Atorvastatin improves endothelial function in renal-transplant recipients

Efficacy and safety of statin therapy in kidney transplant recipients: a systematic review and meta-analysis

BACKGROUND

Dyslipidemia represents an important risk factor for cardiovascular diseases, although its optimal management after kidney transplantation remains unclear. The present meta-analysis aimed to shed light on the efficacy and safety of statins among kidney transplant recipients, evaluating their potential effects on the risk of cardiovascular events, mortality and graft survival.

METHODS

Medline, Scopus, Web of Science, CENTRAL, Clinicaltrials.gov and Google Scholar were systematically searched from their inception through April 20, 2024. Both randomized controlled trials and observational studies evaluating the effects of statin administration after kidney transplantation were held eligible. Random-effects models were fitted using the maximum likelihood method, while the certainty of evidence was appraised following the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) approach.

RESULTS

Overall, 27 studies (10 randomized controlled trials and 17 observational studies) were included. Statin use compared to no use was associated with a lower risk of major adverse cardiovascular events [Relative risk (RR): 0.87, 95% confidence interval (CI): 0.67-0.96, moderate certainty] and overall mortality (RR: 0.84, 95% CI: 0.74-0.94, low certainty). The risk of graft loss did not differ between the compared groups (RR: 0.72, 95% CI: 0.48-1.08, very low certainty). Regarding safety endpoints, statin use was associated with a lower risk of hepatotoxicity (RR: 0.81, 95% CI: 0.70-0.93, moderate certainty), but with a greater risk of rhabdomyolysis (RR: 1.37, 95% CI: 1.10-1.70, low certainty) and cataract (RR: 1.22, 95% CI: 1.14-1.31, moderate certainty). No statistically significant differences between the compared groups with and without statin use were observed concerning the risk of creatine kinase elevation, post-transplant diabetes mellitus, hip fracture, venous thromboembolism, or cancer.

CONCLUSIONS

Among kidney transplant recipients, statin use is associated with a lower risk of cardiovascular events and better patient survival, presenting an acceptable safety profile. Further large-scale studies are needed to determine the optimal statin dosing strategy and lipid-lowering goals, depending on comorbidities and immunosuppression regimens.

REGISTRATION

https://doi.org/10.17504/protocols.io.5qpvok3yzl4o/v1 .

Influence of Simvastatin on Aspects of Thrombogenesis in CAPD Patients

← Background

Patients on continuous ambulatory peritoneal dialysis (CAPD) are prone to dyslipidemia and have a high risk of cardiovascular death. Statins show beneficial effects on serum lipids and thrombogenesis in various groups of patients, but prospective studies have so far not been performed on CAPD patients.

← Aim

To determine the effects of 6 month's treatment with simvastatin on platelet function and some hemostatic parameters, markers of endothelial cell injury, in 14 CAPD patients with hypercholesterolemia.

← Methods

Simvastatin was given in a dose of 10 mg at bedtime. Commercially available kits were used for all determinations.

← Results

Cholesterol and low density lipoprotein fell significantly as early as after 1 month of the therapy ( p < 0.001). Platelet aggregation in whole blood and plateletrich plasma was transiently decreased by simvastatin therapy. The fibrinolytic activity index increased significantly after 6 months of simvastatin administration ( p < 0.05), reaching values observed in the control group, whereas euglobulin clot lysis time, which was also significantly shortened after 6 months ( p < 0.05), did not reach values obtained in healthy volunteers. Vascular cell adhesion molecule, thrombomodulin, and protein Z decreased significantly after 3 months of the therapy ( p < 0.05, p < 0.05, and p < 0.01, respectively), whereas intercellular adhesion molecule decreased after 6 months ( p < 0.05). Vascular endothelial growth factor and its receptor, protein Z, total tissue factor pathway inhibitor (TFPI), TFPI/Xa complexes, and thrombin activatable fibrinolysis inhibitor concentration and activity fell significantly after 6 months of treatment with simvastatin (all p < 0.05). Tissue plasminogen activator concentration increased after 1 month ( p < 0.01 after 1 month, p < 0.05 after 3 and 6 months), whereas total homocysteine fell after 6 months of simvastatin therapy ( p < 0.05). Truncated TFPI decreased significantly as early as after 1 month of therapy ( p < 0.05 after 1 month, p < 0.01 after 3 and 6 months).

← Conclusion

Simvastatin is an effective hypolipemic agent in CAPD patients. It favorably affects platelet aggregation and the extrinsic coagulation pathway, improves fibrinolysis, and ameliorates endothelial dysfunction. Simvastatin might reduce the risk of thrombotic complications in CAPD patients.

Lipid lowering in dialysis patients with cardiovascular disease who are awaiting kidney transplantation

Dyslipidemias are highly prevalent in chronic kidney disease, end-stage renal disease, and kidney transplant patients. These dyslipidemias are associated with high cardiovascular risk and mortality. Many clinical trials have shown that statin therapy can significantly reduce adverse cardiovascular events in chronic kidney disease patients and kidney transplant recipients. However, three major trials did not show a benefit of statin therapy in end-stage renal disease patients on dialysis. Major guidelines either recommend against the use of statins in patients on dialysis or provide no recommendations about statin use for this complex patient population. As a result, we suspect many patients on dialysis are not on statins, even if they have known atherosclerotic cardiovascular disease. When these patients receive kidney transplants, the risk of adverse cardiovascular events increases in the peri-operative period. Although there are no randomized clinical trials looking at statin use in these patients, we suggest that statin use be considered in patients with a history of atherosclerotic cardiovascular disease, to potentially minimize peri-operative cardiovascular complications. We also recommend further research to determine whether statin therapy in dialysis patients awaiting kidney transplant is associated with better survival.

Atorvastatin Improves Peritoneal Sclerosis Induced by Hypertonic PD Solution in Rats

Background

Peritoneal sclerosis is a complication of peritoneal dialysis and results in ultrafiltration failure. It is related to chronic peritoneal injury due to dialysis solution content and recurrent peritonitis. Statins have anti-inflammatory properties which may be of value in modulating responses to injury. We evaluated the capacity of atorvastatin to modify peritoneal alterations secondary to hypertonic glucose.

Methods

Thirty-two non-uremic rats were divided into three groups: group I (Sham) rats received no treatment (n=11), group II received hypertonic (3.86%, 10 ml/day) PD solution (n=10) and group III received hypertonic PD solution (10 ml/day) plus 80 mg/L atorvastatin in drinking water (n=11). After four weeks, a one-hour peritoneal equilibration test (PET) was performed with 3.86% PD solution. Dialysate-to-plasma urea ratio (D/P urea), glucose reabsorption (D1/D0 glucose), ultrafiltration volume (UF), dialysate protein, TGF-ß1 and VEGF levels were determined.

Results

Administration of atorvastatin resulted in preserved UF (4.9±0.8 vs 7.5±0.6 mL, p <0.01), protein loss (2.2±0.2 vs 2.1±0.1 g/L, p >0.05), and peritoneal thickness (53±3 vs 26±4 μm, p <0.01). D1/D0 glucose was significantly reduced in the dextrose group (0.70±0.02 vs 0.56±0.04, p <0.01). Both higher levels of TGF-ß1 (206±40 vs 474±120 pg/mL, p<0.05), and VEGF in dialysate effluent (4±0.4 vs 7.9±3 pg/mL, p>0.05), was determined in the dextrose group.

Conclusion

Exposure to hypertonic glucose solution resulted in alterations in peritoneal transport manifested by a rapid dissipation of the glucose gradient and resultant impaired UF response. Administration of atorvastatin led to prevention of these alterations. We suggest that the anti-inflammatory properties of statins are useful in providing protection of the peritoneal membrane from the effects of hypertonic glucose.

Effects of Low-Dose Atorvastatin on Vascular Responses in Patients Undergoing Percutaneous Coronary Intervention With Stenting

Background: The primary endpoint of this study was to evaluate the effects of low-dose atorvastatin on carotid intima-media thickness (IMT) and endothelial function, and the secondary endpoint comprised restenosis and target lesion revascularization (TLR) in patients undergoing percutaneous coronary intervention (PCI) with stenting for the treatment of coronary artery disease.

Methods: Two hundred five consecutive patients (mean age, 60 years) undergoing PCI were prospectively randomized to usual therapy (control group, n = 100) or to 10 mg of atorvastatin daily plus usual therapy (statin group, n = 105). Carotid IMT, endothelial function (flow-mediated dilatation [FMD] of the brachial artery), and coronary angiograms were taken before the study and 6 months after randomization. The 6-month follow-up measurements of the above factors were obtained in 83 patients (83%) of the control group and in 97 patients (92%) of the statin group.

Results: No significant differences were noted in the baseline clinical and angiographic findings in either group. FMD was significantly improved during the 6 months in the statin group (4.38% ± 1.7% vs 4.85% ± 1.6%, P = .003), but did not change in the control group. Carotid IMT did not show any significant changes at 6 months in either group. There was a trend in favor of statin in terms of restenosis rate (26.8% vs 36.1%, P = .177) and TLR rate (18.6% vs 25.3%, P = .274). The changes of FMD were significantly correlated with the changes of total cholesterol and the changes of low-density lipoprotein, respectively ( r= -0.336, P = .009, and r = -0.310, P = .046).

Conclusion: Low-dose atorvastatin reduces endothelial dysfunction as measured by FMD, which coincides with the beneficial effects on lipid profiles, and can decrease restenosis and TLR rate in patients undergoing PCI with stenting.

The association between atorvastatin administration and plasma total homocysteine levels in renal transplant recipients

BACKGROUND

Statins improve prognosis in patients with coronary heart diseases by decreasing the incidence of vascular events. Excess prevalence of hyperhomocysteinemia, an independent risk factor of cardiovascular diseases, has been observed in stable renal transplant recipients (RTRs).

OBJECTIVES

The objective of our study was to evaluate the association between atorvastatin administration and plasma total homocysteine (tHcy) levels in RTRs.

PATIENTS AND METHODS

We performed a retrospective cross-sectional study in 148 cyclosporine A (CsA) treated stable RTRs. We compared tHcy level and other demographic and clinical variables in RTRs with and without atorvastatin.

RESULTS

58.1% of the 148 RTRs were treated with atorvastatin (20-40 mg/day). Mean tHcy levels were lower in patients treated with atorvastatin compared to nonusers (14.80 ± 5.13 µmol/l versus 16.95 ± 7.87 µmol/l, P = 0.04). The comparison of 85 patients treated with atorvastatin and 61 non-users revealed that those subjects with atorvastatin were older, with higher estimated creatinine clearance and elevated body mass index (BMI). They were more likely to have higher systolic blood pressure and CsA trough level (C0). The association between lower tHcy levels and atorvastatin use was confirmed in the multivariate regression model (P = 0.004). However tHcy levels were independently and negatively associated with serum folate (P = 0.0001) and vitamin B12 levels (P = 0.001) and positively with serum BUN (P = 0.001) and diastolic blood pressure (P = 0.024) as well.

CONCLUSIONS

These data support the association between lower tHcy levels and atorvastatin administration in RTRs. Further clinical trials are recommended to clarify homocysteine lowering effect of atorvastatin.

Diclofenac and Its Acyl Glucuronide: Determination of In Vivo Exposure in Human Subjects and Characterization as Human Drug Transporter Substrates In Vitro

Although the metabolism and disposition of diclofenac (DF) has been studied extensively, information regarding the plasma levels of its acyl-β-d-glucuronide (DF-AG), a major metabolite, in human subjects is limited. Therefore, DF-AG concentrations were determined in plasma (acidified blood derived) of six healthy volunteers following a single oral DF dose (50 mg). Levels of DF-AG in plasma were high, as reflected by a DF-AG/DF ratio of 0.62 ± 0.21 (Cmax mean ± S.D.) and 0.84 ± 0.21 (area under the concentration-time curve mean ± S.D.). Both DF and DF-AG were also studied as substrates of different human drug transporters in vitro. DF was identified as a substrate of organic anion transporter (OAT) 2 only (Km = 46.8 µM). In contrast, DF-AG was identified as a substrate of numerous OATs (Km = 8.6, 60.2, 103.9, and 112 µM for OAT2, OAT1, OAT4, and OAT3, respectively), two organic anion-transporting polypeptides (OATP1B1, Km = 34 µM; OATP2B1, Km = 105 µM), breast cancer resistance protein (Km = 152 µM), and two multidrug resistance proteins (MRP2, Km = 145 µM; MRP3, Km = 196 µM). It is concluded that the disposition of DF-AG, once formed, can be mediated by various candidate transporters known to be expressed in the kidney (basolateral, OAT1, OAT2, and OAT3; apical, MRP2, BCRP, and OAT4) and liver (canalicular, MRP2 and BCRP; basolateral, OATP1B1, OATP2B1, OAT2, and MRP3). DF-AG is unstable in plasma and undergoes conversion to parent DF. Therefore, caution is warranted when assessing renal and hepatic transporter-mediated drug-drug interactions with DF and DF-AG.

Symmetric dimethylarginine as predictor of graft loss and all-cause mortality in renal transplant recipients

Supplemental digital content is available in the text.

Background

Elevated symmetric dimethylarginine (SDMA) has been shown to predict cardiovascular events and all cause mortality in diverse populations. The potential role of SDMA as a risk marker in renal transplant recipients (RTR) has not been investigated.

Methods

We analyzed SDMA in the placebo arm of the Assessment of Lescol in Renal Transplantation study, a randomized controlled trial of fluvastatin in RTR. Mean follow-up was 5.1 years. Patients were grouped into quartiles based on SDMA levels at study inclusion. Relationships between SDMA and traditional risk factors for graft function and all-cause mortality were analyzed in 925 RTR using univariate and multivariate survival analyses.

Results

In univariate analysis, SDMA was significantly associated with renal graft loss, all-cause death, and major cardiovascular events. After adjustment for established risk factors including estimated glomerular filtration rate, an elevated SDMA-level (4th quartile, >1.38 μmol/L) was associated with renal graft loss; hazard ratio (HR), 5.51; 95% confidence interval (CI), 1.95–15.57; P=0.001, compared to the 1st quartile. Similarly, SDMA in the 4th quartile was independently associated with all-cause mortality (HR, 4.56; 95% CI, 2.15–9.71; P<0.001), and there was a strong borderline significant trend for an association with cardiovascular mortality (HR, 2.86; 95% CI, 0.99–8.21; P=0.051).

Conclusion

In stable RTR, an elevated SDMA level is independently associated with increased risk of all-cause mortality and renal graft loss.

Effect of atorvastatin on the angiogenic responsiveness of coronary endothelial cells in normal and streptozotocin (STZ) induced diabetic rats

Atorvastatin, a lipid lowering agent, possesses various pleiotropic vasculoprotective effects, but its role in coronary angiogenesis is still controversial. Our objective was to study the effects of atorvastatin on the angiogenic responsiveness of coronary endothelial cells (cEC) from normal and diabetic rats. Male Wistar rats were distributed among 9 groups; (i) normal rats, (ii) 30 day diabetic rats, (iii) 60 day diabetic rats, (iv) normal rats administered a low dose of atorvastatin (1 mg/kg body mass, per oral (p.o.), for 15 days); (v) 30 day diabetic rats administered a low dose of atorvastatin; (vi) 60 day diabetic rats administered a low dose of atorvastatin; (vii) normal rats administered a high dose of atorvastatin (5 mg/kg, p.o., for 15 days); (viii) 30 day diabetic rats administered a high dose of atorvastatin; (ix) 60 day diabetic rats administered a high dose of atorvastatin. Each group was further divided into 2 subgroups, (i) sham ischemia-reperfusion and (ii) rats hearts that underwent ischemia-reperfusion. Angiogenic responsiveness the and nitric oxide (NO) releasing properties of the subgroups of cECs were studied using a chorioallantoic membrane assay and the Griess method, respectively. Atorvastatin treatment significantly increased VEGF-induced angiogenic responsiveness and the NO-releasing properties of cECs from all of the subgroups, compared with their respective non-treated subgroups except for the late-phase diabetic rat hearts that underwent ischemia-reperfusion, and the high dose of atorvastatin treatment groups. These effects of atorvastatin were significantly inhibited by pretreatment of cECs with l-NAME, wortmannin, and chelerythrine. Thus, treatment with a low dose of atorvastatin improves the angiogenic responsiveness of the cECs from normal and diabetic rats, in the presence of VEGF, via activation of eNOS-NO release.

Common carotid wall shear stress and carotid atherosclerosis in end-stage renal disease patients

Decrease of arterial wall shear stress (WSS) is associated with higher probability of atherosclerotic plaque development in many disease conditions. End-stage renal diseases (ESRD) patients suffer from vascular disease frequently, but its nature differs from general population. This study was aimed at proving an association between common carotid wall shear stress and the presence of carotid bifurcation plaques in a group of ESRD patients. ESRD subjects, planned for the creation of a dialysis access and therapy were included. Wall shear rate (WSR) was used as a surrogate of WSS and was analyzed in the common carotid arteries by duplex ultrasonography. Intima media thickness (IMT) was measured at the same site. The presence/absence of carotid bifurcation plaques was recorded. The endothelial function was estimated by the levels of von Willebrand factor (vWf). 35 ESRD patients were included (19 females, 17 diabetics). Atherosclerotic plaque was present in 53 % of bifurcations. Wall shear rate was lower in arteries with plaques (349+/-148 vs. 506+/-206 s(-1), p=0.005) and was directly related to the height of IMT and inversely to the activity of vWf (r= -0.65, p=0.016). Lower wall shear rate in the common carotid arteries is linked to the endothelial dysfunction and to the presence of atherosclerotic plaques in carotid bifurcations in ESRD subjects. Faster arterial dilatation may facilitate this process in ESRD subjects.

Pleiotropic vasoprotective effects of statins: the chicken or the egg?

Statins (3-hydroxy-3-methyl glutaryl coenzyme A [HMG-CoA] reductase inhibitors) are the most commonly used lipid-lowering drugs. Their main lipid-lowering effect is achieved by an increase in the expression of low-density lipoprotein cholesterol receptors associated with inhibition of cholesterol synthesis through inhibition of HMG-CoA reductase - the first and rate-limiting step in cholesterol synthesis. However, beyond cholesterol synthesis inhibition, inhibition of the HMG-CoA reductase affects as well the synthesis of other molecules with significant roles in different, yet often intercalating, metabolic pathways. On this basis, and supported by an increasing series of advocating epidemiological and experimental data, an extended dialogue has been established over the last few years regarding the nonlipid or "pleiotropic" actions of statins.

Calcineurin inhibitor effects on glucose metabolism and endothelial function following renal transplantation

BACKGROUND

Calcineurin inhibitors (CNI) are involved in the development of post-transplant diabetes mellitus (PTDM). Changes in insulin secretion and sensitivity contribute to the development of PTDM and are associated with endothelial function.

METHODS

In a pre-defined substudy of a previously published randomized trial in renal transplant recipients we compared the effect of CNI treatment (n = 23) with complete CNI-avoidance (n = 21) on insulin secretion and sensitivity (oral glucose tolerance test) as well as endothelial function (laser Doppler flowmetry), 10 wk and 12 months following transplantation.

RESULTS

Insulin sensitivity differed 10 wk post-transplant and was significantly better after 12 months in patients never treated with CNI drugs [0.091 (0.050) vs. 0.083 (0.036) micromol/kg/min/pmol/L, p = 0.043]. Insulin secretion tended to be higher in CNI treated patients at both time points (p = 0.068). Endothelial function was not significantly different at week 10 [540 (205) vs. 227 (565) arbitary units x minutes, p = 0.35] or month 12 [510 (620) vs. 243 (242), p = 0.33].

CONCLUSIONS

Findings in the present study indicate that long-term CNI treatment negatively affects glucose metabolism and this may contribute to the increased risk for premature cardiovascular disease in CNI treated renal transplant recipients. Further studies to elucidate this hypothesis are, however, needed.

Atorvastatin Treatment in the Short Term: Does It Induce Renoprotection or Vasculoprotection in Renal Transplantation?

INTRODUCTION

Proteinuria and dyslipidemia are nonimmune risk factors implicated in the deterioration of kidney function and associated with an increased risk of accelerated atherogenesis. Statin therapy, used for cholesterol reduction, has shown a renoprotective effect in animal models, particularly in cases of proteinuria. This may occur through lipid-independent mechanisms, such as improved endothelial dysfunction/vascular biology, reduced inflammatory cytokine production (transforming growth factor-beta 1 [TGF-beta1]), and regulation of fibrogenic responses. We studied mechanisms of action of agents, such as statins, to change proteinuria, inflammatory parameters, and TGF-beta1 plasma levels in relation to vascular tone.

METHODS

Fifty-six kidney transplant recipients (30 men and 26 women of overall mean age 54 +/- 13 years) were treated posttransplantation with atorvastatin (10 mg/d) for 12 weeks without renin-angiotensin-system blockade drugs. Inflammatory variables, biochemical parameters, lipid profile, renal function, and TGF-beta1 levels were determined at baseline and at 3 months. Vascular stiffness was evaluated using pulse wave velocity (PWV).

RESULTS

Baseline TGF-beta1 plasma levels were higher among transplant recipients than healthy controls, namely 8.12 ng/mL (range, 5.82-13.12) to 2.55 (range, 1.78- 4.35) (P < .01). Furthermore, the levels remained higher after the treatment with atorvastatin, namely, 7.59 (range, 4.97-12.35) to 2.55 (range, 1.78-4.35) ng/mL (P < .01). Atorvastatin treatment significantly decreased total cholesterol as well as low-density lipoprotein cholesterol plasma levels, but did not modify mean blood pressure (MBP), proteinuria, creatinine clearance, or inflammatory factors. Reduction in TGF-beta1 plasma levels was statistically significant among patients with PWV >9.75 (m/s) (pathology reference value) namely, from 10.7 ng/mL (range, 7.02-13.98) to 6.7 (range, 3.96-11.94) (P = .038). Among older patients, atorvastatin significantly decrease TGF-beta1 plasma levels: from 9.5 ng/mL (range, 6.45-14.44) to 5.65 (range, 3.63-9.48; P < .05). The decreased TGF-beta1 was not related to changes in lipid profiles.

CONCLUSIONS

Atorvastatin (10 mg/d) improved the lipid profile and moreover among older patients with worse PWV (>9.75 m/s), TGF-beta1 levels were significantly reduced. Our results suggested that statins displayed potent actions distinct from their hypolipidemic effects.

HMG-CoA reductase inhibitors and the kidney

During the last two decades, numerous studies have demonstrated that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) diminish the risk of cardiovascular morbidity and mortality. Although these studies have focused primarily on the ability of statins to lower circulating levels of low-density lipoprotein cholesterol, more recent research has shown that statins may protect the vasculature via pleiotropic effects not directly related to lipid lowering. These include adjustments in cell-signaling pathways that play a role in atherogenesis and that affect the expression of inflammatory elements, curtail oxidative stress, and enhance endothelial function. More recently, researchers have begun to explore whether these agents exert similar beneficial effects in renal parenchymal and renovascular disease. This review examines the available evidence that dyslipidemia may augment the inflammatory reaction of cytokines in patients with renal disease and that statins may improve renal dysfunction by altering the response of the kidney to dyslipidemia, even in persons with end-stage renal disease on dialysis or with renal transplantation. In this context, some data suggest that statin-mediated alterations in inflammatory responses and endothelial function may reduce proteinuria and the rate of progression of kidney disease.

Do Statins Reduce Blood Pressure?

A meta-analysis was performed of the effect of 3hydroxy3methylglutaryl-coenzyme A reductase inhibitors (statins) on blood pressure in humans including the randomized, controlled trials of statin therapy (20 trials and 828 patients) in which concomitant antihypertensive treatment (if any) remained unchanged throughout the study. A total of 291 and 272 patients were given a statin or placebo, respectively, in parallel group trials, whereas 265 took part in crossover trials receiving a statin and placebo (or probucol, in 1 trial). Systolic blood pressure was significantly lower in patients on statin than in those on placebo or control hypolipidemic drug (mean difference: -1.9 mm Hg; 95% CI: -3.8 to -0.1). The effect was greater when the analysis was restricted to studies with a baseline systolic blood pressure >130 mm Hg (Delta systolic blood pressure: -4.0; 95% CI: -5.8 to -2.2 mm Hg). There was a trend for lower diastolic blood pressure in patients receiving statin therapy compared with control: -0.9 mm Hg (95% CI: -2.0 to 0.2) overall and -1.2 mm Hg (95% CI: -2.6 to 0.1) in studies with a baseline diastolic blood pressure >80 mm Hg. In general, the higher the baseline blood pressure, the greater the effect of statins on blood pressure (P=0.066 for systolic blood pressure and P=0.023 for diastolic blood pressure). The blood pressure response to statins was unrelated to age, changes in serum cholesterol, or length of the trial. In conclusion, statin therapy has a relatively small but statistically significant and clinically meaningful effect on blood pressure.

Serum markers of vascular inflammation in dyslipemia

Atherosclerosis is widely recognized as an inflammatory disease because systemic and local inflammatory events mediate all phases of plaque development and progression. Basic and clinical studies have focused on identifying potentially useful markers of inflammation. In this article, we review the inflammatory pathogenesis of atherosclerosis, and highlight recent results of several of the more promising markers of inflammation for cardiovascular risk assessment. Of these markers, the most reliable and accessible for clinical use is currently high-sensitivity C-reactive protein (CRP). At present, most clinical guidelines do not recommend routine measurement of these inflammatory markers. However, these serum markers of vascular inflammation may be useful as an adjunct to lipid screening, especially for patients whose lipid values may not be severely elevated, but who are at intermediate risk according to scoring systems that take into account multiple established risk factors. In addition, since the pleiotropic effects of statins include the inhibition of inflammatory response, serum inflammatory markers could also be useful for monitoring this action. Nevertheless, several issues have to be evaluated before the measurements of inflammatory markers can be used for cardiovascular risk prediction in either clinical practice or in clinical trials evaluating anti-atherosclerotic drugs.

Effects of Immunosuppressive Drugs on Serum Lipid Levels in Renal Transplant Recipients

BACKGROUND

Hyperlipidemia is an important metabolic disorder that is common among renal transplant recipients. This study investigated the possible effects of transplantation and immunosuppressive drugs on lipid profiles in this patient group.

METHODS

We retrospectively evaluated the records of 179 patients who underwent renal transplantation between 1996 and 2000, recording lipid profile findings-total cholesterol (TC), low-density lipoprotein cholesterol (LDLc), high-density lipoprotein cholesterol (HDLc), and triglyceride (TG)-before and at least 6 months after transplantation. We also recorded patient demographics, underlying renal disorder, and immunosuppressive drug regimens.

RESULTS

Sixty-nine (38.5%) patients were women and 110 men (61.5%). The mean age (+/- SD) of the 179 recipients was 35.7 +/- 11.8 years (range, 11 to 62 years). The respective pre- versus posttransplantation lipid profile findings were: TC, 171.6 +/- 42.4 mg/dL versus 204.7 +/- 45.3 mg/dL, P < .001; LDLc, 114.5 +/- 34.5 mg/dL versus 142.2 +/- 39.7 mg/dL, P < .001; HDLc, 46.7 +/- 13.6 mg/dL versus 42.5 +/- 12.3 mg/dL, P = .001; TG, 142.9 +/- 55.7 mg/dL versus 178.8 +/- 71.8 mg/dL, P < .001. Increased lipid levels were found to be independent of patient age, sex, donor type, and immunosuppressive drug regimen.

CONCLUSION

The results suggested that antihyperlipidemic drugs should be administered routinely to renal transplant recipients irrespective of the immunosuppressive drug regimen or graft source.

Association between insulin resistance and endothelial dysfunction in renal transplant recipients

BACKGROUND

Endothelial dysfunction is a common finding in renal transplant recipients (RTR) and is related to impaired local regulation of vasodilative and vasoconstrictive substances, such as nitric monoxide (NO) and endothelin-1 (ET-1). In non-transplanted patients, an association between impaired endothelial function and insulin resistance has been shown. Whether such an association also exists in RTR is unknown.

OBJECTIVE

The aim of the present study was to examine whether insulin resistance is associated with endothelial dysfunction in RTR.

MATERIAL AND METHODS

A total of 47 RTR in a stable phase six yr post-transplant were included in the statistical analysis. The immunosuppressive therapy was based on cyclosporine and prednisolone. Non-invasive assessment of endothelial function was performed with laser Doppler flowmetry of the forearm skin vasculature after local acetylcholine stimulation. Oral glucose tolerance tests comprising both glucose and insulin measurements were used to calculate insulin sensitivity (IS) indices. NO, ET-1 and von Willebrand factor were measured in fasting plasma samples.

RESULTS

Normal glucose tolerance was found in 31 RTR. In these subjects, both IS (r(2) = 0.164, p = 0.044) and plasma NO (r(2) = 0.326, p = 0.002) were significantly correlated with endothelial function. Patients with glucose intolerance (n = 16) had higher plasma ET-1 and lower NO levels, but the association between IS and endothelial function was not significant in these subjects. In the total patient cohort, IS and endothelial function tended to be correlated (p = 0.127).

CONCLUSIONS

Endothelial dysfunction is significantly associated with insulin resistance in normoglycemic RTR but explains a rather small part of the variation. In glucose-intolerant recipients, IS appears to be more critically dependent on other factors not revealed in the present study.

Effect of low doses of atorvastatin on adiponectin, glucose homeostasis, and clinical inflammatory markers in kidney transplant recipients

INTRODUCTION

Various studies describe the pleiotropic antiinflammatory and antioxidant effects of atorvastatin, in addition to its hypolipemic effects. It has been suggested that statins modify glucose homeostasis via their antiinflammatory effects. A further hypothesis suggests that the incidence of posttransplantation diabetes is lower in statin-treated patients. This study sought to ascertain whether atorvastatin modifies glucose homeostasis, adiponectin, and inflammatory markers in kidney transplant recipients.

PATIENTS AND METHODS

Sixty-eight kidney transplant recipients (41 men, 27 women; mean age, 53 +/- 12 years) with stable renal function and dyslipidemia were treated with atorvastatin (10 mg/d) for 12 weeks. Glucose, insulin, homeostasis model assessment (HOMA-IR) index, adiponectin, tumor necrosis factor (TNF)-alpha, and serum C-reactive protein (CRP) concentrations were determined at baseline and at 3 months. The lipid profile, renal function parameters (creatinine, creatinine clearance, and proteinuria), as well as GOT, GPT, and CK were determined at baseline and at 3 months.

RESULTS

Treatment with atorvastatin achieved a statistically significant decrease in lipid profile. After 3 months of treatment, 74.6% of patients had total cholesterol and 78.7% low-density lipoprotein (LDL) cholesterol concentrations within reference range (<5.2 and 3.3 mmol/L, respectively). Furthermore, 47.5% of patients attained an LDL concentration <2.59 mmol/L. A greater reduction in total cholesterol (P = .05) and LDL cholesterol (P = .04) was achieved in patients with creatinine clearance <60 mL/min. Atorvastatin did not modify glucose homeostasis parameters, adiponectin, TNF-alpha, or CRP. At baseline and after 3 months of treatment, an inverse correlation was found between adiponectin and glucose, insulin, HOMA- IR index, and creatinine clearance, and a positive correlation was found between adiponectin and high-density lipoprotein (HDL) cholesterol.

CONCLUSION

Atorvastatin at a dose of 10 mg/d in kidney transplant recipients does not modify glucose homeostasis or alter inflammatory markers, despite its hypolipemic effects. Its efficacy to reduce total cholesterol and LDL cholesterol was greater in patients with worse renal function.

Statin therapy in the treatment of Alzheimer disease: what is the rationale?

Alzheimer disease (AD) is a chronic neurodegenerative disorder that is manifested by cognitive decline, neuropsychiatric symptoms, and diffuse structural abnormalities in the brain. Its prevalence is predicted to rise 4-fold in the next 50 years. AD is characterized pathologically by deposition of extracellular beta-amyloid and accumulation of neurofibrillary tangles. Neuronal death and specific neurotransmitter deficits also are part of the pathologic picture. Strategies to delay symptom progression have focused on addressing the neurotransmitter deficits. Strategies to delay the onset or biologic progression of AD largely have targeted the plaques formed by the deposition of beta-amyloid. AD and cardiovascular disease share common risk factors, notably hypercholesterolemia, and occur together more often than expected by chance. Therapy with the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) is the first-line treatment option for hypercholesterolemia, and observational studies have suggested that the risk of AD is reduced in patients who receive statin therapy in midlife. This reduction in risk of AD observed with statin therapy may be due to statins reducing beta-amyloid formation and deposition or to their known anti-inflammatory effects. Two randomized double-blind statin trials in patients with AD to assess the potential for statins to slow disease progression are currently under way. If successful, statin AD primary prevention trials may be developed.

Endothelial Dysfunction in Renal Transplant Recipients

Endothelial dysfunction and damage are systemic processes that are recognised to play a central role in the pathogenesis of hypertension and atherosclerotic cardiovascular disease. Renal failure is associated with impaired endothelium dependent vasodilatation that is partly a consequence of increased circulating levels of asymmetric dimethyl arginine. Endothelial dysfunction persists, although it is improved, after renal transplantation. Statins appear to improve endothelial dysfunction, as does withdrawal of calcineurin inhibitors, although there is no evidence that these strategies improve patient or graft survival. The situation in transplant recipients is complicated by the fact that endothelial dysfunction (within the graft vasculature) may be a separate process contributing to chronic allograft nephropathy and to circulating levels of endothelial cells and their components, thus limiting the utility of circulating markers of endothelial damage in this population.

Rapamycin for treatment of chronic allograft nephropathy in renal transplant patients

Chronic allograft nephropathy (CAN) represents the main cause of renal allograft loss after 1 yr of transplantation. Calcineurin inhibitor (CNI) use is associated with increased graft expression of profibrotic cytokines, whereas rapamycin inhibits fibroblast proliferation. The aim of this randomized, prospective, open-label, single-center study was to evaluate the histologic and clinical effect of rapamycin on biopsy-proven CAN. Eighty-four consecutive patients who had biopsy-proven CAN and received a transplant were randomized to receive either a 40% CNI reduction plus mycophenolate mofetil (group 1; 50 patients) or immediate CNI withdrawal and rapamycin introduction with a loading dose of 0.1 mg/kg per d and a maintaining dose aiming at through levels of 6 to 10 ng/ml (group 2; 34 patients). The follow-up period was 24 mo. At the end of follow-up, 25 patients (group 1, 10 patients; group 2, 15 patients) underwent a second biopsy. CAN lesions were graded according to Banff criteria. alpha-Smooth muscle actin (alpha-SMA) protein expression was evaluated in all biopsies as a marker of fibroblast activation. Graft function and Banff grading were superimposable at randomization. Graft survival was significantly better in group 2 (P = 0.0376, chi2 = 4.323). CAN grading worsened significantly in group 1, whereas it remained stable in group 2. After 24 mo, all group 1 biopsies showed an increase of alpha-SMA expression at the interstitial and vascular levels (P < 0.001); on the contrary, alpha-SMA expression was dramatically reduced in group 2 biopsies (P = 0.005). This study demonstrates that rapamycin introduction/CNI withdrawal improves graft survival and reduces interstitial and vascular alpha-SMA expression, slowing down the progression of allograft injury in patients with CAN.

Pleiotropic effects of 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitors on renal function

Pleiotropic, or non-lipid-dependent, effects mediated by 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have important clinical implications for the cardiovascular (CV) system. Atherosclerosis is an inflammatory process accompanied by increases in levels of plasma inflammatory markers and accumulation of immune cells within atherosclerotic plaques. Statins not only decrease serum lipid levels, but also inhibit signaling molecules at several points in inflammatory pathways. The anti-inflammatory effects and improved endothelial function associated with statin therapy are thought to be partly responsible for the reduction in CV morbidity and mortality. In analogy, patients with chronic kidney disease administered statins for CV risk reduction show evidence of improved renal function. However, whether statins confer similar protective benefits on the kidney has not been established. Several lines of evidence suggest that similar etiologic and pathological processes may be involved in CV and chronic kidney diseases. If inflammation and functional changes in the renovascular endothelium contribute to the progression of kidney disease, statins are likely to be effective in the treatment of renal disease. In this review, we critically consider emerging data indicating that statins may modulate renal function by altering the inflammatory response of the kidney and renal vasculature to dyslipidemia. Whether the amelioration of renal function by statins is separable from the lipid-lowering effects of these drugs still remains to be delineated. Other questions that remain to be addressed and issues that should be investigated also are presented.

Impact of statin treatment on 1-year functional and histologic renal allograft outcome

BACKGROUND

Statins are antilipidemic agents that exhibit a variety of cellular effects independent of their lipid-lowering action. A retrospective study was undertaken to establish the impact of statins on graft outcome in the first year posttransplantation.

METHODS

Data from patients with uniform immunosuppression (cyclosporine, mycophenolate mofetil, and prednisolone) who underwent transplantation at the authors' unit from 1997 to 2002 were reviewed. Patients prescribed statins were compared with those not on a statin. Mean change in creatinine clearance (CrCl) from 3 to 12 months posttransplantation was calculated. Histomorphometric analysis was used to quantify fractional interstitial area and collagen III deposition in matched preperfusion and 12-month protocol biopsy specimens.

RESULTS

Seventy-seven patients met study criteria: statin, n=44 patients; nonstatin, n=33 patients. Median time to commencing a statin was 5 weeks. At 3 months, CrCl (+/-SEM) was similar: 51.6+/-2.9 mL/min (statin) versus 51.3+/-1 mL/min (nonstatin). At 12 months, the mean change in CrCl was 4.1+/-1 mL/min (statin) compared with -2.0+/-1.8 mL/min (nonstatin), resulting in a difference of 6.13 mL/min at 12 months (P<0.005). Mean preperfusion fractional interstitial areas were similar (23.9+/-1.6%; P=not significant [NS]). On 12-month biopsy specimens, the fractional interstitial area had increased to 34+/-3.2% in the nonstatin group (P<0.005), with no change in the statin group. Interstitial collagen III deposition was similar in preperfusion biopsy specimens (10.4+/-1%; P=NS), but at 12 months it was significantly greater in the nonstatin group (17.6+/-1%; P<0.05)

CONCLUSIONS

Early introduction of statins may be associated with improved 1-year graft outcome.

Evaluating Cardiovascular Pathophysiology and Anatomy in Atherosclerosis

The process of atherosclerosis begins with endothelial dysfunction from impaired bioavailability of NO and progresses through multiple stages of plaque development. Impaired endothelial function decreases NO and increases oxidized macromolecules such as low-density lipoprotein cholesterol. Oxidized low-density lipoprotein cholesterol accumulates in subendothelial space, forming plaques that may eventually compromise the lumen. Acute coronary events result from plaque rupture and consequent thrombus formation and abrupt occlusion of the vessel lumen. New diagnostic methods such as flow-mediated dilation of the brachial artery can detect endothelial dysfunction, and intravascular ultrasound can detect early plaque formation in the arterial wall. These techniques may provide a means to identify patients at risk for adverse cardiovascular outcomes, thereby enabling physicians to potentially prevent adverse events by early initiation of lipid-lowering therapy.

Are 3-Hydroxy-3-Methylglutaryl-CoA Reductase Inhibitors Renoprotective?: Table 1

Statins reduce serum cholesterol and cardiovascular morbidity and mortality. The mechanisms for these beneficial effects are reviewed. Altered inflammatory responses and improved endothelial function mediated by statins are thought to be partly responsible for the reduction of morbidity and mortality as a result of cardiovascular events. In analogy, whether statins confer similar benefits on the kidney has not been established. This review critically considers the available data whereby dyslipidemia mediates renal dysfunction by modulating the inflammatory response to diverse cytokines. Also reviewed is the emerging database indicating that statins may modulate renal function by altering the response of the kidney to dyslipidemia.

Optimal lipid modification: the rationale for combination therapy

BACKGROUND

An emphasis on more aggressive lipid-lowering, particularly of low-density lipoprotein cholesterol, to improve patient outcomes has led to an increased use of combination lipid-lowering drugs. This strategy, while potentially beneficial, has triggered concerns regarding fears of adverse effects, harmful drug interactions, and patient nonadherence.

OBJECTIVE

To present key data regarding combination lipid-altering therapy including use, rationale, major trials, benefits, potential adverse effects, compliance issues, and limitations.

METHOD

Literature was obtained from MEDLINE (1966 - June 2005) and references from selected articles.

RESULTS

A substantial body of evidence from epidemiological data and clinical trials indicates that aggressive lipid modification, especially low-density lipoprotein reduction, is associated with reduced cardiovascular events. Numerous studies utilizing various combinations of cholesterol-lowering agents including statin/fibrate, statin/niacin, statin/bile acid resin, and statin/ezetimibe have demonstrated significant changes in the lipid profile with acceptable safety. Long-term trials of combination therapy evaluating clinical outcomes or surrogate markers of cardiovascular disease, while limited, are promising.

CONCLUSION

Combining lipid-altering agents results in additional improvements in lipoproteins and has the potential to further reduce cardiovascular events beyond that of monotherapy.

Plasma kinetics of a cholesterol-rich microemulsion in patients submitted to heart transplantation

BACKGROUND

Development of coronary graft disease is currently the main cause of late heart-transplantation (HT) failure. HT patients frequently show hypercholesterolemia as well as alterations in chylomicron metabolism. These postHT changes may be important in coronary graft disease development. To clarify whether hypercholesterolemia is caused by decreased low-density lipoprotein (LDL) removal from the plasma, we studied the plasma kinetics of a cholesterol-rich emulsion that binds to LDL receptor.

METHODS

We studied 13 HT patients and 13 healthy normolipidemic subjects paired for sex, age, and body mass index. An emulsion labeled with C-cholesteryl oleate was injected intravenously, and blood samples were collected in predetermined intervals (5 minutes, 1, 2, 4, 6, and 8 hours) to determine the radioactivity decay curves and to calculate the fractional clearance rates (FCR).

RESULTS

The plasma level of total cholesterol, LDL cholesterol, high-density lipoprotein cholesterol, and apo B were greater in HT group than in the control group (P<0.005). FCR C-cholesteryl oleate was smaller in HT patients when compared with the control group (P=0.02).

CONCLUSION

The results showed that HT patients have a deficiency in the mechanisms of LDL removal from the plasma, as tested by the cholesterol-rich emulsion, and this may be important in the development of coronary graft disease.

Effects of HMG-CoA reductase inhibitors on coagulation and fibrinolysis processes

Recent large clinical trials have demonstrated that HMG-CoA reductase inhibitors, or statins, markedly reduce morbidity and mortality when used in the primary and secondary prevention of cardiovascular disease. It has been established that the benefits of statin therapy in cardiovascular disease can be explained not only by the lipid-lowering potential of statins but also by nonlipid-related mechanisms (so-called "pleiotropic effects") that contribute to the positive effect of statins on the incidence of cardiovascular events. The coagulation and fibrinolytic systems are two separate but reciprocally linked enzyme cascades that regulate the formation and breakdown of fibrin. Numerous studies have demonstrated that disturbances of coagulation and fibrinolysis contribute to the development and progression of atherosclerosis, and that they affect the incidence of atherosclerosis-related clinical events. High plasma levels or activities of fibrinogen, factor VII, factor VIII, von Willebrand factor (vWF), soluble thrombomodulin, tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) are thought to be associated with increased morbidity and mortality related to cardiovascular disease. Experimental studies and many clinical studies have recently shown that statins produce favourable effects on haemostatic parameters, including those that are risk factors for cardiovascular disease. Statins diminish procoagulant activity, which is observed at different stages of the coagulation cascade, including tissue factor (TF) activity, conversion of prothrombin to thrombin and thrombin activity. In some studies, statins also reduced fibrinogen levels. By altering the levels and activities of tPA and PAI-1, statins seem to stimulate fibrinolysis. The data on the effects of combined treatment with statins and other drugs on haemostasis are rather limited. They suggest that statins combined with fibric acid derivatives, omega-3 fatty acids and 17beta-estradiol are superior to statins alone. The only two clinical studies performed in patients with acute coronary syndromes showed a relatively weak effect of statins on haemostasis in those patients. Although various statins may produce different effects on individual variables, there are no convincing data showing that differences in their physicochemical and pharmacokinetic properties significantly alter their net effect on excessive procoagulant activity. Apart from the lipid-lowering effect, statins suppress the synthesis of several important nonsterol isoprenoids derived from the mevalonate pathway, especially farnesyl and geranylgeranyl pyrophosphates, which via enhanced protein prenylation, are involved in the regulation of many cellular processes. It is presumed that the inhibitory effect of statins on the mevalonate pathway is involved in the regulation of some key steps of coagulation and fibrinolysis processes. In this way they probably regulate the synthesis of TF, tPA and PAI-1, and perhaps they also control the generation and activity of thrombin. The beneficial effects of statins on coagulation and fibrinolysis may be responsible for their ability to decrease the number of cardiovascular events. The lipid-independent effects of statins on haemostasis may contribute to the marked decrease in the incidence rates of mortality, hospitalisation and revascularisation in patients treated with these drugs.

Fluvastatin reduces atherogenic lipids without any effect on native endothelial function early after kidney transplantation

BACKGROUND

Cardiovascular risk is greatly increased in renal transplant recipients. 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor (statin) therapy may reduce cardiovascular risk by improving both dyslipidemia and endothelial function. We therefore performed this study to assess the effect of fluvastatin on endothelial function in renal transplant recipients.

METHODS

This randomized, placebo-controlled, double-blind designed study investigated the effect of fluvastatin on endothelial function. Thirty-seven recipients received fluvastatin 40 mg/d and 35 received placebo during the first 12 wk following transplantation. All patients initially received cyclosporin A, prednisolone and azathioprine. At the end of treatment, endothelial function was assessed in the forearm skin microvasculature by laser Doppler flowmetry following acetylcholine stimulation. Samples were taken for measurements of serum lipids and vasoactive markers.

RESULTS

There were no differences in endothelial function between fluvastatin recipients and controls, AUCACh was 656 +/- 479 and 627 +/- 518 AU min, respectively (fluv vs. control, p > 0.65). In the placebo limb, total cholesterol and LDL cholesterol increased 22 +/- 12% and 22 +/- 18%, respectively in the first 12 wk following transplantation. The respective values were 18 +/- 13% (p = 0.010) and 34 +/- 19% (p = 0.0013) lower at 12 wk in the fluvastatin treated patients. Plasma ET-1, BigET-1 and urinary excretion of cGMP were not significantly different between treatment groups (p > 0.55).

CONCLUSION

Although fluvastatin 40 mg/d significantly lowers cholesterol it does not affect endothelial function the first 3 months after renal transplantation. The lack of effect on endothelial function is consistent with a lack of effect on vasoactive substances.

Early vascular benefits of statin therapy

Large-scale trials established that statin administration in hypercholesterolaemic individuals and patients with coronary heart disease (CHD) significantly reduces the risk of vascular events and death. This benefit was primarily attributed to their actions on lipids. This review focuses on the benefits (clinical and experimental) of statins observed soon (approximately 12 weeks) after their administration. Statins rapidly increase nitric oxide production and improve endothelial function (e.g. increased flow-mediated dilatation). Similarly, antioxidant properties decrease the susceptibility of low density lipoprotein cholesterol to oxidation. Statins inhibit the migration of macrophages and smooth muscle cell proliferation leading to an antiproliferative effect and the stabilisation of atherosclerotic plaques. Anti-inflammatory effects include a reduction in serum C-reactive protein levels, inflammatory and proinflammatory cytokines (e.g. IL-6, IL-8), adhesion molecules (e.g. ICAM-1, VCAM-1) and other acute phase proteins. Statins influence the haemostatic system. They reduce tissue factor expression and platelet activity, whereas fibrinolysis can be enhanced. Statins improve microalbuminuria, renal function, hypertension and arterial wall stiffness. A significant reduction of the carotid intima media thickness (IMT) was also reported early after statin treatment. These early effects of statins probably contribute to the significant reduction in vascular events seen in some 'short-term' studies. There is a need to further elucidate the rapid and non-lipid lowering properties of statins.

Blood pressure reduction with HMG-CoA reductase inhibitors in renal transplant recipients

BACKGROUND

Besides lowering lipid levels, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) modulate endothelial function and decrease vascular tone. The effect of statin therapy on blood pressure has not been previously examined in renal transplant recipients.

METHODS

We identified 113 stable recipients with graft survival>1 year and started on a statin >or=1 year post-transplant with no subsequent alteration in type or dose, as well as >or=6 months' follow-up post-statin introduction along with no changes in antihypertensive medication type or dosage. This "statin" group was compared to a control group matched 1:1 by age, gender, donor source, year of transplant, and time since transplant who met identical criteria but were not begun on a statin. Baseline, 6 months, and 12 months outpatient blood pressure were reviewed and compared along with other possible blood pressure predictors. A multivariate analysis was performed controlling for other influences on blood pressure change.

RESULTS

Blood pressure and baseline characteristics other than lipid levels were similar in the two groups. The systolic, diastolic, and mean arterial blood pressure decreased by 7 mm Hg (P = 0.005), 3 mm Hg (P = 0.05), and 4 mm Hg (P = 0.007), respectively, at 12 months' post-statin introduction, while no blood pressure change was seen in the control group (P = NS). At 12 months, the systolic, diastolic, and mean arterial blood pressures were lower in the statin group compared to the control group (P = 0.05, 0.03, and 0.02, respectively). These changes in blood pressure were independent of changes in serum lipid levels.

CONCLUSION

Renal transplant recipients exhibit a significant blood pressure reduction associated with statin therapy. This finding has important mechanistic and clinical implications in the management of cardiovascular disease risk factors in this population.

Immunomodulatory effects of statins: mechanisms and potential impact on arteriosclerosis

Clinical trials with statins have demonstrated a marked reduction of cardiovascular mortality. However, it remains controversial whether these clinical benefits stem from powerful cholesterol-lowering effects of statins or whether they are due in part to their cholesterol-independent effects on vascular function, plaque growth, plaque rupture, or thrombosis. The identification of several mechanisms through which statins decrease the recruitment of monocytes and T cells into the arterial wall and inhibit T cell activation and proliferation in vitro have prompted speculations that immunomodulatory effects of statins may be beneficial in recipients of organ transplants. Hypercholesterolemia is frequent in these patients, and delayed-type hypersensitivity reactions in the arterial walls of the graft may be compounded by chronic inflammation associated with conventional atherogenesis. To assess the potential clinical relevance of immunomodulatory effects of statins, the role of the immune system in atherogenesis and the effects of statins in vitro in experimental models and in clinical trials will be reviewed. It is concluded that despite solid in vitro evidence, clinical evidence for an independent immunosuppressive effect of statins in organ transplant patients is presently insufficient; however, further investigation of their in vivo occurrence and clinical relevance is warranted.