The very high cardiovascular risk in heterozygous familial hypercholesterolemia: Analysis of 734 French patients.

BACKGROUND: Heterozygous familial hypercholesterolemia (heFH) is a genetic disease causing high levels of low-density lipoprotein cholesterol (LDL-C). Although this population is at high cardiovascular (CV) risk, the risk is variable within patients depending on additional risk factors. CV disease risk groups have been defined by the Nouvelle Société Francophone d'Athérosclérose (NSFA) and by the National Lipid Association recommendations. OBJECTIVES: The study aimed to describe a sample of French heFH patients, comparing patients at very high risk (VHR) and patients at high risk in terms of demographic and clinical characteristics as well as biological measurements and disease management. METHODS: Cross-sectional retrospective analysis on 734 patients hospitalized after 2005 in 5 academic centers. RESULTS: When considering NSFA classification, 550 (74.9%) patients belonged to the VHR group. Most patients in the VHR group presented more than 1 risk factor, the most prevalent ones being Lp(a) > 50 mg/dL and smoking. Patients in the VHR group were older (50.6 vs 45.0 years old, P = .0002), and presented a higher body mass index (25.5 kg/m(2) vs 23.3 kg/m(2), P < .0001). The proportion of patients with carotid arterial plaque was higher in the VHR group (59.8% vs 48.6%, P = .06). Total cholesterol (2.41 g/L on average) and LDL-C (1.65 g/L on average) were not found to be significantly different. Maximum level of lipid-lowering treatments were used in 34% of cases in the VHR group, significantly higher than 16% in the high-risk group (P = .001). Very similar results were found when using the National Lipid Association recommendations. CONCLUSION: This study provides a detailed description of French heFH patients according to their CV risk. Patients with very high CV risk had usually more advanced carotid plaques and were treated with heavier lipid-lowering drugs although their LDL-C level remained similar. This highlights the significant burden of this population.

Hormonal contraception in women at risk of vascular and metabolic disorders: guidelines of the French Society of Endocrinology.

Hormonal contraceptive methods are widely used in France, including not only oral estrogen-progestin combinations but also non-oral estrogen-progestin delivery methods (patches, vaginal rings), as well as oral forms, implants and intra-uterine devices that deliver only a progestin. Hormonal contraception has only a modest impact on lipid and carbohydrate metabolism, but estrogen-progestin contraceptives have been linked to a variety of vascular risks. Overall, the risk of venous thrombosis is multiplied by a factor of about 4, depending on age, the compounds used, and other risk factors (including biological thrombophilia and a personal history of thrombosis), whereas the risk of arterial events is only increased in women with risk factors. Available data suggest there is no excess risk with progestin-based contraceptives, but far fewer studies have been conducted. At the initiative of the French Society of Endocrinology, an expert group met in 2010 in order to reach a consensus on the use of hormonal contraceptive methods in women with vascular or metabolic risk factors, based on available data and international guidelines published by WHO in 2009 and subsequently adapted to the United States context. The following text, intentionally limited to hormonal contraception, is intended to serve as a guide when prescribing in specific clinical situations, such as a family or personal history of arterial or venous thromboembolism, or the existence of cardiovascular risk factors (hypertension, smoking, diabetes, dyslipidemia, obesity).

Intronic mutations outside of Alu-repeat-rich domains of the LDL receptor gene are a cause of familial hypercholesterolemia.

Familial hypercholesterolemia (FH), a frequent monogenic condition complicated by premature cardiovascular disease, is characterized by high allelic heterogeneity at the low-density lipoprotein receptor ( LDLR) locus. Despite more than a decade of genetic testing, knowledge about intronic disease-causing mutations has remained limited because of lack of available genomic sequences. Based on the finding from bioinformatic analysis that Alu repeats represent 85% of LDLR intronic sequences outside exon-intron junctions, we designed a strategy to improve the exploration of genomic regions in the vicinity of exons in 110 FH subjects from an admixed population. In the first group of 42 patients of negative mutation carriers, as previously established by former screening strategies (denaturing gradient gel electrophoresis, DNA sequencing with former primers overlapping splice-sites, Southern Blotting), about half ( n=22) were found to be carriers of at least one heterozygous mutation. Among a second group of 68 newly recruited patients, 27% of mutation carriers ( n=37) had a splicing regulatory mutation. Overall, out of the 54 mutations identified, 13 were intronic, and 18 were novel, out of which nearly half were intronic. Two novel intronic mutations (IVS8-10G-->A within the polypyrimidine tract and IVS7+10G-->A downstream of donor site) might create potential aberrant splice sites according to neural-network computed estimation, contrary to 31 common single nucleotide variations also identified at exon-intron junctions. This new strategy of detecting the most likely disease-causing LDLR mutations outside of Alu-rich genomic regions reveals that intronic mutations may have a greater impact than previously reported on the molecular basis of FH.