Hypercaloric Diet Promotes Metabolic Disorders and Impaired Kidney Function

Poor dietary habits such as overconsumption of hypercaloric diets characterized by a high content of fructose and fat are related to metabolic abnormalities development such as obesity, diabetes, and dyslipidemia. Accumulating evidence supports the hypothesis that if energy intake gradually exceeds the body's ability to store fat in adipose tissue, the prolonged metabolic imbalance of circulating lipids from endogenous and exogenous sources leads to ectopic fat distribution in the peripheral organs, especially in the heart, liver, and kidney. The kidney is easily affected by dyslipidemia, which induces lipid accumulation and reflects an imbalance between fatty acid supply and fatty acid utilization. This derives from tissue lipotoxicity, oxidative stress, fibrosis, and inflammation, resulting in structural and functional changes that lead to glomerular and tubule-interstitial damage. Some authors indicate that a lipid-lowering pharmacological approach combined with a substantial lifestyle change should be considered to treat chronic kidney disease (CKD). Also, the new therapeutic target identification and the development of new drugs targeting metabolic pathways involved with kidney lipotoxicity could constitute an additional alternative to combat the complex mechanisms involved in impaired kidney function. In this review article, we first provide the pathophysiological evidence regarding the impact of hypercaloric diets, such as high-fat diets and high-fructose diets, on the development of metabolic disorders associated with impaired renal function and the molecular mechanisms underlying tissue lipid deposition. In addition, we present the current progress regarding translational strategies to prevent and/or treat kidney injury related to the consumption of hypercaloric diets.

Impact of fenofibrate therapy on serum uric acid concentrations: a review and meta-analysis

Fenofibrate is a marketed fibric acid derivative for lipid-lowering in patients with lipid disorders. Numerous studies have proven fenofibrate had a certain effect on serum uric acid, here we conducted this study to quantitatively assess the effect of fenofibrate intervention in modulating serum uric acid concentration and the influence on serum creatinine. The PubMed, Embase and Cochrane were systematically searched for randomized controlled trials update to January, 2020. Primary endpoints focused on serum uric acid concentration and serum creatinine concentration. The pooled effects were calculated as weighted mean difference (WMD) by a random-effects model. Finally, 9 studies representing 487 patients were included in the meta-analysis. The meta-analysis demonstrated that fenofibrate significantly reduced serum uric acid levels (WMD -1.32 mg/dL, 95%CI -1.61 to -1.03, p < 0.001) and an elevated level in serum creatinine (WMD 0.09 mg/dL, 95%CI 0.02 to 0.15, p < 0.001) following fenofibrate therapy compared with placebo. The present study provided strong evidence that fenofibrate intervention exerted a significant reduction on serum uric acid and a mild increase on serum creatinine. Meta-analysis suggested that there were no significant association between the serum uric acid lowering effect with either dose or treatment duration. Overall, our meta-analysis ascertained that fenofibrate have potential therapeutic effects in patients with lipid metabolic abnormalities but with mid nephrotoxicity. There is strong evidence to provide future direction of practical application and clinical researches of fenofibrate.

Long-Term Efficacy and Safety of Pemafibrate, a Novel Selective Peroxisome Proliferator-Activated Receptor-α Modulator (SPPARMα), in Dyslipidemic Patients with Renal Impairment

Pemafibrate (K-877) is a novel selective peroxisome proliferator-activated receptor-α modulator (SPPARMα) with a favorable benefit-risk balance. Previous clinical trials of pemafibrate used stringent exclusion criteria related to renal functions. Therefore, we investigated its safety and efficacy in a broader range of patients, including those with chronic kidney disease (CKD). In this multicenter, single-arm, open-label, phase III trial, 0.2⁻0.4 mg/day pemafibrate was administered for 52 weeks to 189 patients with hypertriglyceridemia and an estimated glomerular filtration rate (eGFR) ≥ 45 mL/min/1.73 m² on statin or regardless of eGFR when statin was not administered. Post-hoc analyses were performed on subgroups stratified by baseline eGFR. Triglyceride levels decreased by 45.9% at week 52 (last-observation-carried-forward). These reductions were not correlated with baseline eGFR. The eGFR < 30 mL/min/1.73 m² subgroup showed the greatest reduction in chylomicron, very low-density lipoprotein, small low-density lipoprotein cholesterol levels, and an increase in high-density lipoprotein cholesterol levels. The incidences of adverse events and adverse drug reactions were 82.0% and 31.7%, respectively, and these were not associated with baseline eGFR. In CKD patients, pemafibrate blood concentrations were not elevated. Pemafibrate showed a good safety profile and efficacy in correcting lipid abnormalities in a broad range of patients, including those with CKD.

The effects of dual PPARα/γ agonism compared with ACE inhibition in the BTBRob/ob mouse model of diabetes and diabetic nephropathy

The leptin‐deficient BTBRob/ob mouse develops progressive albuminuria and morphological lesions similar to human diabetic nephropathy (DN), although whether glomerular hyperfiltration, a recognized feature of early DN that may contribute to renal injury, also occurs in this model is not known. Leptin replacement has been shown to reverse the signs of renal injury in this model, but in contrast, the expected renoprotection by angiotensin‐converting enzyme (ACE) inhibition in BTBRob/ob mice seems to be limited. Therefore, to investigate the potential renal benefits of improved metabolic control in this model, we studied the effect of treatment with the dual peroxisome proliferator‐activated receptor (PPAR) α/γ agonist AZD6610 and compared it with the ACE inhibitor enalapril. AZD6610 lowered plasma glucose and triglyceride concentrations and increased liver size, but had no significant effect in reducing albuminuria, whereas enalapril did have an effect. Nephrin and WT1 mRNA expression decreased in the kidneys of BTBRob/ob mice, consistent with podocyte injury and loss, but was unaffected by either drug treatment: at the protein level, both nephrin and WT1‐positive cells per glomerulus were decreased. Mesangial matrix expansion was reduced in AZD6610‐treated mice. GFR, measured by creatinine clearance, was increased in BTBRob/ob mice, but unaffected by either treatment. Unexpectedly, enalapril‐treated mice showed intrarenal arteriolar vascular remodeling with concentric thickening of vessel walls. In summary, we found that the BTBRob/ob mouse model shows some similarities to the early changes seen in human DN, but that ACE inhibition or PPARα/γ agonism afforded limited or no kidney protection.

Effect of Fenofibrate Medication on Renal Function

BACKGROUND

Fibrates are widely used to treat hypertriglyceridemia, a risk factor for arteriosclerosis, but these compounds have been associated with renal dysfunction. This study aimed to investigate the effects of fibrates on renal function in relatively healthy adult subjects with no cardiovascular diseases.

METHODS

This retrospective study included 558 outpatients who were prescribed 160 mg fenofibrate (fenofibrate group) or 10 mg atorvastatin (control group) between August 2007 and October 2015. The groups were randomly matched using propensity scores at a 1:1 ratio. Serum creatinine levels and estimated glomerular filtration rates before and after treatment were compared between the two groups.

RESULTS

Patients in the fenofibrate group showed greater changes in serum creatinine levels than those in the control group (9.73%±9.83% versus -0.89%±7.37%, P<0.001). Furthermore, 55.1% of patients in the fenofibrate group, but only 6.1% of those in the control group, exhibited a serum creatinine level increase ≥0.1 mg/dL (P<0.001). The fenofibrate group showed significantly greater declines in the estimated glomerular filtration rate than the control group (-10.1%±9.48% versus 1.42%±9.42%, P<0.001). Moreover, 34.7% of the fenofibrate group, but only 4.1% of the control group, exhibited an estimated glomerular filtration rate decrease ≥10 mL/min·1.73 m² (P<0.001).

CONCLUSION

Fenofibrate treatment resulted in increased serum creatinine levels and reduced estimated glomerular filtration rates in a primary care setting. Therefore, regular renal function monitoring should be considered essential during fibrate administration.

Treatment of dyslipidemia in allogeneic hematopoietic stem cell transplant patients

As survival rates in allogeneic hematopoietic stem cell transplantation (HSCT) continue to improve, attention to long-term complications, including cardiovascular disease, becomes a major concern. Cardiovascular disease and dyslipidemia are a common, yet often overlooked occurrence post-HSCT that results in significant morbidity and mortality. Also, increasing evidence shows that several anti-hyperlipidemia medications, the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors in particular, may have a role in modulating graft-versus-host disease (GVHD). However, factors such as drug-drug interactions, adverse effect profiles, and the relative efficacy in lowering cholesterol and triglyceride levels must be taken into account when choosing safe and effective lipid-lowering therapy in this setting. This review seeks to provide guidance to the clinician in the management of dyslipidemia in the allogeneic HSCT population, taking into account the recently published American College of Cardiology/American Heart Association guidelines on hyperlipidemia management, special considerations in this challenging population, and the evidence for each agent's potential role in modulating GVHD.

Fenofibrate and dipyridamole treatments in low-doses either alone or in combination blunted the development of nephropathy in diabetic rats

Low-doses of fenofibrate and dipyridamole have pleiotropic renoprotective actions in diabetic rats. This study investigated their combined effect relative to their individual treatments and lisinopril in rats with diabetic nephropathy. Streptozotocin (55mg/kg, i.p., once)-administered diabetic rats were allowed for 10 weeks to develop nephropathy. Diabetic rats after 10 weeks developed nephropathy with discernible renal structural and functional changes as assessed in terms of increase in kidney weight to body weight ratio (KW/BW), and elevations of serum creatinine, urea and uric acid, which accompanied with elevated serum triglycerides and decreased high-density lipoproteins. Hematoxylin-eosin, periodic acid Schiff and Masson trichrome staining confirmed renal pathological changes in diabetic rats that included glomerular capsular wall distortion, mesangial cell expansion, glomerular microvascular condensation, tubular damage and degeneration and fibrosis. Low-dose fenofibrate (30mg/kg, p.o., 4 weeks) and low-dose dipyridamole (20mg/kg, p.o., 4 weeks) treatment either alone or in combination considerably reduced renal structural and functional abnormalities in diabetic rats, but without affecting the elevated glucose level. Fenofibrate, but not dipyridamole, significantly prevented the lipid alteration and importantly the uric acid elevation in diabetic rats. Lisinopril (5mg/kg, p.o., 4 weeks, reference compound), prevented the hyperglycemia, lipid alteration and development of diabetic nephropathy. Lipid alteration and uric acid elevation, besides hyperglycemia, could play key roles in the development of nephropathy. Low-doses of fenofibrate and dipyridamole treatment either alone or in combination markedly prevented the diabetes-induced nephropathy. Their combination was as effective as to their individual treatment, but not superior in preventing the development of diabetic nephropathy.

Fenofibrate-associated nephrotoxicity: a review of current evidence

PURPOSE

The literature describing fenofibrate-associated nephrotoxicity was reviewed.

SUMMARY

Fenofibrate-associated nephrotoxicity is an underrecognized adverse effect that is being reported with increasing frequency in the medical literature. A MEDLINE search identified articles describing fenofibrate-associated nephrotoxicity. Two retrospective chart reviews reported this adverse reaction in transplant recipients and patients with renal insufficiency. A case series of six patients noted that the adverse reaction also occurred in patients without a predisposition to renal injury. Two small prospective studies have examined fenofibrate-associated nephrotoxicity, with conflicting findings regarding the mechanism. Finally, a large retrospective review and a population-based cohort study found that patients with preexisting renal disease or taking high-dosage fenofibrate have a higher risk of developing fenofibrate-associated nephrotoxicity. Fenofibrate-associated nephrotoxicity was shown to be reversible with both discontinuation and continued use of fenofibrate, though one study found that the elevations in serum creatinine (SCr) levels were permanent in study participants. Some argue that SCr elevations described in these articles were not due to renal toxicity but may be attributed to reversible mechanisms. While several mechanisms may be biologically plausible, none of the theories have been tested in clinical trials. A possible mechanism for the increase in SCr levels may include changes in renal hemodynamics causing volume depletion and the impairment of generation of vasodilatory prostaglandins, leading to renal vasoconstriction.

CONCLUSION

Fenofibrate-associated nephrotoxicity is an underrecognized adverse drug reaction. Several published reports have detailed possible etiologies; however, data detailing the true incidence of fenofibrate-associated nephrotoxicity and its associated risk factors are limited.

Are PPAR alpha agonists a rational therapeutic strategy for preventing abnormalities of the diabetic kidney?

The uncontrolled diabetes mellitus may result in the induction of diabetic nephropathy, one of the detrimental microvascular complications of diabetes mellitus. Diabetic nephropathy is associated with glomerular hypertrophy, glomerulosclerosis, tubulointerstitial fibrosis, mesangial cell expansion, followed by albuminuria and reduction in glomerular filtration rate. Indeed, no promising therapeutic options are available in the present clinical scenario to manage efficiently the diabetic nephropathy. Nevertheless, angiotensin converting enzyme inhibitors and angiotensin-II-AT(1) receptor blockers are currently employed to improve structural and functional status of the diabetic kidney. These interventions, however, are not optimal in improving overall outcomes of diabetic nephropathy. Hence, there is a continuing need of developing promising therapeutic interventions to manage this insidious condition adequately. Recent bench and clinical studies strongly suggest the potentials of peroxisome proliferator-activated receptor alpha (PPARα) agonists in the management of diabetic nephropathy by keeping the view that renal lipid accumulation-induced lipotoxicity is one of risk factors for nephropathy during chronic diabetes mellitus. As inflammation, oxidative stress and dyslipidemia are common consequences of renal dysfunction, PPARα agonists could serve as promising therapeutic agents for controlling the progression of diabetic nephropathy. In fact, fenofibrate, a hypolipidemic agent acts as a PPARα agonist, reduced renal lipotoxicity, inflammation, fibrosis and oxidative stress, and subsequently prevented the symptoms of diabetic nephropathy. However, fenofibrate has been shown to cause renal dysfunction in established renal disorders. The present review addressed the rationale of employing PPARα agonists in the management of diabetic nephropathy.

Evaluation of the incidence and risk factors for development of fenofibrate-associated nephrotoxicity

BACKGROUND

Fenofibrate-associated nephrotoxicity has been described in two randomized controlled trials and several observational studies. However, little is known regarding its incidence and the population(s) at risk.

OBJECTIVE

This study aims to quantify the incidence and identify potential risk factors for development of nephrotoxicity in patients receiving fenofibrate.

METHODS

A retrospective, observational study was conducted in the South Texas Veterans Health Care System. Data were collected regarding baseline demographics, concurrent medical conditions, medications, laboratory results, and fenofibrate use.

RESULTS

Within 6 months after initiation of fenofibrate in 428 patients, 115 (27%) experienced an increase in serum creatinine of ≥ 0.3 mg/dL. Any renal disease (P = .001), chronic kidney disease (P = .01), and diabetes (P = .02) were significantly more prevalent in patients with fenofibrate-associated nephrotoxicity. Patients with nephrotoxicity had significantly greater serum creatinine (1.2 [SD 0.3] vs. 1.1 mg/dL [SD 0.3], P = .0002) and lower estimated glomerular filtration rate (72 [SD 20] vs 81 mL/min/1.73 m² [SD 20], P < .0001) at baseline. These patients also had greater use of calcium channel blockers (P = .0003), furosemide (P = .02), and angiotensin-converting enzyme inhibitors (P = .02). The incidence of nephrotoxicity was significantly greater in patients initiated on high-dose versus those on low-dose fenofibrate (P = .002). In a multivariable regression model, renal disease (P = .02), high-dose fenofibrate (P = .001), and dihydropyridine calcium channel blocker use (P = .02) were determined to be independent predictors of development of increased serum creatinine on fenofibrate.

CONCLUSION

This observational study suggests fenofibrate-associated nephrotoxicity occurs more frequently than previously reported, particularly in patients with renal disease and in those receiving high-dose fenofibrate or concomitant calcium channel blockers.

An Increase in Serum Creatinine after Initiation of Fenofibrate in an HIV-Infected Individual: A Case Report and Review of the Literature

Hypertriglyceridemia is common among patients infected with HIV and often requires treatment with a triglyceride-lowering medication, such as fenofibrate. Studies have shown that fenofibrate has the potential to increase serum creatinine, a phenomenon that seems to occur more in patients with baseline renal dysfunction or who are on medications that can affect renal hemodynamics. HIV-infected individuals are at an increased risk of developing renal problems and may be a target population for fenofibrate-induced increases in serum creatinine. The purpose of this report is to describe a case of an HIV-infected individual who experienced a considerable increase in serum creatinine after initiating fenofibrate, and to highlight this underreported yet important adverse effect. Additionally, we discuss the postulated mechanisms, relevant literature among HIV noninfected individuals, and potential risk factors.