporedbom vrijednosti LDL-K određenog sa sve tri jednadžbe korištenjem BlandAltman metode i Passing-Bablok regresijske analize na sljedeći način: u cijelom
rasponu vrijednosti LDL-K, te unutar skupina podijeljenih prema terapijskim ciljnim
vrijednostima LDL-K (LDL-F) (≤ 1,3 mmol/L, 1,4 - 1,7 mmol/L, 1,8 - 2,5 mmol/L, 2,6
- 2,9 mmol/L, ≥ 3 mmol/L) definirane preporukama ECA/ESC utvrđena su statistički
značajna odstupanja pri čemu Friedewaldova jednadžba mjeri niže vrijednosti od
Martin/Hopkinsove i Sampsonove jednadžbe. Stupanj slaganja klasifikacije
ispitanika u pojedine skupine ovisno o vrijednosti LDL-K procijenjenog
Friedewaldovom i Martin/Hopkinsovom jednadžbom iznosi 0,94 (95%CI 0,92 –
0,95), odnosno 0,96 (95%CI 0,94 -0,97) kada se ispitanici klasificiraju ovisno o
vrijednosti LDL-K procijenjenog Friedewaldovom i Sampsonovom jednadžbom.
Zaključak:
Ovim ispitivanjem utvrđeno je da su prisutna statistički značajna odstupanja između
vrijednosti LDL-K procijenjenih s tri različite jednadžbe pri čemu Friedewaldova
jednadžba mjeri niže vrijednosti od Martin/Hopkinsove i Sampsonove jednadžbe.
Srednja vrijednost razlike raste s snižavanjem vrijednosti LDL-K i najveća odstupanja
su prisutna upravo kod vrijednosti LDL-K koje su važni terapijski ciljevi kod osoba s
velikim i vrlo velikim kardiovaskularnim rizikom. Procjena vrijednosti LDL-K
Friedewaldovom jednadžbom u tih osoba može dovesti do pogrešnog terapijskog
pristupa i posljedično do lošijeg kardiovaskularnog ishoda te ju je uputno zamijeniti
Martin/Hopkinsovom ili Sampsonovom jednadžbom. |
| Abstract (english) | The estimation of LDL cholesterol (LDL-C) using the Friedewald equation does not
require additional financial costs, therefore laboratories around the world, including
those in the Republic of Croatia, use it more than direct methods for determining the
value of LDL-C. Due to its limitations, and in accordance with the recommendations
of the European Society of Cardiology (ESC) from 2021, it should be replaced by the
Martin/Hopkins or Sampson equation. Considering the differences in the estimation
of LDL-C using different equations and in accordance with good laboratory practice,
it is necessary to perform method comparison, which has not yet been done in
Croatia.
Objectives:
This research will compare LDL-C values estimated by the Friedewald,
Martin/Hopkins and Sampson equations. According to the obtained LDL-C values,
the degree of agreement in the classification of patients into cardiovascular risk
groups will be determined.
Patients and Methods:
A retrospective study was conducted in the Department of Laboratory Diagnostics
of the Special Hospital for Medical Rehabilitation Varaždinske Toplice. For the
purposes of this study, only the results of total cholesterol, triglycerides, HDL-C and
LDL-C were used, which were requested and obtained during the routine laboratory
analysis in the period from 01/01/2021 until 30/11/2023 and which were available
within the laboratory information system (LIS). Subjects whose triglyceride
concentration was higher than 4.5 mmol/L were excluded from further research
(N=21). A total of 655 subjects (291 men and 364 women) were included in the
study. The concentration of LDL-C was estimated using the Friedewald,
Martin/Hopkins and Sampson equations.
Results:
By comparing the value of LDL-C estimated by all three equations using the BlandAltman method and Passing-Bablok regression analysis as follows: in the entire
range of LDL-C values, and within groups divided according to the therapeutic
target values of LDL-C (LDL-F) ( ≤ 1.3 mmol/L, 1.4 – 1.7 mmol/L, 1.8 – 2.5 mmol/L,
2.6 – 2.9 mmol/L, ≥ 3 mmol/L) defined by ECA/ESC recommendations statistically
significant differences were found, whereby the Friedewald equation measures
lower values than the Martin/Hopkins and Sampson equations. The degree of
agreement in the classification of subjects into individual groups depending on the
value of LDL-C estimated by Friedewald and Martin/Hopkins equation was 0.94
(95%CI 0.92 – 0.95) and 0.96 (95%CI 0.94 -0.97) when subjects are classified
depending on the value of LDL-C estimated by the Friedewald and Sampson
equation.
Conclusion:
This study determined that there were statistically significant differences between
LDL-C values estimated with three different equations, with the Friedewald equation
measuring lower values than the Martin/Hopkins and Sampson equations. The mean
value of the difference increases with lowering of LDL-C values, and the largest
deviations are present for LDL-C values, which are important therapeutic goals in
people with high and very high cardiovascular risk. The assessment of LDL-C values
by the Friedewald equation in these individuals may lead to a wrong therapeutic
approach and consequently to a worse cardiovascular outcome thus this equation
should be replaced by the Martin/Hopkins or Sampson equation. |
