Increased FH-Risk-Score and Diabetes Are Cardiovascular Risk Equivalents in Heterozygous Familial Hypercholesterolemia

Evaluation of glycemic status and subclinical atherosclerosis in familial hypercholesterolemia subjects with or without LDL receptor mutation

BACKGROUND

Familial hypercholesterolemia (FH) is a genetic condition characterized by elevated LDL-C and increased cardiovascular risk. Beyond LDL-C levels, the impact of genotype on glucose homeostasis has not been well evaluated. We aimed to evaluate the impact of genotype on glycemic status and on atherosclerotic injury in FH subjects.

METHODS

We conducted a cross-sectional study on 322 FH subjects not on lipid-lowering therapy and without history of cardiovascular disease. Biochemical and genetic analyses as well as vascular profile assessment were obtained from all subjects. The study population was divided into two groups according to genotype: LDL receptor (LDLR) group and non-LDLR (NLDLR) group.

RESULTS

The LDLR group exhibited a higher prevalence of low glycemic status (LGS) than the NLDLR group (44.1% vs. 26%, p < 0.01), whereas a high glycemic status (HGS) was more prevalent in the NLDLR group compared with LDLR group (74% vs. 55.9%, p < 0.01). The NLDLR group exhibited a higher prevalence of peripheral atherosclerotic plaques than the LDLR group (93.4% vs. 73%, p < 0.05), while coronary artery calcification (CAC) presence was more prevalent in the LDLR group compared with the NLDLR group (74.7% vs. 48%, p < 0.01). In a secondary analysis the study population was stratified into three groups based on LDLR genotype: NLDLR, LDLR defective, LDLR null groups. The prevalence of LGS progressively increased from the NLDLR to the LDLR null group, while HGS showed an inverse trend (p for trend < 0.05). Peripheral atherosclerotic plaque prevalence decreased from the NLDLR to the LDLR null group (p for trend < 0.05), while CAC prevalence increased progressively in the three groups (p for trend < 0.01). Logistic regression analysis showed that FH groups with an LDLR mutation were inversely associated with HGS (p for both < 0.01) and the LDLR null group exhibited the strongest association.

CONCLUSIONS

FH subjects with NLDLR mutations exhibited a worse glycemic profile, while null LDLR mutations showed the strongest inverse association with HGS. The integrations of genetic, lipid and glucose data could be useful to better identify the metabolic profile and the atherosclerosis distribution in FH subjects.

RESEARCH INSIGHTS

WHAT IS CURRENTLY KNOWN ABOUT THIS TOPIC?: Familial hypercholesterolemia (FH) is characterized by elevated LDL-C levels. LDLR null mutations protected pancreatic β-cells from cholesterol accumulation. NGS has improved FH diagnosis by analysis of all genes implicated in the lipid disorder. WHAT IS THE KEY RESEARCH QUESTION?: What is the impact of FH genotype (monogenic with or without LDLR mutation/polygenic) on glycemic status? WHAT IS NEW?: FH population was characterized by a heterogeneous glycemic profile according to LDLR mutation. LDL-C and plasma glucose could modulate the distribution of subclinical atherosclerosis. HOW MIGHT THIS STUDYINFLUENCE CLINICAL PRACTICE?: Genetic, lipid, glucose data could better identify the metabolic and atherosclerotic profiles in FH.

Extreme LDL-C concentration is associated with increased cardiovascular disease in women with homozygous familial hypercholesterolemia

BACKGROUND

Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disease of low-density lipoprotein cholesterol (LDL-C) metabolism. Despite the devastating effect of this disease on atherosclerotic cardiovascular health, the disease phenotype and severity are more heterogeneous than previously thought. The predictors of atherosclerotic cardiovascular disease (ASCVD) in HoFH patients have never been systematically studied.

OBJECTIVE

To investigate the univariate and multivariate predictors of ASCVD in HoFH patients.

METHODS

Patients from the Canadian HoFH Registry were included in the present retrospective longitudinal study. Data for these patients were collected using a standardized questionnaire between 2019 and 2022 in 19 academic sites across Canada. Predictors of ASCVD were evaluated using Cox proportional hazards models.

RESULTS

Among 48 HoFH patients, 26 (54%) of them had at least 1 ASCVD event. The average age at baseline was 19 ± 15 years and women represented 56% of the cohort. The independent predictors of ASCVD events were male sex (HR 2.57 [1.13-5.84]), diabetes (HR 16.22 [3.38-77.97]), and LDL-C above the median of 14.45 mmol/L (559 mg/dL) (HR 3.10 [1.24-7.76]). When performing subgroup analysis according to sex, the presence of LDL-C above the median was associated with a significantly higher probability of ASCVD (88% vs 43%, P = .005) in women, but not in men (100% at age 40 in both groups, P = .98).

CONCLUSION

This study reported for the first time the univariate and multivariate predictors of ASCVD in HoFH patients. We demonstrate that predictors of ASCVD in HoFH differ in males and females with respect to LDL-C levels.

Familial hypercholesterolemia-Plus: is the metabolic syndrome changing the clinical picture of familial hypercholesterolemia?

PURPOSE OF REVIEW

The purpose of this review article was to describe recent advances in our knowledge about how diabetes and metabolic syndrome are changing the face of familial hypercholesterolemia.

RECENT FINDINGS

Heterozygous familial hypercholesterolemia, most commonly caused by disruption to LDL receptor function, leads to lifelong elevation of LDL cholesterol and increased risk of atherosclerotic cardiovascular disease. Familial hypercholesterolemia was originally described as a form of 'pure' hypercholesterolemia, in the sense that levels of LDL were uniquely affected. Studies of familial hypercholesterolemia among individuals of predominantly Western European descent conformed to the perception that individuals with familial hypercholesterolemia tended to be lean and otherwise metabolically healthy. More recently, as we have studied familial hypercholesterolemia in more diverse global populations, we have learned that in some regions, rates of diabetes and obesity among familial hypercholesterolemia patients are very high, mirroring the global increases in the prevalence of metabolic disease.

SUMMARY

When diabetes and metabolic disease coexist, they amplify the cardiovascular risk in familial hypercholesterolemia, and may require more aggressive treatment.

Peripheral artery disease: an underdiagnosed condition in familial hypercholesterolemia? A systematic review

PURPOSE

Familial hypercholesterolemia (FH) is one of the most common inherited diseases characterized by elevated LDL-cholesterol levels, leading to early-onset atherosclerosis. While the association between FH and coronary and carotid artery disease is well-established, its association with peripheral artery disease (PAD) is less robust. This systematic review aims at exploring existing evidence on PAD prevalence and incidence in FH individuals.

METHODS

A comprehensive search was conducted on MEDLINE and Embase databases, for studies published between January 2013 and December 2023, evaluating prevalence and incidence of PAD in FH patients. Literature reviews, case reports, responses to editors and non-English language articles were excluded.

RESULTS

The initial research provided 53 results. After article screening, 28 articles were fully reviewed and 24 were finally included in the analysis. Among these, 19 reported PAD prevalence, while 5 PAD incidence over a mean follow-up time of 8.7 years. PAD prevalence and incidence ranged from 0.3 to 60% and from 0.5 to 4.2% respectively, probably reflecting the heterogeneity in PAD definition criteria.

CONCLUSION

This systematic review sheds light on the limited number of studies on PAD in FH patients. Particularly, considering the potential positive effects of newly available lipid-lowering strategies on PAD outcomes, addressing this research gap is pivotal for a more comprehensive understanding of peripheral vascular manifestations in FH patients and for optimal management of this population.

Genetic Counseling and Genetic Testing for Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is one of the most common autosomal codominant Mendelian diseases. The major complications of FH include tendon and cutaneous xanthomas and coronary artery disease (CAD) associated with a substantial elevation of serum low-density lipoprotein levels (LDL). Genetic counseling and genetic testing for FH is useful for its diagnosis, risk stratification, and motivation for further LDL-lowering treatments. In this study, we summarize the epidemiology of FH based on numerous genetic studies, including its pathogenic variants, genotype-phenotype correlation, prognostic factors, screening, and usefulness of genetic counseling and genetic testing. Due to the variety of treatments available for this common Mendelian disease, genetic counseling and genetic testing for FH should be implemented in daily clinical practice.