Screening for familial hypercholesterolemia in Sri Lanka: A laboratory-based multicenter study

Abstract

Background: Familial hypercholesterolemia (FH) is a genetic lipid disorder characterized by increased concentrations of low-density lipoprotein cholesterol (LDL-C) in the circulatory system, resulting in a markedly increased vulnerability in the development of atherosclerotic cardiovascular disease at an early age. The prevalence of FH in a Sri Lankan setting was identified in a tertiary hospital laboratory and a primary care family practice laboratory by performing opportunistic screening for index cases using laboratory criteria as a starting point. Methodology: This study assessed the prevalence of FH using the Dutch Lipid Clinic Network (DLCN) Criteria score. The evaluation was conducted over 6 months in both a tertiary hospital laboratory and a primary care laboratory. Once patients were identified by high LDL, the patients were recruited to the study and assessed clinically. Secondary causes were excluded, and clinical evaluations of the patients were done to see if they had clinical features of FH. Results: Of the total of 3039 serum lipid profiles that were reviewed, there were 42 (1.38%) lost to follow-up. There were 72 samples with high LDL (190 mg/dL) ≥4.9 mmol/L (190 mg/dL). Of the patients with LDL >4.9 mmol/L, 16 (0.52%) cases with identified secondary causes (untreated hypothyroidism [n = 13], nephrotic syndrome [n = 3], and no secondary investigations [n = 14]) were excluded. In total, the point prevalence of likely phenotypical FH based on DLCN (probable or confirmed) and an LDL-C >4.9 mmol/L was calculated as approximately 14/3039 (1:217). Conclusions: The point prevalence of FH in patients undergoing lipid profile testing in a tertiary hospital laboratory and a primary care laboratory was 1:217 which is comparable with the prevalence of FH in the general population in the world (based on 1 in 200–250). Based on the laboratory criteria, initiating screening for FH in resource-limited settings could be an effective screening strategy to identify patients with FH. Until national screening programs are established, the laboratory as an avenue to trigger screening for FH is useful in lower-middle-income countries like Sri Lanka.