Statin therapy in kidney disease populations: potential benefits beyond lipid lowering and the need for clinical trials

Relationship of serum total cholesterol and triglyceride with risk of mortality in maintenance hemodialysis patients: a multicenter prospective cohort study

OBJECTIVE

The relationship between serum total cholesterol (TC) and triglyceride (TG) levels and mortality in maintenance hemodialysis (MHD) patients remains inconsistent. We aimed to explore the individual and combined association of TC and TG levels with the risk of mortality in Chinese MHD patients.

METHODS

1036 MHD patients were enrolled in this multicenter, prospective cohort study. The serum levels of total cholesterol and triglycerides were measured at baseline. The primary outcome was all-cause mortality and secondary outcome was cardiovascular disease (CVD) mortality.

RESULTS

During a median follow-up duration of 4.4 years (IQR= 2.0-7.9 years), 549 (53.0%) patients died, and 297 (28.7%) deaths were attributed to CVD. Compared with patients with TC levels in the first three quartiles (<182.5 mg/dL), a significantly higher risk of all-cause mortality was found in participants with TC in the fourth quartile (hazard ratio [HR], 1.43; 95% confidence interval [CI], 1.17-1.76). However, a significantly lower risk of all-cause mortality was observed in participants with TG in the fourth quartile (≥193.9 mg/dL) (HR, 0.78; 95%CI: 0.63-0.98), compared with participants with TG in the first three quartiles. Similar trends were observed in CVD mortality. When analyzed jointly, patients with lower TC (<182.5 mg/dL) and higher TG (≥193.9 mg/dL) levels had the lowest risk of all-cause mortality and CVD mortality.Conclusions: In MHD patients in southern China, higher TC levels were associated with higher risk of mortality, while higher TG levels were related to lower risk of mortality. Patients with lower TC and higher TG levels had the best survival prognosis.

Dietary intake, anthropometric measurements, biochemistry profile and their associations with chronic kidney disease and diabetes mellitus

The chronic kidney disease (CKD) and diabetes mellitus (DM) are considered a serious public health problem. The objective was investigating the association of DM with the anthropometric measures, biochemical profile and dietary intake in patients with CKD. Is a cross-sectional study done in 2017, with 51 patients previously diagnosed with CKD. We collect socio-demographic, lifestyle variables, anthropometric measurements, biochemical profile and dietary intake. We using the Kolmogorov–Smirnov test, followed by Pearson's χ² test and Student's t test. Data were analysed using several multivariable logistic regression models, including the socio-demographic, anthropometric, dietary intake and biochemical variable. Variables with P ≤ 0⋅20 in the univariate analyses were selected and kept in the block in the simple and multiple logistic regression analysis, to determine the differences between the categories and the factors associated with the presence of DM or not, remaining in the model final, only the significant variables (P ≤ 0⋅05). Each variable was adjusted for all other variables included in the univariate analysis. The strength of the association was assessed by the odds ratio and 95% confidence intervals (CI). The multivariate logistic regression analysis evidenced that the increase of 1 cm in waist circumference and 1 mg/dl in VLDL-c values increases the chance of DM, respectively, by 8⋅4% (OR 1⋅076; P 0⋅05) and 8⋅8% (OR 1⋅102; P 0⋅01). In contrast, an increase of 1 mg/dl in total cholesterol decreases the chance of developing DM by 3⋅1% (OR 0⋅965; P 0⋅01), that is, it becomes a protective factor. The present study identified the associations between overweight, dietary intake and biochemical tests.

Potential role for statins in sickle cell disease

The complex pathophysiology of sickle cell disease (SCD) is remarkably similar to that observed in other chronic vascular diseases and involves multiple biologic pathways triggered by ischemia reperfusion injury, coagulation activation, and inflammation. Statins are potent lipid-lowering agents commonly used to reduce the risk of cardiovascular disease. Independent of their lipid lowering effect, statins have been shown to down-regulate inflammatory mediators and endothelial adhesion molecules, reduce tissue factor expression and restore nitric oxide bioavailability. The pleiotropic effects of statins make these agents attractive therapeutic candidates for SCD. This article reviews available evidence for the potential role of statins in SCD.

Hyperlipidemia and long-term outcomes in nondiabetic chronic kidney disease

BACKGROUND AND OBJECTIVES

Dyslipidemia confers a paradoxical survival advantage in patients with kidney failure. Data are limited in the earlier stages of chronic kidney disease (CKD).

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

This was a cohort study in 840 subjects with stage 3 to 4 CKD enrolled in the Modification of Diet in Renal Disease study. Cox models were used to examine the relationship of total cholesterol (TC), non-HDL-cholesterol (NHDL-C), triglycerides (TG), and HDL-cholesterol (HDL-C) with all-cause and cardiovascular disease (CVD) mortality and progression to kidney failure.

RESULTS

During a mean follow-up of 10 years, there were 208 deaths, 128 deaths from CVD, and 554 subjects reached kidney failure. There was no association between tertiles of any of the lipid variables and mortality; the lowest HDL-C tertile (1.44, 1.18 to 1.78) had increased risk of kidney failure but covariate adjustment abolished this association. In analyses with lipids as continuous variables, there was a significant association with all-cause mortality for TC (hazard ratio [HR] per 10-mg/dl increase, 95% confidence intervals [CI] = 1.03, 1.0 to 1.06) that disappeared with covariate adjustment; there was no association of TG, HDL-C, and NHDL-C as continuous variables with all-cause or CVD mortality. There was a significant inverse association between HDL-C and kidney failure (HR = 0.93, CI = 0.87 to 0.99) in an unadjusted Cox model that was attenuated after adjustment for covariates (HR = 0.98 CI = 0.91 to 1.06).

CONCLUSIONS

In this cohort, with predominantly nondiabetic CKD patients, hyperlipidemia is not an independent predictor of long-term outcomes.

Comparable renovascular protective effects of moxonidine and simvastatin in rats exposed to cigarette smoke

Renovascular impairment plays a major role in smoking-induced nephrotoxicity. This study investigated the effect of the imidazoline I(1)-receptor/alpha(2)-adrenoceptor agonist moxonidine, as compared to the lipid lowering drug simvastatin, on abnormalities induced by cigarette smoke (CS) in renovascular reactivity. Six rat groups were used: control, CS (twice a day for 6weeks), simvastatin, moxonidine, CS+simvastatin, and CS+moxonidine. CS exposure increased plasma urea and creatinine and reduced plasma and renal nitrate/nitrite (NOx). In isolated perfused phenylephrine-preconstricted kidneys of CS rats, vasodilator responses to carbachol or isoprenaline, but not papaverine, were attenuated. Nitric oxide synthase (NOS) inhibition by N(G)-nitro-L-arginine (L-NNA) reduced carbachol vasodilations in control but not CS kidneys, suggesting the impairment of NOS activity by CS. Simultaneous administration of moxonidine or simvastatin abolished CS-induced abnormalities in indices of renal function, NOx, and vasodilations caused by carbachol or isoprenaline. The possibility whether alterations in antioxidant or lipid profiles contributed to the interaction was investigated. CS increased renal malondialdyde and decreased glutathione, and glutathione peroxidase, superoxide dismutase and catalase activities. Further, CS reduced plasma HDL and increased cholesterol, triglycerides, and LDL. Simvastatin or moxonidine abolished the deleterious CS effects on antioxidant activity; the lipid profile was normalized by simvastatin only. These findings highlight that renovascular dysfunction caused by CS and the underlying oxidative damage is evenly attenuated by moxonidine and simvastatin.

Effect of rosuvastatin on capillary filtration of albumin and blood pressure in rats with streptozotocin-induced diabetes

An increase in capillary filtration of albumin (CFA) is well demonstrated in diabetes. Statins may exert a protective effect against endothelial dysfunction. The aim of this study was to test whether rosuvastatin may prevent the increase in peripheral CFA in diabetic rats and the role of blood pressure lowering. Rats with streptozotocin-induced diabetes were randomized to receive either rosuvastatin 20mg/kg/d (group R) or both rosuvastatin 20mg/kg/d and mevalonate 20mg/kg/d (group RM) or no treatment (group U). CFA index was measured on a limb by a non-invasive isotopic test using technetium-labelled albumin, at three time points: at mean age of 3 months, before treatment; at 5 and 8 months, i.e. after 2 and 5 months of treatment. At 3 months, interstitial albumin retention (AR) was markedly increased in the 3 groups. From 3 to 5 months, AR increased significantly in group U, decreased in group R and in group RM. At 5 and 8 months, AR was significantly lower in groups R and RM than in group U. Systolic blood pressure (SBP) was measured at 8 months and was significantly lower in group R than in group U and RM. At 8 months, serum cholesterol levels were not different between the three groups whereas triglycerides were significantly lower in groups R and RM than in group U. In conclusion, in diabetic rats rosuvastatin prevents the increase in peripheral CFA and induces a decrease in blood pressure. The beneficial effect of rosuvastatin on endothelial function does not seem to result from blood pressure reduction nor lipid lowering effects.

Statins benefit outcomes of renal transplant recipients on a sirolimus-cyclosporine regimen

BACKGROUND

Statins offer a strategy to address dyslipidemia commonly experienced by immunosuppressed transplant recipients.

METHODS

This single-center, retrospective study of 325 recipients (mean posttransplant follow-up of over 6 years; 75.0+/-26.0 months) correlated four adverse outcomes-biopsy-confirmed acute rejection episodes, biopsy-confirmed chronic rejection/allograft nephropathy, graft loss, or death-with demographic and posttreatment variables. Patients were treated with a combination of sirolimus (SRL), cyclosporine (CsA), and various durations of steroids. Statins were prescribed for 259/325 (79%) recipients whose serum cholesterol exceeded 240 mg/dL and discontinued when the creatine phosphokinase increased fivefold (3.4%) or the liver function, threefold (3.0%) above normal.

RESULTS

Upon univariate (hazard ratio [HR] 0.16; P<.001) and multivariate analysis (HR 0.38; P=.02), statins were markedly protective against acute rejection episodes. They reduced occurrence of chronic nephropathy/chronic rejection (HR 0.60; P=.03 and HR 0.52; P=.01, respectively). Incidences of graft loss were diminished (HR 0.26; P<.001 and HR 0.49; P=.01, respectively). Finally, the mortality rate was decreased (HR 0.21, P=.001 and HR 0.26, P=.01, respectively). Upon multivariate analysis, a reduced incidence of acute rejection was correlated with greater exposure to SRL (HR 0.78, P=.016) and CsA (HR 0.39; P=.006).

CONCLUSIONS

This study demonstrated compelling effects of statins against all adverse outcomes among patients treated with SRL-based, CsA-containing regimens. The profoundly dyslipidemic properties of SRL may explain these unique findings compared with previous studies on patients treated with CsA-based regimens.

The safety of statins in clinical practice

Statins are effective cholesterol-lowering drugs that reduce the risk of cardiovascular disease events (heart attacks, strokes, and the need for arterial revascularisation). Adverse effects from some statins on muscle, such as myopathy and rhabdomyolysis, are rare at standard doses, and on the liver, in increasing levels of transaminases, are unusual. Myopathy--muscle pain or weakness with blood creatine kinase levels more than ten times the upper limit of the normal range--typically occurs in fewer than one in 10,000 patients on standard statin doses. However, this risk varies between statins, and increases with use of higher doses and interacting drugs. Rhabdomyolysis is a rarer and more severe form of myopathy, with myoglobin release into the circulation and risk of renal failure. Stopping statin use reverses these side-effects, usually leading to a full recovery. Asymptomatic increases in concentrations of liver transaminases are recorded with all statins, but are not clearly associated with an increased risk of liver disease. For most people, statins are safe and well-tolerated, and their widespread use has the potential to have a major effect on the global burden of cardiovascular disease.

Renal function and risk of coronary heart disease in general populations: new prospective study and systematic review

BACKGROUND

End-stage chronic kidney disease is associated with striking excesses of cardiovascular mortality, but it is uncertain to what extent renal function is related to risk of subsequent coronary heart disease (CHD) in apparently healthy adults. This study aims to quantify the association of markers of renal function with CHD risk in essentially general populations.

METHODS AND FINDINGS

Estimated glomerular filtration rate (eGFR) was calculated using standard prediction equations based on serum creatinine measurements made in 2,007 patients diagnosed with nonfatal myocardial infarction or coronary death during follow-up and in 3,869 people without CHD in the Reykjavik population-based cohort of 18,569 individuals. There were small and nonsignificant odds ratios (ORs) for CHD risk over most of the range in eGFR, except in the lowest category of the lowest fifth (corresponding to values of <60 ml/min/1.73 m2), in which the OR was 1.33 (95% confidence interval 1.01-1.75) after adjustment for several established cardiovascular risk factors. Findings from the Reykjavik study were reinforced by a meta-analysis of six previous reports (identified in electronic and other databases) involving a total of 4,720 incident CHD cases (including Reykjavik), which yielded a combined risk ratio of 1.41 (95% confidence interval 1.19-1.68) in individuals with baseline eGFR less than 60 ml/min/1.73 m2 compared with those with higher values.

CONCLUSIONS

Although there are no strong associations between lower-than-average eGFR and CHD risk in apparently healthy adults over most of the range in renal function, there may be a moderate increase in CHD risk associated with very low eGFR (i.e., renal dysfunction) in the general population. These findings could have implications for the further understanding of CHD and targeting cardioprotective interventions.

Inverse association between lipid levels and mortality in men with chronic kidney disease who are not yet on dialysis: effects of case mix and the malnutrition-inflammation-cachexia syndrome

High total cholesterol is associated with lower mortality in dialysis patients, but the relationship between lipid levels and mortality in patients who have chronic kidney disease (CKD) and are not yet on dialysis is poorly described. This study examined the association between lipid levels and all-cause and cardiovascular mortality in 986 male patients (age 67.4 +/- 10.9 yr; race 23.7% black) who had CKD and were not yet on dialysis. Associations were determined in fixed-covariate and time-dependent Cox models, before and after adjustment for components of case mix and surrogates for malnutrition-inflammation-cachexia syndrome (MICS). Lower total cholesterol quartiles were associated with higher all-cause mortality in a fixed-covariate model that was adjusted for age, race, and body mass index (hazard ratio [95% confidence interval] for cholesterol <153, 153 to 182, and 183 to 215 versus >215 mg/dl: 1.91 [1.35 to 2.69], 1.36 [0.96 to 1.92], 1.10 [0.78 to 1.57]; P < 0.001 for trend), but this association was attenuated after adjustment for case mix (P = 0.023 for trend) and abolished after additional adjustment for MICS (P = 0.14 for trend), with time-dependent Cox models showing similar results. Similar tendencies also were detected in the association between levels of LDL cholesterol with total and cardiovascular mortality and triglycerides with all-cause mortality in both fixed-covariate and time-dependent analyses. Lower lipid levels are associated with higher mortality in patients who have moderate and advanced CKD and are not yet on dialysis. This inverse association is explained in part by case-mix characteristics and the presence of surrogates for MICS.

The second United Kingdom Heart and Renal Protection (UK-HARP-II) Study: a randomized controlled study of the biochemical safety and efficacy of adding ezetimibe to simvastatin as initial therapy among patients with CKD

BACKGROUND

Evaluating the effects of decreasing low-density lipoprotein (LDL) cholesterol levels requires large randomized trials. In preparation for such a trial, we assessed the biochemical efficacy, safety, and tolerability of adding ezetimibe, 10 mg/d, to simvastatin, 20 mg/d, as initial therapy for such patients.

METHODS

Two hundred three patients (152 predialysis patients with creatinine levels > or = 1.7 mg/dL [> or = 150 micromol/L], 18 patients on peritoneal dialysis therapy, and 33 patients on hemodialysis therapy) were randomly assigned to the administration of simvastatin, 20 mg/d, plus ezetimibe, 10 mg/d; or simvastatin, 20 mg, plus placebo ezetimibe daily.

RESULTS

After 6 months, allocation to simvastatin monotherapy was associated with a 31-mg/dL (0.8-mmol/L) decrease in nonfasting LDL cholesterol levels compared with baseline. Allocation to simvastatin plus ezetimibe produced an additional 18-mg/dL (0.47-mmol/L) decrease in LDL cholesterol level, representing an incremental 21% reduction over that achieved with simvastatin monotherapy (P < 0.0001). There were no statistically significant effects of the addition of ezetimibe to simvastatin on triglyceride or high-density lipoprotein cholesterol levels. Ezetimibe was not associated with an excess risk of abnormal liver function test results or of elevated creatine kinase levels and did not impair absorption of fat-soluble vitamins. There were no serious adverse events caused by study treatment.

CONCLUSION

This 6-month study shows that the addition of ezetimibe to simvastatin, 20 mg/d, as initial therapy for patients with chronic kidney disease was well tolerated and produced an additional 21% decrease in LDL cholesterol levels. The clinical efficacy and safety of combination therapy in this population are now being assessed in a large randomized trial.

Management of Dyslipidemia in Special Populations

Dyslipidemia is a significant contributor to morbidity and mortality in the industrialized world. Because it is often intertwined with other medical conditions, its management is becoming progressively more complex. Populations that pose a particular challenge to clinicians include diabetic patients, children and adolescents, elderly persons, transplant patients, patients with the human immunodeficiency virus, and patients with chronic kidney disease. When establishing lipid goals, it is imperative to have a thorough understanding of the evidence, or lack thereof, supporting the use of lipid-lowering agents among these patients. To maximize the benefits and minimize the risks of pharmacological intervention, clinicians must consider not only the unique alterations in the lipid profile of the aforementioned populations but also individual changes in patients' pharmacokinetic and pharmacodynamic parameters, as well as the potential for drug-drug and drug-disease interactions.

Effects of fluvastatin treatment on lipid profile, C-reactive protein trend, and renal function in dyslipidemic patients with chronic renal failure

The purpose of this trial was to evaluate the effects of fluvastatin on the lipid pro-file and on renal function, as measured by creatinine clearance, in dyslipidemic patients with chronic renal failure. In this 8-month prospective, open-label, randomized, parallel-group trial, 130 patients (70 men and 60 women), after a 2-month washout period following previous lipid-lowering treatments, were randomly assigned to fluvastatin XL 80 mg given once daily (80 patients) or to standard treatment (50 patients). Mean total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglyceride values after 3 and 6 months of treatment with fluvastatin showed statistically significant improvement compared with standard treatment. Improved renal function, as measured by creatinine clearance, was observed at the end of the 6-month treatment period in approximately 65% of patients treated with fluvastatin. The increase in creatinine clearance consistently reached 10% to 15% of baseline values. A statistically significant reduction in C-reactive protein (CRP) over baseline values was observed in approximately 75% of patients treated with fluvastatin. Furthermore, mean values of CRP for the fluvastatin standard treatment groups, respectively, were 6.78 and 10.19 at 3 months and 4.47 and 11 at 6 months. Both treatments were well tolerated. No major adverse events were noted. Results of this study suggest that fluvastatin treatment in patients with chronic renal failure is effective in improving the lipid profile, and it demonstrates good safety and tolerability. Furthermore, fluvastatin may contribute to improved nephroprotection in this patient population.