Impact of improved low-density lipoprotein cholesterol assessment on guideline classification in the modern treatment era-Results from a racially diverse Brazilian cross-sectional study

Background: The Martin/Hopkins low-density lipoprotein cholesterol equation (LDL-C_N) was previously demonstrated as more accurate than Friedewald LDL-C estimation (LDL-C_F) in a North American database not able to take race into account.

Objectives: We hypothesized that LDL-C_N would be more accurate than LDL-C_F and correlate better with LDL particle number (LDL-P) in a racially diverse Brazilian cohort.

Methods: We performed a cross-sectional analysis of 4897 participants in the Brazilian Longitudinal Study of Adult Health, assessing LDL-C_F and LDL-C_N accuracy via overlap with ultracentrifugation-based measurement among clinical guideline LDL-C categories as well as mg/dL and percent error differences. We analyzed by triglyceride categories and correlated LDL-C estimation with LDL-P.

Results: LDL-C_N demonstrated improved accuracy at 70 to <100 and <70 mg/dL (P < .001), with large errors ≥20 mg/dL about 9 times more frequent in LDL-C_F at LDL-C <70 mg/dL, mainly due to underestimation. Among individuals with LDL-C <70 mg/dL and triglycerides ≥150 mg/dL, 65% vs 100% of ultracentrifugation-based low-density lipoprotein cholesterol calculation fell within appropriate categories of estimated LDL-C_F and LDL-C_N, respectively (P < .001). Similar results were observed when analyzed for age, sex, and race. Participants at LDL-C <70 and 70 to <100 mg/dL with discordantly elevated LDL-C_N vs LDL-C_F had a 58.5% and 41.5% higher LDL-P than those with concordance (P < .0001), respectively.

Conclusions: In a diverse Brazilian cohort, LDL-C_N was more accurate than LDL-C_F at low LDL-C and high triglycerides. LDL-C_N may avoid underestimation of LDL-C and better reflect atherogenic lipid burden in low particle size, high particle count states.