SEX DISPARITIES IN THE TREATMENT AND OUTCOMES OF FAMILIAL HYPERCHOLESTEROLEMIA

Familial hypercholesterolemia (FH), an inherited condition equally prevalent in males and females, is characterized by elevated low-density lipoprotein cholesterol (LDL-C) in the blood. If left untreated, FH leads to the development of premature atherosclerotic cardiovascular disease (ASCVD) and death. Many barriers to care in FH exist, which can result in low rates of diagnosis and suboptimal treatment and outcomes. Sex disparities have been identified as an important barrier to care in CVD, however their influence on treatment and lipid target achievement in FH remains to be explored.

Here we performed a longitudinal registry analysis of sex differences in treatment and lipid level achievement in Heterozygous FH (HeFH) patients at the MUHC. Patients were included in the study if they were diagnosed as either “definite”, “probable”, or “possible” FH based on the Simon-Broome criteria, Dutch Lipid Clinic Network criteria, or the new Canadian FH definition. Differences between males and females were calculated using a t-test or chi-squared test. There were 127 females and 162 males from the McGill FH Registry included in the analysis. The mean age at the initial clinic visit was 49±17 years for females and 45±16 years for males (p=0.04). First, we analyzed sex differences in lipid lowering medication use. At the most recent clinic visit, there were more males (89%) than females (76%) taking statins (p=0.7), and only 35% of females were on high-intensity statins, compared to 74% of males (p=0.002). Interestingly, statin intolerance was reported in 40% of females and 22% of males (p=0.02). We then examined guideline-recommended lipid target achievement between both sexes. At baseline, males and females had similar mean LDL-C levels of 6.9±2.2 mmol/L and 6.7±1.6 mmol/L respectively (p=0.7). Despite this, at the most recent visit, 55% of males reached a target LDL-C of ≤ 2.5 mmol/L compared to just 32% of females (p=0.02). As well, from baseline to most recent visit, females reduced their LDL-C by 51%, whereas males lowered their LDL-C by 62% (p=0.01). Thus, fewer females are reaching appropriate guideline-based target LDL-C levels compared to males.

Our analysis reveals a sex bias in FH patients in favour of males in regard to treatment intensity and lipid level target achievement. Identifying these imbalances will allow us to break down these barriers in care through educational initiatives and additional training, to improve quality of life and life expectancy of individuals with FH.