Proprotein convertase subtilisin/kexin type 9 (PCSK9) and clinical outcomes in dialysis patients.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9), a factor accelerating the degradation of LDL receptors, was associated with a gender-dependent risk for cardiovascular (CV) events in the general population and with all-cause and CV mortality in two relatively small studies in black Africans and South Korean haemodialysis patients. The effect modification by gender was untested in these studies. METHODS: The study enrolled 1188 dialysis patients from the Prospective Registry of The Working Group of Epidemiology of Dialysis Region Calabria (PROGREDIRE) cohort. PCSK9 was measured by colorimetric enzyme-linked immunosorbent assay. The primary outcomes were all-cause and CV mortality. Statistical analysis included Cox regression analysis and effect modification analysis. RESULTS: During a median 2.9-year follow-up, out of 494 deaths, 278 were CV-related. In unadjusted analyses, PCSK9 levels correlated with increased all-cause (HRfor1ln unit increase: 1.23, 95% CI 1.06-1.43, p =.008) and CV mortality (HRfor1ln unit increase: 1.26, 95% CI 1.03-1.54, p =.03). After multivariate adjustment, these associations were no longer significant (all-cause mortality, HRfor 1 ln unit increase: 1.16, 95% CI .99-1.36, p =.07; CV mortality, HRfor1ln unit increase: 1.18, 95% CI .95-1.46, p =.14). However, in fully adjusted interaction analyses, a doubling in the risk of this outcome in women was registered (Women, HRfor1ln unit increase: 1.88, 95% CI 1.27-2.78, p =.002; Men, HRfor1ln unit increase: 1.07, 95% CI .83-1.38, p =.61; p for effect modification: .02). CONCLUSIONS: PCSK9 levels are unrelated to all-cause mortality in haemodialysis patients but, like in studies of the general population, independently of other risk factors, entail a doubling in the risk of CV events in women in this population.

The safety of a low protein diet in older adults with advanced chronic kidney disease.

BACKGROUND: A low protein diet (LPD) is recommended to patients with advanced chronic kidney disease (CKD), whereas geriatric guidelines recommend a higher amount of protein. The aim of this study was to evaluate the safety of LPD treatment in older adults with advanced CKD. METHODS: The EQUAL study is a prospective, observational study, including patients ≥65 years, incident estimated glomerular filtration rate <20 ml/min/1.73m², in six European countries with follow-up up till six years. Nutritional status was assessed by 7-point subjective global assessment (SGA) every 3-6 months. Prescribed diet (gram protein/kilogram/bodyweight) was recorded on every study visit; measured protein intake was available in three countries. Time to death and decline in nutritional status (SGA decrease by ≥2 points) were analysed using marginal structural models with dynamic inverse probability of treatment and censoring weights. RESULTS: Out of 1738 adults (631 prescribed LPD at any point during follow-up) there were 1319 with repeated SGA measurements of which 267 (20%) declined in SGA ≥ 2 points and 565 (32.5%) died. There was no difference in survival or decline in nutritional status for patients prescribed LPD ≤0.8 g/kg ideal bodyweight (Odds Ratio (OR) for mortality 1.15 (95% Confidence interval (CI) 0.86-1.55) and OR for decline in SGA 1.11 (95% CI 0.74-1.66) in the adjusted models. In patients prescribed LPD <0.6 g/kg ideal bodyweight, the results were similar. There was a significant interaction with LPD and higher age >75 years, lower SGA, and higher comorbidity burden for both mortality and nutritional status decline. CONCLUSIONS: In older adults with CKD approaching end-stage kidney disease, a traditional LPD prescribed and monitored according to routine clinical practice in Europe appears to be safe.

Protein Biomarkers and Major Cardiovascular Events in Older People With Advanced CKD: The European Quality (EQUAL) Study.

Rationale & Objective: Cardiovascular disease is the leading cause of morbidity and mortality in chronic kidney disease (CKD). We investigated 184 inflammatory and cardiovascular proteins to determine their potential as biomarkers for major cardiovascular events (MACEs). Study Design: The European Quality (EQUAL) is an observational cohort study that enrolled people aged ≥65 years with an estimated glomerular filtration rate ≤20 mL/min/1.73 m2. Setting & Participants: Recruited participants were split into the discovery (n = 611) and replication cohorts (n = 292). Exposure: Levels of 184 blood proteins were measured at the baseline visit, and each protein was analyzed individually. Outcome: MACE. Analytical Approach: Cox proportional hazard models adjusted for age, sex, estimated glomerular filtration rate, previous MACE, and country were used to determine the risk of MACE. Proteins with false discovery rate adjusted P values of <0.05 in the discovery cohort were tested in the replication cohort. Sensitivity analyses were performed by adjusting for traditional risk factors, CKD-specific risk factors, and level of proteinuria and segregating atherosclerotic and nonatherosclerotic MACE. Results: During a median follow-up of 2.9 years, 349 people (39%) experienced a MACE. Forty-eight proteins were associated with MACE in the discovery cohort; 9 of these were reproduced in the replication cohort. Three of these proteins maintained a strong association with MACE after adjustment for traditional and CKD-specific risk factors and proteinuria. Tenascin (TNC), fibroblast growth factor-23 (FGF-23), and V-set and immunoglobulin domain-containing protein 2 (VSIG2) were associated with both atherosclerotic and nonatherosclerotic MACE. All replicated proteins except carbonic anhydrase 1 and carbonic anhydrase 3 were associated with nonatherosclerotic MACE. Limitations: Single protein concentration measurements and limited follow-up time. Conclusions: Our findings corroborate previously reported relationships between FGF-23, vascular cell adhesion protein-1, TNC, and placental growth factor with cardiovascular outcomes in CKD. We identify 5 proteins not previously linked with MACE in CKD that may be targets for future therapies. Plain-Language Summary: Kidney disease increases the risk of heart disease, stroke, and other vascular conditions. Blood tests that predict the likelihood of these problems may help to guide treatment, but studies are needed in people with kidney disease. We analyzed blood tests from older people with kidney disease, looking for proteins associated with higher risk of these conditions. Nine proteins were identified, of which 3 showed a strong effect after all other information was considered. This work supports previous research regarding 4 of these proteins and identifies 5 additional proteins that may be associated with higher risk. Further work is needed to confirm our findings and to determine whether these proteins can be used to guide treatment.

The impact of gender on the risk of cardiovascular events in older adults with advanced chronic kidney disease.

Background: Patients with chronic kidney disease (CKD) are at a higher risk of major adverse cardiovascular events (MACE) compared with the general population, but gender differences in this risk, especially in older adults, are not fully known. We aim to identify gender differences in the risk of MACE in older European CKD patients, and explore factors that may explain these differences. Methods: The European Quality study (EQUAL) is a prospective study on stage 4-5 CKD patients, ≥65 years old, not on dialysis, from Germany, Italy, the Netherlands, Poland, Sweden and the UK. Cox regression and cumulative incidence competing risk curves were used to identify gender differences in MACE risks. Mediation analysis was used to identify variables which may explain risk differences between men and women. Results: A total of 417 men out of 1134 (37%) and 185 women out of 602 women (31%) experienced at least one MACE, over a follow-up period of 5 years. Women had an 18% lower risk of first MACE compared with men (hazard ratio 0.82; 95% confidence interval 0.69-0.97; P = .02), which was attenuated after adjusting for pre-existing cardiometabolic comorbidities and cardiovascular risk factors. There were no significant gender differences in the risk of recurrent MACE or fatal MACE. The risk difference in MACE by gender was larger in patients aged 65-75 years, compared with patients over 75 years. Conclusions: In a cohort of older adults with advanced CKD, women had lower risks of MACE. These risk differences were partially explained by pre-existing cardiometabolic comorbidities and cardiovascular risk factors.

Perampanel as only add-on epilepsy treatment in elderly: A subgroup analysis of real-world data from retrospective, multicenter, observational study.

INTRODUCTION: Drug management of epilepsy in the elderly presents unique but data on this population are scarce. This study aimed to assess the effectiveness and tolerability of perampanel (PER) used as only add-on to a background anti-seizure medication (ASM) in the elderly in a real-world setting. METHODS: We performed a subgroup analysis of patients aged ≥65 years included in a previous 12-month multicenter study on adults. Treatment discontinuation, seizure frequency, and adverse events were recorded at 3, 6 and 12 months after PER introduction. Sub-analyses by early (≤1 previous ASM) or late PER add-on were also conducted. RESULTS: The sample included 65 subjects (mean age: 75.7 ± 7.2 years), with mainly focal (73.8%) epilepsy. The mean PER daily dose was ≈4 mg during all follow-up. Retention rates at 3, 6, and 12 months were 90.5%, 89.6%, and 79.4%ly. The baseline median normalized per 28-day seizure number significantly decreased at 3-, 6- and 12-month visits. One year after PER introduction, the responder rate (≥50% reduction in baseline seizure frequency) was 89.7%, with a seizure freedom rate of 72.4%. Adverse events occurred in 22 (34.9%) patients with dizziness and irritability being the most frequent. No major differences between early (41 patients, 63.1%), and late add-on groups were observed. CONCLUSION: Adjunctive PER was effective and well-tolerated when used as only add-on treatment in elderly people with epilepsy in clinical practice, thus representing a suitable therapeutic option in this age category.

Home Pulse Pressure Predicts Death and Cardiovascular Events in Peritoneal Dialysis Patients.

Increased arterial hypertension represents a prevalent condition in peritoneal dialysis patients that is often related to volume expansion. Pulse pressure is a robust predictor of mortality in dialysis patients, but its association with mortality is unknown in peritoneal patients. We investigated the relationship between home pulse pressure and survival in 140 PD patients. During a mean follow-up of 35 months, 62 patients died, and 66 experienced the combined event death/CV events. In a crude COX regression analysis, a five-unit increase in HPP was associated with a 17% increase in the hazard ratio of mortality (HR: 1.17, 95% CI 1.08-1.26 p < 0.001). This result was confirmed in a multiple Cox model adjusted for age, gender, diabetes, systolic arterial pressure, and dialysis adequacy (HR: 1.31, 95% CI 1.12-1.52, p = 0.001). Similar results were obtained considering the combined event death-CV events as an outcome. Home pulse pressure represents, in part, arterial stiffness, and it is strongly related to all-cause mortality in peritoneal patients. In these high cardiovascular risk populations, it is important to maintain optimal blood pressure control, but it is fundamental to consider all the other cardiovascular risk indicators, such as pulse pressure. Home pulse pressure measurement is easy and feasible and can add important information for the identification and management of high-risk patients.

Clinical and patient-reported trajectories at end-of-life in older patients with advanced CKD.

BACKGROUND: We explore longitudinal trajectories of clinical indicators, patient-reported outcomes, and hospitalizations, in the years preceding death in a population of older patients with advanced chronic kidney disease (CKD). METHODS: The EQUAL study is a European observational prospective cohort study with an incident eGFR <20 ml/min per 1.73 m2 and ≥65 years of age. The evolution of each clinical indicator was explored using generalized additive models during the 4 years preceding death. RESULTS: We included 661 decedents with a median time to death of 2.0 years (IQR 0.9-3.2). During the years preceding death, eGFR, Subjective Global Assessment score, and blood pressure declined, with accelerations seen at 6 months preceding death. Serum hemoglobin, hematocrit, cholesterol, calcium, albumin, and sodium values declined slowly during follow-up, with accelerations observed between 6 and 12 months preceding death. Physical and mental quality of life declined linearly throughout follow-up. The number of reported symptoms was stable up to 2 years prior to death, with an acceleration observed at 1 year prior to death. The rate of hospitalization was stable at around one hospitalization per person year, increasing exponentially at 6 months preceding death. CONCLUSIONS: We identified clinically relevant physiological accelerations in patient trajectories that began ∼6 to 12 months prior to death, which are likely multifactorial in nature, but correlate with a surge in hospitalizations. Further research should focus on how to effectively use this knowledge to inform patient and family expectations, to benefit the planning of (end-of-life) care, and to establish clinical alert systems.

Serum Potassium and Risk of Death or Kidney Replacement Therapy in Older People With CKD Stages 4-5: Eight-Year Follow-up.

RATIONALE & OBJECTIVE: Hypokalemia may accelerate kidney function decline. Both hypo- and hyperkalemia can cause sudden cardiac death. However, little is known about the relationship between serum potassium and death or the occurrence of kidney failure requiring replacement therapy (KRT). We investigated this relationship in older people with chronic kidney disease (CKD) stage 4-5. STUDY DESIGN: Prospective observational cohort study. SETTING & PARTICIPANTS: We followed 1,714 patients (≥65 years old) from the European Quality (EQUAL) study for 8 years from their first estimated glomerular filtration rate (eGFR)<20mL/min/1.73m2 measurement. EXPOSURE: Serum potassium was measured every 3 to 6 months and categorized as≤3.5,>3.5-≤4.0,>4.0-≤4.5,>4.5-≤5.0 (reference),>5.0-≤5.5, >5.5-≤6.0, and>6.0mmol/L. OUTCOME: The combined outcome death before KRT or start of KRT. ANALYTICAL APPROACH: The association between categorical and continuous time-varying potassium and death or KRT start was examined using Cox proportional hazards and restricted cubic spline analyses, adjusted for age, sex, diabetes, cardiovascular disease, renin-angiotensin-aldosterone system (RAAS) inhibition, eGFR, and subjective global assessment (SGA). RESULTS: At baseline, 66% of participants were men, 42% had diabetes, 47% cardiovascular disease, and 54% used RAAS inhibitors. Their mean age was 76±7 (SD) years, mean eGFR was 17±5 (SD) mL/min/1.73m2, and mean SGA was 6.0±1.0 (SD). Over 8 years, 414 (24%) died before starting KRT, and 595 (35%) started KRT. Adjusted hazard ratios for death or KRT according to the potassium categories were 1.6 (95% CI, 1.1-2.3), 1.4 (95% CI, 1.1-1.7), 1.1 (95% CI, 1.0-1.4), 1 (reference), 1.1 (95% CI, 0.9-1.4), 1.8 (95% CI, 1.4-2.3), and 2.2 (95% CI, 1.5-3.3). Hazard ratios were lowest at a potassium of about 4.9mmol/L. LIMITATIONS: Shorter intervals between potassium measurements would have allowed for more precise estimations. CONCLUSIONS: We observed a U-shaped relationship between serum potassium and death or KRT start among patients with incident CKD 4-5, with a nadir risk at a potassium level of 4.9mmol/L. These findings underscore the potential importance of preventing both high and low potassium in patients with CKD 4-5. PLAIN-LANGUAGE SUMMARY: Abnormal potassium blood levels may increase the risk of death or kidney function decline, especially in older people with chronic kidney disease (CKD). We studied 1,714 patients aged≥65 years with advanced CKD from the European Quality (EQUAL) study and followed them for 8 years. We found that both low and high levels of potassium were associated with an increased risk of death or start of kidney replacement therapy, with the lowest risk observed at a potassium level of 4.9 mmol/L. In patients with CKD, the focus is often on preventing high blood potassium. However, this relatively high optimum potassium level stresses the potential importance of also preventing low potassium levels in older patients with advanced CKD.

Association between CKD-MBD and mortality in older patients with advanced CKD-results from the EQUAL study.

BACKGROUND: Chronic kidney disease-mineral and bone disorder (CKD-MBD) is a common complication of CKD; it is associated with higher mortality in dialysis patients, while its impact in non-dialysis patients remains mostly unknown. We investigated the associations between parathyroid hormone (PTH), phosphate and calcium (and their interactions), and all-cause, cardiovascular (CV) and non-CV mortality in older non-dialysis patients with advanced CKD. METHODS: We used data from the European Quality study, which includes patients aged ≥65 years with estimated glomerular filtration rate ≤20 mL/min/1.73 m2 from six European countries. Sequentially adjusted Cox models were used to assess the association between baseline and time-dependent CKD-MBD biomarkers and all-cause, CV and non-CV mortality. Effect modification between biomarkers was also assessed. RESULTS: In 1294 patients, the prevalence of CKD-MBD at baseline was 94%. Both PTH [adjusted hazard ratio (aHR) 1.12, 95% confidence interval (CI) 1.03-1.23, P = .01] and phosphate (aHR 1.35, 95% CI 1.00-1.84, P = .05), but not calcium (aHR 1.11, 95% CI 0.57-2.17, P = .76), were associated with all-cause mortality. Calcium was not independently associated with mortality, but modified the effect of phosphate, with the highest mortality risk found in patients with both hypercalcemia and hyperphosphatemia. PTH level was associated with CV mortality, but not with non-CV mortality, whereas phosphate was associated with both CV and non-CV mortality in most models. CONCLUSIONS: CKD-MBD is very common in older non-dialysis patients with advanced CKD. PTH and phosphate are independently associated with all-cause mortality in this population. While PTH level is only associated with CV mortality, phosphate seems to be associated with both CV and non-CV mortality.

Symptom Burden before and after Dialysis Initiation in Older Patients.

BACKGROUND AND OBJECTIVES: For older patients with kidney failure, lowering symptom burden may be more important than prolonging life. Dialysis initiation may affect individual kidney failure-related symptoms differently, but the change in symptoms before and after start of dialysis has not been studied. Therefore, we investigated the course of total and individual symptom number and burden before and after starting dialysis in older patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The European Quality (EQUAL) study is an ongoing, prospective, multicenter study in patients ≥65 years with an incident eGFR ≤20 ml/min per 1.73 m2. Using the dialysis symptom index (DSI), 30 symptoms were assessed every 3-6 months between 2012 and 2021. Scores for symptom number range from zero to 30 and, for burden, from zero to 150, with higher scores indicating more severity. Using mixed effects models, we studied symptoms during the year preceding and the year after dialysis initiation. RESULTS: We included 456 incident patients on dialysis who filled out at least one DSI during the year before or after dialysis. At dialysis initiation, mean (SD) participant age was 76 (6) years, 75% were men, mean (SD) eGFR was 8 (3) ml/min per 1.73 m2, 44% had diabetes, and 46% had cardiovascular disease. In the year before dialysis initiation, symptom number increased +3.6 (95% confidence interval [95% CI], +2.5 to +4.6) and symptom burden increased +13.3 (95% CI, +9.5 to +17.0). In the year after, symptom number changed -0.9 (95% CI, -3.4 to +1.5) and burden decreased -5.9 (95% CI, -14.9 to -3.0). At dialysis initiation, "fatigue," "decreased interest in sex," and "difficulty becoming sexually aroused" had the highest prevalence of 81%, 69%, and 68%, respectively, with a burden of 2.7, 2.4, and 2.3, respectively. "Fatigue" somewhat improved after dialysis initiation, whereas the prevalence and burden of sexual symptoms further increased. CONCLUSIONS: Symptom burden worsened considerably before and stabilized after dialysis initiation. "Fatigue," "decreased interest in sex," and "difficulty becoming sexually aroused" were considered most burdensome, of which only "fatigue" somewhat improved after dialysis initiation.

Predicting Kidney Failure, Cardiovascular Disease and Death in Advanced CKD Patients.

Introduction: Predicting the timing and occurrence of kidney replacement therapy (KRT), cardiovascular events, and death among patients with advanced chronic kidney disease (CKD) is clinically useful and relevant. We aimed to externally validate a recently developed CKD G4+ risk calculator for these outcomes and to assess its potential clinical impact in guiding vascular access placement. Methods: We included 1517 patients from the European Quality (EQUAL) study, a European multicentre prospective cohort study of nephrology-referred advanced CKD patients aged ≥65 years. Model performance was assessed based on discrimination and calibration. Potential clinical utility for timing of referral for vascular access placement was studied with diagnostic measures and decision curve analysis (DCA). Results: The model showed a good discrimination for KRT and "death after KRT," with 2-year concordance (C) statistics of 0.74 and 0.76, respectively. Discrimination for cardiovascular events (2-year C-statistic: 0.70) and overall death (2-year C-statistic: 0.61) was poorer. Calibration was fairly accurate. Decision curves illustrated that using the model to guide vascular access referral would generally lead to less unused arteriovenous fistulas (AVFs) than following estimated glomerular filtration rate (eGFR) thresholds. Conclusion: This study shows moderate to good predictive performance of the model in an older cohort of nephrology-referred patients with advanced CKD. Using the model to guide referral for vascular access placement has potential in combating unnecessary vascular surgeries.

The association between TMAO, CMPF, and clinical outcomes in advanced chronic kidney disease: results from the European QUALity (EQUAL) Study.

BACKGROUND: Trimethylamine N-oxide (TMAO), a metabolite from red meat and fish consumption, plays a role in promoting cardiovascular events. However, data regarding TMAO and its impact on clinical outcomes are inconclusive, possibly due to its undetermined dietary source. OBJECTIVES: We hypothesized that circulating TMAO derived from fish intake might cause less harm compared with red meat sources by examining the concomitant level of 3-carboxy-4-methyl-5-propyl-2-furanpropionate (CMPF), a known biomarker of fish intake, and investigated the association between TMAO, CMPF, and outcomes. METHODS: Patients were recruited from the European QUALity (EQUAL) Study on treatment in advanced chronic kidney disease among individuals aged ≥65 y whose estimated glomerular filtration rate (eGFR) had dropped for the first time to ≤20 mL/min per 1.73 m2 during the last 6 mo. The association between TMAO, CMPF, and outcomes including all-cause mortality and kidney replacement therapy (KRT) was assessed among 737 patients. Patients were further stratified by median cutoffs of TMAO and CMPF, suggesting high/low red meat and fish intake. RESULTS: During a median of 39 mo of follow-up, 232 patients died. Higher TMAO was independently associated with an increased risk of all-cause mortality (multivariable HR: 1.46; 95% CI: 1.17, 1.83). Higher CMPF was associated with a reduced risk of both all-cause mortality (HR: 0.79; 95% CI: 0.71, 0.89) and KRT (HR: 0.80; 95% CI: 0.71, 0.90), independently of TMAO and other clinically relevant confounders. In comparison to patients with low TMAO and CMPF, patients with low TMAO and high CMPF had reduced risk of all-cause mortality (adjusted HR: 0.49; 95% CI: 0.31, 0.73), whereas those with high TMAO and high CMPF showed no association across adjusted models. CONCLUSIONS: High CMPF conferred an independent role in health benefits and might even counteract the unfavorable association between TMAO and outcomes. Whether higher circulating CMPF concentrations are due to fish consumption, and/or if CMPF is a protective factor, remains to be verified.

Quality of Life before and after the Start of Dialysis in Older Patients.

BACKGROUND AND OBJECTIVES: In older people with kidney failure, improving health-related quality of life is often more important than solely prolonging life. However, little is known about the effect of dialysis initiation on health-related quality of life in older patients. Therefore, we investigated the evolution of health-related quality of life before and after starting dialysis in older patients with kidney failure. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The European Quality study is an ongoing prospective, multicenter study in patients aged ≥65 years with an incident eGFR ≤20 ml/min per 1.73 m2. Between April 2012 and December 2021, health-related quality of life was assessed every 3-6 months using the 36-item Short-Form Health Survey (SF-36), providing a mental component summary (MCS) and a physical component summary (PCS). Scores range from zero to 100, with higher scores indicating better health-related quality of life. With linear mixed models, we explored the course of health-related quality of life during the year preceding and following dialysis initiation. RESULTS: In total, 457 patients starting dialysis were included who filled out at least one SF-36 during follow-up. At dialysis initiation, mean ± SD age was 76±6 years, eGFR was 8±3 ml/min per 1.73 m2, 75% were men, 9% smoked, 45% had diabetes, and 46% had cardiovascular disease. Median (interquartile range) MCS was 53 (38-73), and median PCS was 39 (27-58). During the year preceding dialysis, estimated mean change in MCS was -13 (95% confidence interval, -17 to -9), and in PCS, it was -11 (95% confidence interval, -15 to -7). In the year following dialysis, estimated mean change in MCS was +2 (95% confidence interval, -7 to +11), and in PCS, it was -2 (95% confidence interval, -11 to +7). Health-related quality-of-life patterns were similar for most mental (mental health, role emotional, social functioning, vitality) and physical domains (physical functioning, bodily pain, role physical). CONCLUSIONS: Patients experienced a clinically relevant decline of both mental and physical health-related quality of life before dialysis initiation, which stabilized thereafter. These results may help inform older patients with kidney failure who decided to start dialysis.

Long-Term Effect of Physical Exercise on the Risk for Hospitalization and Death in Dialysis Patients: A Post-Trial Long-Term Observational Study.

BACKGROUND AND OBJECTIVES: In the EXerCise Introduction to Enhance Performance in Dialysis (EXCITE) trial, a simple, personalized 6-month walking exercise program at home during the day off of dialysis improved the functional status and the risk for hospitalization in patients with kidney failure. In this post-trial observational study, we tested whether the same intervention was associated with a lower long-term risk of death or hospitalization (combined end point) during a follow-up extended up to 36 months. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In total, 227 patients (exercise, n=104; control, n=123) completed the 6-month trial and entered the post-trial observational study. Data were analyzed by unadjusted and adjusted Cox regression analyses and Bayesian analysis. RESULTS: In the long-term observation (up to 36 months), 134 events were recorded (eight deaths not preceded by hospitalization and 126 hospitalizations, which were followed by death in 38 cases). The long-term risk for hospitalization or death was 29% lower (hazard ratio, 0.71; 95% confidence interval, 0.50 to 1.00), and in an analysis stratified by adherence to the walking exercise program during the 6-month trial, the subgroup with high adherence (>60% of prescribed sessions) had a 45% lower risk as compared with the control group (hazard ratio, 0.55; 95% confidence interval, 0.35 to 0.87). A Bayesian analysis showed that the posterior probability of a hazard ratio of 0.71 (95% confidence interval, 0.50 to 1.00) for the risk of the composite outcome observed in the post-trial observational study was 93% under the conservative prior and 97% under the optimistic prior. Sensitivity analyses restricted to the risk of hospitalization only or censoring patients at the time of transplantation fully confirmed these findings. CONCLUSIONS: A simple, personalized, home-based, low-intensity exercise program was associated with a lower risk of hospitalization. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: EXerCise Introduction to Enhance Performance in Dialysis (EXCITE), NCT01255969.

The legacy effect of a home walking exercise programme in kidney failure patients on dialysis.

BACKGROUND: The EXerCise Introduction To Enhance performance (EXCITE) trial (J Am Soc Nephrol 28: 1259-1268, 2017) in dialysis patients showed that a 6-month home walking exercise programme improves physical function and two dimensions of the Kidney Disease Quality of Life Short Form (KDQOLSF-SF™) questionnaire. Whether improvements in physical function achieved by exercise interventions are maintained in the long term has never been tested in the dialysis population. METHODS: In this post-trial study embedded in the EXCITE trial, we tested the response to the 6 min walking test (6MWT) and the 5-time Sit-To-Stand (5STS) tests and the KDQOLSF-SF™ from the 6th month (end of the trial) to the 36th month. RESULTS: Among the 227 patients of the EXCITE trial cohort, 162 underwent at least three out of four testing visits (baseline, 6, 18 and/or 36 months) contemplated by the study protocol and 89 during all four testing visits. In the primary analysis by the linear mixed model, the gain in walking distance achieved in the 6th month in the exercise group [between-arms difference: +36 m, 95% confidence interval (CI): 22-51, P < .001] was maintained at the 18th month (between-arms difference: +37 m, 95% CI: 19-57, P < .001) and reduced to 23 m (95% CI: -4 to 49 meters, P = .10) at the 36th month. Overall, the post-trial difference in walking distance trajectories between the two study arms was highly significant (P = .004). Furthermore, the walking distance changes at the 6th (r = 0.34, P = .018) and 18th month (r = 0.30, P = .043) were directly related to the number of structured exercise sessions completed during the trial (i.e. the first 6 month). No such effect was registered in the response to the 5STS or in quality of life as measured by the KDQOLSF-SF™. CONCLUSIONS: In dialysis patients, the benefits of a 6-month structured walking programme outlast the duration of the intervention and postpone the loss of walking performance which naturally occurs in this population, but does not affect the quality of life (QoL) and the response to the STS test.

The relationship between uremic toxins and symptoms in older men and women with advanced chronic kidney disease.

Background: Patients with stage 4/5 chronic kidney disease (CKD) suffer from various symptoms. The retention of uremic solutes is thought to be associated with those symptoms. However, there are relatively few rigorous studies on the potential links between uremic toxins and symptoms in patients with CKD. Methods: The EQUAL study is an ongoing observational cohort study of non-dialyzed patients with stage 4/5 CKD. EQUAL patients from Germany, Poland, Sweden and the UK were included in the present study (n = 795). Data and symptom self-report questionnaires were collected between April 2012 and September 2020. Baseline uric acid and parathyroid hormone and 10 uremic toxins were quantified. We tested the association between uremic toxins and symptoms and adjusted P-values for multiple testing. Results: Symptoms were more frequent in women than in men with stage 4/5 CKD, while levels of various uremic toxins were higher in men. Only trimethylamine N-oxide (TMAO; positive association with fatigue), p-cresyl sulfate (PCS) with constipation and 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (negative association with shortness of breath) demonstrated moderately strong associations with symptoms in adjusted analyses. The association of phenylacetylglutamine with shortness of breath was consistent in both sexes, although it only reached statistical significance in the full population. In contrast, TMAO (fatigue) and PCS and phenylacetylglutamine (constipation) were only associated with symptoms in men, who presented higher serum levels than women. Conclusion: Only a limited number of toxins were associated with symptoms in persons with stage 4/5 CKD. Other uremic toxins, uremia-related factors or psychosocial factors not yet explored might contribute to symptom burden.

[Study designs adopted in epidemiology of chronic diseases]. / I disegni di studio utilizzati nella ricerca epidemiologica delle malattie croniche.

Clinical research is gaining interest among healthcare professionals. This review provides an in-depth analysis of key study designs used in epidemiology, which can help researchers use the right methodology to design and conduct a research project. Case-control studies evaluate the association between an exposure to a specific risk factor and a study endpoint. Cross-sectional studies are indicated to assess the prevalence of a given risk factor. Cohort studies consist of longitudinal studies, in which a population is followed over time. These studies allow to evaluate the association between a risk factor and one or more study endpoints which are absent at the time of the population enrollment. Experimental studies are designed to test the efficacy and safety of an intervention. Generally, they include two groups of individuals who are assigned to either an experimental treatment or a standard treatment, respectively. Meta-analyses are studies that summarize the evidence already published concerning a specific research question and constitute an important source for evidence-based medicine and for the production and updating of guidelines.

Early morning hemodynamic changes and left ventricular hypertrophy and mortality in hemodialysis patients.

INTRODUCTION: An exaggeration of the early morning increase in BP, a phenomenon accompanied by a parallel rise in heart rate (HR), is a marker of high cardiovascular risk. The early morning changes in these parameters have not been investigated in the hemodialysis population. METHODS: In a pilot, single center study including a series of 58 patients we measured the pre-awakening BP and HR surges and the nocturnal dipping of the same parameters as well as other established indicators of autonomic function (weighted 24 h systolic BP and HR variability) and tested their relationship with the left ventricular mass index (LVMI) and with the risk of death over a median follow up of 40 months. RESULTS: The pre-awakening HR surge (r = - 0.46, P = 0.001) but not the corresponding BP surge (r = - 0.1, P = 0.98) was associated with LVMI and the risk of death [HR (1 unit): 0.89, 95% CI 0.83-0.96, P = 0.001]. The link between the pre-awakening HR surge with these outcome measures was robust and largely independent of established risk factors in the hemodialysis population, including the nocturnal dipping of BP. Weighted 24 h systolic BP and HR variability did not correlate with LVMI (all P > 0.11) nor with the risk of death (P > 0.11) and were also independent of the nocturnal dipping of systolic BP and HR. CONCLUSION: This pilot study suggests that the low early morning changes in HR, likely reflecting enhanced sympathetic activity, entail a high risk for left ventricular hypertrophy (LVH) and mortality in the hemodialysis population.