Prevalence of clinical familial hypercholesterolaemia among patients with high cholesterol levels.

INTRODUCTION: Familial hypercholesterolaemia (FH) can be diagnosed using clinical criteria or by direct mutation identification. The prevalence of clinical FH in Danish lipid clinics remains unknown. The objective of this study was to explore the prevalence of clinical FH in patients admitted on suspicion of FH with plasma low-density lipoprotein cholesterol (LDL-C) concentration ≥ 5.0 mmol/l. METHODS: We reviewed the medical records of 653 patients consecutively (from 1 January 2013 to 1 May 2017) referred to the lipid clinic at Viborg Regional Hospital, Denmark. Patients with LDL-C concentration > 4.9 mmol/l were selected. Clinical FH was assessed using the Dutch Lipid Clinic Network (DLCN) and Simon Broome criteria. RESULTS: Using DLCN, 315 patients (median 82% (95% confidence interval (CI): 78-86%)) had possible FH, 33 patients (median 9% (95% CI: 6-11%)) had probable FH and 36 patients (median 9% (95% CI: 6-12%)) had definite FH. Thus, a total of 69 patients (median 18% (95% CI: 14-22%)) had probable/definite FH. Using the Simon Broome criteria, 284 (median 74% (95% CI: 70-78%)) patients did not have FH, 67 patients (median 17% (95% CI: 14-21%)) had possible FH and 33 patients (median 9% (95% CI; 6-11%)) had definite FH, resulting in a total of 100 (median 26% (95% CI: 22-30%)) patients having possible/definite FH. The concordance between DLCN and Simon Broome FH was high among patients with definite FH (> 90%), but low among patients with probable or possible FH. CONCLUSIONS: Clinical FH was common among patients with LDL-C concentration ≥ 5.0 mmol/l referred to a Danish lipid clinic. However, the concordance between the DLCN and the Simon Broome criteria was low in a specialised clinical setting. FUNDING: The study was supported by a SANOFI grant. TRIAL REGISTRATION: not relevant.