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

BACKGROUND AND OBJECTIVE: High lipoprotein(a) [Lp(a)] levels are a risk factor for atherosclerotic cardiovascular disease (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 personal ICD-10 diagnosis of ASCVD, aortic valve stenosis, resistant hypercholesterolemia (low-density lipoprotein cholesterol >160 mg/dL on statin therapy), and family history of ASCVD or high Lp(a). 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/ethnicity, socioeconomic score (based on zip codes), public health coverage and the presence of Lp(a) orders. RESULTS: 4% of our cohort (N=2,249 in 56,833) had an Lp(a) order (17.3% of whom identified as Hispanic, 8.7% non-Hispanic Black, 47.5% non-Hispanic White, and 27% Asian/other). Non-Hispanic Black and Hispanic patients had lower rates of Lp(a) orders (0.17% and 0.28%, respectively) when compared to non-Hispanic White patients (2.35%), p < 0.001, however, their median Lp(a) levels were higher, p < 0.001. Individuals on Medicaid or belonging to deprived socioeconomic groups were less likely to have an Lp(a) order (incidence rate ratio [IRR] = 0.40, p < 0.001 and IRR = 0.39, p < 0.001 respectively). Certain diagnosis (carotid stenosis, family history of ASCVD and familial hypercholesterolemia) and multiple diagnoses (>2) resulted in more Lp(a) orders compared to only one diagnosis (p < 0.001). CONCLUSIONS: Lp(a) ordering is low in patients with or at risk for ASCVD. Non-Hispanic Black and Hispanic patients are less likely to have an Lp(a) order. Individuals on Medicaid and residing in socioeconomically deprived neighborhoods are less likely to have an Lp(a) order. Lp(a) orders depend on the type and number of patients’ diagnoses.