In an international cohort of patients with homozygous familial hypercholesterolemia (HoFH), the incidence of myocardial infarction (MI) was higher in men than women, but no difference was found between men and women for the age when HoFH was diagnosed or when the first atherosclerotic cardiovascular disease (ASCVD) event occurred, according to a study published Feb. 14 in JAMA Cardiology.

Janneke W. C. M. Mulder, MD, et al., conducted sex-specific analyses to examine differences in age at diagnosis, risk factors, lipid-lowering treatment (LLT), and ASCVD morbidity and mortality in patients with HoFH using data from 751 patients (389 women and 362 men) in the HoFH International Clinical Collaborators (HICC) registry, which includes patients from 88 institutions across 38 countries. Data in HICC were collected from February 2016 and December 2020 and analyzed from June 2022 to June 2023.

Results showed similarities between women and men for the age at the time of HoFH diagnosis (13 years vs. 11 years), untreated LDL-C levels (mean 579 mg/dL vs. 596 mg/dL), and prevalence of cardiovascular risk factors (except smoking) (38 of 266 women vs. 59 of 217 men). The prevalence of MI was lower in women (31 of 389 [8.0%]) than men (59 of 362 [16.3%]). Notably, the age at first MI was similar in women and men (39 and 38 years, respectively).

Also similar between women and men were treated LDL-C levels as well as LLT, especially statins (248 of 276 women [89.9%] vs. 235 of 258 men [91.1%]) and lipoprotein apheresis (115 of 317 women [36.3%] vs. 118 of 304 men [38.8%]).

Researchers also found that 16 years after HoFH diagnosis, women compared with men, had a statistically significant lower cumulative incidence of MI (5.0% vs. 13.7%, respectively), along with nonsignificant lower incidence of all-cause mortality (3.0% vs. 4.1%) and cardiovascular mortality (2.6% vs. 4.1%).

In what the authors note is the first study to assess sex differences in patients with HoFH, to their knowledge, they write, “The findings indicate that both women and men with HoFH have a very high risk of premature ASCVD, suggesting that early diagnosis and treatment are important steps in attenuating excessive cardiovascular risk in both sexes.”