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.

Urinary Kidney Injury Biomarkers Are Associated with Ischemia-Reperfusion Injury Severity in Kidney Allograft Recipients

BACKGROUND

We explored the potential of emerging and conventional urinary kidney injury biomarkers in recipients of living donor (LD) or donation after circulatory death (DCD) kidney transplantation, patients with chronic kidney disease (CKD), and individuals from the general population.

METHODS

Urine samples from kidney allograft recipients with mild (LD; n = 199) or severe (DCD; n = 71) ischemia-reperfusion injury (IRI) were analyzed for neutrophil gelatinase-associated lipocalin (NGAL), insulin-like growth factor-binding protein 7 (IGFBP7), tissue inhibitor of metalloproteinases 2 (TIMP2), kidney injury molecule-1 (KIM-1), chemokine C-X-C motif (CXCL9), solute carrier family 22 member 2 (SLC22A2), nephrin, and uromodulin (UMOD) by quantitative multiplex LC-MS/MS analysis. The fold-change in biomarker levels was determined in mild and severe IRI and in patients with CKD stage 1-2 (n = 127) or stage ≥3 (n = 132) in comparison to the general population (n = 1438). Relationships between the biomarkers and total protein, β2-microglobulin (B2M), creatinine, and osmolality were assessed.

RESULTS

NGAL, IGFBP7, TIMP2, KIM-1, CXCL9, and UMOD were quantifiable, whereas nephrin and SLC22A2 were below the limit of detection. Kidney injury biomarkers were increased up to 6.2-fold in allograft recipients with mild IRI and 8.3-fold in recipients with severe IRI, compared to the reference population, with the strongest response observed for NGAL and B2M. In CKD stage 1-2, B2M, NGAL, IGFBP7, TIMP2, KIM-1, UMOD, and CXCL9 were not altered, but in individuals with CKD stage ≥3, B2M, NGAL, and KIM-1 were increased up to 1.3-fold. IGFBP7, TIMP2, NGAL, and CXCL9 were strongly correlated (all r ≥ 0.8); correlations with B2M and TP were smaller (all r ≤ 0.6).

CONCLUSIONS

IRI, but not stable CKD, was associated with increased urinary levels of kidney injury biomarkers determined by LC-MS/MS. Absolute and multiplexed protein quantitation by LC-MS/MS is an effective strategy for biomarker panel evaluation for translation toward the clinical laboratory.

Association of omega 3 polyunsaturated fatty acids with incident chronic kidney disease: pooled analysis of 19 cohorts

OBJECTIVE

To assess the prospective associations of circulating levels of omega 3 polyunsaturated fatty acid (n-3 PUFA) biomarkers (including plant derived α linolenic acid and seafood derived eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid) with incident chronic kidney disease (CKD).

DESIGN

Pooled analysis.

DATA SOURCES

A consortium of 19 studies from 12 countries identified up to May 2020.

STUDY SELECTION

Prospective studies with measured n-3 PUFA biomarker data and incident CKD based on estimated glomerular filtration rate.

DATA EXTRACTION AND SYNTHESIS

Each participating cohort conducted de novo analysis with prespecified and consistent exposures, outcomes, covariates, and models. The results were pooled across cohorts using inverse variance weighted meta-analysis.

MAIN OUTCOME MEASURES

Primary outcome of incident CKD was defined as new onset estimated glomerular filtration rate <60 mL/min/1.73 m2. In a sensitivity analysis, incident CKD was defined as new onset estimated glomerular filtration rate <60 mL/min/1.73 m2 and <75% of baseline rate.

RESULTS

25 570 participants were included in the primary outcome analysis and 4944 (19.3%) developed incident CKD during follow-up (weighted median 11.3 years). In multivariable adjusted models, higher levels of total seafood n-3 PUFAs were associated with a lower incident CKD risk (relative risk per interquintile range 0.92, 95% confidence interval 0.86 to 0.98; P=0.009, I2=9.9%). In categorical analyses, participants with total seafood n-3 PUFA level in the highest fifth had 13% lower risk of incident CKD compared with those in the lowest fifth (0.87, 0.80 to 0.96; P=0.005, I2=0.0%). Plant derived α linolenic acid levels were not associated with incident CKD (1.00, 0.94 to 1.06; P=0.94, I2=5.8%). Similar results were obtained in the sensitivity analysis. The association appeared consistent across subgroups by age (≥60 v <60 years), estimated glomerular filtration rate (60-89 v ≥90 mL/min/1.73 m2), hypertension, diabetes, and coronary heart disease at baseline.

CONCLUSIONS

Higher seafood derived n-3 PUFA levels were associated with lower risk of incident CKD, although this association was not found for plant derived n-3 PUFAs. These results support a favourable role for seafood derived n-3 PUFAs in preventing CKD.

Effect of residual kidney function and dialysis adequacy on chronic pruritus in dialysis patients

BACKGROUND

Chronic Kidney Disease-associated pruritus (CKD-aP) is common in dialysis patients, associated with lower quality of life and increased risk of death. We investigated the association between residual eGFR, dialysis adequacy or serum phosphate level and CKD-aP in incident dialysis patients.

METHODS

1256 incident hemodialysis (HD) and 670 peritoneal dialysis (PD) patients (>18y) from the Netherlands Cooperative Study on the Adequacy of Dialysis study were included (1997-2007) and followed until death, transplantation, or max 10y. CKD-aP was measured using a single item of the KDQOL-36. The associations were studied by logistic and linear regression analyses, adjusted for potential baseline confounders.

RESULTS

At baseline mean (SD) age was 60 (16), 62% were men and median (IQR) residual eGFR was 3.4 (1.7-5.3) ml/min/1.73m2. The prevalence of CKD-aP (∼70%) was similar in HD and PD. It was observed that 12 months after starting dialysis (after multivariable adjustment) each 1 ml/min/1.73m2 higher residual eGFR, one unit higher total weekly Kt/V, or 1 mmol/L lower serum phosphate level was associated with lower burden of CKD-aP in HD and PD patients of -0.05 (95%CI:-0.09;-0.02) and -0.09 (95%CI:-0.13;-0.05), -0.15 (95%CI:-0.26;-0.05) and -0.35 (95%CI:-0.54;-0.16), and of -0.34 (95%CI:-0.17;-0.51) and -0.45 (95%CI:-0.19;-0.71), respectively. We found no association between dialysis Kt/V and CKD-aP.

CONCLUSIONS

Higher residual eGFR and lower serum phosphate level, but not the dialysis dose, were related with lower burden of CKD-aP in dialysis patients.

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.

Environmental factors and mobility predict COVID-19 seasonality in the Netherlands

BACKGROUND

We recently showed that seasonal patterns of COVID-19 incidence and Influenza-Like Illnesses incidence are highly similar, in a country in the temperate climate zone, such as the Netherlands. We hypothesize that in The Netherlands the same environmental factors and mobility trends that are associated with the seasonality of flu-like illnesses are predictors of COVID-19 seasonality as well.

METHODS

We used meteorological, pollen/hay fever and mobility data from the Netherlands. For the reproduction number of COVID-19 (R_t), we used daily estimates from the Dutch State Institute for Public Health. For all datasets, we selected the overlapping period of COVID-19 and the first allergy season: from February 17, 2020 till September 21, 2020 (n = 218). Backward stepwise multiple linear regression was used to develop an environmental prediction model of the R_t of COVID-19. Next, we studied whether adding mobility trends to an environmental model improved the predictive power.

RESULTS

Through stepwise backward multiple linear regression four highly significant (p < 0.01) predictive factors are selected in our combined model: temperature, solar radiation, hay fever incidence, and mobility to indoor recreation locations. Our combined model explains 87.5% of the variance of R_t of COVID-19 and has a good and highly significant fit: F(4, 213) = 374.2, p < 0.00001. This model had a better overall predictive performance than a solely environmental model, which explains 77.3% of the variance of R_t (F(4, 213) = 181.3, p < 0.00001).

CONCLUSIONS

We conclude that the combined mobility and environmental model can adequately predict the seasonality of COVID-19 in a country with a temperate climate like the Netherlands. In this model higher solar radiation, higher temperature and hay fever are related to lower COVID-19 reproduction, and higher mobility to indoor recreation locations is related to an increased COVID-19 spread.

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.

Depression, anxiety and quality of life of hemodialysis patients before and during the COVID-19 pandemic

OBJECTIVE

To investigate the impact of the coronavirus pandemic on mental health in hemodialysis patients, we assessed depression, anxiety and quality of life with valid mental health measures before and after the start of the pandemic.

METHODS

Data were used from 121 hemodialysis patients from the ongoing prospective multicenter DIVERS-II study. COVID-19 related stress was measured with the Perceived Stress Scale - 10, depression with the Beck Depression Inventory - second edition (BDI-II)), anxiety with the Beck Anxiety Inventory (BAI) and quality of life with the Short Form - 12 (SF-12). Scores during the first and second COVID-19 wave in the Netherlands were compared to data prior to the pandemic with linear mixed models.

RESULTS

No significant differences were found in BDI-II, BAI and SF-12 scores between before and during the pandemic. During the first wave, 33% of participants reported COVID-19 related stress and in the second wave 37%. These patients had higher stress levels (mean difference (MD) 4.7 (95%CI 1.5; 8.0), p = 0.005) and BDI-II scores (MD 4.9 (95%CI 0.7; 9.0), p = 0.021) and lower SF-12 mental component summary scores (MD -5.3 (95%CI -9.0, -1.6), p = 0.006) than patients who did not experienced COVID-19 stress. These differences were already present before the pandemic.

CONCLUSION

The COVID-19 pandemic does not seem to influence mental health in hemodialysis patients. However, a substantial subgroup of patients with pre-existent mental health problems may be more susceptible to experience COVID-19 related stress.

Internet-based treatment for depressive symptoms in hemodialysis patients: A cluster randomized controlled trial

OBJECTIVE

To investigate the effectiveness of a guided internet-based self-help intervention for hemodialysis patients with depressive symptoms.

METHOD

Chronic hemodialysis patients from nine Dutch hospitals with a depression score on the Beck Depression Inventory - second edition (BDI-II) of ≥10, were cluster-randomized into a five modules guided internet-based self-help problem solving therapy intervention or a parallel care-as-usual control group. Clusters were based on hemodialysis shift. The primary outcome depression was measured with the BDI-II. Analysis was performed with linear mixed models.

RESULTS

A total of 190 hemodialysis patients were cluster-randomized to the intervention (n = 89) or control group (n = 101). Post-intervention measurement was completed by 127 patients (67%) and more than half of the patients (54%) completed the intervention. No significant differences were found on the BDI-II score between the groups (mean difference - 0.1, 95%CI -3.0; 2.7, p = 0.94). Per protocol sensitivity analysis showed comparable results. No significant differences in secondary outcomes were observed between groups.

CONCLUSIONS

Guided internet-based self-help problem solving therapy for hemodialysis patients with depressive symptoms does not seem to be effective in reducing these symptoms as compared to usual care. Future research should examine how to best design content and accessibility of an intervention for depressive symptoms in hemodialysis patients.

TRIAL REGISTRATION

Dutch Trial Register: Trial NL6648 (NTR6834) (prospectively registered 13th November 2017).

Variation in glucocorticoid sensitivity and the relation with obesity

Increasing evidence points to a relation between increased glucocorticoid (GC) exposure and weight gain. In support, long-term cortisol measurements using hair analysis revealed that many individuals with obesity appear to have cortisol values in the high physiological range. The mechanisms behind this relationship need to be determined in order to develop targeted therapy to reach sustainable weight loss in these subgroups. The effect of GCs is not only determined by the plasma concentration of GCs but also by individual differences in GC sensitivity and the target tissue, which can be analyzed by functional GC assays. GC sensitivity is influenced by multiple genetic and acquired (e.g., disease-related) factors, including intracellular GC availability, hormone binding affinity, and expression levels of the GC receptors and their isoforms, as well as factors involved in the modulation of gene transcription. Interindividual differences in GC sensitivity also play a role in the response to exogenous GCs, with respect to both therapeutic and adverse effects. Accordingly, in this review, we summarize current knowledge on mechanisms that influence GC sensitivity and their relationships with obesity and discuss personalized treatment options targeting the GC receptor.

Health-Related Quality-of-Life Trajectories over Time in Older Men and Women with Advanced Chronic Kidney Disease

BACKGROUND AND OBJECTIVES

The effect of sex on longitudinal health-related quality of life remains unknown in CKD. Here we assess differences in the sex-specific evolution of health-related quality of life in older men and women with advanced CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The European Quality Study on Treatment in Advanced Chronic Kidney Disease is a European observational prospective cohort study in referred patients with CKD and an incident eGFR<20 ml/min per 1.73 m² who are ≥65 years of age not on dialysis. Health-related quality of life was measured using the 36-Item Short Form Survey at 3- to 6-month intervals between April 2012 and September 2020, providing Physical Component Summary and Mental Component Summary scores. Trajectories were modeled by sex using linear mixed models, and sex differences in health-related quality-of-life slope were explored.

RESULTS

We included 5345 health-related quality-of-life measurements in 1421 participants. At baseline, women had considerably lower mean Physical Component Summary (42) and Mental Component Summary (60) compared with men (Physical Component Summary: 55; Mental Component Summary: 69; P<0.001). However, during follow-up, Physical Component Summary and Mental Component Summary scores declined approximately twice as fast in men (Physical Component Summary: 2.5 per year; 95% confidence interval, 1.8 to 3.1; Mental Component Summary: 2.7 per year; 95% confidence interval, 2.0 to 3.4) compared with in women (Physical Component Summary: 1.1 per year; 95% confidence interval, 0.1 to 2.0; Mental Component Summary: 1.6 per year; 95% confidence interval, 0.7 to 2.6). This difference was partly attenuated after adjusting for important covariates, notably eGFR decline. Higher serum phosphate, lower hemoglobin, and the presence of preexisting diabetes were associated with lower Physical Component Summary and Mental Component Summary scores in men but to a lesser extent in women.

CONCLUSIONS

Among older men and women with advanced CKD, women had lower health-related quality of life at baseline, but men experienced a more rapid decline in health-related quality of life over time.

Itching in dialysis patients: impact on health-related quality of life and interactions with sleep problems and psychological symptoms – results from the RENINE/PROMs registry

Background

Itching (pruritus) is common in dialysis patients, but little is known about its impact on health-related quality of life (HRQOL), sleep problems and psychological symptoms. This study investigates the impact of itching in dialysis patients by looking into the persistence of itching, the effect of itching on the course of HRQOL and the combined effect of itching with sleep problems and with psychological symptoms on HRQOL.

Methods

Data were obtained from the RENINE/PROMs registry and included 2978 dialysis patients who completed patient-reported outcome measures between 2018 and 2020. Itching, sleep problems and psychological symptoms were assessed with the Dialysis Symptom Index (DSI) and HRQOL with the 12-item Short Form Health Survey. Effects of itching on HRQOL and interactions with sleep problems and psychological symptoms were investigated cross-sectionally and longitudinally using linear regression and linear mixed models.

Results

Half of the patients experienced itching and in 70% of them, itching was persistent. Itching was associated with a lower physical and mental HRQOL {−3.35 [95% confidence interval (CI) −4.12 to −2.59) and −3.79 [95% CI −4.56 to −3.03]}. HRQOL remained stable during 2 years and trajectories did not differ between patients with or without itching. Sleep problems (70% versus 52%) and psychological symptoms (36% versus 19%) were more common in patients with itching. These symptoms had an additional negative effect on HRQOL but did not interact with itching.

Conclusions

The persistence of itching, its impact on HRQOL over time and the additional effect on HRQOL of sleep problems and psychological symptoms emphasize the need for recognition and effective treatment of itching to reduce symptom burden and improve HRQOL.

Association Between Lipophilic Beta-Blockers and Depression in Diabetic Patients on Chronic Dialysis

Background:

Depression is associated with lower quality of life and increased risk of mortality. The prevalence of depression in chronic dialysis patients, as well as in patients with diabetes, is more than 20%. It is debated whether use of beta-blockers increases the risk of depression. Therefore, we examined in chronic dialysis patients with and without diabetes, the association between beta-blockers and depressive symptoms.

Methods:

Data were collected from the DIVERS-I study, a multicentre prospective cohort among chronic dialysis patients in the Netherlands. Depressive symptoms were assessed with the Beck Depression Inventory (BDI-II). We defined depressive symptoms as a BDI-II score ⩾16. The cross-sectional association at baseline between depressive symptoms and beta-blocker use in chronic dialysis patients, was studied by multivariable logistic regression adjusted for potential confounders.

Results:

We included 684 chronic dialysis patients, of whom 43% had diabetes mellitus, and 57% used a beta-blocker of which 97% were lipophilic. After multivariable adjustment, the OR (95% CI) for depressive symptoms in patients with compared to without diabetes was 1.41 (1.00-1.98), and in beta-blocker users compared to non-users 1.12 (0.80-1.56), respectively. Dialysis patients with diabetes and beta-blocker use compared to those without diabetes and not using beta-blockers had an OR of 1.73 (1.12-2.69) for depressive symptoms. The association was stronger in dialysis patients with diabetes and lipophilic beta-blocker use with an OR of 1.77 (1.14-2.74).

Conclusions:

We found a possible association between lipophilic beta-blocker use and depressive symptoms in chronic dialysis patients with diabetes.

Serum Potassium and Mortality Risk in Hemodialysis Patients: A Cohort Study

Rationale & Objective

Both hypo- and hyperkalemia can cause fatal cardiac arrhythmias. Although predialysis serum potassium level is a known modifiable risk factor for death in patients receiving hemodialysis, especially for hypokalemia, this risk may be underestimated. Therefore, we investigated the relationship between predialysis serum potassium level and death in incident hemodialysis patients and whether there is an optimum level.

Study Design

Prospective multicenter cohort study.

Setting & Participants

1,117 incident hemodialysis patients (aged >18 years) from the Netherlands Cooperative Study on the Adequacy of Dialysis-2 study were included and followed from their first hemodialysis treatment until death, transplantation, switch to peritoneal dialysis, or a maximum of 10 years.

Exposure

Predialysis serum potassium levels were obtained every 6 months and divided into 6 categories: ≤4.0 mmol/L, >4.0 mmol/L to ≤4.5 mmol/L, >4.5 mmol/L to ≤5.0 mmol/L, >5.0 mmol/L to ≤5.5 mmol/L (reference), >5.5 mmol/L to ≤6.0 mmol/L, and >6.0 mmol/L.

Outcomes

6-month all-cause mortality.

Analytical Approach

Cox proportional hazards and restricted cubic spline analyses with time-dependent predialysis serum potassium levels were used to calculate the adjusted HRs for death.

Results

At baseline, the mean age of the patients was 63 years (standard deviation, 14 years), 58% were men, 26% smoked, 24% had diabetes, 32% had cardiovascular disease, the mean serum potassium level was 5.0 mmol/L (standard deviation, 0.8 mmol/L), 7% had a low subjective global assessment score, and the median residual kidney function was 3.5 mL/min/1.73 m² (IQR, 1.4-4.8 mL/min/1.73 m²). During the 10-year follow-up, 555 (50%) deaths were observed. Multivariable adjusted HRs for death according to the 6 potassium categories were as follows: 1.42 (95% CI, 1.01-1.99), 1.09 (95% CI, 0.82-1.45), 1.21 (95% CI, 0.94-1.56), 1 (reference), 0.95 (95% CI, 0.71-1.28), and 1.32 (95% CI, 0.97-1.81).

Limitations

Shorter intervals between potassium measurements would have allowed for more precise mortality risk estimations.

Conclusions

We found a U-shaped relationship between serum potassium level and death in incident hemodialysis patients. A low predialysis serum potassium level was associated with a 1.4-fold stronger risk of death than the optimal level of approximately 5.1 mmol/L. These results may imply the cautious use of potassium-lowering therapy and a potassium-restricted diet in patients receiving hemodialysis.

Comparable seasonal pattern for COVID-19 and flu-like illnesses

BACKGROUND

During the first wave of COVID-19 it was hypothesized that COVID-19 is subject to multi-wave seasonality, similar to Influenza-Like Illnesses since time immemorial. One year into the pandemic, we aimed to test the seasonality hypothesis for COVID-19.

METHODS

We calculated the average annual time-series for Influenza-Like Illnesses based on incidence data from 2016 till 2019 in the Netherlands, and compared these with two COVID-19 time-series during 2020/2021 for the Netherlands. We plotted the time-series on a standardized logarithmic infection scale. Finally, we calculated correlation coefficients and used univariate regression analysis to estimate the strength of the association between the time-series of COVID-19 and Influenza-Like Illnesses.

RESULTS

The time-series for COVID-19 and Influenza-Like Illnesses were strongly and highly significantly correlated. The COVID-19 peaks were all during flu season, and lows were all in the opposing period. Finally, COVID-19 meets the multi-wave characteristics of earlier flu-like pandemics, namely a short first wave at the tail-end of a flu season, and a longer and more intense second wave during the subsequent flu season.

CONCLUSIONS

We conclude that seasonal patterns of COVID-19 incidence and Influenza-Like Illnesses incidence are highly similar, in a country in the temperate climate zone, such as the Netherlands. Further, the COVID-19 pandemic satisfies the criteria of earlier respiratory pandemics, namely a first wave that is short-lived at the tail-end of flu season, and a second wave that is longer and more severe.This seems to imply that the same factors that are driving the seasonality of Influenza-Like Illnesses are causing COVID-19 seasonality as well, such as solar radiation (UV), temperature, relative humidity, and subsequently seasonal allergens and allergies.

Plasma fatty acids and kidney function decline in post-myocardial infarction patients of the Alpha Omega Cohort

BACKGROUND AND AIMS

Age-related kidney function decline is accelerated in patients with coronary heart disease (CHD). CHD and chronic kidney disease may share common etiologies. We examined plasma fatty acids (FAs) as novel biomarkers of kidney function decline after myocardial infarction (MI).

METHODS AND RESULTS

The analysis included 2329 Dutch post-MI patients aged 60-80y (Alpha Omega Cohort) most receiving state-of-the-art medications. Plasma FAs (% total FAs) in cholesteryl esters were assessed at baseline (2002-2006), and ∼40 months change in creatinine-cystatin C based glomerular filtration rate was estimated (eGFR, in ml/min per 1.73 m²). Beta coefficients for annual eGFR change in relation to plasma linoleic acid (LA; 50.1% of total FAs in CE), omega-3 FAs (EPA + DHA; 1.7%), odd-chain FAs (C15:0 and C17:0; 0.2%), and C14:0 (0.7%) were obtained from linear regression analyses adjusted for age, sex, smoking, and alcohol intake. Mean baseline eGFR ±SD was 78.5 ± 18.7, which declined by 4.7 ± 13.1 during follow-up, or 1.4 ± 3.9 per year. The annual decline in eGFR was less in patients with higher plasma LA (adjusted beta: 0.40 for LA >47 vs ≤ 47%, 95% CI: 0.01; 0.78; p = 0.046). Associations of plasma LA with annual eGFR decline were stronger in 437 patients with diabetes (1.21, 0.24; 2.19) and in 402 patients with CKD (eGFR<60; 0.90, -0.09; 1.89). Weaker, non-significant associations with kidney function decline were observed for the other plasma FAs.

CONCLUSION

Higher plasma LA may be a good predictor of less kidney function decline after MI, particularly in patients with diabetes. The Alpha Omega Cohort is registered with clinicaltrials.gov, NCT03192410.

Lower gastrointestinal bleeding in a patient receiving sevelamer: Case report

Phosphate binders such as sevelamer are widely used in patients with chronic kidney disease to lower serum phosphate levels. We present a case of a 67-year-old woman with lower gastrointestinal bleeding after 9 days of using sevelamer carbonate (Renvela^®). Sigmoidoscopy revealed multiple deep ulcers (diameter 10–15 mm) and mucosal oedema. Histologic examination showed deposition of sevelamer crystals in these rectal ulcers. We hypothesized that the lower gastrointestinal bleeding was caused by deposition of sevelamer crystals. After cessation of sevelamer, gastrointestinal bleeding stopped. Deposition of sevelamer crystals in the gastrointestinal tract is a rare complication of sevelamer therapy. There are only 17 other recorded cases of gastrointestinal deposition of sevelamer crystals. This adverse effect should be considered in all patients taking sevelamer who present with gastrointestinal symptoms, such as gastrointestinal bleeding and abdominal pain. When sevelamer is discontinued, symptoms and mucosal damage appear to revert.

Can pollen explain the seasonality of flu-like illnesses in the Netherlands?

Current models for flu-like epidemics insufficiently explain multi-cycle seasonality. Meteorological factors alone, including the associated behavior, do not predict seasonality, given substantial climate differences between countries that are subject to flu-like epidemics or COVID-19. Pollen is documented to be allergenic, it plays a role in immuno-activation and defense against respiratory viruses, and seems to create a bio-aerosol that lowers the reproduction number of flu-like viruses. Therefore, we hypothesize that pollen may explain the seasonality of flu-like epidemics, including COVID-19, in combination with meteorological variables. We have tested the Pollen-Flu Seasonality Theory for 2016-2020 flu-like seasons, including COVID-19, in the Netherlands, with its 17.4 million inhabitants. We combined changes in flu-like incidence per 100 K/Dutch residents (code: ILI) with pollen concentrations and meteorological data. Finally, a predictive model was tested using pollen and meteorological threshold values, inversely correlated to flu-like incidence. We found a highly significant inverse correlation of r(224) = -0.41 (p < 0.001) between pollen and changes in flu-like incidence, corrected for the incubation period. The correlation was stronger after taking into account the incubation time. We found that our predictive model has the highest inverse correlation with changes in flu-like incidence of r(222) = -0.48 (p < 0.001) when average thresholds of 610 total pollen grains/m³, 120 allergenic pollen grains/m³, and a solar radiation of 510 J/cm² are passed. The passing of at least the pollen thresholds, preludes the beginning and end of flu-like seasons. Solar radiation is a co-inhibitor of flu-like incidence, while temperature makes no difference. However, higher relative humidity increases with flu-like incidence. We conclude that pollen is a predictor of the inverse seasonality of flu-like epidemics, including COVID-19, and that solar radiation is a co-inhibitor, in the Netherlands.

P1445ESPECIALLY HYPOKALEMIA IS A RISK FACTOR FOR ALL-CAUSE MORTALITY IN INCIDENT HEMODIALYSIS PATIENTS

Background and Aims

Both hypo- and hyperkalemia can potentially induce fatal cardiac arrhythmias in the general population. However, little is known about the effect of potassium as a modifiable risk factor in hemodialysis (HD) patients. Therefore, we investigated the relation between serum potassium level and all-cause mortality in incident HD patients and whether there is an optimum serum potassium level to pursue.

Method

All incident HD patients (&gt;18 y) from the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD), a prospective multi-center cohort study, were included. These patients were followed from the start of their first dialysis treatment until death, transplantation or a maximum of 2 years. Serum potassium levels were obtained at fixed 6-month time intervals and divided into six categories: ≤ 4.0, &gt; 4.0 - ≤ 4.5, &gt; 4.5 - ≤ 5.0, &gt; 5.0 - ≤ 5.5 (reference), &gt; 5.5 - ≤ 6.0 and &gt; 6.0 mmol/L. Using a Cox proportional-hazards model with serum potassium category as a time-dependent variable, hazard ratios (HR) for all-cause mortality were calculated, adjusted for baseline age, sex, current smoking, diabetes and residual kidney function.

Results

In total, 1278 HD patients were included. At baseline, mean (±SD) age was 64 (±14) years, 60% were men, 23% were current smokers, 21% had diabetes and the median (interquartile range) residual kidney function was 3.0 (1.5-4.8) ml/min/1.73m2. Mean (±SD) serum potassium level was 4.8 (±0.8) mmol/L. The prevalence of the six potassium categories was: 10%, 19%, 26%, 22%, 15% and 8%, respectively. A total of 298 (23%) deaths was observed during 2 years of follow-up. After multivariable adjustment the HR (95% CI) for any death according to the six potassium categories were: 2.5 (1.5-4.3), 1.9 (1.2-3.0), 1.6 (1.0-2.5), 1 (reference), 1.3 (0.8-2.2) and 1.7 (1.0-3.0).

Conclusion

We found a U-shaped relation between serum potassium and all-cause mortality in incident hemodialysis patients. Especially, low serum potassium was a 2.5-fold stronger risk factor for all-cause mortality compared to normal serum potassium. Our results indicate an optimum serum potassium level between 5.0 - 5.5 mmol/L, emphasizing that potassium lowering therapy should be used with caution in hemodialysis patients.

Superior Long-term Survival for Simultaneous Pancreas-Kidney Transplantation as Renal Replacement Therapy: 30-Year Follow-up of a Nationwide Cohort

OBJECTIVE

In patients with type 1 diabetes and end-stage renal disease, it is controversial whether a simultaneous pancreas-kidney (SPK) transplantation improves survival compared with kidney transplantation alone. We compared long-term survival in SPK and living- or deceased-donor kidney transplant recipients.

RESEARCH DESIGN AND METHODS

We included all 2,796 patients with type 1 diabetes in the Netherlands who started renal replacement therapy between 1986 and 2016. We used multivariable Cox regression analyses adjusted for recipient age and sex, dialysis modality and vintage, transplantation era, and donor age to compare all-cause mortality between deceased- or living-donor kidney and SPK transplant recipients. Separately, we analyzed mortality between regions where SPK transplant was the preferred intervention (80% SPK) versus regions where a kidney transplant alone was favored (30% SPK).

RESULTS

Of 996 transplanted patients, 42%, 16%, and 42% received a deceased- or living-donor kidney or SPK transplant, respectively. Mean (SD) age at transplantation was 50 (11), 48 (11), and 42 (8) years, respectively. Median (95% CI) survival time was 7.3 (6.2; 8.3), 10.5 (7.2; 13.7), and 16.5 (15.1; 17.9) years, respectively. SPK recipients with a functioning pancreas graft at 1 year (91%) had the highest survival (median 17.4 years). Compared with deceased-donor kidney transplant recipients, adjusted hazard ratios (95% CI) for 10- and 20-year all-cause mortality were 0.79 (0.49; 1.29) and 0.98 (0.69; 1.39) for living-donor kidney and 0.67 (0.46; 0.98) and 0.79 (0.60; 1.05) for SPK recipients, respectively. A treatment strategy favoring SPK over kidney transplantation alone showed 10- and 20-year mortality hazard ratios of 0.56 (0.40; 0.78) and 0.69 (0.52; 0.90), respectively.

CONCLUSIONS

Compared with living- or deceased-donor kidney transplantation, SPK transplant was associated with improved patient survival, especially in recipients with a long-term functioning pancreatic graft, and resulted in an almost twofold lower 10-year mortality rate.

Dietary protein intake and kidney function decline after myocardial infarction: the Alpha Omega Cohort

BACKGROUND

Post-myocardial infarction (MI) patients have a doubled rate of kidney function decline compared with the general population. We investigated the extent to which high intake of total, animal and plant protein are risk factors for accelerated kidney function decline in older stable post-MI patients.

METHODS

We analysed 2255 post-MI patients (aged 60-80 years, 80% men) of the Alpha Omega Cohort. Dietary data were collected with a biomarker-validated 203-item food frequency questionnaire. At baseline and 41 months, we estimated glomerular filtration rate based on the Chronic Kidney Disease Epidemiology Collaboration equations for serum cystatin C [estimated glomerular filtration rate (eGFRcysC)] alone and both creatinine and cystatin C (eGFRcr-cysC).

RESULTS

Mean [standard deviation (SD)] baseline eGFRcysC and eGFRcr-cysC were 82 (20) and 79 (19) mL/min/1.73 m2. Of all patients, 16% were current smokers and 19% had diabetes. Mean (SD) total protein intake was 71 (19) g/day, of which two-thirds was animal and one-third plant protein. After multivariable adjustment, including age, sex, total energy intake, smoking, diabetes, systolic blood pressure, renin-angiotensin system blocking drugs and fat intake, each incremental total daily protein intake of 0.1 g/kg ideal body weight was associated with an additional annual eGFRcysC decline of -0.12 (95% confidence interval -0.19 to -0.04) mL/min/1.73 m2, and was similar for animal and plant protein. Patients with a daily total protein intake of ≥1.20 compared with <0.80 g/kg ideal body weight had a 2-fold faster annual eGFRcysC decline of -1.60 versus -0.84 mL/min/1.73 m2. Taking eGFRcr-cysC as outcome showed similar results. Strong linear associations were confirmed by restricted cubic spline analyses.

CONCLUSION

A higher protein intake was significantly associated with a more rapid kidney function decline in post-MI patients.

Effect of different types of statins on kidney function decline and proteinuria: a network meta-analysis

Previous studies showed that statins reduce the progression of kidney function decline and proteinuria, but whether specific types of statins are more beneficial than others remains unclear. We performed a network meta-analysis of randomized controlled trials (RCT) to investigate which statin most effectively reduces kidney function decline and proteinuria. We searched MEDLINE, Embase, Web of Science, and the Cochrane database until July 13, 2018, and included 43 RCTs (>110,000 patients). We performed a pairwise random-effects meta-analysis and a network meta-analysis according to a frequentist approach. We assessed network inconsistency, publication bias, and estimated for each statin the probability of being the best treatment. Considerable heterogeneity was present among the included studies. In pairwise meta-analyses, 1-year use of statins versus control reduced kidney function decline by 0.61 (95%-CI: 0.27; 0.95) mL/min/1.73 m² and proteinuria with a standardized mean difference of -0.58 (95%-CI:-0.88; -0.29). The network meta-analysis for the separate endpoints showed broad confidence intervals due to the small number available RCTs for each individual comparison. In conclusion, 1-year statin use versus control attenuated the progression of kidney function decline and proteinuria. Due to the imprecision of individual comparisons, results were inconclusive as to which statin performs best with regard to renal outcome.

Geriatric Assessment and the Relation with Mortality and Hospitalizations in Older Patients Starting Dialysis

BACKGROUND AND OBJECTIVES

A geriatric assessment (GA) is a structural method for identifying frail patients. The relation of GA findings and risk of death in end-stage kidney disease (ESKD) is not known. The objective of the GA in OLder patients starting Dialysis Study was to assess the association of GA at dialysis initiation with early mortality and hospitalization.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Patients ≥65 years old were included just prior to dialysis initiation. All participants underwent a GA, including assessment of (instrumental) activities of daily living (ADL), mobility, cognition, mood, nutrition, and comorbidity. In addition, a frailty screening (Fried Frailty Index, [FFI]) was applied. Outcome measures were 6- and 12-month mortality, and 6-month hospitalization. Associations with mortality were assessed with cox-regression adjusting for age, sex, comorbidity burden, smoking, residual kidney function and dialysis modality. Associations with hospitalization were assessed with logistic regression, adjusting for relevant confounders.

RESULTS

In all, 192 patients were included, mean age 75 ± 7 years, of whom 48% had ≥3 geriatric impairments and were considered frail. The FFI screening resulted in 46% frail patients. Mortality rate was 8 and 15% at 6- and 12-months after enrolment, and transplantation rate was 2 and 4% respectively. Twelve-month mortality risk was higher in patients with ≥3 impairments (hazard ratio [HR] 2.97 [95% CI 1.19-7.45]) compared to less impaired patients. FFI frail patients had a higher risk of 12-month mortality (HR 7.22 [95% CI 2.47-21.13]) and hospitalization (OR 1.93 [95% CI 1.00-3.72]) compared to fit patients. Malnutrition was associated with 12-month mortality, while impaired ADL and depressive symptoms were associated with 12-month mortality and hospitalization.

CONCLUSIONS

Frailty as assessed by a GA is related to mortality in elderly patients with ESKD. Individual components of the GA are related to both mortality and hospitalization. As the GA allows for distinguishing between frail and fit patients initiating dialysis, it is potentially of added value in the decision-making process concerning dialysis initiation.

Low Birth Weight and Kidney Function in Middle-Aged Men and Women: The Netherlands Epidemiology of Obesity Study

RATIONALE & OBJECTIVE

Chronic kidney disease (CKD), defined as estimated glomerular filtration rate (eGFR)<60mL/min/1.73m², is a risk factor for cardiovascular morbidity and mortality. Little is known about low birth weight and risk for CKD in middle-aged adults in the general population. We estimated the causal association between birth weight and eGFR in a Dutch cohort of middle-aged men and women.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

6,671 participants in the Netherlands Epidemiology of Obesity (NEO) Study. Replication study using data for 133,814 participants studied by the CKDGen consortium.

EXPOSURE

Birth weight was self-reported and also based on an instrumental variable, 59 birth weight-associated genetic variants, derived from an independent data source.

OUTCOME

eGFR at the age of 45 to 65 years.

ANALYTICAL APPROACH

We assessed the association between self-reported birth weight and eGFR in the NEO Study using multivariable linear regression, adjusted for age, sex, education, smoking, and alcohol use. The effect of the instrument on eGFR was estimated using separate 2-sample Mendelian randomization analyses: one using individual data from the NEO cohort and one using summary data from the CKDGen consortium.

RESULTS

At baseline, mean eGFR was 86±12.4 (SD) mL/min/1.73m². After multivariable adjustment, self-reported birth weight was not associated with kidney function in middle age. Two-sample Mendelian randomization analysis showed that in the NEO cohort, for each 500-g lower birth weight defined using genetic variants, there was a 3.7 (95% CI, 0.5-6.9)-mL/min/1.73m² lower eGFR at the age of 45 to 65 years. However, using CKDGen summary-level data, there was a smaller nonsignificant relationship between birth weight and eGFR.

LIMITATIONS

Birth weight was self-reported.

CONCLUSIONS

Lower birth weight defined using genetic variants was associated with lower eGFRs in Dutch middle-aged adults. However, this finding was not replicated within the CKDGen consortium.

Association of Initiation of Maintenance Dialysis with Functional Status and Caregiver Burden

BACKGROUND AND OBJECTIVES

Little is known about the functional course after initiating dialysis in elderly patients with ESKD. The aim of this study was to assess the association of the initiation of dialysis in an elderly population with functional status and caregiver burden.

DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS

This study included participants aged ≥65 years with ESKD who were enrolled in the Geriatric Assessment in Older Patients Starting Dialysis study. All underwent a geriatric assessment and a frailty screening (Fried Frailty Index and Groningen Frailty Indicator) at dialysis initiation. Functional status (activities of daily life and instrumental activities of daily life) and caregiver burden were assessed at baseline and after 6 months. Decline was defined as loss of one or more domains in functional status, stable as no difference between baseline and follow-up, and improvement as gain of one or more domains in functional status. Logistic regression was performed to assess the association between the combined outcome functional decline/death and potential risk factors.

RESULTS

Of the 196 included participants functional data were available for 187 participants. Mean age was 75±7 years and 33% were women. At the start of dialysis, 79% were care dependent in functional status. After 6 months, 40% experienced a decline in functional status, 34% remained stable, 18% improved, and 8% died. The prevalence of high caregiver burden increased from 23%-38% (P=0.004). In the multivariable analysis age (odds ratio, 1.05; 95% confidence interval, 1.00 to 1.10 per year older at baseline) and a high Groningen Frailty Indicator compared with low score (odds ratio, 1.97; 95% confidence interval, 1.05 to 3.68) were associated with functional decline/death.

CONCLUSIONS

In patients aged ≥65 years, functional decline within the first 6 months after initiating dialysis is highly prevalent. The risk is higher in older and frail patients. Loss in functional status was mainly driven by decline in instrumental activities of daily life. Moreover, initiation of dialysis is accompanied by an increase in caregiver burden.

Thoracic and abdominal pain in a 28-year-old woman with a failing kidney transplant

This case report describes a young, immunocompromised patient who presented with thoracic pain. After an extensive workup, she was diagnosed with a varicella zoster virus infection with involvement of the gastric mucosa, pancreas and lungs for which she was treated with acyclovir. Although the viral load decreased significantly, the patient had persistent postherpetic neuralgia and nausea.

Lower body mass index and mortality in older adults starting dialysis

Lower body mass index (BMI) has consistently been associated with mortality in elderly in the general and chronic disease populations. Remarkably, in older incident dialysis patients no association of BMI with mortality was found. We performed an in-depth analysis and explored possible time-stratified effects of BMI. 908 incident dialysis patients aged ≥65 years of the NECOSAD study were included, and divided into tertiles by baseline BMI (<23.1 (lower), 23.1–26.0 (reference), ≥26.0 (higher) kg/m²). Because the hazards changed significantly during follow-up, the effect of BMI was modeled for the short-term (<1 year) and longer-term (≥1 year after dialysis initiation). During follow-up (median 3.8 years) 567 deaths occurred. Lower BMI was associated with higher short-term mortality risk (adjusted-HR 1.63 [1.14–2.32] P = 0.007), and lower longer-term mortality risk (adjusted-HR 0.81 [0.63–1.04] P = 0.1). Patients with lower BMI who died during the first year had significantly more comorbidity, and worse self-reported physical functioning compared with those who survived the first year. Thus, lower BMI is associated with increased 1-year mortality, but conditional on surviving the first year, lower BMI yielded a similar or lower mortality risk compared with the reference. Those patients with lower BMI, who had limited comorbidity and better physical functioning, had better survival.

Cardiovascular Risk Factors Accelerate Kidney Function Decline in Post-Myocardial Infarction Patients: The Alpha Omega Cohort Study

Introduction

Impaired kidney function is a robust risk factor for cardiovascular mortality. Age-related annual kidney function decline of 1.0 ml/min per 1.73 m² after age 40 years is doubled in post-myocardial infarction (MI) patients.

Methods

We investigated the impact of the number of cardiovascular risk factors (including unhealthy lifestyle) on annual kidney function decline, in 2426 post-MI patients (60-80 years) of the prospective Alpha Omega Cohort study. Glomerular filtration rate was estimated by serum cystatin C (eGFR_cysC) and combined creatinine-cystatin C (eGFR_cr-cysC), using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations from 2012. Data were analyzed by multivariable linear and logistic regression.

Results

At baseline, mean (SD) eGFR_cysC and eGFR_cr-cysC were 81.5 (19.6) and 78.5 (18.7) ml/min per 1.73 m², respectively. Of all patients, 79% were men, 19% had diabetes, 56% had high blood pressure (≥140/90 mm Hg), 16% were current smokers, 56% had high serum low-density lipoprotein (LDL of ≥2.5 mmol/l), and 23% were obese (body mass index of ≥30.0 kg/m²). After multivariable adjustment, the additional annual eGFR_cysC decline (95% confidence interval) was as follows: in patients with versus without diabetes, -0.90 (-1.23 to -0.57) ml/min per 1.73 m²; in patients with high versus normal blood pressure, -0.50 (-0.76 to -0.24) ml/min per 1.73 m²; in obese versus nonobese patients, -0.31 (-0.61 to 0.01) ml/min per 1.73 m²; and in current smokers versus nonsmokers, -0.19 (-0.54 to 0.16) ml/min per 1.73 m². High LDL was not associated with accelerated eGFR_cysC decline. Similar results were obtained with eGFR_cr-cysC.

Conclusion

In older, stable post-MI patients without cardiovascular risk factors, the annual kidney function decline was -0.90 (-1.16 to -0.65) ml/min per 1.73 m². In contrast, in post-MI patients with ≥3 cardiovascular risk factors, the annual kidney function decline was 2.5-fold faster, at -2.37 (-2.85 to -1.89) ml/min per 1.73 m².

Body-fat indicators and kidney function decline in older post-myocardial infarction patients: The Alpha Omega Cohort Study

Background Obesity increases risk of hypertension and diabetes, the leading causes of end-stage renal disease. The effect of obesity on kidney function decline in stable post-myocardial infarction patients is poorly documented. This relation was investigated in a large cohort of older post-myocardial infarction patients. Design Data were analysed from 2410 post-myocardial infarction patients in the Alpha Omega Trial, aged 60-80 years receiving optimal pharmacotherapy treatment (79% men, 18% diabetes). Methods Cystatin C based estimated glomerular filtration rate (eGFRcysC) was calculated at baseline and after 41 months, using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Obesity was defined as body mass index ≥ 30 kg/m2 and high waist circumference as ≥102 and ≥88 cm for men and women. The relation between body mass index, waist circumference and annual eGFRcysC decline was evaluated by linear regression. Results At baseline, mean (standard deviation) eGFRcysC was 81.5 (19.6) ml/min/1.73 m2, 23% of all patients were obese. After multivariable adjustment, the annual mean (95% confidence interval) eGFRcysC decline in men and women was -1.45 (-1.59 to -1.31) and -0.92 (-1.20 to -0.63) ml/min/1.73 m2, respectively ( p = 0.001). Obese versus non-obese patients and patients with high versus normal waist circumference experienced greater annual eGFRcysC decline. Men and women showed an additional annual eGFRcysC decline of -0.35 (-0.56 to -0.14) and -0.21 (-0.55 to 0.14) ml/min/1.73 m2 per 5 kg/m2 body mass index increment ( p for interaction 0.3). Conclusions High compared to normal body mass index or waist circumference were associated with more rapid kidney function decline in older stable post-myocardial infarction patients receiving optimal drug therapy.

Listeria Endocarditis: A Diagnostic Challenge

A 74-year-old hemodialysis patient with a history of an atrial septum defect closure, coronary bypass surgery, and a St. Jude aortic prosthetic valve was diagnosed with pneumonia and volume overload. Blood cultures were positive for Listeria monocytogenes, and amoxicillin was given for 2 weeks. Immediately after discontinuation of amoxicillin, fever relapsed. Transthoracic and transesophageal echocardiography showed no sign of endocarditis. Given the fever relapse and 3 positive minor Duke criteria, an 18F-FDG PET-CT scan (18F-fluorodeoxyglucose-positron emission tomography-computed tomography) scan was performed. This scan showed activity at the aortic root, proximal ascending aorta, and inferior wall of the heart, making Listeria monocytogenes endocarditis a likely explanation. Amoxicillin was given for 6 weeks with good clinical result. Diagnosing a life-threatening Listeria monocytogenes endocarditis can be challenging and an 18F-FDG PET-CT scan can be helpful.

Kidney function and specific mortality in 60-80 years old post-myocardial infarction patients: A 10-year follow-up study

Chronic kidney disease (CKD) is highly prevalent among older post-myocardial infarction (MI) patients. It is not known whether CKD is an independent risk factor for mortality in older post-MI patients with optimal cardiovascular drug-treatment. Therefore, we studied the relation between kidney function and all-cause and specific mortality among older post-MI patients, without severe heart failure, who are treated with state-of-the-art pharmacotherapy. From 2002-2006, 4,561 Dutch post-MI patients were enrolled and followed until death or January 2012. We estimated Glomerular Filtration Rate (eGFR) with cystatin C (cysC) and creatinine (cr) using the CKD-EPI equations and analyzed the relation with any and major causes of death using Cox models and restricted cubic splines. Mean (SD) for age was 69 years (5.6), 79% were men, 17% smoked, 21% had diabetes, 90% used antihypertensive drugs, 98% used antithrombotic drugs and 85% used statins. Patients were divided into four categories of baseline eGFRcysC: ≥90 (33%; reference), 60-89 (47%), 30-59 (18%), and <30 (2%) ml/min/1.73m2. Median follow-up was 6.4 years. During follow-up, 873 (19%) patients died: 370 (42%) from cardiovascular causes, 309 (35%) from cancer, and 194 (22%) from other causes. After adjustment for age, sex and classic cardiovascular risk factor, hazard ratios (95%-confidence intervals) for any death according to the four eGFRcysC categories were: 1 (reference), 1.4 (1.1-1.7), 2.9 (2.3-3.6) and 4.4 (3.0-6.4). The hazard ratios of all-cause and cause-specific mortality increased linearly below kidney functions of 80 ml/min/1.73 m2. Weaker results were obtained for eGFRcr. To conclude, we found in optimal cardiovascular drug-treated post-MI patients an inverse graded relation between kidney function and mortality for both cardiovascular as well as non-cardiovascular causes. Risk of mortality increased linearly below kidney function of about 80 ml/min/1.73 m2.

Kidney dysfunction, systemic inflammation and mental well-being in elderly post-myocardial infarction patients

Background

The aim was to investigate whether mild kidney dysfunction and low-grade inflammation in post-myocardial infarction patients are independently associated with markers of mental well-being (i.e. depressive and apathy symptoms, and dispositional optimism).

Methods

In post-myocardial infarction patients, kidney function was assessed by estimated glomerular filtration rate (eGFR) calculated from the combined CKD-EPI formula based on serum levels of both creatinine and cystatine C. Systemic inflammation was assessed using high sensitivity C-reactive protein (hs-CRP) levels. The 15-item Geriatric Depression Scale (GDS-15), the 3-item apathy subscale and the 4-item optimism questionnaire (4Q) were used to measure mental well-being and were analyzed using linear multivariable regression analysis.

Results

Of the 2355 patients, mean age was 72.3 (range 63–84) years and 80.1% were men. After multivariable adjustment, a poorer kidney function was associated with more depressive symptoms (β = -0.084, p < 0.001), more apathy symptoms (β = -0.101, p < 0.001), and less dispositional optimism (β = 0.072, p = 0.002). Moreover, higher levels of hs-CRP were associated with more depressive symptoms (β = 0.051, p = 0.013), more apathy symptoms (β = 0.083, p < 0.001) and less dispositional optimism (β = -0.047 p = 0.024). Apathy showed the strongest independent relation with both low eGFR and high hs-CRP.

Conclusions

In post-myocardial infarction patients, impaired kidney function and systemic inflammation showed a stronger association with apathy than with depressive symptoms and dispositional optimism.

Recipient obesity and outcomes after kidney transplantation: a systematic review and meta-analysis

BACKGROUND

The prevalence of obesity is increasing globally and is associated with chronic kidney disease and premature mortality. However, the impact of recipient obesity on kidney transplant outcomes remains unclear. This study aimed to investigate the association between recipient obesity and mortality, death-censored graft loss and delayed graft function (DGF) following kidney transplantation.

METHODS

A systematic review and meta-analysis was conducted using Medline, Embase and the Cochrane Library. Observational studies or randomized controlled trials investigating the association between recipient obesity at transplantation and mortality, death-censored graft loss and DGF were included. Obesity was defined as a body mass index (BMI) of ≥30 kg/m(2). Obese recipients were compared with those with a normal BMI (18.5-24.9 kg/m(2)). Pooled estimates of hazard ratios (HRs) for patient mortality or death-censored graft loss and odds ratios (ORs) for DGF were calculated.

RESULTS

Seventeen studies including 138 081 patients were analysed. After adjustment, there was no significant difference in mortality risk in obese recipients [HR = 1.24, 95% confidence interval (CI) = 0.90-1.70, studies = 5, n = 83 416]. However, obesity was associated with an increased risk of death-censored graft loss (HR = 1.06, 95% CI = 1.01-1.12, studies = 5, n = 83 416) and an increased likelihood of DGF (OR = 1.68, 95% CI = 1.39-2.03, studies = 4, n = 28 847).

CONCLUSIONS

Despite having a much higher likelihood of DGF, obese transplant recipients have only a slightly increased risk of graft loss and experience similar survival to recipients with normal BMI.

Effect of omega-3 fatty acids on kidney function after myocardial infarction: the Alpha Omega Trial

BACKGROUND AND OBJECTIVES

Kidney function gradually decreases with age, and myocardial infarction accelerates this deterioration. Omega-3 (n-3) fatty acids may slow down the decline of kidney function. The effect of marine and plant-derived n-3 fatty acids on kidney function in patients after myocardial infarction was examined.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In the Alpha Omega Trial, 2344 patients with history of myocardial infarction ages 60-80 years old (81% men) were randomized to one of four trial margarines. The patients received an additional targeted amount of 400 mg/d eicosapentaenoic acid and docosahexaenoic acid, 2 g/d α-linolenic acid, eicosapentaenoic acid-docosahexaenoic acid plus α-linolenic acid, or placebo for 40 months. Serum cystatin C and serum creatinine were assessed at baseline and after 40 months. Creatinine-cystatin C-based GFR was estimated with the Chronic Kidney Disease Epidemiology Collaboration equation.

RESULTS

Patients consumed 19.9 g margarine/d, providing an additional 239 mg/d eicosapentaenoic acid with 159 mg/d docosahexaenoic acid, 1.99 g/d α-linolenic acid, or both in the active treatment groups. After 40 months, compared with baseline, mean (±SD) creatinine-cystatin C-based GFR was -6.9 (±12.6), -4.8 (±13.4), -6.2 (±12.8), and -6.0 (±13.0) ml/min per 1.73 m(2) in the placebo, eicosapentaenoic acid-docosahexaenoic acid, α-linolenic acid, and eicosapentaenoic acid-docosahexaenoic acid plus α-linolenic acid groups, respectively. After 40 months, in patients receiving eicosapentaenoic acid-docosahexaenoic acid compared with placebo, the decline in creatinine-cystatin C-based GFR was 2.1 less (95% confidence interval, 0.6 to 3.6; P<0.01) ml/min per 1.73 m(2); other comparisons were not statistical significant. Odds ratios (95% confidence intervals) of incident CKD (<60 ml/min per 1.73 m(2)) and rapid decline of kidney function (≥3 ml/min per year) for eicosapentaenoic acid-docosahexaenoic acid compared with placebo were 0.83 (0.58 to 1.18) and 0.85 (0.67 to 1.08), respectively.

CONCLUSIONS

Long-term supplementation with 400 mg/d eicosapentaenoic acid-docosahexaenoic acid provides a small beneficial effect on kidney function in patients with a history of myocardial infarction.

No effect of n-3 fatty acids on high-sensitivity C-reactive protein after myocardial infarction: the Alpha Omega Trial

BACKGROUND

Persistent inflammation plays a role in the pathogenesis of atherosclerosis. n-3 Fatty acids may have anti-inflammatory effects. This study examined the effect of plant-derived alpha-linolenic acid (ALA) and marine n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on high-sensitivity C-reactive protein (hsCRP), a systemic marker of (low-grade) inflammation.

DESIGN/METHODS

A supplementary study in the Alpha Omega Trial: a multicenter, double-blind, randomized, placebo-controlled trial of low-dose n-3 fatty acids. Patients were enrolled from 2002 to 2006 and followed for 40 months. A total of 2425 patients, aged 60-80 years (79% men), with a history of myocardial infarction, were randomly assigned to margarines supplemented with a targeted additional intake of 400 mg/day EPA and DHA, 2 g/day ALA, EPA-DHA plus ALA, or placebo for 40 months.

RESULTS

Patients consumed on average 19.8 g margarine/day, providing an additional amount of 238 mg/day EPA with 158 mg/day DHA, 1.98 g/day ALA, or both, in the active treatment groups. In the placebo group, the geometric mean hsCRP (95% confidence interval (CI)) was 1.84 mg/l (95% CI: +1.70 to +2.00) at baseline and 1.98 mg/l (95% CI: 1.82 to 2.15) after 40 months (p < 0.0001). hsCRP levels were not affected by ALA (-5% versus placebo; 95% CI: -14% to +6%, p = 0.37), EPA-DHA (-8% versus placebo; 95% CI: -17% to +2%, p = 0.13), or EPA-DHA plus ALA (-3% versus placebo; 95% CI: -12% to +8%, p = 0.62).

CONCLUSIONS

Long-term supplementation with modest amounts of EPA-DHA, whether or not in combination with ALA, did not affect hsCRP levels in patients with a history of myocardial infarction.

TRIAL REGISTRATION CLINICALTRIALSGOV NUMBER

NCT00127452.

An uncommon cause of Staphylococcus aureus sepsis

We describe a case of Staphylococcus aureus sepsis after acupuncture for chronic fatigue syndrome (CFS). Sepsis is a rare, but potentially fatal complication of acupuncture. The most common cause of bacterial infection after acupuncture is S. aureus. The effectiveness of acupuncture for the treatment of CFS is not proven, therefore the potential benefits should be weighed against the risks.

Obesity and mortality risk among younger dialysis patients

BACKGROUND AND OBJECTIVES

Many studies show that obesity in dialysis patients is not strongly associated with mortality but not whether this modest association is constant over age. This study investigated the extent to which the relation of body mass index (BMI) and mortality differs between younger and older dialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Adult dialysis patients were prospectively followed from their first dialysis treatment for 7 years or until death or transplantation. Patients were stratified by age (<65 or ≥65 years) and baseline BMI (<20, 20-24 [reference], 25-29, and ≥30 kg/m(2)).

RESULTS

The study sample included 984 patients younger than 65 years and 765 patients 65 years or older; cumulative survival proportions at end of follow-up were 50% and 16%. Age-standardized mortality rate was 1.7 times higher in obese younger patients than those with normal BMI, corresponding to an excess rate of 5.2 deaths/100 patient-years. Mortality rates were almost equal between obese older patients and those with normal BMI. Excess rates of younger and older patients with low compared with normal BMI were 8.7 and 1.1 deaths/100 patient-years. After adjustment for age, sex, smoking, comorbidity, and treatment modality, hazard ratios by increasing BMI were 2.00, 1, 0.95, and 1.57 for younger patients and 1.07, 1, 0.88, and 0.91 for older patients, implying that obesity is a 1.7-fold (95% confidence interval, 1.1- to 2.9-fold) stronger risk factor in younger than older patients.

CONCLUSIONS

In contrast to older dialysis patients, younger patients with low or very high BMI had a substantially elevated risk for death.

Haemodialysis catheters increase mortality as compared to arteriovenous accesses especially in elderly patients

BACKGROUND

Catheter use has been associated with an increased mortality risk in haemodialysis patients. However, differences in the all-cause and cause-specific mortality risk between catheter use and arteriovenous access use in young and elderly haemodialysis patients have not yet been investigated.

METHODS

In this prospective cohort study of 1109 incident haemodialysis patients from 38 centres in the Netherlands, hazard ratios (HRs) with 95% confidence intervals (95% CIs) were calculated for 2-year all-cause, infection-related and cardiovascular mortality in patients with a catheter as compared to patients with an arteriovenous access stratified for age (< 65 years and ≥ 65 years).

RESULTS

Of the 1109 patients, 919 had an arteriovenous access and 190 had a catheter. The mortality rate was 76 per 1000 person-years in young patients with an arteriovenous access, 129 per 1000 person-years in young patients with a catheter, 222 per 1000 person-years in elderly patients with an arteriovenous access and 427 per 1000 person-years in elderly patients with a catheter. The adjusted HR was 3.15 (95% CI: 2.09-4.75) for elderly patients with a catheter as compared to young patients with an arteriovenous access. The adjusted HRs in elderly patients with a catheter as compared to elderly patients with an arteriovenous access were 1.54 (95% CI: 1.13-2.12) for all-cause mortality, 1.60 (95%: CI 0.62-4.19) for infection-related mortality and 1.67 (95% CI: 1.04-2.68) for cardiovascular mortality.

CONCLUSIONS

Especially, elderly haemodialysis patients with a catheter have an increased all-cause, infection-related and cardiovascular mortality risk as compared to patients with an arteriovenous access.

A haemodialysis patient with back pain: brown tumour as a cause of spinal cord compression under cinacalcet therapy

A 43-year-old haemodialysis patient was admitted to hospital because of paroxysmal pain in the upper abdominal region radiating to the back. Laboratory tests showed severe hyperparathyroidism [intact parathyroid hormone (iPTH) 69 pmol/L; reference range: 1.3-6.8 pmol/L], hypercalcaemia (2.79 mmol/L), hyperphosphataemia (1.6 mmol/L) and elevated serum total alkaline phosphatase (200 U/L). After developing a disturbed sensation and paraesthesia in both feet, epidural compression of the spinal cord was suspected. Magnetic resonance imaging showed a tumour that severely compressed the myelum of the thoracic spine. Histological investigation revealed a brown tumour or osteoclastoma, an erosive bony lesion caused by increased osteoclastic activity and peritrabecular fibrosis. A brown tumour is a benign tumour that is a rare complication of severe renal hyperparathyroidism. The brown tumour developed despite a 1-year treatment of the patient with cinacalcet, which, however, did not result in a major decrease in serum iPTH concentration (from 110 to 69 pmol/L: 37% reduction). Urgent decompressive neurosurgery and subtotal parathyroidectomy resulted in a complete recovery.