The prevalence of familial hypercholesterolemia in the West Siberian region of the Russian Federation: A substudy of the ESSE-RF

BACKGROUND The prevalence of familial hypercholesterolemia (FH) in Russia has not previously been evaluated. The aim of our study was to investigate the prevalence of FH in the population of the West Siberian region of Russia, and then estimate the frequency of coronary artery disease (CAD) and treatment with cholesterol-lowering medication in FH patients. METHODS The sample of our study consisted of participants from the population-based cohort of The Epidemiology of Cardiovascular Risk Factors and Diseases in Regions of the Russian Federation Study (ESSE-RF), conducted in the Tyumen and Kemerovo regions (1,630 and 1,622 people, respectively, aged 25-64). All participants who had LDL-cholesterol higher than 4.9 mmol/l and who had LDL-cholesterol less than or equal to 4.9 mmol/l but had statin therapy were examined and interviewed by experts in FH. RESULTS The prevalence of patients with definite FH was 0.24% (one in 407) (95% confidence interval [CI]: 0.06%-0.42%), with probable FH was 0.68% (one in 148) (95% CI: 0.38%-0.98%), and with definite or probable FH combined was 0.92% (one in 108) (95% CI: 0.58%-1.26%). 40% (95% CI: 20.8%-59.2%) of patients with definite or probable FH had CAD. However, only 23% (95% CI: 6.3%-39.7%) of patients with definite or probable FH were on statins. The odds ratios for CAD and myocardial infarction (MI), adjusted for age, gender, region, smoking, hypertension, and diabetes mellitus, were 3.71 (95% CI: 1.58-8.72) (p = 0.003) and 4.06 (95% CI: 0.89-18.55) (р = 0.070) respectively for individuals with definite or probable FH relative to those who were unlikely to have FH. CONCLUSIONS The prevalence of FH in Russia may be significantly higher than previously estimated. There is underdiagnosis and undertreatment of FH in Russia.