Statins in Chronic Kidney Disease: Cardiovascular Risk and Kidney Function

Causal effects of gut microbiota on the risk of chronic kidney disease: a Mendelian randomization study

Background

Previous studies have reported that gut microbiota is associated with an increased risk of chronic kidney disease (CKD) progression. However, whether gut microbiota has a causal effect on the development of CKD has not been revealed. Thus, we aimed to analyze the potential causal effect of gut microbiota on the risk of CKD using mendelian randomization (MR) study.

Materials and Methods

Independent single nucleotide polymorphisms closely associated with 196 gut bacterial taxa (N = 18340) were identified as instrumental variables. Two-sample MR was performed to evaluate the causal effect of gut microbiota on CKD (N = 480698), including inverse-variance-weighted (IVW) method, weighted median method, MR-Egger, mode-based estimation and MR-PRESSO. The robustness of the estimation was tested by a series of sensitivity analyses including Cochran’s Q test, MR-Egger intercept analysis, leave-one-out analysis and funnel plot. Statistical powers were also calculated.

Results

The genetically predicted higher abundance of order Desulfovibrionales was causally associated with an increased risk of CKD (odds ratio = 1.15, 95% confidence interval: 1.05-1.26; p = 0.0026). Besides, we also detected potential causalities between nine other taxa (Eubacterium eligens group, Desulfovibrionaceae, Ruminococcaceae UCG-002, Deltaproteobacteria, Lachnospiraceae UCG-010, Senegalimassilia, Peptostreptococcaceae, Alcaligenaceae and Ruminococcus torques group) and CKD (p < 0.05). No heterogeneity or pleiotropy was detected for significant estimates.

Conclusion

We found that Desulfovibrionales and nine other taxa are associated with CKD, thus confirming that gut microbiota plays an important role in the pathogenesis of CKD. Our work also provides new potential indicators and targets for screening and prevention of CKD.

Di-(2-ethylhexyl) Phthalate Limits the Lipid-Lowering Effects of Simvastatin by Promoting Protein Degradation of Low-Density Lipoprotein Receptor: Role of PPARγ-PCSK9 and LXRα-IDOL Signaling Pathways

Dialysis prevents death from uremia in patients with end-stage renal disease (ESRD). Nevertheless, during hemodialysis, circulating levels of di-(2-ethylhexyl) phthalate (DEHP) are increased due to phthalates leaching from medical tubes. Statins are an effective therapy for reducing the risks associated with cardiovascular diseases in patients with chronic kidney disease; however, the mechanism by which statins fail to reduce cardiovascular events in hemodialysis ESRD patients remains unclear. In this study, we investigated whether DEHP and its metabolites interfere with the lipid-lowering effect of statins in hepatocytes. In Huh7 cells, treatment with DEHP and its metabolites abolished the simvastatin-conferred lipid-lowering effect. Mechanistically, DEHP down-regulated the expression of low-density lipoprotein receptor (LDLR) and led to a decrease in LDL binding, which was mediated by the activation of the PPARγ-PCSK9 and LXRα-IDOL signaling pathways. Additionally, the NOX-ROS-TRPA1 pathway is involved in the DEHP-mediated inhibition of LDLR expression and LDL binding activity. Blockage of this pathway abrogated the DEHP-mediated inhibition in the LDLR expression and LDL binding of simvastatin. Collectively, DEHP induces the activation of the NOX-ROS-TRPA1 pathway, which in turn activates PPARγ-PCSK9- and LXRα-IDOL-dependent signaling, and, ultimately, diminishes the statin-mediated lipid-lowering effect in hepatocytes.

Atorvastatin lowers serum calcium levels in lithium-users: results from a randomized controlled trial

BACKGROUND

Although lithium is considered the gold-standard treatment for bipolar disorder (BD), it is associated with a variety of major endocrine and metabolic side effects, including parathyroid hormone (PTH) dependent hypercalcemia. Aside from surgery and medication discontinuation, there are limited treatments for hypercalcemia. This paper will assess data from a randomized controlled trial (RCT).

METHODS

This is a secondary analysis of an RCT that explored the effects of atorvastatin (n = 27) versus placebo (n = 33) on lithium-induced nephrogenic diabetes insipidus (NDI) in patients with BD and major depressive disorder (MDD) using lithium (n = 60), over a 12-week period. This secondary analysis will explore serum calcium levels and thyroid stimulating hormone (TSH) measured at baseline, week 4, and week 12.

RESULTS

At 12-weeks follow-up while adjusting results for baseline, linear regression analyses found that corrected serum calcium levels were significantly lower in the treatment group (mean (M) = 2.30 mmol/L, standard deviation (SD) = 0.07) compared to the placebo group (M = 2.33 mmol/L, SD = 0.07) (β = - 0.03 (95% C.I.; - 0.0662, - 0.0035), p = 0.03) for lithium users. There were no significant changes in TSH.

CONCLUSION

In lithium users with relatively normal calcium levels, receiving atorvastatin was associated with a decrease in serum calcium levels. Although exciting, this is a preliminary finding that needs further investigation with hypercalcemic patients. Future RCTs could examine whether atorvastatin can treat PTH dependent hypercalcemia due to lithium and other causes.

The Effect of Statin on Anemia in Patients with Chronic Kidney Disease and End-Stage Kidney Disease: A Systematic Review and Meta-Analysis

Although erythropoietin-stimulating agents are effective in treating anemia in patients with end-stage kidney disease (ESKD) undergoing hemodialysis, some ESKD patients, especially those with inflammation, continue to suffer from anemia. Statin, an inhibitor of hydroxymethylglutaryl-CoA (HMG-CoA) reductase with lipid-lowering effects, may have a pleiotropic effect in reducing inflammation, and thus increase hemoglobin (Hb) level. We searched the PubMed, Embase, and Cochrane databases for relevant studies. The population of interest comprised advanced chronic kidney disease (CKD) patients and ESKD patients receiving hemodialysis with statin treatment. The included study designs were randomized control trial/cohort study/pre-post observational study, and outcomes of interest were Hb, erythropoietin resistance index (ERI) and ferritin. PRISMA 2020 guidelines were followed, and risk of bias (RoB) was assessed using the RoB 2.0 tool in randomized controlled trials, and the Newcastle-Ottawa scale (NOS) in cohort studies. We eventually included ten studies (5258 participants), comprising three randomized controlled trials and seven cohort studies. Overall, Hb increased by 0.84 g/dL (95% confidence interval [CI]: −0.02 to 1.70) in all groups using statins, including single-arm cohorts, and by 0.72 g/dL (95% CI: −0.02 to 1.46) in studies with placebo control. Hb levels were higher in the study group than in the control group, with a mean difference of 0.18 g/dL (95% CI: 0.04–0.32) at baseline and 1.0 g/dL (95% CI: 0.13–1.87) at the endpoint. Ferritin increased by 9.97 ng/mL (95% CI: −5.36 to 25.29) in the study group and decreased by 34.01 ng/mL (95% CI: −148.16 to 80.14) in the control group; ferritin fluctuation was higher in the control group. In conclusion, statin may improve renal anemia in ESKD patients receiving hemodialysis and regular erythropoietin-stimulating agents. Future studies with more rigorous methodology and larger sample size study should be performed to confirm this beneficial effect.

Statin Utilization among Patients with Acute Coronary Syndrome: Systematic Review

BACKGROUND: The early use of statin with intensive regimen has been recommended by the recent guidelines as the prevention of acute coronary syndrome (ACS) related events among the high-risk patients. Meanwhile, the inconsistent statin utilization for targeted patient in current practice is still an issue. AIM: This study aims to review the utilization rate of statin among patients with ACS. METHODS: A systematic search of relevant studies published between inceptions to June 2020 was conducted in PubMed. Patients and intervention domains were used to build up the searching formula. A study was eligible for inclusion if it was an original study of patients with ACS and it examined the utilization of statin. The risk of bias was assessed using Axis and NOS checklist. RESULTS: Among the 49 eligible studies, 38 were cohort studies while the others were cross-sectional studies. The utilization rate of statin at hospital admission ranged from 16% to 61% while 25% to 75% during the hospitalization. Of the total studies, 35 studies reported the statin rate at discharge ranging from 58% to 99%. Almost all studies revealed the reduction of statin utilization rate along the follow-up period. The number of statins prescribed was found to be lower among female and elderly patients. CONCLUSION: Despite the established benefits of statin among patients with ACS, our study revealed that statin was underutilized for secondary prevention after ACS. To improve patients’ clinical outcomes with ACS, efforts should be made to increase optimal treatment and compliance with a statin.

A double-blind, randomized, placebo-controlled pilot trial of atorvastatin for nephrogenic diabetes insipidus in lithium users

OBJECTIVE

Lithium remains an important treatment for mood disorders but is associated with kidney disease. Nephrogenic diabetes insipidus (NDI) is associated with up to 3-fold risk of incident chronic kidney disease among lithium users. There are limited randomized controlled trials (RCT) for treatments of lithium-induced NDI, and existing therapies can be poorly tolerated. Therefore, novel treatments are needed for lithium-induced NDI.

METHOD

We conducted a 12-week double-blind pilot RCT to assess the feasibility and efficacy of 20 mg/d atorvastatin vs placebo in the treatment of NDI in chronic lithium users. Patients, recruited between September 2017 and October 2018, were aged 18 to 85, currently on a stable dose of lithium, and determined to have NDI.

RESULTS

Urinary osmolality (UOsm) at 12 weeks adjusted for baseline was not statistically different between groups (+39.6 mOsm/kg [95% CI, -35.3, 114.5] in atorvastatin compared to placebo groups). Secondary outcomes of fluid intake and aquaporin-2 excretions at 12 weeks adjusted for baseline were -0.13 L [95% CI, -0.54, 0.28] and 98.68 [95% CI, -190.34, 387.70], respectively. A moderate effect size was observed for improvements in baseline UOsm by ≥100 mOsm/kg at 12 weeks in patients who received atorvastatin compared to placebo (38.45% (10/26) vs 22.58% (7/31); Cohen's d = 0.66).

CONCLUSION

Among lithium users with NDI, atorvastatin 20 mg/d did not significantly improve urinary osmolality compared to placebo over a 12-week period. Larger confirmatory trials with longer follow-up periods may help to further assess the effects of statins on NDI, especially within patients with more severe NDI.

State of the art - sirtuin 1 in kidney pathology - clinical relevance

Sirtuins represent a group of nicotinamide adenine dinucleotide dependent histone deacetylases, which regulates various biological pathways by promoting chromatin silencing and transcriptional repression. Therefore, they are linked to cellular energy metabolism, mitochondrial biogenesis, stress response, apoptosis, inflammation and fibrosis. Since sirtuin 1 became a promising candidate for targeted therapies of numerous conditions, researchers have been investigating its activator. As for now, natural agents and antidiabetic drug - metformin, have been found to activate sirtuin 1. Sirtuin 1 is able to improve kidney outcomes by direct impact on kidney cells, regulation of non-specific processes generally involved in pathogenesis of age-dependent and metabolic disorders and improvement of the comorbid diseases. This review discusses the state of the art knowledge on the role of sirtuin 1 on kidney pathology.

A higher ratio of refined grain to whole grain is associated with a greater likelihood of chronic kidney disease: a population-based study

A growing number of studies suggest that diet and renal function are related. However, little is known about the link between both whole grain (WG) and refined grain (RG) consumption and kidney function parameters. Thus, we investigated the association of WG and RG with urinary albumin to creatinine ratio (ACR) and prevalent chronic kidney disease (CKD). Data from participants of the National Health and Nutrition Examination Surveys (NHANES) from 2005 to 2010 were collected. Estimated glomerular filtration rate (eGFR) was calculated by the CKD Epidemiology Collaboration equation. Survey design and sample weights were taken into consideration for statistical analyses. Finally, we included 16 325 participants from NHANES, 6·9 % of whom had prevalent CKD. In models adjusted for age, sex, race, fasting blood glucose, blood pressure, adiposity, hypertension and diabetes status, mean eGFR significantly increased across increasing quartiles of WG (Q1: 88·2 v. Q4: 95·4 ml/min per 1·73 m2, P<0·001), whereas it significantly decreased across increasing quartiles of RG (Q1: 97·2 v. Q4: 88·4 ml/min per 1·73 m2, P<0·001). Furthermore, serum uric acid levels and ACR significantly decreased across quartiles of WG (both P<0·001). In multivariable-adjusted logistic regression models, the likelihood of prevalent CKD was 21 % lower in the highest WG quartile compared with the lowest one. In conclusion, our results shed light on the beneficial impact of WG on kidney function and CKD, whereas RG is adversely associated with eGFR.

Comparative Effectiveness of Inclisiran 100, 300, and 500 mg in a Population with Hyperlipidemia: A Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

To our knowledge, inclisiran was the first agent composed of small interfering RNAs (siRNAs) to be preliminarily used to reduce proatherogenic lipoprotein cholesterol levels. Inclisiran was evaluated in large clinical trials but did not receive government approval. The ability of inclisiran to reduce low-density lipoprotein cholesterol (LDL-C) greatly improved its chances of becoming a novel therapeutic option for patients with hyperlipidemia.

OBJECTIVE

Our goal was to summarize the preliminary effectiveness and safety data for inclisiran.

METHODS

We conducted a comprehensive search of PubMed, Scopus, Web of Science, the OVID EMB Reviews database, and Clinical Trials with the keyword "inclisiran" to find all related randomized controlled trials (RCTs). Five recently published RCTs involving 583 adults aged 18-65 years with hyperlipidemia were included in the analysis.

RESULTS

Subgroup analysis suggested that inclisiran 100 mg (standard mean difference [SMD] - 2.09; 95% confidence interval [CI] - 2.51 to - 1.66; p < 0.05), 300 mg (SMD - 2.74; 95% CI - 3.61 to - 1.87; p < 0.05), and 500 mg (SMD - 2.21; 95% CI - 2.62 to - 1.80; p < 0.05) significantly (p < 0.05) reduced LDL-C and total cholesterol even though pooled analysis showed no LDL-C-lowering effect (SMD 0.15; 95% CI - 0.34 to 0.04; p = 0.116). Compared with patients receiving placebo, pooled and subgroup analysis of patients receiving inclisiran showed no favorable changes in triglycerides or high-density lipoprotein cholesterol (p > 0.05). The most commonly reported adverse events were musculoskeletal pain, nasopharyngitis, headache, and elevated C-reactive protein (CRP), none of which were significant (p > 0.05).

CONCLUSIONS

To date, inclisiran has been effective in treating hyperlipidemia. Major adverse events were not identified, although other possible adverse events may be discovered with more RCTs and extensive long-term follow-up.

Atorvastatin in the treatment of Lithium-induced nephrogenic diabetes insipidus: the protocol of a randomized controlled trial

BACKGROUND

Lithium is the gold-standard treatment for bipolar disorder, is highly effective in treating major depressive disorder, and has anti-suicidal properties. However, clinicians are increasingly avoiding lithium largely due to fears of renal toxicity. Nephrogenic Diabetes Insipidus (NDI) occurs in 15-20% of lithium users and predicts a 2-3 times increased risk of chronic kidney disease (CKD). We recently found that use of statins is associated with lower NDI risk in a cross-sectional study. In this current paper, we describe the methodology of a randomized controlled trial (RCT) to treat lithium-induced NDI using atorvastatin.

METHODS

We will conduct a 12-week, double-blind placebo-controlled RCT of atorvastatin for lithium-induced NDI at McGill University, Montreal, Canada. We will recruit 60 current lithium users, aged 18-85, who have indicators of NDI, which we defined as urine osmolality (UOsm) < 600 mOsm/kg after 10-h fluid restriction. We will randomize patients to atorvastatin (20 mg/day) or placebo for 12 weeks. We will examine whether this improves measures of NDI: UOsm and aquaporin (AQP2) excretion at 12-week follow-up, adjusted for baseline.

RESULTS

Not applicable.

CONCLUSION

The aim of this clinical trial is to provide preliminary data about the efficacy of atorvastatin in treating NDI. If successful, lithium could theoretically be used more safely in patients with a reduced subsequent risk of CKD, hypernatremia, and acute kidney injury (AKI). If future definitive trials confirm this, this could potentially allow more patients to benefit from lithium, while minimizing renal risk.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02967653 . Registered in February 2017.

Regional evidence and international recommendations to guide lipid management in Asian patients with type 2 diabetes with special reference to renal dysfunction

The anticipated increase in the prevalence and incidence of type 2 diabetes in Asia, and its associated cardiovascular-renal complications, will place a significant burden on patients, caregivers, and society. Despite the proven effectiveness of lipid management in reducing these complications, there are major treatment gaps, especially in Asian patients with young-onset diabetes and chronic kidney disease (CKD). Recent international guidelines recommended the adoption of absolute risk estimation of atherosclerosis and cardiovascular disease to guide treatment intensity. These recommendations replaced the previous strategy of using low-density lipoprotein cholesterol targets to guide initiation and intensification of lipid lowering, albeit still widely practiced in Asia. The latest guidelines also highlight the high risk of atherosclerosis and cardiovascular disease (ASCVD) for people with diabetes, who should be protected with statins, except for young patients without other risk factors, who will need yearly monitoring of blood lipid levels. Given the propensity of Asian patients with diabetes to develop CKD and the amplifying effect of CKD on ASCVD, the use of statins in Asian patients is particularly important. Due to interethnic differences in drug metabolism, rosuvastatin, which is largely cleared by the kidney, should be prescribed in low dosages (5-10 mg daily) in Asian populations. Conversely, epidemiological and experimental data confirm pleotropic and organ-protective effects of atorvastatin, with proven safety in Asian populations within a daily dose range of 10-40 mg. Thus, there is a need for Asian countries to review and align their lipid-lowering treatment guidelines to reduce the substantial burden of diabetes in the Asian region.

Guggulsterone Attenuated Lipopolysaccharide-Induced Inflammatory Responses in Mouse Inner Medullary Collecting Duct-3 Cells

Guggulsterone (GS) is a phytosterol that has been used to treat inflammatory diseases such as colitis, obesity, and thrombosis. Although many previous studies have examined activities of GS, the effect of GS on lipopolysaccharide (LPS)-induced inflammatory responses in mouse inner medullary collecting duct-3 (mIMCD-3) cells have not been examined. Therefore, here, we investigated the anti-inflammatory action of GS on mIMCD-3 cells exposed to LPS. LPS treatment on mIMCD-3 cells produced pro-inflammatory molecules such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) significantly; however, GS treatment significantly inhibited the production of pro-inflammatory molecules. In addition, GS inhibited the degradation of Iκ-Bα and translocation of NF-κB on mIMCD-3 cells. These results suggest that GS could inhibit inflammatory responses in collecting duct cells which could contribute to kidney injury during systemic infection.

High-intensity statin therapy in patients with chronic kidney disease: a systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy and safety of high-intensity statin therapy in patients with chronic kidney disease (CKD).

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

Randomised controlled trials (RCTs) comparing high-intensity statin therapy (atorvastatin 80 mg or rosuvastatin 20/40 mg) with moderate/mild statin treatment or placebo were derived from the databases (PubMed, Embase, Ovid, the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, and ISI Web of Knowledge).

OUTCOME MEASURE

Primary end points: clinical events (all-cause mortality, stroke, myocardial infarction and heart failure); secondary end points: serum lipid, renal function changes and adverse events.

RESULTS

A total of six RCTs with 10,993 adult patients with CKD were included. A significant decrease in stroke was observed in the high-intensity statin therapy group (RR 0.69, 95% CI 0.56 to 0.85). However, the roles of high-intensity statin in decreasing all-cause mortality (RR 0.85, 95% CI 0.67 to 1.09), myocardial infarction (RR 0.69, 95% CI 0.40 to 1.18) and heart failure (RR 0.73, 95% CI 0.48 to 1.13) remain unclear with low evidence. High-intensity statin also had obvious effects on lowering the LDL-C level but no clear effects on renal protection. Although pooled results showed no significant difference between the intervention and control groups in adverse event occurrences, it was still insufficient to put off the doubts that high-intensity statin might increase adverse events because of limited data sources and low quality evidences.

CONCLUSIONS

High-intensity statin therapy could effectively reduce the risk of stroke in patients with CKD. However, its effects on all-cause mortality, myocardial infarction, heart failure and renal protection remain unclear. Moreover, it is hard to draw conclusions on the safety assessment of intensive statin treatment in this particular population. More studies are needed to credibly evaluate the effects of high-intensity statin therapy in patients with CKD.