Association of Monogenic vs Polygenic Hypercholesterolemia With Risk of Atherosclerotic Cardiovascular Disease

The clinical applicability of polygenic risk scores for LDL-cholesterol: considerations, current evidence and future perspectives

PURPOSE OF REVIEW

The current review describes the development, clinical relevance and potential caveats of polygenic risk scores (PRS) for LDL cholesterol (LDL-C).

RECENT FINDINGS

In recent years, a large number of common variants have been shown to have a small effect on LDL-C levels. The aggregate effect of all of these variants on LDL-C levels can be captured in a PRS and an elevated number of LDL-C increasing common variants is considered to be a cause of high LDL-C levels in patients with familial hypercholesterolemia (FH) without a large effect, rare mutation. PRS do not only serve as a tool in diagnostics, but are also helpful in cardiovascular disease (CVD) risk prediction. Moreover, PRS modulate CVD risk even in patients without a monogenic FH. However, future larger scale PRS directly aimed at CVD risk may serve as more sensitive tools to identify individuals with severely increased CVD risk.

SUMMARY

LDL-C PRS help explain part of hypercholesterolemia in a proportion of dyslipidemic patients that do not have monogenic FH. Nevertheless, the CVD risk conferred by current PRS does not appear to match that of monogenic FH. LDL-C PRS are currently not widely used in clinical care.

Personalized medicine in lipid-modifying therapy

The choice of lipid-modifying treatment is largely based on the absolute level of cardiovascular risk and baseline lipid profile. Statins are the first-line treatment for most patients requiring reduction of low-density-lipoprotein cholesterol (LDL-C) and ezetimibe and proprotein convertase subtilisin/kexin type 9 inhibitors can be added to reach LDL-C targets. Statins have some adverse effects that are somewhat predictable based on phenotypic and genetic factors. Fibrates or omega-3 fatty acids can be added if triglyceride levels remain elevated. The RNA-targeted therapeutics in development offer the possibility of selective liver targeting for specific lipoproteins such as lipoprotein(a) and long-term reduction of LDL-C with infrequent administration of a small-interfering RNA may help to overcome the problem of adherence to therapy.

Development of genome-wide polygenic risk scores for lipid traits and clinical applications for dyslipidemia, subclinical atherosclerosis, and diabetes cardiovascular complications among East Asians

Background

The clinical utility of personal genomic information in identifying individuals at increased risks for dyslipidemia and cardiovascular diseases remains unclear.

Methods

We used data from Biobank Japan (n = 70,657–128,305) and developed novel East Asian-specific genome-wide polygenic risk scores (PRSs) for four lipid traits. We validated (n = 4271) and subsequently tested associations of these scores with 3-year lipid changes in adolescents (n = 620), carotid intima-media thickness (cIMT) in adult women (n = 781), dyslipidemia (n = 7723), and coronary heart disease (CHD) (n = 2374 cases and 6246 controls) in type 2 diabetes (T2D) patients.

Results

Our PRSs aggregating 84–549 genetic variants (0.251 < correlation coefficients (r) < 0.272) had comparably stronger association with lipid variations than the typical PRSs derived based on the genome-wide significant variants (0.089 < r < 0.240). Our PRSs were robustly associated with their corresponding lipid levels (7.5 × 10^− 103 < P < 1.3 × 10^− 75) and 3-year lipid changes (1.4 × 10^− 6 < P < 0.0130) which started to emerge in childhood and adolescence. With the adjustments for principal components (PCs), sex, age, and body mass index, there was an elevation of 5.3% in TC (β ± SE = 0.052 ± 0.002), 11.7% in TG (β ± SE = 0.111 ± 0.006), 5.8% in HDL-C (β ± SE = 0.057 ± 0.003), and 8.4% in LDL-C (β ± SE = 0.081 ± 0.004) per one standard deviation increase in the corresponding PRS. However, their predictive power was attenuated in T2D patients (0.183 < r < 0.231). When we included each PRS (for TC, TG, and LDL-C) in addition to the clinical factors and PCs, the AUC for dyslipidemia was significantly increased by 0.032–0.057 in the general population (7.5 × 10^− 3 < P < 0.0400) and 0.029–0.069 in T2D patients (2.1 × 10^− 10 < P < 0.0428). Moreover, the quintile of TC-related PRS was moderately associated with cIMT in adult women (β ± SE = 0.011 ± 0.005, P_trend = 0.0182). Independent of conventional risk factors, the quintile of PRSs for TC [OR (95% CI) = 1.07 (1.03–1.11)], TG [OR (95% CI) = 1.05 (1.01–1.09)], and LDL-C [OR (95% CI) = 1.05 (1.01–1.09)] were significantly associated with increased risk of CHD in T2D patients (4.8 × 10^− 4 < P < 0.0197). Further adjustment for baseline lipid drug use notably attenuated the CHD association.

Conclusions

The PRSs derived and validated here highlight the potential for early genomic screening and personalized risk assessment for cardiovascular disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-021-00831-z.

Serum Urate Polygenic Risk Score Can Improve Gout Risk Prediction: A Large-Scale Cohort Study

Gout is a painful inflammatory arthritis affecting more than 8 million Americans. Identifying high-risk patients in early life could potentially encourage people to adopt lifestyle changes to prevent gout. Polygenic risk score (PRS) provides an overall estimate of an individual's genetic liability to develop a disease and can be used for early identification of high-risk individuals. In this study, we validated a previously reported PRS in an independent cohort. The urate-PRS was constructed from 110 significant urate-associated variants identified in Europeans. Phenome-wide and PRS-wide association study showed the urate-PRS is highly specifically associated with gout (phecode: 274.10; beta = 1.495 [1.372, 1.619], p = 4.37e-124). Urate-PRS alone did not performed in the gout prediction (area under the receiver operating characteristic curve, AUROC = 0.640); however, the addition of PRS upon demographics significantly improved the model performance, yielding an AUROC of 0.804 from 0.777 (DeLong test p = 3.66e−9). Trans-ethnic PRS and European-specific PRS showed similar prediction performance. We observed increasing gout prevalence and odds ratio (OR) across the PRS quintiles. Our study showed 8.2% of the cohort had more than 2.5 odds for gout than remainders, indicating that urate-PRS may be a better marker than age and sex to stratify patient risk. With the rapid growth of large biorepositories, such as All of Us, urate-PRS can be applied quickly and widely in population to estimate individual's risk, providing a powerful tool for gout preventive purpose in population health.

Polygenic Risk Score for Low-Density Lipoprotein Cholesterol Is Associated With Risk of Ischemic Heart Disease and Enriches for Individuals With Familial Hypercholesterolemia

BACKGROUND

The clinical implications of a polygenic risk score (PRS) for LDL-C (low-density lipoprotein cholesterol) are not well understood, both within the general population and individuals with familial hypercholesterolemia (FH).

METHODS

We developed the LDL-C PRS using Least Absolute Shrinkage and Selection Operator regression in 377 286 White British participants from UK Biobank and tested its association with LDL-C according to FH variant carrier status in another 41 748 whole-exome sequenced individuals. Next, we tested for an enrichment of FH variant carriers among individuals with severe hypercholesterolemia and low LDL-C PRS. Last, we contrasted the effect of the LDL-C PRS, measured LDL-C and FH variant carrier status on risk of ischemic heart disease among 3010 cases and 38 738 controls.

RESULTS

Among the 41 748 whole-exome sequenced White British individuals, 1-SD increase in the LDL-C PRS was associated with elevated LDL-C among both FH variant carriers (0.34 [95% CI, 0.22-0.47] mmol/L) and noncarriers (0.42 [95% CI, 0.42-0.43] mmol/L). Among individuals with severe hypercholesterolemia, FH variant carriers were enriched in those with a low LDL-C PRS (odds ratio, 2.20 [95% CI, 1.66-2.71] per SD). Each SD increase in the LDL-C PRS was associated with risk of ischemic heart disease to the comparable magnitude as measured LDL-C (odds ratio, 1.24 [95% CI, 1.20-1.29] and odds ratio, 1.15 [95% CI, 1.09-1.23], respectively). The LDL-C PRS was not strongly associated with other traditional ischemic heart disease risk factors.

CONCLUSIONS

An LDL-C PRS could be used to identify individuals with a higher probability of harboring FH variants. The association between ischemic heart disease and the LDL-C PRS was comparable to measured LDL-C, likely because the PRS reflects lifetime exposure to LDL-C levels.

Association of KATP Gene Polymorphisms with Dyslipidemia and Ischemic Stroke Risks Among Hypertensive Patients in South China

ATP-sensitive potassium channels (KATP) couple vascular reactivity and metabolism with ischemic protection which makes them potential targets for prevention and management of ischemic stroke (IS). This study investigates the potential association between KATP polymorphisms and hypertension (HTN), dyslipidemia, and consequently ischemic stroke (IS). Nine hundred and fourteen (914) patients genotyped for KATP polymorphisms (rs2285676, rs1799858, rs4148671, rs61928479, and rs141294036) were analyzed. KATP rs141294036 (CC, adjusted OR = 1.59, 95%CI: 1.17-2.14, P = 0.003) was related to higher HTN risk. Meanwhile, rs2285676 (AA + GA, adjusted OR = 1.53, 95%CI: 1.08-2.19, P = 0.018) was associated with increased triglyceride level (≥ 1.7 mmol/L). rs2285676 (AA + GA, adjusted OR = 1.80, 95% CI: 1.24-2.61, P = 0.002), rs1799858 (TT + CT, adjusted OR = 1.68, 95% CI: 1.17-2.42, P = 0.005), and rs141294036 (TT + CT, adjusted OR = 1.90, 95% CI: 1.30-2.78, P = 0.001) were related to increased low-density lipoprotein cholesterol (≥ 1.8 mmol/L). rs2285676 (AA + GA, adjusted OR = 2.57, 95% CI: 1.74-3.82, P < 0.001) and rs141294036 (TT + CT, adjusted OR = 1.93, 95% CI: 1.27-2.93, P = 0.002) were related to increased apolipoprotein B (≥ 65 mg/dL). In addition, the 5 KATP polymorphisms were non-correlated with three types of dyslipidemia (total cholesterol, high-density lipoprotein cholesterol, and apolipoprotein AI). After median 50.6 month of follow-up, participants carrying CC genotype of rs141294036 showed correlation with elevated risk of new onset IS (adjusted HR = 2.55, 95% CI: 1.23-5.27, P = 0.012). These novel findings suggest that KATP rs141294036 is associated with increased risk of HTN, dyslipidemia, and IS. Based on these correlations, KATP rs141294036 could be a promising target for early and personalized therapeutics as well as prevention strategies for the aforementioned clinical pathologies.

Identifying familial hypercholesterolemia in an early onset ischemic cerebrovascular disease patient and the cascade screening in the pedigree: a case report

Familial hypercholesterolemia (FH) is one of the most common inherited metabolic disorders characterized by elevated low-density lipid cholesterol (LDL-C) levels that lead to coronary artery disease at an early age and a low occurrence of cerebrovascular disease. Low-density lipoprotein receptor (LDLR) gene mutation is the most common cause of FH. Here, we report a case of a 47-year-old woman who had multiple carotid artery stenosis and brain ischemic foci, an elevated level of LDL-C, underwent eyelid xanthoma excision, and a family history of hyperlipidemia. Thereafter, she was diagnosed with FH according to the Dutch Lipid Clinical Network criteria and whole genome sequencing revealed compound heterozygous LDLR mutations. However, she denied a history of coronary heart disease (CAD). The patient underwent stenting of the right subclavicular artery and right internal carotid artery in our hospital. Lipid-lowering drugs were also administered to prevent stroke recurrence. During a 3-year follow-up, the blood lipid level of the patient reduced, and the condition of intracranial and extracranial vascular stenosis improved. Furthermore, a cascade screening was performed in her pedigree, and 7/9 family members were found to have elevated LDL-C, 6/7 were found to carry one of the two LDLR variants detected in the proband, and in 4/6, the carotid intima-media thickness was ≥1 mm, which was predicted as a high risk factor of cerebrovascular disease. Her relatives with high risks of cardiovascular or cerebrovascular diseases have been under lipid monitoring and management of risk factors since then. To date, no cardiovascular or cerebrovascular event has been reported. In conclusion, this case reminds us to consider FH screening in early-onset stroke or transient ischemic attack patients with elevated LDL-C level. Our report also demonstrates the beneficial role of genetic testing and cascade screening in the relatives of FH patients.

Unique roles of rare variants in the genetics of complex diseases in humans

Genome-wide association studies have identified >10,000 genetic variants associated with various phenotypes and diseases. Although the majority are common variants, rare variants with >0.1% of minor allele frequency have been investigated by imputation and using disease-specific custom SNP arrays. Rare variants sequencing analysis mainly revealed have played unique roles in the genetics of complex diseases in humans due to their distinctive features, in contrast to common variants. Unique roles are hypothesis-free evidence for gene causality, a precise target of functional analysis for understanding disease mechanisms, a new favorable target for drug development, and a genetic marker with high disease risk for personalized medicine. As whole-genome sequencing continues to identify more rare variants, the roles associated with rare variants will also increase. However, a better estimation of the functional impact of rare variants across whole genome is needed to enhance their contribution to improvements in human health.

Unveiling the Metabolic Profile of First-Episode Drug-Naïve Schizophrenia Patients: Baseline Characteristics of a Longitudinal Study Among Han Chinese

Objective: Metabolic and other medical conditions are frequently comorbid with schizophrenia. As they might be the side-effects of antipsychotic treatment, studying first-episode drug-naïve schizophrenia (FDSZ) provides a unique opportunity to investigate a direct pathogenic link between metabolic changes and schizophrenia. Here, we presented the methods and baseline unique metabolic profile of FDSZ patients without medical comorbidities unveiling subthreshold indices of metabolic disturbances. Method: Drug-naïve individuals diagnosed with schizophrenia but without any previous medical conditions were invited to participate in the study. Participants were submitted to structured psychiatric and cognitive assessments, laboratory and neuroimaging tests. Subjects will be followed after antipsychotic treatment at 6, 24 and 48 weeks. Results: During an 8-month-period, out of 103 patients presenting with first episode psychosis, 67 subjects (43.3% men, 56.7% women) were enrolled in the study. They had a mean ± SD age of 32.1 ± 8.7 years, with a mean BMI of 21.1 kg/m² and 11.3 ± 3.6 years of schooling. Less than 1/3 reported a family history of mental illness. Upon laboratory assessment, 10.4%, 7.5%, and 11.9% of patients were identified with hyperhomocysteinemia, hypertriglyceridemia and hyperprolactinemia, respectively, with percentages of women relatively higher than men except for hypertriglyceridemia. Conclusions: First episode schizophrenia patients, especially women, present subclinical metabolic abnormalities, independent of antipsychotic treatment.

Genetics of Hypercholesterolemia: Comparison Between Familial Hypercholesterolemia and Hypercholesterolemia Nonrelated to LDL Receptor

Severe hypercholesterolemia (HC) is defined as an elevation of total cholesterol (TC) due to the increase in LDL cholesterol (LDL-C) >95th percentile or 190 mg/dl. The high values of LDL-C, especially when it is maintained over time, is considered a risk factor for the development of atherosclerotic cardiovascular disease (ASCVD), mostly expressed as ischemic heart disease (IHD). One of the best characterized forms of severe HC, familial hypercholesterolemia (FH), is caused by the presence of a major variant in one gene (LDLR, APOB, PCSK9, or ApoE), with an autosomal codominant pattern of inheritance, causing an extreme elevation of LDL-C and early IHD. Nevertheless, an important proportion of serious HC cases, denominated polygenic hypercholesterolemia (PH), may be attributed to the small additive effect of a number of single nucleotide variants (SNVs), located along the whole genome. The diagnosis, prevalence, and cardiovascular risk associated with PH has not been fully established at the moment. Cascade screening to detect a specific genetic defect is advised in all first- and second-degree relatives of subjects with FH. Conversely, in the rest of cases of HC, it is only advised to screen high values of LDL-C in first-degree relatives since there is not a consensus for the genetic diagnosis of PH. FH is associated with the highest cardiovascular risk, followed by PH and other forms of HC. Early detection and initiation of high-intensity lipid-lowering treatment is proposed in all subjects with severe HC for the primary prevention of ASCVD, with an objective of LDL-C <100 mg/dl or a decrease of at least 50%. A more aggressive reduction in LDL-C is necessary in HC subjects who associate personal history of ASCVD or other cardiovascular risk factors.

Familial hypercholesterolemia and cardiovascular disease in older individuals

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is characterized by high LDL-cholesterol (LDL-C) and early atherosclerotic cardiovascular disease (ASCVD). With a lipid lowering therapy (LLT), most individuals with FH may have a longer ASCVD-free survival. However, there is scant data about older individuals with FH.

METHODS

We compared characteristics of genetically defined FH older individuals with age-matched non-FH counterparts.

RESULTS

From 4111 genotyped individuals, 462 older than 60 years were included (198 positive and 264 negative for FH variants). There were no differences regarding median age [%25; 75%] 66.0 (62.0; 71.0) and 66.0 (62.2; 71.0) years, p = 0.68 for FH and non-FH, respectively. In both groups, there was a higher frequency of females, however, there were more males in the FH group 37.4% vs. 24.2%, p = 0.002. No differences were seen between FH and non-FH in LLT use: 88.5% vs. 91.5%, p = 0.29. Despite a longer LLT duration in FH patients (with 11.0 (7.0; 20.0) vs. 7.0 (3.0; 13.0) years, p < 0.001), treatment was started late in both groups: at 54.0 (47.0; 61.0) and 59.0 (52.0; 64.0) years, p < 0.001, in FH and non-FH, respectively. FH had greater frequencies of previous and early ASCVD (40.9% vs. 27.3%, p = 0.002, and 22.2% vs. 9.0%, p < 0.001). In FH, male sex [HR (95%CI)] 2.67 (1.50-4.73), p = 0.001, and LLT onset age 0.96 (0.93-0.99), p = 0.009, were independently associated with ASCVD.

CONCLUSIONS

Among hypercholesterolemic older individuals participating in a cascade screening program, the genetic diagnosis of FH was associated with higher ASCVD rates, emphasizing the relevance of a monogenic defect as the cause of long-lasting hypercholesterolemia and ASCVD risk, particularly in men.

Calcified Aortic Valve Disease in Patients With Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is a rare autosomal gene deficiency disease with increased low-density lipoprotein cholesterol, xanthoma, and premature coronary heart disease. Calcified aortic valve disease (CAVD) is prevalent in FH patients, resulting in adverse events and heavy health care burden. Aortic valve calcification is currently considered an active biological process, which shares several common risk factors with atherosclerosis, including aging, hypertension, dyslipidemia, and so on. Unfortunately, the pathogenesis and therapy of CAVD in FH are still controversial. There is no pharmacological intervention recommended to delay the development of CAVD in FH, and the only effective treatment for severe CAVD is aortic valve replacement. In this review, we summarize the detailed description of the pathophysiology, molecular mechanism, risk factors, and treatment of CAVD in FH patients.

Insights into the potential benefits of black soybean (Glycine max L.) polyphenols in lifestyle diseases

Black soybean (Glycine max L.), a cultivar containing abundant polyphenols in its seed coat such as anthocyanins and flavan-3-ols, has been reported to possess various health benefits toward lifestyle diseases. In this review article, the safety evaluation of polyphenol-rich black soybean seed coat extract (BE) and absorption of BE polyphenols are summarized. Additionally, we describe the antioxidant activity of BE polyphenols and their ability to induce antioxidant enzymes. The health benefits of BE and its polyphenols, such as anti-obesity and anti-hyperglycemic activities through the activation of AMP-activated protein kinase and translocation of glucose transporter 4, respectively, are also discussed. Furthermore, we found that black soybean polyphenols were involved in the improvement of vascular function. These emerging data require further investigation in scientific studies and human trials to evaluate the prevention of lifestyle diseases using black soybean polyphenols.

Polygenic Contribution to Low-Density Lipoprotein Cholesterol Levels and Cardiovascular Risk in Monogenic Familial Hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) is a common autosomal codominant genetic disorder, which causes elevated levels of low-density lipoprotein cholesterol (LDL-C) and increased risk of premature atherosclerotic cardiovascular disease (ASCVD). Even among individuals with monogenic FH, there is substantial interindividual variability in LDL-C levels and risk of ASCVD. We assessed the influence of an LDL-C polygenic score on levels of LDL-C and risk of ASCVD for individuals with monogenic FH.

METHODS

We constructed a weighted LDL-C polygenic score, composed of 28 single-nucleotide variants, for individuals with monogenic FH from the British Columbia FH (n=262); Nutrition, Metabolism and Atherosclerosis Clinic (n=552); and UK Biobank cohorts (n=306). We assessed the association between LDL-C polygenic score with LDL-C levels and ASCVD risk using linear regression and Cox-proportional hazard models, respectively. ASCVD was defined as myocardial infarction, coronary or carotid revascularization, transient ischemic attack, or stroke. The results from individual cohorts were combined in fixed-effect meta-analyses.

RESULTS

Levels of LDL-C were significantly associated with LDL-C polygenic score in the Nutrition, Metabolism and Atherosclerosis Clinic cohort, UK Biobank cohort, and in the meta-analysis (β [95% CI]=0.13 [0.072-0.19] per a 20% increase in LDL-C polygenic score percentile, P<0.0001). Additionally, an elevated LDL-C polygenic score (≥80th percentile) was associated with a trend towards increased ASCVD risk in all 3 cohorts individually. This association was statistically significant in the meta-analysis (hazard ratio [95% CI]=1.48 [1.02-2.14], P=0.04).

CONCLUSIONS

Polygenic contributions to LDL-C explain some of the heterogeneity in clinical presentation and ASCVD risk for individuals with FH.

Genetic and metabolic factors: the perfect combination to treat metabolic associated fatty liver disease

The prevalence of nonalcoholic or more recently re-defined metabolic associated fatty liver disease (MAFLD) is rapidly growing worldwide. It is characterized by hepatic fat accumulation exceeding 5% of liver weight not attributable to alcohol consumption. MAFLD refers to an umbrella of conditions ranging from simple steatosis to nonalcoholic steatohepatitis which may finally progress to cirrhosis and hepatocellular carcinoma. MAFLD is closely related to components of the metabolic syndrome and to environmental factors. In addition to the latter, genetic predisposition plays a key role in MAFLD pathogenesis and strictly contributes to its progressive forms. The candidate genes which have been related to MAFLD hereditability are mainly involved in lipids remodeling, lipid droplets assembly, lipoprotein packaging and secretion, de novo lipogenesis, and mitochondrial redox status. In the recent years, it has emerged the opportunity to translate the genetics into clinics by aggregating the genetic variants mostly associated with MAFLD in polygenic risk scores. These scores might be used in combination with metabolic factors to identify those patients at higher risk to develop more severe liver disease and to schedule an individual therapeutic approach.

Prevalence Of familial hypercholeSTerolaemia (FH) in Italian Patients with coronary artERy disease: The POSTER study

BACKGROUND AND AIMS

Familial hypercholesterolaemia (FH) is a powerful risk factor for cardiovascular (CV) events. High levels of low-density lipoprotein cholesterol (LDL-C) since birth are linked to the early onset of atherosclerotic disease. A genetic mutation determining FH is present in about one subject out of 250; FH should be more represented among subjects with a documented diagnosis of coronary artery disease (CAD). The POSTER Study evaluated the prevalence of FH in Italian patients with a recent CAD event.

METHODS

Eighty-two cardiology centres enrolled patients with a documented CAD event; CV risk profile, drug therapy and biochemical parameters were collected. Dutch Lipid Clinic Network (DLCN) criteria were used to define patients with a potential FH diagnosis (score ≥6); these patients underwent molecular testing for genetic diagnosis of FH.

RESULTS

Overall, 5415 patients were enrolled and the main index events were myocardial infarction with ST-elevation, non ST-elevation acute coronary syndrome (ACS), or a recent coronary revascularization (34.8%, 37.2%, and 28% respectively). Mean age was 66 ± 11 years, men were 78%; about 40% were already treated with statins, proportion that increased after the acute event (96.5%). Based on the DLCN score, the prevalence of potential FH was 5.1%, 0.9% of them had a diagnosis of definite FH (score >8). These patients were younger than patients with a score <6 (56 ± 10 vs 66 ± 11, p < 0.001), and LDL-C levels were in most of them (~87%) >190 mg/dL. FH was genetically confirmed in 42 subjects (15.9%); genetic diagnosis was defined as not conclusive for FH in 63 patients (23.9%). Finally, in 159 subjects (60.2%) no pathogenic mutations in the tested genes were identified, defining them as negative for monogenic familial hypercholesterolemia.

CONCLUSIONS

Results underscore a relatively high prevalence of potential FH in patients with a recent CAD event. Therefore, an early identification of these subjects may help improve the management of their high CV risk and, by cascade screening, identify possible FH relatives.

Clinical and Genetic Characteristics of Familial Hypercholesterolemia at Sultan Qaboos University Hospital in Oman

Objectives

We sought to describe the clinical and genetic characteristics of patients with familial hypercholesterolemia (FH) that presented to the lipid clinic at Sultan Qaboos University Hospital, Muscat, Oman.

Methods

Patients who presented with high low-density lipoprotein cholesterol (LDL-C) levels (> 189.0 mg/dL or 4.9 mmol/L) were recruited to the study. FH was diagnosed according to the Dutch Lipid Clinic Network criteria. Analyses were performed using univariate statistics.

Results

The study enrolled 450 patients with a mean age of 48.0±12.0 years, 56.0% (n = 252) were males and 11.3% (n = 51) were smokers. At admission, the proportion of ‘probable/definite’, ‘possible’, and ‘unlikely’ FH were 27.6% (n = 124), 70.0% (n = 315), and 2.4% (n = 11), respectively. Overall, 26.0% (n = 117) of patients had hypertension, 22.4% (n = 101) had a history of coronary artery disease, and 17.3% (n = 78) had diabetes mellitus. Those with ‘probable/definite’ FH were more likely to be prescribed high-intensity statin therapy (75.8% vs. 54.5%; p < 0.001) and statin ezetimibe combination (50.8% vs. 27.3%; p < 0.001) when compared to the ‘unlikely’ FH cohort. Additionally, those with very high atherosclerotic vascular disease (ASCVD) risk were also associated with high-intensity statin therapy (54.7% vs. 42.7%; p = 0.006) and statin ezetimibe combination (26.4% vs. 17.2%; p = 0.023). Patients with ‘probable/definite’ FH were less likely to achieve their LDL-C goal attainment compared to those with ‘unlikely’ FH (13.0% vs. 57.1%; p < 0.001). Furthermore, those with very high ASCVD risk were less likely to achieve their LDL-C goals compared to the high ASCVD risk cohort (9.6% vs. 32.0%; p < 0.001).

Conclusions

FH patients are underdiagnosed, undertreated, and less likely to attain their LDL-C goals in Oman.

The emerging field of polygenic risk scores and perspective for use in clinical care

Genetic testing is used widely for diagnostic, carrier and predictive testing in monogenic diseases. Until recently, there were no genetic testing options available for multifactorial complex diseases like heart disease, diabetes and cancer. Genome-wide association studies (GWAS) have been invaluable in identifying single-nucleotide polymorphisms (SNPs) associated with increased or decreased risk for hundreds of complex disorders. For a given disease, SNPs can be combined to generate a cumulative estimation of risk known as a polygenic risk score (PRS). After years of research, PRSs are increasingly used in clinical settings. In this article, we will review the literature on how both genome-wide and restricted PRSs are developed and the relative merit of each. The validation and evaluation of PRSs will also be discussed, including the recognition that PRS validity is intrinsically linked to the methodological and analytical approach of the foundation GWAS together with the ethnic characteristics of that cohort. Specifically, population differences may affect imputation accuracy, risk magnitude and direction. Even as PRSs are being introduced into clinical practice, there is a push to combine them with clinical and demographic risk factors to develop a holistic disease risk. The existing evidence regarding the clinical utility of PRSs is considered across four different domains: informing population screening programs, guiding therapeutic interventions, refining risk for families at high risk, and facilitating diagnosis and predicting prognostic outcomes. The evidence for clinical utility in relation to five well-studied disorders is summarized. The potential ethical, legal and social implications are also highlighted.

ATP-sensitive potassium channels gene polymorphism rs1799858 affects the risk of macro-/micro-vascular arteriosclerotic event in patients with increased low-density lipoprotein cholesterol levels

Background

Plasma concentration of low-density lipoprotein cholesterol (LDL-C) is causally related to the risk of arteriosclerotic events. Whether ATP-sensitive potassium channels (KATP) genetic variants predict increased LDL-C concentration (≥1.8 mmol/L) and risk of macro-/micro-vascular arteriosclerotic event remain elusive.

Methods

A total of 320 subjects with increased LDL-C concentration (≥1.8 mmol/L) and 320 counterpart subjects (< 1.8 mmol/L) from the South China were enrolled in this study. Three KATP polymorphisms (rs1799858, rs4148671 and rs78148713) were genotyped by the Sequenom MassARRAY system. Binary logistic regression analysis was used to evaluate the association of the 3 KATP variants with increased LDL-C concentration and carotid artery stenosis (CAS) ≥50%. Two-way ANOVA was used to analyze the association of the 3 KATP variants with microalbumin in urine (MAU) and high-sensitivity C-reactive protein (HsCRP) levels. Cox proportional hazards regression analysis was used to retrospectively analyse the association of the optimal variant with the risk of new onset/recurrent acute myocardial infarction (AMI).

Results

Among the 3 studied KATP gene single nucleotide polymorphisms (SNPs), only rs1799858 (TT + CT genotype) was associated with elevated risk of LDL-C ≥ 1.8 mmol/L (adjusted OR = 2.25, 95% CI: 1.31–3.85, P = 0.003) and CAS ≥50% (adjusted OR = 2.80, 95% CI: 1.12–6.98, P = 0.028). KATP SNP rs1799858 was also associated with increased MAU (P = 0.013) and HsCRP (P = 0.027) levels. The follow-up for an average of 51.1-months revealed that participants carrying the T-allele (TT + CT) of rs1799858 was associated with high risk of new onset/recurrent AMI (adjusted HR = 2.90, 95% CI: 1.06–7.94, P = 0.038).

Conclusion

The KATP SNP rs1799858 may be an optimal genetic predisposition marker for increased LDL-C concentration (≥1.8 mmol/L) and its related macro-/micro-vascular arteriosclerotic event risk. The KATP variant rs1799858 was associated with higher risk of macro-/micro-vascular arteriosclerotic events in patients with elevated serum LDL-C levels.

Nutrition and Genetics in NAFLD: The Perfect Binomium

Nonalcoholic fatty liver disease (NAFLD) represents a global healthcare burden since it is epidemiologically related to obesity, type 2 diabetes (T2D) and Metabolic Syndrome (MetS). It embraces a wide spectrum of hepatic injuries, which include simple steatosis, nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis and hepatocellular carcinoma (HCC). The susceptibility to develop NAFLD is highly variable and it is influenced by several cues including environmental (i.e., dietary habits and physical activity) and inherited (i.e., genetic/epigenetic) risk factors. Nonetheless, even intestinal microbiota and its by-products play a crucial role in NAFLD pathophysiology. The interaction of dietary exposure with the genome is referred to as 'nutritional genomics,' which encompasses both 'nutrigenetics' and 'nutriepigenomics.' It is focused on revealing the biological mechanisms that entail both the acute and persistent genome-nutrient interactions that influence health and it may represent a promising field of study to improve both clinical and health nutrition practices. Thus, the premise of this review is to discuss the relevance of personalized nutritional advices as a novel therapeutic approach in NAFLD tailored management.