Relationship Between Mortality and Cancer-Bearing Status at Time of Dialysis Initiation

Relationship between serum sodium level at dialysis initiation and all-cause mortality

BACKGROUND

Hyponatremia is a common electrolyte disorder in patients with chronic kidney disease. In addition, hyponatremia is associated with mortality in patients with chronic kidney disease, including those on dialysis. However, few studies have examined this relationship in patients with incident dialysis.

METHODS

We used a database of multicenter prospective cohort studies that included 1520 incident dialysis patients. The baseline was set at the time of dialysis initiation. The enrolled patients were classified into five groups according to their serum sodium levels (< 130 mEq/L, 130-134 mEq/L, 135-139 mEq/L, 140-144 mEq/L, and ≥ 145 mEq/L). Multivariate Cox proportional hazards analysis was conducted to determine factors associated with all-cause mortality.

RESULTS

A total of 392 all-cause deaths occurred during the follow-up period. The ultrafiltration volume per body weight during the first dialysis session was more significant in the groups with the lowest and highest sodium levels. The percentage of patients using loop diuretics and thiazide was higher in the group with lower sodium levels (< 130 mEq/L and 130-134 mEq/L). All-cause mortality was significantly different among the five groups (p = 0.025). Multivariate analysis indicated that all-cause mortality was significantly higher in the group with the lowest sodium level compared to the group with a serum sodium level of 135-139 mEq/L (hazard ratio: 1.61, 95% confidence interval: 1.04-2.49).

CONCLUSION

Hyponatremia of < 130 mEq/L at dialysis initiation was significantly associated with all-cause mortality. We considered the results relevant to underlying conditions, including cardiovascular disease and medications.

Distribution and association of cancer with mortality in end-stage renal disease patients receiving dialysis

BACKGROUND AND AIMS

Cancer in end-stage renal disease (ESRD) patients is an important comorbidity to be taken into consideration while planning for renal replacement therapy (RRT) options due to its associated increased mortality. This study aims to investigate the natural history and association of cancer with all-cause mortality in an ESRD population receiving dialysis.

METHOD

The study was conducted on 1271 ESRD patients receiving dialysis between January 2012 and December 2017. A comparative analysis was carried out between 119 patients with and 1152 without cancer history at entry into this study (baseline). A 1:2 (119 cancer: 238 no cancer) propensity score matched sample of 357 patients was also used for analysis. Cox-regression analysis was used to study the strength of the association between cancer and all-cause mortality. Kaplan-Meier (KM) analysis was used to demonstrate the difference in cumulative survival between the groups. A competing risk analysis was also carried out to calculate the probability of competing events (death, transplant and incident cancer).

RESULTS

At baseline, 10.1% of the cohort had a history of cancer (current and past) with the annual incident rate being 1.3%. Urological cancers were the leading site of cancer. The median age of our cohort was 63 years with a predominance of males (63%) and Caucasians (79%). The majority (69%) of the cohort were receiving haemodialysis. 47% had a history of diabetes with 88% being hypertensive. During a median follow-up of 28 months, the proportion of deaths observed was similar between the groups in the matched sample (cancer 49.6 versus no-cancer 52.1%, p value 0.77). In a univariable Cox-regression model, there was no significant association between cancer and all-cause mortality (HR 1.28; 95% CI 0.97-1.67; p = 0.07). The KM estimates showed similar observations in the cumulative survival between the groups (matched sample log-rank, p value 0.85). In competing risk analysis, the cumulative probability of death at 5 years was non-significantly higher in the cancer group (cancer group 64% vs no cancer group 51%, p value 0.16).

CONCLUSIONS

In our real-world multi-morbid dialysis cohort of 119 cancer patients, baseline cancer history did not prove to be an independent risk factor for all-cause mortality in the first 5 years of follow-up, suggesting the need for a case-by-case approach in provision of RRT options, including transplantation.

Race and Mortality in CKD and Dialysis: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study

RATIONALE & OBJECTIVES

Few studies have investigated racial disparities in survival among dialysis patients in a manner that considers risk factors and mortality during the phase of kidney disease before maintenance dialysis. Our objective was to explore racial variations in survival among dialysis patients and relate them to racial differences in comorbid conditions and rates of death in the setting of kidney disease not yet requiring dialysis therapy.

STUDY DESIGN

Retrospective cohort study.

SETTINGS & PARTICIPANTS

3,288 black and white participants in the Chronic Renal Insufficiency Cohort (CRIC), none of whom were receiving dialysis at enrollment.

EXPOSURE

Race.

OUTCOME

Mortality.

ANALYTIC APPROACH

Cox proportional hazards regression was used to examine the association between race and mortality starting at: (1) time of dialysis initiation and (2) entry into the CRIC.

RESULTS

During 7.1 years of median follow-up, 678 CRIC participants started dialysis. Starting from the time of dialysis initiation, blacks had lower risk for death (unadjusted HR, 0.67; 95% CI, 0.51-0.87) compared with whites. Starting from baseline CRIC enrollment, the strength of the association between some risk factors and dialysis was notably stronger for whites than blacks. For example, the HR for dialysis onset in the presence (vs absence) of heart failure at CRIC enrollment was 1.30 (95% CI, 1.01-1.68) for blacks versus 2.78 (95% CI, 1.90-4.50) for whites, suggesting differential severity of these risk factors by race. When we included deaths occurring both before and after dialysis, risk for death was higher among blacks (vs whites) starting from CRIC enrollment (HR, 1.41; 95% CI, 1.22-1.64), but this finding was attenuated in adjusted models (HR, 1.08; 95% CI, 0.91-1.28).

LIMITATIONS

Residual confounding.

CONCLUSIONS

The apparent survival advantage among blacks over whites treated with dialysis may be attributed to selected transition of a subset of whites with more severe comorbid conditions onto dialysis.

Prediction model for cardiovascular events or all-cause mortality in incident dialysis patients

Some variables including age, comorbidity of diabetes, and so on at dialysis initiation are associated with patient prognosis. Cardiovascular (CV) events are a major cause of death, and adequate models that predict prognosis in dialysis patients are warranted. Therefore, we created models using some variables at dialysis initiation. We used a database of 1,520 consecutive dialysis patients (median age, 70 years; 492 women [32.4%]) from a multicenter prospective cohort study. We established the primary endpoint as a composite of the incidence of first CV events or all-cause death. A multivariable Cox proportional hazard regression model was used to construct a model. We considered a complex and a simple model. We used area under the receiver operating characteristic curve (AUROC) to assess and compare the predictive performances of the prediction models and evaluated the improvement in discrimination using the complex model versus the simple model using net reclassification improvement (NRI). We then assessed integrated discrimination improvement (IDI) to evaluate improvements in average sensitivity and specificity. Of 392 deaths, 152 were CV-related. Totally, 506 CV events occurred during the follow-up period (median 1,285 days). Finally, 692 patients reached the primary endpoint. Baseline data were set at dialysis initiation. AUROC for the primary endpoint was 0.737 (95% confidence interval [CI], 0.712–0.761) in the simple model and 0.765 (95% CI, 0.741–0.788) in the complex model. There were significant intergroup differences in NRI (0.44; 95% CI, 0.34–0.53; p < 0.001) and IDI (0.02; 95% CI, 0.02–0.03; p < 0.001). We prepared a Shiny R application for each model to automatically calculate the predicted occurrence probability (https://statacademy.shinyapps.io/App_inaguma_20190717/). The complex model made more accurate predictions than the simple model. However, the intergroup difference was not significant. Hence, the simple model was more useful than the complex model. The tool was useful in a real-world clinical setting because it required only routinely available variables. Moreover, we emphasized that the tool could predict the incidence of CV events or all-cause mortality for individual patients. In the future, we must confirm its external validity in other prospective cohorts.

Risks of female genital tract related cancers (gynecological cancers) or breast cancer in women with and without chronic kidney disease: A population-based cohort study in Taiwan

This article aims to test the hypothesis that the risk of female genital tract related cancer (gynecological cancer: GC) or breast cancer (BC) of women with chronic kidney disease (CKD) might be different from that of those women without CKD.A nationwide 17-year historic cohort study using the National Health Insurance Research Database (NHIRD) of Taiwan and the Registry for Catastrophic Illness Patients was conducted. A total of 3045 women with a diagnosis of CKD from 1996 to 2013 and 3045 multivariable-matched controls (1:1) were selected. We used Cox regression, and computed hazard ratios (HRs) with 95% confidence intervals (95% CIs) to determine the risk of GC or BC in women.The GC incidence rates (IRs, per 10,000 person-years) of the CKD and non-CKD women were 11.02 and 19.09, respectively, contributing to a significantly decreased risk of GCs (crude HR 0.57, 95% CI 0.39-0.81; adjusted HR 0.44, 95% CI 0.30-0.65) in the CKD women. The GC IR was relatively constant in the CKD women among the different age categories (IR ranged from 8.10 to 12.29). On contrast, the non-CKD women had a progressive and continuous increase of GC IR in the advanced age, which was more apparent at age ≥50 years (IR 17.16 for 50-59; IR 23.05 for 60-69; and IR 31.62 for ≥70, respectively), contributing to the lower risk of GC in the CKD women than that in the non-CKD women. There was no difference of BC incidence between women with and without CKD.The findings of the lower risk of GCs in the CKD women in Taiwan are worthy of further evaluation.

Relationship Between Mortality and Cancer-Bearing Status in Patients With Chronic Kidney Disease Who Attended an Educational Program

Patients with malignancy have a poorer prognosis than others do, which must be taken into consideration when treating them for chronic kidney disease (CKD). However, there are few studies investigating their prognosis. This was an observational study of 515 (394 men and 121 women) stable non-dialysis patients with CKD who attended a CKD educational program. Mean age was 68.8 ± 13.0 years. Median follow-up was 968.5 days. Mean creatinine was 3.4 ± 1.6 mg/dL. Of these, 63 had malignancy and 452 did not; 20.6% of the former and 11.9% of the latter group died by the end of the study period (P = 0.0548). Malignancy was not associated with all-cause mortality (HR: 1.3475, 95% CI: 0.7202-2.5214, P = 0.3507) but with malignancy-associated mortality (HR: 3.9477, 95% CI: 1.6348-9.5331, P = 0.0023). Renal replacement therapy was not associated with mortality. Since malignancy greatly affects the prognosis, it must be taken into consideration when treating these patients.