Isfahan familial hypercholesterolemia cohort (IFHC) study: Methods, insights and early results

Familial hypercholesterolemia (FH) is the most common monogenic disorder in humans. There is a lack of data on the clinical characteristics and natural history of FH patients in Iran, which necessitates performing a longitudinal study.

In this five-year prospective longitudinal cohort study, we enrolled patients with high LDL cholesterol who were registered in the Iranian Registry of Hypercholesterolemia (IFHR), diagnosed as definite and probable FH cases based on the Dutch Lipid Clinic Network Score (DLCN ≥6). General characteristics, lipid profiles, and cardiovascular disease assessments were evaluated in the baseline phase, and whole blood samples were stored for future genetic and epigenetic studies. This study will evaluate the incidence and recurrence rates of cardiovascular disease (CVD) and mortality as the main outcomes during five years of follow-up.

During the initial year, we successfully identified and enrolled patients with FH. We are reporting the whole methodology and the results of the first 50 who were followed up. At the study's outset, the patients exhibited a mean age of 50.27±12.06 years, with 64% being men and 36% women. The mean LDL level recorded was 312.8 ±106.3 mg/dL, with the highest LDL concentration observed at 623.5 mg/dL. A total of 62.0% of patients were on lipid-lowering treatment mostly of the PCAD group.

In this paper, we present the design and methodology of the Isfahan Familial Hypercholesterolemia Cohort (IFHC) study in detail with the aim of helping future research generate evidence from comprehensive IFHC data sources.