Race/ethnicity and socioeconomic status affect the assessment of lipoprotein(a) levels in clinical practice.

Background and Objective: High Lp(a) levels are a risk factor for ASCVD, however Lp(a) ordering in clinical practice is low. This study examines how race/ethnicity and socioeconomic status influence Lp(a) ordering. Methods: This is a single center, retrospective study (2/1/2020-6/30/2023) using electronic medical records of adults with at least one ICD-10 diagnosis of ASCVD or resistant hyperlipidemia (LDL-C >160 mg/dL on statin therapy). We evaluated Lp(a) level differences among racial/ethnic groups and sexes. We also assessed associations between diagnosis type, diagnosis number, age at diagnosis, race, socioeconomic score (based on zip codes), public health coverage and presence of Lp(a) orders. Results: 4% of our cohort (N=56,833) had an Lp(a) order (17.3% Hispanic, 8.7% non-Hispanic Black, 47.5% non-Hispanic White and, 27% Asian/others). Non-Hispanic Black and Hispanic patients had lower rates of Lp(a) orders (0.17%, 0.28%, respectively) when compared to non-Hispanic White patients (2.35%), p<0.001, however, their median Lp(a) levels were higher. Individuals belonging to deprived socioeconomic groups or on Medicaid, were less likely to have an Lp(a) order (RR=0.39, p<0.001 and RR=0.40, p<0.001 respectively). Certain diagnoses (carotid stenosis, family history of ASCVD and FH) and multiple diagnoses (>2) resulted in more Lp(a) orders compared to those with only one diagnosis (p<0.001). Conclusions: Lp(a) ordering is low in patients with ASCVD. Non-Hispanic Black and Hispanic patients at risk are less likely to have an Lp(a) order. Individuals residing in socioeconomically deprived neighborhoods and on Medicaid are also less like have Lp(a) order. Lp(a) orders depend on the type and number of patients' diagnoses.