Clinical and genetic characteristics of familial hypercholesterolemia patients with type 2 diabetes

Predictors of cardiovascular risk in familial hypercholesterolemia

PURPOSE OF REVIEW

Familial hypercholesterolemia is associated with an increased risk of cardiovascular disease. The current international guidelines of the main scientific societies consider that, all people with Familial Hypercholesterolemia have a high or very high cardiovascular risk. However, the occurrence of atherosclerotic cardiovascular disease is very heterogeneous in this population. Stratifying risk within people with familial hypercholesterolemia is essential to identify individuals who require intensive cholesterol-lowering therapies.

RECENT FINDINGS

In the last year, several studies have been published focusing on the contribution of diabetes to Familial Hypercholesterolemia, the role of stroke, as a manifestation of atherosclerotic disease, and the external validation of the SAFEHEART risk equation in the English population diagnosed with Familial Hypercholesterolemia.

SUMMARY

It is necessary the development of a tool that allows us to identify, in a simple, reproducible, and universal way, patients who may have a high risk of suffering a cardiovascular event and who are susceptible to more intensive treatments to reduce cholesterol levels.

Prevalence of Diabetes and Its Association with Atherosclerotic Cardiovascular Disease Risk in Patients with Familial Hypercholesterolemia: An Analysis from the Hellenic Familial Hypercholesterolemia Registry (HELLAS-FH)

Familial hypercholesterolemia (FH) and type 2 diabetes mellitus (T2DM) are both associated with a high risk of atherosclerotic cardiovascular disease (ASCVD). Little is known about the prevalence of T2DM and its association with ASCVD risk in FH patients. This was a cross-sectional analysis from the Hellenic Familial Hypercholesterolemia Registry (HELLAS-FH) including adults with FH (n = 1719, mean age 51.3 ± 14.6 years). Of FH patients, 7.2% had a diagnosis of T2DM. The prevalence of ASCVD, coronary artery disease (CAD), and stroke was higher among subjects with T2DM compared with those without (55.3% vs. 23.3%, 48.8% vs. 20.7%, 8.3% vs. 2.7%, respectively, p < 0.001). When adjusted for age, systolic blood pressure, smoking, body mass index, hypertension, waist circumference, triglyceride levels, high-density lipoprotein cholesterol levels, and gender, T2DM was significantly associated with prevalent ASCVD [OR 2.0 (95% CI 1.2−3.3), p = 0.004]. FH patients with T2DM were more likely to have undergone coronary revascularization than those without (14.2% vs. 4.5% for coronary artery bypass graft, and 23.9% vs. 11.5% for percutaneous coronary intervention, p < 0.001). T2DM is associated with an increased risk for prevalent ASCVD in subjects with FH. This may have implications for risk stratification and treatment intensity in these patients.

Cardiovascular Outcomes in Patients With Both Diabetes and Phenotypic Familial Hypercholesterolemia: A Nationwide Register-Based Cohort Study

OBJECTIVE

Patients with diabetes or familial hypercholesterolemia (FH) have an increased incidence of cardiovascular diseases compared with the population, but whether this risk is exacerbated in patients with combined traits is unknown.

RESEARCH DESIGN AND METHODS

In this Swedish nationwide, register-based cohort study, patients with diabetes were included between 2002 and 2020. Adjusted Cox proportional hazards models were used to assess the risk of cardiovascular events in patients with or without phenotypic FH (≥6 points for phenotypic FH according to Dutch Lipid Clinic Network criteria) compared with general population control subjects without diabetes as reference.

RESULTS

A total of 45,585 patients with type 1 diabetes (227,923 control subjects) and 655,250 patients with type 2 diabetes (655,250 control subjects) were followed for a median of 14.1 and 7.9 years, respectively. Of those, 153 and 7,197, respectively, had phenotypic FH. Compared with control subjects, patients with diabetes and phenotypic FH had higher risk of cardiovascular mortality (type 1: hazard ratio 21.3 [95% CI 14.6-31.0]; type 2: 2.40 [2.19-2.63]) and of a cardiovascular event (type 1: 15.1 [11.1-20.5]; type 2: 2.73 [2.58-2.89]). Further, patients with diabetes and phenotypic FH had higher LDL-cholesterol levels during observation (P < 0.05) and increased risk of all major cardiovascular outcomes (P < 0.0001) than patients with diabetes but without FH. The proportion receiving lipid-lowering treatment was higher in patients with phenotypic FH (P < 0.0001).

CONCLUSIONS

Patients with both diabetes and phenotypic FH are more at risk for adverse cardiovascular outcomes and have higher LDL-cholesterol levels despite receiving intensified lipid-lowering therapy.

Diabetes and Familial Hypercholesterolemia: Interplay between Lipid and Glucose Metabolism

Familial hypercholesterolemia (FH) is a genetic disease characterized by high low-density lipoprotein (LDL) cholesterol (LDL-c) concentrations that increase cardiovascular risk and cause premature death. The most frequent cause of the disease is a mutation in the LDL receptor (LDLR) gene. Diabetes is also associated with an increased risk of cardiovascular disease and mortality. People with FH seem to be protected from developing diabetes, whereas cholesterol-lowering treatments such as statins are associated with an increased risk of the disease. One of the hypotheses to explain this is based on the toxicity of LDL particles on insulin-secreting pancreatic β-cells, and their uptake by the latter, mediated by the LDLR. A healthy lifestyle and a relatively low body mass index in people with FH have also been proposed as explanations. Its association with superimposed diabetes modifies the phenotype of FH, both regarding the lipid profile and cardiovascular risk. However, findings regarding the association and interplay between these two diseases are conflicting. The present review summarizes the existing evidence and discusses knowledge gaps on the matter.

Comorbidities with Familial Hypercholesterolemia (FH): A Systematic Review

Familial hypercholesterolemia (FH) is linked to high levels of low-density lipoprotein cholesterol (LDL-C), atherosclerotic, and aortic stenosis to a lesser extent. We looked at the incidence of prevalent comorbid disorders other than cardiovascular disease (CVD), such as diabetes, chronic kidney disease (CKD), hypertension, and cancer in heterozygous FH (HeFH) patients. PubMed, Web of Science, and Google Scholar were searched systematically for studies reporting comorbidities in FH patients. Finally, 23 studies were included after excluding duplicates, papers with unrelated titles, reviews, abstracts, and papers with not sufficient data. Results showed that among the comorbidities that have been studied; FH patients had a greater prevalence of CKD. In terms of diabetes, the data are inconsistent, with some research indicating a higher prevalence of diabetes in FH patients and mostly indicating the opposite. Polymorphism study showed that hypertension has been linked to FH; however, the prevalence of the hypertensive subjects varies among FH groups. In comparison to the general population, cancer was found to have a lower or similar prevalence in FH patients. More research is needed in this area due to the variability of the results of the relationship between diabetes and FH and the small number of studies on cancer. In conclusion only CKD can be considered as an important and prevalent comorbidity in FH population after CVDs.

Impact of diabetes on coronary severity and cardiovascular outcomes in patients with heterozygous familial hypercholesterolaemia

AIMS

Type 2 diabetes mellitus (T2DM) is an independent risk factor for cardiovascular disease. However, the association between T2DM and coronary artery disease (CAD) in patients with heterozygous familial hypercholesterolaemia (HeFH) has not been thoroughly evaluated. Our study aimed to assess the effect of T2DM on CAD severity and hard cardiovascular endpoints in a HeFH cohort.

METHODS AND RESULTS

A total of 432 patients with HeFH with a molecular and/or clinical Dutch Lipid Clinic Network score ≥6 (definite and probable) were enrolled. Patients were divided into a T2DM group (n = 99) and a non-T2DM group (n = 333). The severity of coronary stenosis was assessed by the number of diseased vessels and Gensini, SYNTAX, and Jeopardy scores. Hard endpoints included a composite of non-fatal myocardial infarction, non-fatal stroke, and cardiac death. Cox regression and Kaplan-Meier analyses were used to evaluate the effect of T2DM on hard cardiovascular endpoints. The prevalence of CAD was higher in patients with T2DM compared with those without (96.0% vs. 77.5%, respectively; P < 0.001). Patients with T2DM demonstrated a greater number of diseased vessels (P = 0.029) and more severe coronary lesions with high Gensini, SYNTAX, and Jeopardy score tertiles (P = 0.031, P = 0.001, and P = 0.024, respectively). During a median of 3.75 years up to a maximum of 9 years of follow-up, hard endpoints occurred in 13 of 99 patients with T2DM and 16 of 333 without T2DM at baseline. Compared with patients without T2DM, patients with T2DM were at a significantly greater risk of hard endpoints [multivariate adjusted hazard ratio (HR) 2.32, 95% confidence interval (CI) 1.02-4.84; P = 0.025]. Additionally, patients with T2DM and good glucose control (HbA1c < 7.0%) were at a lower risk of hard endpoints compared with those with poor glucose control (HbA1c ≥ 7.0%, HR 0.08, 95% CI 0.01-0.56; P = 0.011).

CONCLUSION

We conclude that T2DM is an independent predictor of CAD severity when assessed by number of diseased vessels, Gensini, SYNTAX, Jeopardy scores, and hard cardiovascular endpoints, suggesting that T2DM could be further used for risk stratification of patients with HeFH.

Lipoprotein metabolism in familial hypercholesterolemia

Familial hypercholesterolemia (FH) is one of the most common genetic disorders in humans. It is an extremely atherogenic metabolic disorder characterized by lifelong elevations of circulating LDL-C levels often leading to premature cardiovascular events. In this review, we discuss the clinical phenotypes of heterozygous and homozygous FH, the genetic variants in four genes (LDLR/APOB/PCSK9/LDLRAP1) underpinning the FH phenotype as well as the most recent in vitro experimental approaches used to investigate molecular defects affecting the LDL receptor pathway. In addition, we review perturbations in the metabolism of lipoproteins other than LDL in FH, with a major focus on lipoprotein (a). Finally, we discuss the mode of action and efficacy of many of the currently approved hypocholesterolemic agents used to treat patients with FH, with a special emphasis on the treatment of phenotypically more severe forms of FH.

Clinical and genetic differences between heterozygous familial hypercholesterolemia patients with and without type 2 diabetes

INTRODUCTION AND OBJECTIVES

The lower prevalence of type 2 diabetes mellitus (T2DM) in patients with heterozygous familial hypercholesterolemia (HeFH) could explain why T2DM has not always been identified as an independent predictor of cardiovascular disease (CVD) in different familial hypercholesterolemia cohort studies. The aim of the present study was to evaluate clinical and genetic aspects of HeFH patients with T2DM in the dyslipidemia registry of the Spanish Arteriosclerosis Society.

METHODS

HeFH patients were classified according to the presence or absence of T2DM. The clinical, biochemical and genetic characteristics of the 2 groups were compared.

RESULTS

Of the 2301 patients with primary hypercholesterolemia included in the registry, 1724 with a probable or definite diagnosis according to the Dutch Lipid Clinic Network score were finally included. HeFH patients with T2DM had a higher rate of CVD and a less favorable lipid profile, with higher total cholesterol (366.9±86.7mg/dL vs 342.0±74.7mg/dL; mean difference 24.894; 95%CI, 5.840-43.949) and non-high-density lipoprotein cholesterol (316.9±87.8mg/dL vs 286.4±75.4mg/dL; mean difference 30.500; 95%CI, 11.211-49.790) levels. No significant differences were found between the groups concerning the specific type of HeFH-causing mutation (P=.720). After adjustment for major risk factors, logistic regression analysis confirmed a relationship between T2DM and the presence of CVD (OR, 2.01; 95%CI, 1.18-3.43; P=.010).

CONCLUSIONS

HeFH patients with T2DM have a higher rate of CVD and a less favorable lipid profile, regardless of genetic mutation type. In these patients, T2DM is associated with the presence of CVD.