Effect of Statins on Renal Function in Chronic Kidney Disease Patients

Cardiometabolic comorbidities and complications of obesity and chronic kidney disease (CKD)

Obesity and chronic kidney disease are two ongoing progressive clinical pandemics of major public health and clinical care significance. Because of their growing prevalence, chronic indolent course and consequent complications both these conditions place significant burden on the health care delivery system especially in developed countries like the United States. Beyond the chance coexistence of both of these conditions in the same patient based on high prevalence it is now apparent that obesity is associated with and likely has a direct causal role in the onset, progression and severity of chronic kidney disease. The causes and underlying pathophysiology of this are myriad, complicated and multi-faceted. In this review, continuing the theme of this special edition of the journal on " The Cross roads between Endocrinology and Nephrology" we review the epidemiology of obesity related chronic kidney disease (ORCKD), and its various underlying causes and pathophysiology. In addition, we delve into the consequent comorbidities and complications associated with ORCKD with particular emphasis on the cardio metabolic consequences and then review the current body of evidence for available strategies for chronic kidney disease modulation in ORCKD as well as the potential unique role of weight reduction and management strategies in its improvement and risk reduction.

Statins synergize with phosphodiesterase type 5 inhibitors but not with selective estrogen receptor modulators to prevent myofibroblast transformation in an in vitro model of Peyronie's disease

BACKGROUND

Peyronie's disease (PD) is a fibrotic disorder characterized by plaque formation in the tunica albuginea (TA) of the penis, and we have previously shown that inhibition of transformation of TA-derived fibroblasts to myofibroblasts using a combination phosphodiesterase type 5 (PDE5) inhibitors and selective estrogen receptor modulators (SERMs) is effective in slowing the progression of early PD.

AIM

The study sought to investigate whether combinations of statins with PDE5 inhibitors or SERMs would affect myofibroblast transformation in vitro.

METHODS

Primary fibroblasts were isolated from TA of patients with PD and stimulated with transforming growth factor β1 in the absence and presence of a range of concentrations of statins, PDE5 inhibitors, SERMs, and their combinations for 72 hours before quantifying α-smooth muscle actin using in-cell enzyme-linked immunosorbent assay.

OUTCOMES

The prevention of transforming growth factor β1-induced transformation of TA-derived fibroblasts to myofibroblasts was measured in vitro.

RESULTS

Statins (simvastatin, lovastatin) inhibited myofibroblast transformation in a concentration-dependent manner with half maximal inhibitory concentration values of 0.77 ± 0.07 μM and 0.8 ± 0.13 μM, respectively. Simvastatin inhibited myofibroblast transformation in a synergistic fashion when combined with vardenafil (a PDE5 inhibitor; log alpha >0). Combination of tamoxifen (a SERM) and simvastatin did not show synergy (log alpha <0). When 3 drugs (simvastatin, vardenafil, and tamoxifen) were combined, the effect was not synergistic, but rather was additive.

CLINICAL IMPLICATIONS

A combination of a statin with a PDE5 inhibitor might be useful in the clinic to slow the progression of the disease in patients with early PD; however, caution should be taken with such a combination because of the reported myopathy as a side effect.

STRENGTHS AND LIMITATIONS

The use of primary human cells from patients with PD is a strength of this study. The mechanisms by which these drug classes exert synergy when used in combination was not investigated.

CONCLUSION

This is the first demonstration of an antifibrotic synergy between statins and PDE5 inhibitors.

Effects of Mineralocorticoid Receptor Blockade and Statins on Kidney Injury Marker 1 (KIM-1) in Female Rats Receiving L-NAME and Angiotensin II

Kidney injury molecule-1 (KIM-1) is a biomarker of renal injury and a predictor of cardiovascular disease. Aldosterone, via activation of the mineralocorticoid receptor, is linked to cardiac and renal injury. However, the impact of mineralocorticoid receptor activation and blockade on KIM-1 is uncertain. We investigated whether renal KIM-1 is increased in a cardiorenal injury model induced by L-NAME/ANG II, and whether mineralocorticoid receptor blockade prevents the increase in KIM-1. Since statin use is associated with lower aldosterone, we also investigated whether administering eiSther a lipophilic statin (simvastatin) or a hydrophilic statin (pravastatin) prevents the increase in renal KIM-1. Female Wistar rats (8-10 week old), consuming a high salt diet (1.6% Na+), were randomized to the following conditions for 14 days: control; L-NAME (0.2 mg/mL in drinking water)/ANG II (225 ug/kg/day on days 12-14); L-NAME/ANG II + eplerenone (100 mg/kg/day p.o.); L-NAME/ANG II + pravastatin (20 mg/kg/day p.o.); L-NAME/ANG II + simvastatin (20 mg/kg/day p.o.). Groups treated with L-NAME/ANG II had significantly higher blood pressure, plasma and urine aldosterone, cardiac injury/stroke composite score, and renal KIM-1 than the control group. Both eplerenone and simvastatin reduced 24-h urinary KIM-1 (p = 0.0046, p = 0.031, respectively) and renal KIM-1 immunostaining (p = 0.004, p = 0.037, respectively). Eplerenone also reduced renal KIM-1 mRNA expression (p = 0.012) and cardiac injury/stroke composite score (p = 0.04). Pravastatin did not affect these damage markers. The 24-h urinary KIM-1, renal KIM-1 immunostaining, and renal KIM-1 mRNA expression correlated with cardiac injury/stroke composite score (p < 0.0001, Spearman ranked correlation = 0.69, 0.66, 0.59, respectively). In conclusion, L-NAME/ANG II increases renal KIM-1 and both eplerenone and simvastatin blunt this increase in renal KIM-1.

Fatty kidney: A possible future for chronic kidney disease research

BACKGROUND

Metabolic syndrome is a growing twenty-first century pandemic associated with multiple clinical comorbidities ranging from cardiovascular diseases, non-alcoholic fatty liver disease and polycystic ovary syndrome to kidney dysfunction. A novel area of research investigates the concept of fatty kidney in the pathogenesis of chronic kidney disease, especially in patients with diabetes mellitus or metabolic syndrome.

AIM

To review the most updated literature on fatty kidney and provide future research, diagnostic and therapeutic perspectives on a disease increasingly affecting the contemporary world.

MATERIALS AND METHOD

We performed an extensive literature search through three databases including Embase (Elsevier) and the Cochrane Central Register of Controlled Trials (Wiley) and PubMed/Medline Web of Science in November 2021 by using the following terms and their combinations: 'fatty kidney', 'ectopic fat', 'chronic kidney disease', 'cardiovascular event', 'cardio-metabolic risk', 'albuminuria' and 'metabolic syndrome'. Each study has been individually assessed by the authors.

RESULTS

Oxidative stress and inflammation, Klotho deficiency, endoplasmic reticulum stress, mitochondrial dysfunction and disruption of cellular energy balance appear to be the main pathophysiological mechanisms leading to tissue damage following fat accumulation. Despite the lack of large-scale comprehensive studies in this novel field of research, current clinical trials demonstrate fatty kidney as an independent risk factor for the development of chronic kidney disease and cardiovascular events.

CONCLUSION

The requirement for future studies investigating the pathophysiology, clinical outcomes and therapeutics of fatty kidney is clear.

The Association Between Statin Use and Risk of Chronic Kidney Disease in Community-Dwelling Older People in Shanghai, China

Purpose

The effects of statins on renal outcomes have already been studied in patients with chronic kidney disease (CKD); however, data on the general population are limited. We evaluated the association between statin use and risk of CKD in community-dwelling older people in Shanghai, China.

Patients and Methods

This registry-based cohort study was conducted in four communities in four districts in Shanghai. Participants with an estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m² in 2016 were eligible for the study, and new-onset CKD in 2017, 2018, and 2019 was recorded. Poisson generalized linear models were conducted to examine the relationships among statin therapy, dyslipidemia, and CKD; linear mixed-effects models were conducted to examine the relationships between statin therapy and changes in eGFR. All analyses were performed with both conventional adjustment and propensity score-matching methods.

Results

Of the study cohort of 2455 participants (41.1% men; average age, 68.06 years), 624 (25.4%) were treated with stains. Two propensity score-matched cohorts of 604 participants each were analyzed (statin users and nonusers). Statin use was significantly associated with a decreased risk of new-onset CKD with hazard ratios (HRs) and 95% confidence intervals (CIs) of 0.73 (0.59 to 0.91) (p<0.01) in the unmatched cohort and 0.75 (0.59 to 0.97) (p=0.02) in the matched cohort. There were significant differences in the eGFR decline between statin users and nonusers from baseline to 3 years in the unmatched and matched cohorts (both p<0.05). In addition, both statin users and nonusers with dyslipidemia experienced more new-onset CKD (both p<0.05).

Conclusion

Statin use was significantly associated with a decreased risk of new-onset CKD and a slower decline in eGFR in community-dwelling older people. Meanwhile, dyslipidemia was a risk factor for CKD progression among both statin users and nonusers.

Associations between dietary patterns and stages of chronic kidney disease

BACKGROUND

Studies have revealed that patients with chronic kidney disease (CKD) have dietary patterns different from those of the general population. However, no studies have compared the dietary patterns of between patients with early-stages (stages 1-3a) and late-stages (stages 3b-5) of CKD. Our objective was to investigate the associations between dietary patterns in early and late-stage CKD.

METHODS

We analyzed 4480 participants with CKD at various stages based on the data recorded between 2007 and 2016 from the database of the American National Health and Nutrition Examination Survey.

RESULTS

In total, 3683 and 797 participants had early and late-stage CKD, respectively. Through principal components analysis, the dietary intake dimension was reduced from 63 variables to 3 dietary patterns. We adopted logistic regression for analysis. The three dietary patterns are as follows: (1) saturated fatty acids and mono-unsaturated fatty acids (MUFA); (2) vitamins and minerals; and (3) cholesterols and polyunsaturated fatty acids (PUFA). These 3 patterns explained > 50% of dietary nutrient intake. Results indicated that among participants with dietary patterns 2 (vitamins and minerals) and 3 (cholesterols and PUFA), those with low intakes were more likely to have late-stage CKD. The odds ratios for patterns 2 and 3 were 1.74 (95% CI: 1.21-2.50) and 1.66 (95% CI: 1.13-2.43), respectively.

CONCLUSIONS

This study revealed that intakes of vitamins and minerals and cholesterols and PUFA were associated with the stages of CKD.

Drug Therapies Affecting Renal Function: An Overview

Undesirable side effects of medication are inevitable. Due to the role of the kidneys in clearance and filtration, the renal system faces a unique situation when it comes to the side effects of drugs. It has an important role for different classes of drugs to be excreted, and drugs are a key factor for this system to be at risk. Medications in articles were divided into classes using the standard set by the Saudi Pharmaceutical Journal. Many drug classes cause renal insults. The top six classes were pain killers, antibiotics, proton pump inhibitors, antidiabetics, antihyperlipidemics, and agents for erectile dysfunction. Renal insults caused by these agents could vary in severity. Some drugs could cause nephrotoxicity from one dose, while others may only need continuous monitoring. Different populations also operate under different rules, as some people need dose adjustments while others who are medically free of major illnesses do not. A variety of unfavorable outcomes for the kidney could take place, such as acute kidney injury, chronic kidney disease, and end-stage renal disease, and unfortunately, some of these issues could lead to the need for renal replacement therapies. The outcome of this review paper will help multidisciplinary physicians to understand the renal side effects of the most used drug classes in the Kingdom of Saudi Arabia, their destructive mechanisms, and most importantly, the clinical presentations of renal dysfunction in relation to each class. Emphasizing these adverse effects will prevent future unfavorable outcomes, especially in commonly used drugs that are frequently prescribed for different age groups. Moreover, some of these drugs are considered to be over-the-counter medications, which makes them a serious problem that needs to be handled cautiously.

Young adult onset type 2 diabetes versus type 1 diabetes: Progression to and survival on renal replacement therapy

BACKGROUND

Young-onset type 2 diabetes is an aggressive disease characterized by development of diabetic complications, including nephropathy, early in the disease course. However, within the cohort of young-onset type 1 and type 2 diabetes there are limited comparative data regarding progression to ESKD requiring renal replacement therapy or renal-related death (RRT/RRD).

METHODS

Probabilistic linkage of data from the RPAH Diabetes Centre, National Death Index and Australian and New Zealand Dialysis and Transplant Registry was undertaken. Cumulative Incidence Competing Risk and Cox Proportional Hazards Modelling approaches were utilized to examine progression to ESKD in young-onset type 1 and type 2 diabetes (age of diagnosis 15-35 years).

FINDINGS

Unadjusted incidence rates (95% CI) of RRT/RRD in young-onset type 1 and type 2 diabetes were 3.1 (2.3-4.0) and 4.6 (3.7-5.7) per 1000 person years respectively. After adjustment for gender, ethnicity and duration of diabetes, the HR (95% CI) of RRT/RRD in young-onset type 2 diabetes was 2.0 (1.4-2.9). The HR remained higher after further adjustment for first available cholesterol, HbA1c and systolic blood pressure but not BMI. For those who progressed to RRT, prognosis was similar irrespective of diabetes type; cumulative incidence of mortality was 40% in both young-onset type 1 and type 2 diabetes after 6 years of dialysis.

INTERPRETATION

Progression to RRT/RRD is greater in young-onset type 2 diabetes than in young-onset type 1 diabetes. The increased progression is associated with increased BMI. However, once ESKD is reached, individuals with young-onset type 1 and type 2 diabetes do equally poorly.

Association between baseline LDL-C and prognosis among patients with coronary artery disease and advanced kidney disease

BACKGROUND

Lower low-density lipoprotein cholesterol (LDL-C) is significantly associated with improved prognosis in patients with coronary artery disease (CAD). However, LDL-C reduction does not decrease all-cause mortality among CAD patients when renal function impairs. The association between low baseline LDL-C (< 1.8 mmol/L) and mortality is unknown among patients with CAD and advanced kidney disease (AKD). The current study aimed to evaluate prognostic value of low baseline LDL-C level for all-cause death in these patients.

METHODS

In this observational study, 803 CAD patients complicated with AKD (eGFR < 30 mL/min/1.73 m²) were enrolled between January 2008 to December 2018. Patients were divided into two groups (LDL-C < 1.8 mmol/L, n = 138; LDL-C ≥ 1.8 mmol/L, n = 665). We used Kaplan-Meier methods and Cox regression analyses to assess the association between baseline low LDL-C levels and long-term all-cause mortality.

RESULTS

Among 803 participants (mean age 67.4 years; 68.5% male), there were 315 incidents of all-cause death during a median follow-up of 2.7 years. Kaplan-Meier analysis showed that low LDL-C levels were associated with worse prognosis. After adjusting for full 24 confounders (e.g., age, diabetes, heart failure, and dialysis, etc.), multivariate Cox regression analysis revealed that lower LDL-C level (< 1.8 mmol/L) was significantly associated with higher risk of all-cause death (adjusted HR, 1.38; 95% CI, 1.01-1.89).

CONCLUSIONS

Our data demonstrated that among patients with CAD and AKD, a lower baseline LDL-C level (< 1.8 mmol/L) did not present a higher survival rate but was related to a worse prognosis, suggesting a cautiousness of too low LDL-C levels among patients with CAD and AKD.

Comparison of pleiotropic effects of statins vs fibrates on laboratory parameters in patients with dyslipidemia: A retrospective cohort study

Differences in the mechanism of action and potential pleiotropic effects between statins and fibrates would potentially drive a different effect on various laboratory parameters, but this remains controversial because of a paucity of reports comparing them. Therefore, the aim of this study was to compare the effects of statins and fibrates on laboratory parameters in Japanese patients in routine clinical practice.This retrospective cohort study included patients with dyslipidemia who had been newly treated with statin or fibrate monotherapy between January 2005 and December 2017. Patients were randomly matched into two sets of pairs by sex, age, and baseline triglyceride (TG) or low-density lipoprotein (LDL) cholesterol level. The 830 patients in TG-matched pairs (415 fibrate users and 415 matched statin users) and 1172 patients in LDL cholesterol-matched pairs (586 fibrate users and 586 matched statin users) were included in this study. Generalized estimating equations were used to estimate the effects of the drugs on serum creatinine level, estimated glomerular filtration rate (eGFR), urea nitrogen, hemoglobin A1c, aspartate aminotransferase, and alanine aminotransferase (ALT), in addition to LDL cholesterol and TG levels, and red blood cell (RBC) and platelet (PLT) counts, up to 12 months after the start of study drug administration.In TG-matched pairs, the increases in creatinine and urea nitrogen levels (P = .010 and P < .001, respectively) and the decreases in eGFR, ALT level and RBC count (P < .001, P = .003, and P = .014, respectively) were greater in fibrate users than in statin users. The decrease in PLT count was greater in statin users than in fibrate users (P < .001). The mean changes in aspartate aminotransferase and hemoglobin A1c levels were not significantly different between statin users and fibrate users. In LDL cholesterol-matched pairs, the differences in changes of all laboratory parameter levels between statin users and fibrate users were similar to those in TG-matched pairs.We demonstrate here that fibrates have a greater effect of increasing creatinine and urea nitrogen levels and of reducing eGFR, ALT level, and RBC count than statins, and that the lowering effect on PLT count is greater with statins than with fibrates.

Urinary cathepsin L is predictive of changes in albuminuria and correlates with glucosepane in patients with type 2 diabetes in a closed-cohort study

AIMS

Cathepsin D (CTSD) and L (CTSL) are lysosomal proteases which degrade and detoxify advanced glycation end product (AGE)-modified proteins which are predictive of the development of diabetic nephropathy. We aimed to quantify cathepsin levels in urine from patients with type 2 diabetes and to relate these to the amount of urinary free AGEs at baseline and with kidney function after four years of follow-up in this closed cohort study.

METHODS

We established and validated a LC MS/MS method for the quantification of CTSD and CTSL in urine. Patients with type 2 diabetes were screened for diabetic kidney disease and 141 patients were seen at baseline and after four years. CTSD and CTSL and free AGEs were quantified in urine by LC MS/MS at baseline in these patients.

RESULTS

The detection limit of CTSD and CTSL in urine was 2.4 ng/l and 19.1 ng/l, respectively. CTSD (p < 0.0001, r = 0.555) and CTSL (p < 0.0001, r = 0.608) correlated positively with albuminuria at time of recruitment. In addition levels of the proteases but not albuminuria correlated with urinary levels of the major cross-linking AGE glucosepane (CTSD: p = 0.012, r = 0.225; CTSL: p < 0.001, r = 0.376). A strong non-linear association between CTSD (r = 0.568), CTSL (r = 0.588) and change in albuminuria over four years was present. High levels of CTSL (p = 0.007, beta = -0.366) were associated with an improvement of albuminuria after four years.

CONCLUSIONS

A sensitive LC MS/MS assay for the quantification of CTSD and CTSL in urine was established. High CTSL baseline levels were associated with an improvement in albuminuria at follow-up. An increased excretion and thus detoxification of the free form of the pathogenic cross-linking AGE glucosepane could explain the positive predictive value of high CTSL levels on albuminuria.

Plasma triglyceride levels and central obesity predict the development of kidney injury in Chinese community older adults

Objective: Despite the achievement of blood glucose, blood pressure targets, the risk for kidney injury remains high among older adults. This observational retrospective study investigated whether high TG or high WC contribute to this high residual risk for kidney injury.

Methods: A total of 843 elderly from Dongli Community, Tianjin, China, we selected 666 individuals with a baseline estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m² and negative microalbuminuria completing a 3-year follow-up. At baseline, subjects were grouped according to the levels of TG and WC. The primary outcome was the incidence of kidney injury, defined as low eGFR (eGFR <60 mL/min/1.73 m²) or reduced eGFR (eGFR reduced >25%) or UACR ≥30 mg/g.

Results: Overall, 6.01% developed low eGFR, 11.11% reduced eGFR, 25.98% UACR ≥30 mg/g, and 3.45% low eGFR and UACR ≥30mg/g after 3-year follow-up. TG ≥1.7 mmol/L increased the risk of eGFR <60 mL/min/1.73 m² by 1.44-fold, of UACR ≥30 mg/g by 32%, and of developing both abnormality by 1.41-fold in model 1; further adjustment for potential confounders factors, the association is slightly weakened in model 2 and 3; WC (≥90 cm in men and ≥85 cm in women) were associated with a 1.68-fold higher risk of eGFR <60 mL/min/1.73 m² and a 1.43-fold risk of UACR ≥30 mg/g and a 1.89-fold risk of developing both abnormality in model 1. Further adjustment for potential confounders factors, the association is slightly weakened in model 2 and 3.

Conclusions: In a population of Chinese community-dwelling older adults, high TG and central obesity were risk factors for the development of kidney injury over 3 years.

Impact of dyslipidemia on estimated glomerular filtration rate in apparently healthy children and adolescents: the CASPIAN-V study

BACKGROUND

Chronic kidney disease (CKD) is a leading risk factor for development of cardiovascular disease (CVD). Dyslipidemia is also known as risk factor for CVD development. However, the association of dyslipidemia with glomerular injury among healthy children and adolescents remains controversial. We aimed to investigate the relationship between estimated glomerular filtration rate (eGFR) and lipid profile risk factors among healthy children and adolescents.

METHODS

In this nationwide survey, 3808 participants (1992 males, 1816 females), aged 7-18 years, were selected by cluster random sampling method from 30 provinces in Iran. Body mass index (BMI) and systolic and diastolic blood pressures were measured. Blood samples were obtained for serum creatinine, fasting blood glucose, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) determinations. GFR was estimated using Schwartz equation.

RESULTS

Girls had higher eGFR than boys (P = 0.04). In a multiple regression analysis, eGFR demonstrated a positive correlation with systolic blood pressure, BMI, fasting glucose, TC, HDL-C, and TG. By the analysis of covariance, TC, HDL-C, and TG showed a negative correlation with eGFR after adjustments for BMI, systolic and diastolic blood pressures, and fasting glucose (OR = 0.56, 95% CI = 0.29-0.89).

CONCLUSION

The study showed that dyslipidemia is associated with reduced eGFR among the healthy children and adolescents.

Lipid Accumulation and Chronic Kidney Disease. Nutrients. 2019;11. [PMID: 30925738 PMCID: PMC6520701 DOI: 10.3390/nu11040722]

Obesity and hyperlipidemia are the most prevalent independent risk factors of chronic kidney disease (CKD), suggesting that lipid accumulation in the renal parenchyma is detrimental to renal function. Non-esterified fatty acids (also known as free fatty acids, FFA) are especially harmful to the kidneys. A concerted, increased FFA uptake due to high fat diets, overexpression of fatty acid uptake systems such as the CD36 scavenger receptor and the fatty acid transport proteins, and a reduced β-oxidation rate underlie the intracellular lipid accumulation in non-adipose tissues. FFAs in excess can damage podocytes, proximal tubular epithelial cells and the tubulointerstitial tissue through various mechanisms, in particular by boosting the production of reactive oxygen species (ROS) and lipid peroxidation, promoting mitochondrial damage and tissue inflammation, which result in glomerular and tubular lesions. Not all lipids are bad for the kidneys: polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) seem to help lag the progression of chronic kidney disease (CKD). Lifestyle interventions, especially dietary adjustments, and lipid-lowering drugs can contribute to improve the clinical outcome of patients with CKD.