Baseline serum lipids and renal function in chronic kidney disease patients entering the LORD trial

HMG CoA reductase inhibitors (statins) for people with chronic kidney disease not requiring dialysis

BACKGROUND

Cardiovascular disease is the most frequent cause of death in people with early stages of chronic kidney disease (CKD), and the absolute risk of cardiovascular events is similar to people with coronary artery disease. This is an update of a review first published in 2009 and updated in 2014, which included 50 studies (45,285 participants).

OBJECTIVES

To evaluate the benefits and harms of statins compared with placebo, no treatment, standard care or another statin in adults with CKD not requiring dialysis.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 4 October 2023. Studies in the Register are identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov. An updated search will be undertaken every three months.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs that compared the effects of statins with placebo, no treatment, standard care, or other statins, on death, cardiovascular events, kidney function, toxicity, and lipid levels in adults with CKD (estimated glomerular filtration rate (eGFR) 90 to 15 mL/min/1.73 m2) were included.

DATA COLLECTION AND ANALYSIS

Two or more authors independently extracted data and assessed the study risk of bias. Treatment effects were expressed as mean difference (MD) for continuous outcomes and risk ratios (RR) for dichotomous benefits and harms with 95% confidence intervals (CI). The risk of bias was assessed using the Cochrane risk of bias tool, and the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 63 studies (50,725 randomised participants); of these, 53 studies (42,752 participants) compared statins with placebo or no treatment. The median duration of follow-up was 12 months (range 2 to 64.8 months), the median dosage of statin was equivalent to 20 mg/day of simvastatin, and participants had a median eGFR of 55 mL/min/1.73 m2. Ten studies (7973 participants) compared two different statin regimens. We were able to meta-analyse 43 studies (41,273 participants). Most studies had limited reporting and hence exhibited unclear risk of bias in most domains. Compared with placebo or standard of care, statins prevent major cardiovascular events (14 studies, 36,156 participants: RR 0.72, 95% CI 0.66 to 0.79; I2 = 39%; high certainty evidence), death (13 studies, 34,978 participants: RR 0.83, 95% CI 0.73 to 0.96; I² = 53%; high certainty evidence), cardiovascular death (8 studies, 19,112 participants: RR 0.77, 95% CI 0.69 to 0.87; I² = 0%; high certainty evidence) and myocardial infarction (10 studies, 9475 participants: RR 0.55, 95% CI 0.42 to 0.73; I² = 0%; moderate certainty evidence). There were too few events to determine if statins made a difference in hospitalisation due to heart failure. Statins probably make little or no difference to stroke (7 studies, 9115 participants: RR 0.64, 95% CI 0.37 to 1.08; I² = 39%; moderate certainty evidence) and kidney failure (3 studies, 6704 participants: RR 0.98, 95% CI 0.91 to 1.05; I² = 0%; moderate certainty evidence) in people with CKD not requiring dialysis. Potential harms from statins were limited by a lack of systematic reporting. Statins compared to placebo may have little or no effect on elevated liver enzymes (7 studies, 7991 participants: RR 0.76, 95% CI 0.39 to 1.50; I² = 0%; low certainty evidence), withdrawal due to adverse events (13 studies, 4219 participants: RR 1.16, 95% CI 0.84 to 1.60; I² = 37%; low certainty evidence), and cancer (2 studies, 5581 participants: RR 1.03, 95% CI 0.82 to 1.30; I² = 0%; low certainty evidence). However, few studies reported rhabdomyolysis or elevated creatinine kinase; hence, we are unable to determine the effect due to very low certainty evidence. Statins reduce the risk of death, major cardiovascular events, and myocardial infarction in people with CKD who did not have cardiovascular disease at baseline (primary prevention). There was insufficient data to determine the benefits and harms of the type of statin therapy.

AUTHORS' CONCLUSIONS

Statins reduce death and major cardiovascular events by about 20% and probably make no difference to stroke or kidney failure in people with CKD not requiring dialysis. However, due to limited reporting, the effect of statins on elevated creatinine kinase or rhabdomyolysis is unclear. Statins have an important role in the primary prevention of cardiovascular events and death in people who have CKD and do not require dialysis. Editorial note: This is a living systematic review. We will search for new evidence every three months and update the review when we identify relevant new evidence. Please refer to the Cochrane Database of Systematic Reviews for the current status of this review.

Serum Lipids and Risk of Rapid Renal Function Decline in Treated Hypertensive Adults With Normal Renal Function

BACKGROUND

We aim to evaluate the effect of different lipids parameters, including triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), the TG to HDL-C (TG:HDL-C) ratio, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C), on the risk of rapid renal function decline and examine any possible effect modifiers in general hypertensive patients with normal renal function.

METHODS

A total of 12,549 hypertensive patients with estimated glomerular filtration rate (eGFR) ≥60 ml/min/1.73 m2 in the renal sub-study of the China Stroke Primary Prevention Trial were included in the analyses. The primary outcome was rapid renal function decline, defined as an average decline in eGFR ≥ 5 ml/min/1.73 m2 per year.

RESULTS

The median treatment duration was 4.4 years. After the full adjustment for TC, TG, HDL-C, and other major covariates, a significantly higher risk of rapid renal function decline was found in participants with higher TG [≥150 vs. <150 mg/dl, 7.7% vs. 5.5%; odds ratios (OR): 1.27; 95% confidence interval (CI): 1.06-1.51], higher TG:HDL-C ratio [≥2.7 (median) vs. <2.7, 7.7% vs. 5.0%; OR: 1.39; 95% CI: 1.14-1.71), lower TC (≥200 vs. <200 mg/dl, 6.0% vs. 7.0%; OR: 0.79; 95% CI: 0.67-0.93), or lower LDL-C levels (≥130 vs. <130 mg/dl, 6.1% vs. 7.0%; OR: 0.79; 95% CI: 0.67-0.94). Moreover, the increased risk of the primary outcome associated with elevated TG was particularly evident among individuals with lower total homocysteine levels [<12.4 (median) vs. ≥ 12.4 μmol/l, P interaction = 0.036].

CONCLUSIONS

Higher TG and TG:HDL-C ratio were independent risk factors for rapid renal function decline in hypertensive adults with normal renal function.

HMG CoA reductase inhibitors (statins) for people with chronic kidney disease not requiring dialysis

BACKGROUND

Cardiovascular disease (CVD) is the most frequent cause of death in people with early stages of chronic kidney disease (CKD), for whom the absolute risk of cardiovascular events is similar to people who have existing coronary artery disease. This is an update of a review published in 2009, and includes evidence from 27 new studies (25,068 participants) in addition to the 26 studies (20,324 participants) assessed previously; and excludes three previously included studies (107 participants). This updated review includes 50 studies (45,285 participants); of these 38 (37,274 participants) were meta-analysed.

OBJECTIVES

To evaluate the benefits (such as reductions in all-cause and cardiovascular mortality, major cardiovascular events, MI and stroke; and slow progression of CKD to end-stage kidney disease (ESKD)) and harms (muscle and liver dysfunction, withdrawal, and cancer) of statins compared with placebo, no treatment, standard care or another statin in adults with CKD who were not on dialysis.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 5 June 2012 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs that compared the effects of statins with placebo, no treatment, standard care, or other statins, on mortality, cardiovascular events, kidney function, toxicity, and lipid levels in adults with CKD not on dialysis were the focus of our literature searches.

DATA COLLECTION AND ANALYSIS

Two or more authors independently extracted data and assessed study risk of bias. Treatment effects were expressed as mean difference (MD) for continuous outcomes (lipids, creatinine clearance and proteinuria) and risk ratio (RR) for dichotomous outcomes (major cardiovascular events, all-cause mortality, cardiovascular mortality, fatal or non-fatal myocardial infarction (MI), fatal or non-fatal stroke, ESKD, elevated liver enzymes, rhabdomyolysis, cancer and withdrawal rates) with 95% confidence intervals (CI).

MAIN RESULTS

We included 50 studies (45,285 participants): 47 studies (39,820 participants) compared statins with placebo or no treatment and three studies (5547 participants) compared two different statin regimens in adults with CKD who were not yet on dialysis. We were able to meta-analyse 38 studies (37,274 participants).The risk of bias in the included studies was high. Seven studies comparing statins with placebo or no treatment had lower risk of bias overall; and were conducted according to published protocols, outcomes were adjudicated by a committee, specified outcomes were reported, and analyses were conducted using intention-to-treat methods. In placebo or no treatment controlled studies, adverse events were reported in 32 studies (68%) and systematically evaluated in 16 studies (34%).Compared with placebo, statin therapy consistently prevented major cardiovascular events (13 studies, 36,033 participants; RR 0.72, 95% CI 0.66 to 0.79), all-cause mortality (10 studies, 28,276 participants; RR 0.79, 95% CI 0.69 to 0.91), cardiovascular death (7 studies, 19,059 participants; RR 0.77, 95% CI 0.69 to 0.87) and MI (8 studies, 9018 participants; RR 0.55, 95% CI 0.42 to 0.72). Statins had uncertain effects on stroke (5 studies, 8658 participants; RR 0.62, 95% CI 0.35 to 1.12).Potential harms from statin therapy were limited by lack of systematic reporting and were uncertain in analyses that had few events: elevated creatine kinase (7 studies, 4514 participants; RR 0.84, 95% CI 0.20 to 3.48), liver function abnormalities (7 studies, RR 0.76, 95% CI 0.39 to 1.50), withdrawal due to adverse events (13 studies, 4219 participants; RR 1.16, 95% CI 0.84 to 1.60), and cancer (2 studies, 5581 participants; RR 1.03, 95% CI 0.82 to 130).Statins had uncertain effects on progression of CKD. Data for relative effects of intensive cholesterol lowering in people with early stages of kidney disease were sparse. Statins clearly reduced risks of death, major cardiovascular events, and MI in people with CKD who did not have CVD at baseline (primary prevention).

AUTHORS' CONCLUSIONS

Statins consistently lower death and major cardiovascular events by 20% in people with CKD not requiring dialysis. Statin-related effects on stroke and kidney function were found to be uncertain and adverse effects of treatment are incompletely understood. Statins have an important role in primary prevention of cardiovascular events and mortality in people who have CKD.

The impact of pre-intervention rate of kidney function change on the assessment of CKD progression

BACKGROUND

Without a run-in phase, chronic kidney disease (CKD) patients enrolled in clinical trials may not be identified as having progressive disease. The aim of this analysis was to quantify the effects of a run-in phase on kidney function outcome in CKD patients enrolled in the Lipid Lowering and Onset of Renal Disease (LORD) trial.

METHODS

The LORD trial assessed the effects of atorvastatin on the rate of change in the estimated glomerular filtration rate (eGFR) and included patients with serum creatinine 120 μmol/l. In this post hoc analysis, we assessed eGFR change during the 12-month period prior to enrolment, the 3-month run-in phase and the first 12-month period of the trial. Eighty of the original 132 patients (where retrospective data were available) were included. The rate of eGFR change during each period was compared.

RESULTS

Overall kidney function decreased during the 12 months prior to enrolment by (mean, SD) 0.39 ± 0.98 ml/min/1.73 m(2)/month, improved during the 3-month run-in phase by 0.48 ± 2.90 ml/min/1.73 m(2)/month and decreased during the first 12 months of the trial by 0.15 ± 0.57 ml/min/1.73 m(2)/month. However, only 39 % of patients had declining eGFR during the 12 months prior, 19 % in the 3-month run-in and 42 % during the first 12-month study phase.

CONCLUSION

Most patients (>60 %) entering this clinical trial had stable or improving kidney function. Enrolment was associated with further improved kidney function, which may have been due to 'regression to the mean' or to the Hawthorne effect. Investigators should include a run-in period to establish the presence of eGFR decline to use as an inclusion criterion in clinical trials assessing this measure of CKD progression.

Effect of pravastatin on kidney function and urinary protein excretion in autosomal dominant polycystic kidney disease

OBJECTIVE

Autosomal dominant polycystic kidney disease (ADPKD) is progressive, resulting in end-stage kidney failure in most patients. Experimental and clinical studies have suggested that statins may slow the progression of chronic kidney disease in general and ADPKD specifically.

MATERIAL AND METHODS

This randomized open-label clinical trial was conducted to assess the effect of pravastatin 20 mg on kidney function and urinary protein excretion in patients with ADPKD. Sixty patients were initially recruited but 49 of these received either pravastatin 20 mg or no treatment for 2 years. Trial visits were conducted every 3 months, assessing kidney function by estimated glomerular filtration rate and 24 h urine creatinine clearance and urinary protein excretion.

RESULTS

There were no significant (p > 0.05) changes in markers of kidney function or urinary protein excretion between groups over the 2 years despite a significant fall in total serum cholesterol in pravastatin-treated patients (p = 0.029).

CONCLUSION

This trial found that taking 20 mg pravastatin for 2 years had no significant effect on kidney function or urinary protein excretion in patients with ADPKD. The lack of statistical power limits the external validity of these findings. A larger, longer duration study using a higher dose of a more potent statin is required.

Dietary intake of patients with chronic kidney disease entering the LORD trial: adjusting for underreporting

OBJECTIVE

The study objective was to determine the dietary intake of patients with chronic kidney disease before and after filtering for suspected underreporters and to investigate the impact of underreporting on the interpretation of diet data.

DESIGN

This was a cross-sectional study.

SETTING

The study included outpatients from hospitals and clinics in Northern Tasmania, Australia.

PATIENTS

Data from 113 patients enrolled in the Lipid Lowering and Onset of Renal Disease trial were used in this study. Patients with serum creatinine greater than 120 mmol/L were included, and those taking lipid-lowering medication were excluded.

METHODS

Patients completed a 4-day self-report diet diary, and FoodWorks software was used to determine their daily intake of energy, macronutrients, and specific micronutrients. Diet diaries were assessed for likely underreporting using the Goldberg cutoff approach with a ratio of energy intake to estimated resting energy expenditure of 1.27. Nutrient intakes were compared with current National Kidney Foundation's Kidney Disease Outcomes Quality Initiative guidelines, World Health Organization recommendations, recommended daily allowances, and daily values adjusted for energy intake.

RESULTS

Demographics of the patients were as follows: male/female, 71/42; age (mean +/- standard deviation), 60 +/- 15 years; body mass index, 28.6 +/- 6.0 kg/m(2), and serum creatinine, 223.4 +/- 110.0 mmol/L. According to the criteria, 80 patients (70.8%) were underreporting their energy intake. Underreporters were more likely to be female and younger, and have a higher body mass index and elevated serum creatinine. In all patients, daily energy intake (89.6 +/- 32.4 kJ/kg) was lower than recommended (125-145 kJ/kg); however, this was not the case for valid reporters (128.3 +/- 23.7 kJ/kg). Protein intake was higher (0.9 +/- 0.3 g/kg) than recommended (0.75 g/kg) in all patients and even higher (1.2 +/- 0.3 g/kg) in valid reporters. Mean calcium, zinc, and dietary fiber intakes were all below recommendations in all patients, but these differences were not apparent in valid reporters.

CONCLUSION

Interpreting self-report diet diary data from patients with chronic kidney disease without attempting to exclude underreporters will lead to erroneous conclusions, especially in respect to energy, protein, dietary fiber, calcium, and zinc intakes.

Effect of Atorvastatin on Cognitive Function in Patients from the Lipid Lowering and Onset of Renal Disease (LORD) Trial

STUDY OBJECTIVE

To examine the effect of atorvastatin on cognitive function by testing two hypotheses: that atorvastatin 10 mg/day would impair cognitive function, and that other biochemical and demographic measures would better predict cognitive performance than atorvastatin alone.

DESIGN

Randomized, double-blind, placebo-controlled study.

SETTING

Two primary acute care settings in the north and northwest of Tasmania, Australia.

PATIENTS

Fifty-seven patients from the Lipid Lowering and Onset of Renal Disease (LORD) trial.

INTERVENTION

Participants were randomly assigned to receive either atorvastatin 10 mg/day or matching placebo. Cognitive testing was performed in two sessions occurring 12 weeks apart and involved three repeated measures of attention and concentration.

MEASUREMENTS AND MAIN RESULTS

Performance was measured using three standard neuropsychological tests: Digit Symbol Coding subtest, Trail Making Test, and Stroop Color-Word Reading Test. Patients received atorvastatin for a mean of 72.93 weeks and placebo for a mean of 68.85 weeks. Repeated-measures multivariate analysis of variance failed to identify any significant differences between the two groups on any of the three cognitive measures. Multiple regression analyses identified no single factor or combination of plasma cholesterol levels, renal function, liver function, or age that predicted cognitive performance in either the atorvastatin or placebo group on the three measures at either testing session.

CONCLUSION

Atorvastatin 10 mg/day did not produce decrements to cognitive performance. In addition, biochemical and demographic measures and the receipt of atorvastatin versus placebo did not individually or in combination predict cognitive performance on measures of attention and concentration.