Evaluation of the Frequency of Familial Hypercholesterolemia: A Single-Center Experience

Objective: Familial hypercholesterolemia is an autosomal dominant disease associated with elevated low-density lipoprotein cholesterol and increased premature atherosclerosis. In the general population, the frequency of familial hypercholesterolemia has been calculated to be between 1/500-1/200. Although the frequency of familial hypercholesterolemia belonging to different countries has been elaborately reported, the data from Turkey remains insufficient. We aimed to determine the frequency and characteristics of familial hypercholesterolemia in patients from Turkey by screening and analyzing the low-density lipoprotein cholesterol data. Material and Methods: Between May 2017-May 2018, 20151 laboratory records from individuals elaborately admitted to outpatient clinics for any reason were screened retrospectively, and 430 patients with low-density lipoprotein cholesterol levels >= 190 mg/dL were included in the study. Results: We observed a secondary cause (secondary hyperlipidemia, the SH group) in 163 patients and familial hypercholesterolemia in 267 patients (1.32%, the familial hypercholesterolemia group) in patients representing our population. The ratio of female to male participants was higher (76.4% vs. 58.4%) and their mean age was significantly higher in the SH group than in the familial hypercholesterolemia group (56.8 +/- 13.6 vs 47.1 +/- 17.0 years; both p<0.001). Total cholesterol and triglyceride concentrations were higher in the SH group compared to those in the familial hypercholesterolemia group (319.6 +/- 65.1 vs 306.8 +/- 57.6 mg/dL, p=0.003, and 436.8 +/- 308.8 vs 136.0 +/- 55.9 mg/dL, p<0.001, respectively). There was no difference between the two groups in terms of atherosclerotic diseases. Conclusion: The frequency of familial hypercholesterolemia (1/76) in the region we studied was higher than in other societies. Therefore, the diagnosis of familial hypercholesterolemia should be considered in subjects with low-density lipoprotein cholesterol above 190 mg/dL, especially in young males. Early diagnosis is especially important for the prevention of adverse cardiovascular events in patients and their family members.