Contrast-specific propensity scores for causal inference with multiple interventions.

Existing methods that use propensity scores for heterogeneous treatment effect estimation on non-experimental data do not readily extend to the case of more than two treatment options. In this work, we develop a new propensity score-based method for heterogeneous treatment effect estimation when there are three or more treatment options, and prove that it generates unbiased estimates. We demonstrate our method on a real patient registry of patients in Singapore with diabetic dyslipidemia. On this dataset, our method generates heterogeneous treatment recommendations for patients among three options: Statins, fibrates, and non-pharmacological treatment to control patients' lipid ratios (total cholesterol divided by high-density lipoprotein level). In our numerical study, our proposed method generated more stable estimates compared to a benchmark method based on a multi-dimensional propensity score.

Fibrate and the risk of cardiovascular disease among moderate chronic kidney disease patients with primary hypertriglyceridemia.

Introduction: Hypertriglyceridemia is the most prevalent dyslipidemia in patients with chronic kidney disease (CKD). However, research about fibrate treatment in CKD patients is limited, and assessing its benefits becomes challenging due to the frequent concurrent use of statins. Thus, this study is aimed to investigate the role of fibrate in CKD stage 3 patients with hypertriglyceridemia who did not receive other lipid-lowering agents. Methods: This study enrolled patients newly diagnosed CKD3 with LDL-C<100mg/dL and had never received statin or other lipid-lowering agents from Chang Gung Research Database. The participants were categorized into 2 groups based on the use of fibrate: fibrate group and non-fibrate group (triglyceride >200mg/dL but not receiving fibrate treatment). The inverse probability of treatment weighting was performed to balance baseline characteristics. Results: Compared with the non-fibrate group (n=2020), the fibrate group (n=705) exhibited significantly lower risks of major adverse cardiac and cerebrovascular events (MACCEs) (10.4% vs. 12.8%, hazard ratios [HRs]: 0.69, 95% confidence interval [CI]: 0.50 to 0.95), AMI (2.3% vs. 3.9%, HR: 0.52, 95% CI: 0.37 to 0.73), and ischemic stroke (6.3% vs. 8.0%, HR: 0.67, 95% CI: 0.52 to 0.85). The risk of all-cause mortality (5.1% vs. 4.5%, HR: 1.09, 95% CI: 0.67 to 1.79) and death from CV (2.8% vs. 2.3%, HR: 1.07, 95% CI: 0.29 to 2.33) did not significantly differ between the 2 groups. Conclusion: This study suggests that, in moderate CKD patients with hypertriglyceridemia but LDL-C < 100mg/dL who did not take other lipid-lowering agents, fibrates may be beneficial in reducing cardiovascular events.

Use of drugs for hyperlipidaemia and diabetes and risk of primary and secondary brain tumours: nested case-control studies using the UK Clinical Practice Research Datalink (CPRD).

OBJECTIVES: Previous studies have suggested that fibrates and glitazones may have a role in brain tumour prevention. We examined if there is support for these observations using primary care records from the UK Clinical Practice Research Datalink (CPRD). DESIGN: We conducted two nested case-control studies using primary and secondary brain tumours identified within CPRD between 2000 and 2016. We selected cases and controls among the population of individuals who had been treated with any anti-diabetic or anti-hyperlipidaemic medication to reduce confounding by indication. SETTING: Adults older than 18 years registered with a general practitioner in the UK contributing data to CPRD. RESULTS: We identified 7496 individuals with any brain tumour (4471 primary; 3025 secondary) in total. After restricting cases and controls to those prescribed any anti-diabetic or anti-hyperlipidaemic medication, there were 1950 cases and 7791 controls in the fibrate and 480 cases with 1920 controls in the glitazone analyses. Longer use of glitazones compared with all other anti-diabetic medications was associated with a reduced risk of primary (adjusted OR (aOR) 0.89 per year, 95% CI 0.80 to 0.98), secondary (aOR 0.87 per year, 95% CI 0.77 to 0.99) or combined brain tumours (aOR 0.88 per year, 95% CI 0.81 to 0.95). There was little evidence that fibrate exposure was associated with risk of either primary or secondary brain tumours. CONCLUSIONS: Longer exposure to glitazones was associated with reduced primary and secondary brain tumour risk. Further basic science and population-based research should explore this finding in greater detail, in terms of replication and mechanistic studies.

Effect of Fibrate Treatment on Circulating Adipokine Levels: A Systematic Review and Meta-analysis of Randomized Clinical Trials.

BACKGROUND: Fibrates are widely used in the treatment of dyslipidemia and associated metabolic abnormalities; however, their effects on adipokines are unclear. AIM OF THE STUDY: This meta-analysis of clinical trials aimed to evaluate the effect of fibrates on circulating adipokine levels. METHODS: Only randomized controlled trials investigating the impact/effect of fibrate treatment on circulating adipokine levels were included from searches in PubMed-Medline, SCOPUS, ClinicalTrials.gov, Web of Science, and Google Scholar databases. A random effects model and the generic inverse variance method were used for the meta-analysis. Sensitivity analysis was conducted using the leave-one-out method. RESULTS: This meta-analysis of 22 clinical trials showed a significant reduction on/in leptin (WMD: -1.58 ng/mL, 95% CI: -2.96, -0.20, p = 0.02, I2 = 0%), plasminogen activator inhibitor-1 (PAI-1) (WMD: -13.86 ng/mL, 95% CI: -26.70, -1.03, p = 0.03, I2 = 99%), and visfatin (WMD: -1.52 ng/mL, 95% CI: -2.49, -0.56, p = 0.002, I2 = 0%) after fibrate therapy; no significant effect was observed on adiponectin (WMD: -0.69 µg/ml, 95% CI: -1.40, 0.02, p = 0.06, I2 = 83%) and resistin (WMD: -2.27 ng/mL, 95% CI: -7.11, 2.57, p = 0.36, I2 = 0%). The sensitivity analysis was robust only for visfatin, while the effect size was sensitive to one arm for leptin, four for adiponectin, and two for PAI-1. CONCLUSION: This meta-analysis showed that fibrate treatment significantly improves adipokine levels with a decrease in leptin, PAI-1, and visfatin, suggesting potential additional clinical therapeutic benefits through/of fibrate treatment on adipose tissue.

Multifactorial chylomicronemia syndrome.

PURPOSE OF REVIEW: The aim of this review was to understand the role of multifactorial chylomicronemia syndrome (MFCS) as a cause of severe hypertriglyceridemia; to distinguish it from other causes of severe hypertriglyceridemia; and to provide a rational approach to treatment. RECENT FINDINGS: There have been advances in understanding the genetic underpinning of MFCS, and a better appreciation as to how to differentiate it from the much rarer familial chylomicronemia syndrome, in which there are substantial differences in the approach to their treatment. New approaches to triglyceride lowering will help reduce the risk of pancreatitis, the major complication of MFCS. SUMMARY: MCSF is a condition in which plasma triglyceride levels are severely elevated, usually to due exacerbation of common genetic forms of hypertriglyceridemia by secondary causes of hypertriglyceridemia and/or triglyceride-raising drugs. Triglyceride-induced pancreatitis can be prevented by markedly reducing triglyceride levels by treating secondary causes and/or eliminating of triglyceride-raising drugs, and by using triglyceride-lowering drugs, especially fibrates. MFCS also increases cardiovascular disease risk, for which lifestyle measures and drugs are required.

Statin, Ezetimibe, or Fibrate Initiation and Subsequent Use for the Primary and Secondary Prevention of Cardiovascular Diseases among Japanese Patients Aged ≥55 Years: A Nationwide Cohort Study.

The use of lipid-modifying agents (LMAs) other than statins has rarely been reported in real clinical settings. We aimed to compare the initiation and subsequent use of LMA classes for prevention of cardiovascular diseases. Using the national claims database, this retrospective cohort study was conducted on patients aged ≥55 years who initiated to use statins, ezetimibe, or fibrates between Fiscal Years (FYs) 2014 and 2017 as the first pharmacotherapy for dyslipidemia in Japan. A permissible gap for defining persistence was set as the median days of supply of a class to an individual. Kaplan-Meier estimates were calculated for rates. Cohorts for primary prevention without/with risk and secondary prevention comprised 1307438, 908378, and 503059 initiators for statins; 44116, 34206, and 11373 for ezetimibe; and 124511, 96380, and 27751 for fibrates. The persistence rates declined shortly after the therapy initiation regardless of the classes, which was approximately 50% at 1 year for any class for primary prevention without risk. A notable sex difference in terms of persistence rates was observed only for statins of secondary prevention. The restarting rates were similar between prevention settings: approximately 50-60% for statins and 30-40% for ezetimibe and fibrates 1 year after first discontinuation. For ezetimibe and fibrates, approximately 10% of initiators were added or switched to statins within 1 year of initiation. Collectively, any class tended to be discontinued early and some restarted; however, there were some unique classes. The findings are useful for improvement of dyslipidemia therapy.

Impact of Dyslipidemia Medications on the Prevalence of Diabetic Retinopathy Among a Large US Cohort.

BACKGROUND AND OBJECTIVE: Dyslipidemia medications such as statins and fibrates may be associated with a reduction in diabetic retinopathy (DR) progression, but real-world data is lacking. This study evaluates cholesterol-lowering medications and their association with the prevalence of DR and advanced DR complications. PATIENTS AND METHODS: Data was collected using codes from the International Classification of Diseases on TriNetX, a cross-sectional database of over 79 million Americans, between June and August 2022. Prevalence and prevalence odds ratios (POR) were calculated. RESULTS: Patients taking pitavastatin (OR 0.64, 95% CI 0.49, 0.84), fenofibrate (OR 0.83, CI 0.79, 0.87), or evolocumab (OR 0.80, CI 0.68, 0.95) had lower POR of proliferative DR compared to nonproliferative DR. Patients taking any cholesterol medication had a lower POR of vitreous hemorrhage. Patients taking fibrates also had lower POR of neovascular glaucoma. CONCLUSION: This exploratory study highlights positive associations between DR and dyslipidemia and medications that may have fewer worsening events in DR patients. [Ophthalmic Surg Lasers Imaging Retina 2023;54:626-633.].

Differential effects on renal function and glucose metabolism of renal dependent bezafibrate and non-renal dependent pemafibrate in patients with hypertriglyceridemia.

OBJECTIVE: Among fibrates as triglyceride-lowering agents, bezafibrate and fenofibrate are predominantly renally excreted, while pemafibrate is mainly hepatically metabolized and biliary excreted. To elucidate possible different properties among fibrates, this retrospective observational study examined the changes in clinical laboratory parameters, including indices of renal function and glucose metabolism, in cases of switching from bezafibrate to pemafibrate. MATERIALS AND METHODS: In 93 patients with hypertriglyceridemia, the average values of laboratory parameters including serum creatinine, estimated glomerular filtration rate (eGFR), plasma glucose, and hemoglobin A1c on respective two occasions before and after switching from bezafibrate to pemafibrate were evaluated. RESULTS: Triglycerides, low-density and high-density lipoprotein cholesterol, creatine kinase, and uric acid did not change before and after switching from bezafibrate to pemafibrate. Serum creatinine significantly decreased and eGFR significantly increased after switching from bezafibrate to pemafibrate (p < 0.001, respectively). Plasma glucose tended to increase (p = 0.070) and hemoglobin A1c significantly increased (p < 0.001) after switching to pemafibrate. The degrees of changes in creatinine, eGFR, glucose, and hemoglobin A1c before and after drug switching were not affected by the presence or absence of coexisting disease, and with or without drug treatment including statin and renin-angiotensin system inhibitor. CONCLUSION: Our findings indicate that switching from bezafibrate to pemafibrate produces a significant decrease in serum creatinine and increases in eGFR and hemoglobin A1c in patients with hypertriglyceridemia, suggesting that the effects on renal function and glucose metabolism differ among fibrates.

Fibrates, Hypertriglyceridemia, and CVD Risk: Where Do We Stand After the PROMINENT Trial for Triglyceride Lowering?

PURPOSE OF REVIEW: To evaluate recent clinical trials focusing on patients with hypertriglyceridemia. RECENT FINDINGS: Randomized clinical trials have recently been undertaken in hypertriglyceridemic patients to determine whether effective reductions in triglycerides would improve cardiovascular disease (CVD) outcomes. However, the fibric acid derivative, pemafibrate, failed to reduce cardiovascular events despite significant reductions (~ 25-35%) in triglyceride levels and despite background statin therapy. In contrast, icosapent ethyl, a highly purified omega-3 fatty acid was previously shown to reduce CVD events in hypertriglyceridemic patients, despite more modest reductions (~ 20%) in triglyceride levels in statin treated patients. The divergent results obtained in patients with hypertriglyceridemia (HTG), a group at particularly high risk of CVD, especially when coupled with other risk factors, indicates that triglyceride lowering in of itself is insufficient to offset CVD risk. Rather, the effectiveness of therapy in this high-risk cohort may be the result of the suppression of the inherent atherogenic properties associated with HTG.

Very severe hypertriglyceridemia complicating pediatric acute lymphoblastic leukemia treatment: a call for management guidelines.

OBJECTIVES: Severe and very severe hypertriglyceridemia although rare within the pediatric population occur more often among oncology patients, secondary to chemotherapeutic agents. Currently there exists minimal literature to guide management of severe hypertriglyceridemia among pediatric patients. Very-low-fat dietary restriction should be considered over nil per os (NPO) for initial management of severe hypertriglyceridemia in stable pediatric patients. Pediatricians caring for oncology patients must consider chylomicronemia as a potential etiology for presenting symptoms. Pediatric severe hypertriglyceridemia management guidelines are needed as pediatricians must currently rely on anecdotal experiences for management decisions. CASE PRESENTATION: Three children receiving treatment for acute lymphoblastic leukemia required hospitalization for very severe hypertriglyceridemia. Management varied among the cases but included: NPO or very-low-fat diet, insulin, intravenous fluids, fibrates, and omega-3 fatty acids. CONCLUSIONS: These cases suggest that pediatric severe hypertriglyceridemia management, in the absence of pancreatitis should allow a very-low-fat diet initially rather than NPO followed by pharmacologic therapies.

Confirmation of Statin and Fibrate Use from Small-Volume Archived Plasma Samples by High-Throughput LC-MS/MS Method.

Designing studies for lipid-metabolism-related biomarker discovery is challenging because of the high prevalence of various statin and fibrate usage for lipid-lowering therapies. When the statin and fibrate use is determined based on self-reports, patient adherence to the prescribed statin dose regimen remains unknown. A potentially more accurate way to verify a patient's medication adherence is by direct analytical measurements. Current analytical methods are prohibitive because of the limited panel of drugs per test and large sample volume requirement that is not available from archived samples. A 4-min-long method was developed for the detection of seven statins and three fibrates using 10 µL of plasma analyzed via reverse-phase liquid chromatography and tandem mass spectrometry. The method was applied to the analysis of 941 archived plasma samples collected from patients before cardiac catheterization. When statin use was self-reported, statins were detected in 78.6% of the samples. In the case of self-reported atorvastatin use, the agreement with detection was 90.2%. However, when no statin use was reported, 42.4% of the samples had detectable levels of statins, with a similar range of concentrations as the samples from the self-reported statin users. The method is highly applicable in population studies designed for biomarker discovery or diet and lifestyle intervention studies, where the accuracy of statin or fibrate use may strongly affect the statistical evaluation of the biomarker data.

[The PROMINENT trial: swan song of the fibrates]. / De PROMINENT-studie: zwanenzang van de fibraten.

Post hoc analyses of previous fibrate trials have suggested that individuals with type 2 diabetes mellitus with high triglyceride levels and low HDL-cholesterol levels benefit from fibrate therapy even when the overall trial results were neutral. However the PROMINENT (Pemafibrate to Reduce Cardiovascular Outcomes by Reducing Triglycerides in Patients with Diabetes) trial seems to close the door for fibrates. The trial found that fibrates do not reduce the risk of cardiovascular disease among individuals with type 2 diabetes and high triglyceride levels and low HDL cholesterol levels, despite triglyceride lowering. The results of PROMINENT suggest that triglyceride lowering without decreases in the plasma concentration of atherogenic lipoproteins are unlikely to decrease the risk of cardiovascular disease. These results also highlight the importance of rigorously confirmation of post hoc findings before implementation in clinical practice.

Cholestatic Pruritus Treatments in Primary Biliary Cholangitis and Primary Sclerosing Cholangitis: A Systematic Literature Review.

BACKGROUND AND AIMS: We conducted a systematic literature review to understand the evidence supporting treatment decisions for cholestatic pruritus associated with primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC). METHODS: Studies that enrolled ≥ 75% participants with PBC or PSC and reported ≥ 1 endpoint(s) related to efficacy, safety, health-related quality of life (HRQoL) or other patient-reported outcomes were included. Bias was assessed using the Cochrane risk of bias tool for randomised controlled trials (RCTs) and the Quality of Cohort studies tool for non-RCTs. RESULTS: Thirty-nine publications were identified, covering 42 studies and six treatment classes (including investigational and approved products): anion-exchange resins, antibiotics (rifampicin/derivatives), opiates, selective serotonin reuptake inhibitors, fibrates, ileal bile acid transporter inhibitors and other agents not categorised in these six classes. Across studies, median sample size was small (n = 18), 20 studies were over 20 years old, 25 followed patients for ≤ 6 weeks, only 25 were RCTs. Pruritus was assessed using several different tools, with inconsistencies in their application. Cholestyramine, considered first-line therapy for moderate-severe cholestatic pruritus, was assessed in six studies (two RCTs) including 56 patients with PBC and 2 with PSC, with evidence of efficacy demonstrated in only three studies, among which, two RCTs were assessed as having a high risk of bias. Findings were similar for other drug classes. CONCLUSIONS: There is a lack of consistent and reproducible evidence available on efficacy, impact on HRQoL, and safety of cholestatic pruritus treatments, leaving physicians to rely on clinical experience rather than evidence-based medicine for treatment selection.

What is really new in triglyceride guidelines?

PURPOSE OF REVIEW: In this review, we will summarize some of the landmark clinical trials of triglyceride-lowering therapies and review updates in clinical guidelines with regards to treatment of elevated triglyceride levels. RECENT FINDINGS: Accumulating evidence from epidemiologic and Mendelian randomization studies has shown that triglyceride and are causally linked to atherosclerotic cardiovascular disease (ASCVD) and contribute to atherosclerosis. However, most clinical trials evaluating use of triglyceride-lowering therapies, including fibrates, niacin and fish oils [combined eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] have not been able to demonstrate significant cardiovascular risk reduction. REDUCE-IT is the only randomized clinical trial that showed significant cardiovascular benefit with the use of icosapent ethyl esters (a purified EPA), in patients with ASCVD or diabetes with elevated risk on maximally tolerate statin. SUMMARY: Current guidelines and expert consensus documents from multiple societies strongly endorse therapeutic lifestyle interventions to effectively lower TG as the first-line therapy for treatment of hypertriglyceridemia. Evaluation and treatment of secondary causes of hypertriglyceridemia including optimal glycaemic control is crucial. Statins lower ASCVD risk in patients with elevated triglycerides and are first-line for treatment of elevated triglyceride. In a patient with residual mild to moderate hypertriglyceridemia on maximally tolerate statin and elevated cardiovascular risk icosapent, ethyl ester may be used for further ASCVD risk reduction.

Impact of concomitant fibrates on immunotherapy outcomes for advanced non-small cell lung cancer.

BACKGROUND: Peroxisome proliferator-activated receptor agonists such as fibrates restore oxidative metabolism in cytotoxic T-lymphocytes, thereby enhancing response to immune checkpoint inhibitors (ICI) in preclinical models. However, there is no evidence in humans on the clinical impact of fibrates as an adjunct to ICI. METHODS: In this cohort study of Veterans with non-small cell lung cancer (NSCLC) receiving ICI, fibrate exposure was defined as a prescription filled within 90 days of an ICI infusion. Overall survival (OS), measured from the start of ICI, was compared between exposed and unexposed Veterans. Cox multivariable analysis (MVA) was used to identify factors associated with OS. A sensitivity analysis of Veterans with stage IV NSCLC who received docetaxel without ICI was similarly performed. RESULTS: The ICI cohort included 3593 Veterans, of whom 301 (8.5%) coincidentally received a fibrate. Veterans receiving fibrates were more likely to be older, white, male, and married, and to have greater comorbidity burden, but less likely to receive chemotherapy. Coincidental fibrates were associated with improved OS both on MVA (HR 0.86, 95%CI 0.75-0.99) and in a matched subset (HR 0.75, 95%CI 0.63-0.90). In contrast, among the cohort of 968 Veterans treated with chemotherapy, fibrates did not have a significant impact on OS by MVA (HR 0.99, 95%CI 0.79-1.25) or in a matched subset (HR 1.02, 95%CI CI 0.75-1.39). CONCLUSIONS: Concomitant fibrates are associated with improved OS among NSCLC patients receiving ICI but not among those receiving chemotherapy. This hypothesis-generating observation supports a potential role for fibrates as an adjunct to immunotherapy.

UK-Wide Multicenter Evaluation of Second-line Therapies in Primary Biliary Cholangitis.

BACKGROUND & AIMS: Thirty-to-forty percent of patients with primary biliary cholangitis inadequately respond to ursodeoxycholic acid. Our aim was to assemble national, real-world data on the effectiveness of obeticholic acid (OCA) as a second-line treatment, alongside non-licensed therapy with fibric acid derivatives (bezafibrate or fenofibrate). METHODS: This was a nationwide observational cohort study conducted from August 2017 until June 2021. RESULTS: We accrued data from 457 patients; 349 treated with OCA and 108 with fibric acid derivatives. At baseline/pre-treatment, individuals in the OCA group manifest higher risk features compared with those taking fibric acid derivatives, evidenced by more elevated alkaline phosphatase values, and a larger proportion of individuals with cirrhosis, abnormal bilirubin, prior non-response to ursodeoxycholic acid, and elastography readings >9.6kPa (P < .05 for all). Overall, 259 patients (OCA) and 80 patients (fibric acid derivatives) completed 12 months of second-line therapy, yielding a dropout rate of 25.7% and 25.9%, respectively. At 12 months, the magnitude of alkaline phosphatase reduction was 29.5% and 56.7% in OCA and fibric acid groups (P < .001). Conversely, 55.9% and 36.4% of patients normalized serum alanine transaminase and bilirubin in the OCA group (P < .001). The proportion with normal alanine transaminase or bilirubin values in the fibric acid group was no different at 12 months compared with baseline. Twelve-month biochemical response rates were 70.6% with OCA and 80% under fibric acid treatment (P = .121). Response rates between treatment groups were no different on propensity-score matching or on sub-analysis of high-risk groups defined at baseline. CONCLUSION: Across the population of patients with primary biliary cholangitis in the United Kingdom, rates of biochemical response and drug discontinuation appear similar under fibric acid and OCA treatment.

Efficacy of fibrates in the treatment of primary biliary cholangitis: a meta-analysis.

Patients with primary biliary cholangitis (PBC) who respond poorly to ursodeoxycholic acid (UDCA) are increasingly being trialed using fibrates, showing promising results. To further investigate, we performed a meta-analysis to evaluate the benefit of administrating fibrates to patients with PBC. PubMed, EMBASE, and Cochrane library databases were searched using the keywords "bezafibrate", "fenofibrate", "fibrate", "primary biliary cholangitis" and clinical studies involving the use of fibrates in patients with PBC were included. The primary outcome of this study was the effect of fibrates administration on biochemical markers related to cholestasis in patients with PBC, and the secondary outcome was the incidence of treatment-related adverse events. A total of 20 studies with 4783 participants were included in this study. The results revealed that adding fibrates could significantly reduce the levels of ALP (fibrates vs. placebo, MD: - 370.14, P = 0.04; fibrates + UDCA vs. UDCA, MD: - 184.15, P < 0.01), total cholesterol (MD: - 2.82, P = 0.04), GGT (fibrates vs. placebo, MD: - 140.88, P < 0.01; fibrates + UDCA vs. UDCA, MD: - 130.73, P = 0.04), alleviate pruritus symptoms (RD: - 0.20, 95% CI: - 0.39 ~ - 0.01, P = 0.04), and did not significantly increase the incidence of treatment-related side effects. Fibrates can significantly improve liver biochemical parameters and alleviate pruritus in PBC patients.