Sex difference in circulating PCSK9 and its clinical implications

Predictive factors for multivessel disease in patients with acute coronary syndrome: analysis from the CCC-ACS project in China

BACKGROUND

Multivessel disease(MVD) is linked to a poorer prognosis, increased complications, longer hospital stays, and higher in-hospital mortality when compared to single-vessel disease(SVD).The purpose of this study is to explore the clinically relevant predictors of acute cornary syndrome (ACS) combined with MVD.

METHODS

This multicenter retrospective study included 68,378 ACS patients from 240 hospitals.The clinical data were retrospectively analyzed with univariate and multivariate analyses to identify the predictive factors for MVD.

RESULTS

When compared to SVD group, the MVD group showed a higher incidence of Major Adverse Cardiovascular Events(MACCEs), including all-cause death, myocardial infarction, stent thrombosis, and ischemic stroke during hospitalization, These differences were found to be statistically significant (P < 0.05) .The multivariate analysis revealed that age over 75 years (OR: 1.246, 95% CI: 1.176, 1.319), LDL/HDL ratio > 1.98 (OR: 1.245, 95% CI: 1.192, 1.302), history of heart failure (OR: 1.446, 95% CI: 1.143, 1.829), hypertension (OR: 1.274, 95% CI: 1.225, 1.325), diabetes (OR: 1.341, 95% CI: 1.278, 1.406), eGFRs < 60 ml/min·1.73m2 (OR: 1.179, 95% CI: 1.112, 1.249), family history of CAD (OR: 1.236, 95% CI: 1.108, 1.379), and high homocysteine levels (OR: 1.209, 95% CI: 1.029, 1.420) are independent predictors of MVD. The incidence of multivessel disease increased from 37.7 to 58.6% with an increase in the number of predictive factors, while the incidence of single vessel disease decreased from 62.3 to 41.4%. This trend was statistically significant (P trend < 0.001).

CONCLUSIONS

MVD is strongly correlated with a range of risk factors including diabetes, hypertension, LDL/HDL ratio greater than 1.98, hyperhomocysteinemia, family history of CAD, reduced glomerular filtration rate (< 60 ml/(min·1.73m2), age over 75 years, and a history of heart failure. Furthermore, as the number of predictive factors increases, the odds ratio (OR) for patients with MVD also increases, reaching 2.344 times the OR for patients without any predictive factors.

Sex differences in LDL-C reduction response to evolocumab: A propensity score matching analysis

BACKGROUND

Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) have been shown to improve cardiovascular outcomes by reducing low-density lipoprotein cholesterol (LDL-C). However, sex differences in the efficacy of evolocumab remain unclear. This study aimed to investigate sex differences in the efficacy of evolocumab using real-world data.

METHOD

Data were collected from the First Affiliated Hospital of Guangxi Medical University. A total of 416 eligible patients were selected from 1463 patients treated with evolocumab for secondary prevention. Clinical data, including individual characteristics and lipids profiles, were recorded. Propensity score matching (PSM) was used to control for potential confounders, with covariates including age, body mass index, smoking status, and diabetes. All eligible participants were propensity-matched 1:1 for female versus male with a match tolerance of 0.02. The efficacy of evolocumab in females and males was compared by PSM-adjusted analysis.

RESULTS

In the PSM analysis, a significant difference was found in the relative percentage reduction of LDL-C between females and males (-42.7% vs. -54.4%, p < 0.001). In addition, the absolute LDL-C reduction was lower in females compared to males (interquartile range: -1.5 [-2.2, -0.8] mmol/L vs. -1.9 [-2.5, -1.0] mmol/L, p = 0.018). The rate of target LDL-C attainment was lower in females than in males after treatment with evolocumab (21.6% vs. 39.8%, p = 0.009).

CONCLUSION

These results suggest that males have a better response to evolocumab in term of LDL-C reduction compared to females.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) and clinical outcomes in dialysis patients

BACKGROUND

Proprotein convertase subtilisin/kexin type 9 (PCSK9), a factor accelerating the degradation of LDL receptors, was associated with a gender-dependent risk for cardiovascular (CV) events in the general population and with all-cause and CV mortality in two relatively small studies in black Africans and South Korean haemodialysis patients. The effect modification by gender was untested in these studies.

METHODS

The study enrolled 1188 dialysis patients from the Prospective Registry of The Working Group of Epidemiology of Dialysis Region Calabria (PROGREDIRE) cohort. PCSK9 was measured by colorimetric enzyme-linked immunosorbent assay. The primary outcomes were all-cause and CV mortality. Statistical analysis included Cox regression analysis and effect modification analysis.

RESULTS

During a median 2.9-year follow-up, out of 494 deaths, 278 were CV-related. In unadjusted analyses, PCSK9 levels correlated with increased all-cause (HRfor1ln unit increase: 1.23, 95% CI 1.06-1.43, p =.008) and CV mortality (HRfor1ln unit increase: 1.26, 95% CI 1.03-1.54, p =.03). After multivariate adjustment, these associations were no longer significant (all-cause mortality, HRfor 1 ln unit increase: 1.16, 95% CI .99-1.36, p =.07; CV mortality, HRfor1ln unit increase: 1.18, 95% CI .95-1.46, p =.14). However, in fully adjusted interaction analyses, a doubling in the risk of this outcome in women was registered (Women, HRfor1ln unit increase: 1.88, 95% CI 1.27-2.78, p =.002; Men, HRfor1ln unit increase: 1.07, 95% CI .83-1.38, p =.61; p for effect modification: .02).

CONCLUSIONS

PCSK9 levels are unrelated to all-cause mortality in haemodialysis patients but, like in studies of the general population, independently of other risk factors, entail a doubling in the risk of CV events in women in this population.

Monoclonal Anti-PCSK9 Antibodies: Real-World Data

Background: Real-world data on the use of lipid-lowering therapy (LLT) in clinical practice show that about 80% of (very) high-cardiovascular (CV)-risk patients disregard the 2019 European Society of Cardiology (ESC) Guidelines' recommendations on dyslipidemias. The availability of proprotein convertase subtilisin/kexin type 9 monoclonal antibodies (PCSK9mAb) should reduce this gap. Our aim was to provide data on PCSK9mAb use in clinical practice, investigating the achievement of the ESC Guidelines' recommendations in the real world. Methods: Between April 2018 and December 2022, patients who started on PCSK9mAb therapy (140 mg of evolocumab or 75 mg or 150 mg of alirocumab, subcutaneous injection every 2 weeks) were included in a prospective registry. Our cohort consisted of 256 patients: 95 (37.1%) were women (mean age: 65.43 ± 11.12 yrs), 53 (20.7%) were at high CV risk, and 203 (79.3%) were at very high CV risk. Results: After one year of PCSK9mAb treatment, nearly 60% of patients demonstrated full adherence to the ESC Guidelines' recommendations, defined as achieving at least a 50% reduction in low-density lipoprotein cholesterol (LDL-C) levels along with reaching LDL-C target levels (≤55 and ≤70 mg/dL for very high and high risk, respectively). Concomitant high-dose statin therapy emerged as the primary predictor of LDL-C target attainment. Heterozygous familial hypercholesterolemia (HeFH), statin intolerance, and female gender were associated with a significant lower probability of achieving LDL-C target levels. Conclusions: Our analysis confirms that PCSK9mAb treatment is safe and effective, enabling 60% of our cohort to fully achieve the LDL-C guideline recommendations. The use of high-intensity statins emerged as a significant predictor of efficacy. Conversely, familial hypercholesterolemia and female gender were identified as predictors of therapeutic failure. Hence, it is crucial to address disparities in cardiovascular disease prevention between genders and to enhance strategies for managing elevated LDL-C in HeFH patients.

Lipoprotein Metabolism, Dyslipidemia, and Lipid-Lowering Therapy in Women: A Comprehensive Review

Lipid-lowering therapy (LLT) is a cornerstone of atherosclerotic cardiovascular disease prevention. Although LLT might lead to different reductions in low-density lipoprotein cholesterol (LDL-C) levels in women and men, LLT diminishes cardiovascular risk equally effectively in both sexes. Despite similar LLT efficacy, the use of high-intensity statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 inhibitors is lower in women compared to men. Women achieve the guideline-recommended LDL-C levels less often than men. Greater cholesterol burden is particularly prominent in women with familial hypercholesterolemia. In clinical practice, women and men with dyslipidemia present with different cardiovascular risk profiles and disease manifestations. The concentrations of LDL-C, lipoprotein(a), and other blood lipids differ between women and men over a lifetime. Dissimilar levels of LLT target molecules partially result from sex-specific hormonal and genetic determinants of lipoprotein metabolism. Hence, to evaluate a potential need for sex-specific LLT, this comprehensive review (i) describes the impact of sex on lipoprotein metabolism and lipid profile, (ii) highlights sex differences in cardiovascular risk among patients with dyslipidemia, (iii) presents recent, up-to-date clinical trial and real-world data on LLT efficacy and safety in women, and (iv) discusses the diverse medical needs of women and men with dyslipidemia and increased cardiovascular risk.

Italian Association of Hospital Cardiologists Position Paper 'Gender discrepancy: time to implement gender-based clinical management'

It has been well assessed that women have been widely under-represented in cardiovascular clinical trials. Moreover, a significant discrepancy in pharmacological and interventional strategies has been reported. Therefore, poor outcomes and more significant mortality have been shown in many diseases. Pharmacokinetic and pharmacodynamic differences in drug metabolism have also been described so that effectiveness could be different according to sex. However, awareness about the gender gap remains too scarce. Consequently, gender-specific guidelines are lacking, and the need for a sex-specific approach has become more evident in the last few years. This paper aims to evaluate different therapeutic approaches to managing the most common women's diseases.

Sex and statin-related genetic associations at the PCSK9 gene locus: results of genome-wide association meta-analysis

BACKGROUND

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a key player of lipid metabolism with higher plasma levels in women throughout their life. Statin treatment affects PCSK9 levels also showing evidence of sex-differential effects. It remains unclear whether these differences can be explained by genetics.

METHODS

We performed genome-wide association meta-analyses (GWAS) of PCSK9 levels stratified for sex and statin treatment in six independent studies of Europeans (8936 women/11,080 men respectively 14,825 statin-free/5191 statin-treated individuals). Loci associated in one of the strata were tested for statin- and sex-interactions considering all independent signals per locus. Independent variants at the PCSK9 gene locus were then used in a stratified Mendelian Randomization analysis (cis-MR) of PCSK9 effects on low-density lipoprotein cholesterol (LDL-C) levels to detect differences of causal effects between the subgroups.

RESULTS

We identified 11 loci associated with PCSK9 in at least one stratified subgroup (p < 1.0 × 10-6), including the PCSK9 gene locus and five other lipid loci: APOB, TM6SF2, FADS1/FADS2, JMJD1C, and HP/HPR. The interaction analysis revealed eight loci with sex- and/or statin-interactions. At the PCSK9 gene locus, there were four independent signals, one with a significant sex-interaction showing stronger effects in men (rs693668). Regarding statin treatment, there were two significant interactions in PCSK9 missense mutations: rs11591147 had stronger effects in statin-free individuals, and rs11583680 had stronger effects in statin-treated individuals. Besides replicating known loci, we detected two novel genome-wide significant associations: one for statin-treated individuals at 6q11.1 (within KHDRBS2) and one for males at 12q24.22 (near KSR2/NOS1), both with significant interactions. In the MR of PCSK9 on LDL-C, we observed significant causal estimates within all subgroups, but significantly stronger causal effects in statin-free subjects compared to statin-treated individuals.

CONCLUSIONS

We performed the first double-stratified GWAS of PCSK9 levels and identified multiple biologically plausible loci with genetic interaction effects. Our results indicate that the observed sexual dimorphism of PCSK9 and its statin-related interactions have a genetic basis. Significant differences in the causal relationship between PCSK9 and LDL-C suggest sex-specific dosages of PCSK9 inhibitors.

Sex X Time Interactions in Lp(a) and LDL-C Response to Evolocumab

The aim of this study was to evaluate whether there were significant sex x time interactions in lipoprotein(a) (Lp(a)) and low-density lipoprotein cholesterol (LDL-C) response to treatment with the Proprotein Convertase Subtilisin/Kexin type 9 inhibitor (PCSK9i) Evolocumab, in a real-life clinical setting. For this purpose, we pooled data from 176 outpatients (Men: 93; Women: 83) clinically evaluated at baseline and every six months after starting Evolocumab. Individuals who had been on PCSK9i for less than 30 months and nonadherent patients were excluded from the analysis. Over time, absolute values of Lp(a) plasma concentrations significantly decreased in the entire cohort (p-value < 0.001) and by sex (p-value < 0.001 in men and p-value = 0.002 in and women). However, there were no sex-related significant differences. Absolute plasma concentrations of LDL-C significantly decreased over time in the entire cohort and by sex (p-value < 0.001 always), with greater improvements in men compared to women. The sex x time interaction was statistically significant in LDL-C (all p-values < 0.05), while absolute changes in Lp(a) were not influenced by either sex or time (all p-value > 0.05). Our data partially reinforce the presence of differences in response to treatment to PCSK9i between men and women and are essential to gain a better understanding of the relationship between LDL-C and Lp(a) lowering in response to PCSK9i. Further research will clarify whether these sex-related significant differences translate into a meaningful difference in the long-term risk of ASCVD.

Sex differences in efficacy and safety of PCSK9 monoclonal antibodies: A real-world registry

BACKGROUND AND AIMS

Proprotein convertase subtilisin/kexin 9 monoclonal antibodies (PCSK9 mAbs) reduce low-density lipoprotein (LDL-c) with a favourable safety profile. Available data from PCSK9 antibody trials suggest LDL-c reduction is lower in women compared to men. Data in real-world setting is scarce. The aim of this study was to assess sex differences in efficacy and safety of PCSK9 antibodies in clinical care.

METHODS

All patients starting with evolocumab or alirocumab in our lipid clinic were included in a prospective registry. We collected clinical information, including baseline and follow-up mean LDL-C levels after initiation of PCSK9 mAbs treatment. In addition, side effects and PCSK9 mAbs discontinuation were recorded.

RESULTS

We analysed 436 patients (209 women), mean age 58 ± 11 years. Women had higher baseline LDL-c levels compared to men (4.7 ± 1.6 mmol/L vs 4.1 ± 1.4 mmol/L, p < 0.01). PCSK9 mAbs resulted in less relative LDL-c reduction in women compared to men (50% vs 61% p<0.01), but equal absolute LDL-c reduction (respectively 2.3 ± 1.3 mmol/L vs 2.5 ± 1.1 mmol/L, p = 0.087). Women less often reached LDL-c target levels than men (50% vs 72%). No sex differences were observed in reporting of side effects (women 32% vs men 27% p = 0.26) or PCSK9 mAbs discontinuation (women 13% vs men 10%, p = 0.46).

CONCLUSIONS

In clinical practice, PCSK9 mAbs are less effective in reducing LDL-c levels in women compared to men and equally safe, implying the importance of sex differences in PCSK9 metabolism.

Sex Differences in Familial Hypercholesterolemia

PURPOSE OF REVIEW

This review aims to summarize the existing research on sex differences in familial hypercholesterolemia (FH) across the lifespan.

RECENT FINDINGS

From childhood onward, total- and low-density lipoprotein cholesterol (LDL-C) levels in girls are higher than those in boys with FH. By the age of 30 years, women with FH have a higher LDL-C burden than men. In adulthood, women are diagnosed later than men, receive less lipid-lowering treatment, and consequently have higher LDL-C levels. An excessive atherosclerotic cardiovascular disease risk is reported in young female compared to male FH patients. The periods of pregnancy and breastfeeding contribute to treatment loss and increased cholesterol burden. Earlier initiation of treatment, especially in girls with FH, and lifelong treatment during all life stages are important. Future research should aim to recruit both women and men, report sex-specific data, and investigate the impact of the female life course on cardiovascular outcomes. Future guidelines should include sex-specific aspects.

Targeting PCSK9 to tackle cardiovascular disease

Lowering blood cholesterol levels efficiently reduces the risk of developing atherosclerotic cardiovascular disease (ASCVD), including coronary artery disease (CAD), which is the main cause of death worldwide. CAD is caused by plaque formation, comprising cholesterol deposits in the coronary arteries. Proprotein convertase subtilisin kexin/type 9 (PCSK9) was discovered in the early 2000s and later identified as a key regulator of cholesterol metabolism. PCSK9 induces lysosomal degradation of the low-density lipoprotein (LDL) receptor in the liver, which is responsible for clearing LDL-cholesterol (LDL-C) from the circulation. Accordingly, gain-of-function PCSK9 mutations are causative of familial hypercholesterolemia, a severe condition with extremely high plasma cholesterol levels and increased ASCVD risk, whereas loss-of-function PCSK9 mutations are associated with very low LDL-C levels and protection against CAD. Since the discovery of PCSK9, extensive investigations in developing PCSK9 targeting therapies have been performed. The combined delineation of clear biology, genetic risk variants, and PCSK9 crystal structures have been major drivers in developing antagonistic molecules. Today, two antibody-based PCSK9 inhibitors have successfully progressed to clinical application and shown to be effective in reducing cholesterol levels and mitigating the risk of ASCVD events, including myocardial infarction, stroke, and death, without any major adverse effects. A third siRNA-based inhibitor has been FDA-approved but awaits cardiovascular outcome data. In this review, we outline the PCSK9 biology, focusing on the structure and nonsynonymous mutations reported in the PCSK9 gene and elaborate on PCSK9-lowering strategies under development. Finally, we discuss future perspectives with PCSK9 inhibition in other severe disorders beyond cardiovascular disease.

Sex Differences in Therapies against Myocardial Ischemia-Reperfusion Injury: From Basic Science to Clinical Perspectives

Mortality from myocardial infarction (MI) has declined over recent decades, which could be attributed in large part to improved treatment methods. Early reperfusion is the cornerstone of current MI treatment. However, reoxygenation via restored blood flow induces further damage to the myocardium, leading to ischemia-reperfusion injury (IRI). While experimental studies overwhelmingly demonstrate that females experience greater functional recovery from MI and decreased severity in the underlying pathophysiological mechanisms, the outcomes of MI with subsequent reperfusion therapy, which is the clinical correlate of myocardial IRI, are generally poorer for women compared with men. Distressingly, women are also reported to benefit less from current guideline-based therapies compared with men. These seemingly contradicting outcomes between experimental and clinical studies show a need for further investigation of sex-based differences in disease pathophysiology, treatment response, and a sex-specific approach in the development of novel therapeutic methods against myocardial IRI. In this literature review, we summarize the current knowledge on sex differences in the underlying pathophysiological mechanisms of myocardial IRI, including the roles of sex hormones and sex chromosomes. Furthermore, we address sex differences in pharmacokinetics, pharmacodynamics, and pharmacogenetics of current drugs prescribed to limit myocardial IRI. Lastly, we highlight ongoing clinical trials assessing novel pharmacological treatments against myocardial IRI and sex differences that may underlie the efficacy of these new therapeutic approaches.

Plasma Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) as a Possible Biomarker for Severe COVID-19

Proprotein convertase subtilisin/kexin type 9 (PCSK9) reduces low density lipoprotein (LDL) uptake, leading to increased plasma levels of LDL. In addition, PCSK9 has been implicated in inflammation independently of the effects on cholesterol metabolism. The current analysis showed that our 156 patients with systemic inflammatory response syndrome (SIRS) or sepsis had higher plasma PCSK9 levels in contrast with the 68 healthy controls. COVID-19 sepsis patients had increased plasma PCSK9 levels in comparison to sepsis patients not infected by SARS-CoV-2. For further analysis, patients were divided in two groups based on COVID-19. In both sub-cohorts, plasma PCSK9 levels did not correlate with C-reactive protein, leukocyte count, and procalcitonin. Plasma PCSK9 levels of both patient groups did not significantly differ among SIRS/sepsis patients with and without dialysis and patients with and without ventilation. Furthermore, vasopressor therapy was not significantly associated with altered plasma PCSK9 levels. In the non-COVID-19 SIRS/sepsis group, patients with Gram-negative and Gram-positive infections had similar plasma PCSK9 levels as patients without a detectable pathogen in their blood. In conclusion, the current study suggests PCSK9 as a possible biomarker for COVID-19, but this needs to be validated in larger cohorts.

Insight into the role of PCSK9 in glucose metabolism

Diabetes mellitus (DM) is strongly associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD). Proprotein convertase subtilisin/kexin type 9 (PCSK9) was recently identified as an important regulator of circulating low-density lipoprotein-cholesterol (LDL-C) levels via degradation of the LDL receptor, proving to be a valid target to improve lipoprotein profiles and cardiovascular outcomes in patients with ASCVD. Beyond LDL receptor processing and cholesterol homeostasis, the PCSK9 protein has recently been verified to be associated with glucose metabolism. Importantly, clinical trials suggest that treatment with PCSK9 inhibitors for patients with DM is more effective. Hence, in this review, we summarize the current findings derived from experimental, preclinical, and clinical studies regarding the association between PCSK9 and glucose metabolism, including the relationship of PCSK9 genetic mutations to glucose metabolism and diabetes, the link between plasma PCSK9 concentrations and glucose metabolic parameters, the effects of glucose-lowering drugs on plasma PCSK9 levels and the impacts of PCSK9 inhibitors on cardiovascular outcomes of patients with DM. Clinically, exploring this field may improve our understanding regarding the roles of PCSK9 in glucose metabolism and may offer an in-depth interpretation of how PCSK9 inhibitors exert effects on the treatment of patients with DM.

Impact of Sex and Gender on Clinical Management of Patients with Advanced Chronic Liver Disease and Type 2 Diabetes

Gender differences in the epidemiology, pathophysiological mechanisms and clinical features in chronic liver diseases that may be associated with type 2 diabetes (T2D) have been increasingly reported in recent years. This sexual dimorphism is due to a complex interaction between sex- and gender-related factors, including biological, hormonal, psychological and socio-cultural variables. However, the impact of sex and gender on the management of T2D subjects with liver disease is still unclear. In this regard, sex-related differences deserve careful consideration in pharmacology, aimed at improving drug safety and optimising medical therapy, both in men and women with T2D; moreover, low adherence to and persistence of long-term drug treatment is more common among women. A better understanding of sex- and gender-related differences in this field would provide an opportunity for a tailored diagnostic and therapeutic approach to the management of T2D subjects with chronic liver disease. In this narrative review, we summarized available data on sex- and gender-related differences in chronic liver disease, including metabolic, autoimmune, alcoholic and virus-related forms and their potential evolution towards cirrhosis and/or hepatocarcinoma in T2D subjects, to support their appropriate and personalized clinical management.