Abstract
Background: Low-density lipoprotein cholesterol (LDL-C) concentrations are the primary therapeutic target in patients with atherosclerotic cardiovascular disease (ASCVD). However, at low LDL-C concentrations, there is a significant underestimation using the Friedewald equation compared with ultracentrifugation. Methods: In this pilot study, we compared LDL-C concentrations obtained using the Friedewald equation (LDL-F) vs those concentrations from a direct LDL-C (LDL-D) assay in 152 consecutive specimens from patients with triglyceride levels between 200-399 mg/dL and LDL-F <100 mg/dL. Also, we compared LDL-F and LDL-D results to the novel formula (LDL-N). Results: The LDL-F value was significantly lower than that of LDL-D when LDL concentrations were 70-99 mg/dL (P <.001, 14% negative bias), and this decrease was accentuated in specimens with LDL <70 mg/dL, (P <.001, 27% negative bias). When compared with the LDL-N value, LDL-F and LDL-D values showed a 17% and 2% negative bias for specimens with LDL-C values of 70-99 mg/dL and 36% and 1% negative bias, respectively, at LDL-C <70 mg/dL (P <.001 for comparisons of LDL-F and LDL-N values). Conclusions: To provide accurate LDL-C levels in patients at high risk for ASCVD, if beta quantification by ultracentrifugation is unavailable and if LDL-C is <100 mg/dL and triglycerides are 200-399 mg/dL, laboratories should revert to direct LDL-C measurements or use the novel formula. Although LDL-N is more cost-effective, LDL-D can be run on most platforms, does not require a specimen from a fasting individual, is standardized, and has the advantage of being validated in large trials such as the Heart Protection Study.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 220-224 |
| Number of pages | 5 |
| Journal | Lab Medicine |
| Volume | 48 |
| Issue number | 3 |
| DOIs | |
| State | Published - Aug 1 2017 |
| Externally published | Yes |
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Keywords
- Direct LDL-cholesterol
- Friedewald equation
- Heart disease
- Homogenous assays
- LDL
- Triglycerides
ASJC Scopus subject areas
- Clinical Biochemistry
- Biochemistry, medical
Cite this
Underestimation of low density lipoprotein-cholesterol with the friedewald equation versus a direct homogenous low density lipoprotein-cholesterol assay. / Jialal, Ishwarlal; Inn, Michael; Siegel, David; Devaraj, Sridevi.
In: Lab Medicine, Vol. 48, No. 3, 01.08.2017, p. 220-224.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Underestimation of low density lipoprotein-cholesterol with the friedewald equation versus a direct homogenous low density lipoprotein-cholesterol assay
AU - Jialal, Ishwarlal
AU - Inn, Michael
AU - Siegel, David
AU - Devaraj, Sridevi
PY - 2017/8/1
Y1 - 2017/8/1
N2 - Background: Low-density lipoprotein cholesterol (LDL-C) concentrations are the primary therapeutic target in patients with atherosclerotic cardiovascular disease (ASCVD). However, at low LDL-C concentrations, there is a significant underestimation using the Friedewald equation compared with ultracentrifugation. Methods: In this pilot study, we compared LDL-C concentrations obtained using the Friedewald equation (LDL-F) vs those concentrations from a direct LDL-C (LDL-D) assay in 152 consecutive specimens from patients with triglyceride levels between 200-399 mg/dL and LDL-F <100 mg/dL. Also, we compared LDL-F and LDL-D results to the novel formula (LDL-N). Results: The LDL-F value was significantly lower than that of LDL-D when LDL concentrations were 70-99 mg/dL (P <.001, 14% negative bias), and this decrease was accentuated in specimens with LDL <70 mg/dL, (P <.001, 27% negative bias). When compared with the LDL-N value, LDL-F and LDL-D values showed a 17% and 2% negative bias for specimens with LDL-C values of 70-99 mg/dL and 36% and 1% negative bias, respectively, at LDL-C <70 mg/dL (P <.001 for comparisons of LDL-F and LDL-N values). Conclusions: To provide accurate LDL-C levels in patients at high risk for ASCVD, if beta quantification by ultracentrifugation is unavailable and if LDL-C is <100 mg/dL and triglycerides are 200-399 mg/dL, laboratories should revert to direct LDL-C measurements or use the novel formula. Although LDL-N is more cost-effective, LDL-D can be run on most platforms, does not require a specimen from a fasting individual, is standardized, and has the advantage of being validated in large trials such as the Heart Protection Study.
AB - Background: Low-density lipoprotein cholesterol (LDL-C) concentrations are the primary therapeutic target in patients with atherosclerotic cardiovascular disease (ASCVD). However, at low LDL-C concentrations, there is a significant underestimation using the Friedewald equation compared with ultracentrifugation. Methods: In this pilot study, we compared LDL-C concentrations obtained using the Friedewald equation (LDL-F) vs those concentrations from a direct LDL-C (LDL-D) assay in 152 consecutive specimens from patients with triglyceride levels between 200-399 mg/dL and LDL-F <100 mg/dL. Also, we compared LDL-F and LDL-D results to the novel formula (LDL-N). Results: The LDL-F value was significantly lower than that of LDL-D when LDL concentrations were 70-99 mg/dL (P <.001, 14% negative bias), and this decrease was accentuated in specimens with LDL <70 mg/dL, (P <.001, 27% negative bias). When compared with the LDL-N value, LDL-F and LDL-D values showed a 17% and 2% negative bias for specimens with LDL-C values of 70-99 mg/dL and 36% and 1% negative bias, respectively, at LDL-C <70 mg/dL (P <.001 for comparisons of LDL-F and LDL-N values). Conclusions: To provide accurate LDL-C levels in patients at high risk for ASCVD, if beta quantification by ultracentrifugation is unavailable and if LDL-C is <100 mg/dL and triglycerides are 200-399 mg/dL, laboratories should revert to direct LDL-C measurements or use the novel formula. Although LDL-N is more cost-effective, LDL-D can be run on most platforms, does not require a specimen from a fasting individual, is standardized, and has the advantage of being validated in large trials such as the Heart Protection Study.
KW - Direct LDL-cholesterol
KW - Friedewald equation
KW - Heart disease
KW - Homogenous assays
KW - LDL
KW - Triglycerides
UR - http://www.scopus.com/inward/record.url?scp=85028505390&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85028505390&partnerID=8YFLogxK
U2 - 10.1093/labmed/lmx023
DO - 10.1093/labmed/lmx023
M3 - Article
C2 - 28398496
AN - SCOPUS:85028505390
VL - 48
SP - 220
EP - 224
JO - Laboratory Medicine
JF - Laboratory Medicine
SN - 0007-5027
IS - 3
ER -