Extreme LDL-C concentration is associated with increased cardiovascular disease in women with homozygous familial hypercholesterolemia.

Abstract

Background: Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disease of low-density lipoprotein cholesterol (LDL-C) metabolism. Despite the devastating effect of this disease on atherosclerotic cardiovascular health, the disease phenotype and severity are more heterogeneous than previously thought. The predictors of atherosclerotic cardiovascular disease (ASCVD) in HoFH patients have never been systematically studied.

Objective: To investigate the univariate and multivariate predictors of ASCVD in HoFH patients.

Methods: Patients from the Canadian HoFH Registry were included in the present retrospective longitudinal study. Data for these patients were collected using a standardized questionnaire between 2019 and 2022 in 19 academic sites across Canada. Predictors of ASCVD were evaluated using Cox proportional hazards models.

Results: Among 48 HoFH patients, 26 (54 %) of them had at least one ASCVD event. The average age at baseline was 19 ± 15 years and women represented 56 % of the cohort. The independent predictors of ASCVD events were male sex (HR 2.57 (1.13-5.84)), diabetes (HR 16.22 (3.38-77.97)), and LDL-C above the median of 14.45 mmol/L [559 mg/dL] (HR 3.10 (1.24-7.76)). When performing subgroup analysis according to sex, the presence of LDL-C above median was associated with a significantly higher probability of ASCVD (88 % vs. 43 %, p = 0.005) in women, but not in men (100 % at age 40 in both groups, p = 0.98).

Conclusion: This study reported for the first time the univariate and multivariate predictors of ASCVD in HoFH patients. We demonstrate that predictors of ASCVD in HoFH differ in males and females with respect to LDL-C levels.