Effect of Age, Gender, and Diabetes on Excess Death in End-Stage Renal Failure

Sex and the Risk of Atheromatous and Non-Atheromatous Cardiovascular Disease in CKD: Findings From the CKD-REIN Cohort Study

RATIONALE & OBJECTIVE

Sex differences in cardiovascular disease (CVD) are well-established, but whether chronic kidney disease (CKD) modifies these risk differences, and whether they differ between atheromatous (ACVD) and non-atheromatous (N-ACVD) CVD is unknown. Assessing this interaction was the principal goal of this study.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Adults enrolled in the CKD-Renal Epidemiology and Information Network (CKD-REIN) cohort from from 2013 to 2020, a nationally representative sample of 40 nephrology clinics in France.

EXPOSURE

Sex.

OUTCOMES

Fatal and non-fatal composite ACVD events (ischaemic coronary, cerebral, and peripheral artery disease) and composite N-ACVD events (heart failure, haemorrhagic stroke, and arrhythmias).

ANALYTICAL APPROACH

Multivariable cause-specific Cox proportional hazards models.

RESULTS

1,044 women and 1,976 men with moderate to severe CKD (median age, 67 vs. 69; mean estimated glomerular filtration rate [eGFR], 32±12 vs. 33±12 mL/min/1.73m2) were studied. Over a median follow-up of 5.0 (interquartile range, 4.8;5.2) years, the ACVD rate (per 100 patient-years) was significantly lower in women than men: 2.1 (95% confidence interval: 1.6-2.5) vs 3.6 (3.2-4.0) (P<0.01), while the N-ACVD rate was not: 5.7 (5.0-6.5) vs 6.4 (5.8-7.0) (P=0.55). N-ACVD had a steeper relationship with eGFR than did ACVD. There was an interaction (P<0.01) between sex and baseline eGFR and the ACVD hazard: the adjusted hazard ratio for women compared to men was 0.42 (0.25;0.71) at 45 mL/min/1.73m2 and gradually attenuated at lower levels of eGFR, reaching 1.00 (0.62;1.63) at 16 mL/min/1.73m2. In contrast, the N-ACVD hazard did not differ between the sexes across the eGFR range studied.

LIMITATIONS

Cardiovascular biomarkers and sex hormones were not assessed.

CONCLUSION

This study shows how the lower risk of ACVD among women compared to men attenuates fully with kidney disease progression. The equal risk of N-ACVD between sexes across CKD stages and its steeper association with eGFR suggest an important contribution of CKD to the development of this CVD type.

Hydrophilic Modification of Dialysis Membranes Sustains Middle Molecule Removal and Filtration Characteristics

While efficient removal of uremic toxins and accumulated water is pivotal for the well-being of dialysis patients, protein adsorption to the dialyzer membrane reduces the performance of a dialyzer. Hydrophilic membrane modification with polyvinylpyrrolidone (PVP) has been shown to reduce protein adsorption and to stabilize membrane permeability. In this study we compared middle molecule clearance and filtration performance of nine polysulfone-, polyethersulfone-, and cellulose-based dialyzers over time. Protein adsorption was simulated in recirculation experiments, while β2-microglobulin clearance as well as transmembrane pressure (TMP) and filtrate flow were determined over time. The results of this study showed that β2-microglobulin clearance (-7.2 mL/min/m2) and filtrate flow (-54.4 mL/min) decreased strongly during the first 30 min and slowly afterwards (-0.7 mL/min/m2 and -6.8 mL/min, respectively, for the next 30 min); the TMP increase (+37.2 mmHg and +8.6 mmHg, respectively) showed comparable kinetics. Across all tested dialyzers, the dialyzer with a hydrophilic modified membrane (FX CorAL) had the highest β2-microglobulin clearance after protein fouling and the most stable filtration characteristics. In conclusion, hydrophilic membrane modification with PVP stabilizes the removal capacity of middle molecules and filtration performance over time. Such dialyzers may have benefits during hemodiafiltration treatments which aim to achieve high exchange volumes.

Digital variance angiography in patients undergoing lower limb arterial recanalization: cost-effectiveness analysis within the English healthcare setting

Aim: Digital variance angiography (DVA) is a recently developed image processing method capable of improving image quality compared with the traditionally used digital subtraction angiography (DSA), among patients undergoing lower limb x-ray angiography. This study aims to explore the potential cost-effectiveness of DVA from an English National Health Service perspective. Materials & methods: A two-part economic model, consisting of a decision tree and a Markov model, was developed to consider the costs and health outcomes associated with the use of DVA as part of current practice imaging, compared with x-ray angiography using standard DSA. The model explored the impact of DVA on the development of acute kidney injury (AKI), chronic kidney disease and radiation-induced cancer over a lifetime horizon. Both deterministic and probabilistic analyses were performed to assess the cost per quality-adjusted life-year (QALY). Results: Base-case results indicate that DVA results in cost savings of £309 per patient, with QALYs also improving (+0.025) over a lifetime. As shown in sensitivity analysis, a key driver of model results is the relative risk (RR) reduction of contrast-associated acute kidney injury associated with use of DVA. The intervention also decreases the risk of carcinoma over a lifetime. Scenario analyses show that cost savings range from £310 to £553, with QALY gains ranging from 0.048 to 0.109 per patient. Conclusion: The use of DVA could result in a decrease in costs and an increase in QALYs over a lifetime, compared with existing imaging practice. The potential for this technology to offer an economically viable alternative to existing image processing methods, through a reduction in contrast media volume and radiation exposure, has been demonstrated.

Real-world trends in pre-dialysis blood pressure levels of patients undergoing dialysis in Japan using a web-based national database

The prevalence of hypertension is high among patients undergoing dialysis. We extracted data of patients undergoing dialysis between 2012 and 2020 with recorded pre-dialysis systolic blood pressure (SBP) using a web-based national database in Japan. Following the 2019 Japanese Society of Hypertension guidelines, we classified SBP and assessed its trends over time based on sex, age, diabetes status, and the anti-hypertensive medication use. Using the 2020 database, we examined 336,759 Japanese patients undergoing dialysis (114,249 female; 222,510 male). The mean age was 69.4 ± 12.5 years, and the mean SBP was 152.3 ± 24.7 mm Hg. The prevalence rate of pre-dialysis hypertension was 70.2%, with 32.5%, 24.5%, and 13.2% of patients having grade I, grade II, and grade III hypertension, respectively. From 2014 to 2020, prevalence rate of pre-dialysis hypertension and absolute values of pre-dialysis SBP were higher in dialysis patients with diabetes than in those without diabetes across all age groups and sexes. Younger patients with diabetes or those on anti-hypertensive medication exhibited an SBP of approximately 160 mm Hg. Cerebrovascular death in patients with diabetes was associated with a higher rate of pre-dialysis hypertension than that in those without diabetes, and there was a significant difference in the prevalence of grade III hypertension between the two groups. In conclusion, the mean pre-dialysis SBP among patients undergoing dialysis remained high, and younger patients with diabetes or those receiving anti-hypertensive medications had poor blood pressure control. Optimal blood pressure management may be necessary to reduce the risk of cardiovascular mortality.

Long-term Trends in Infection-Related Mortality in Adults Treated With Maintenance Dialysis

RATIONALE & OBJECTIVE

Infection is 1 of the top 3 causes of death in patients receiving maintenance dialysis. We evaluated the trends over time and risk factors for infection-related deaths among people receiving dialysis.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

We included all adults who began dialysis between 1980 and 2018 in Australia and New Zealand.

EXPOSURE

Age, sex, dialysis modality, and dialysis era.

OUTCOME

Infection-related death.

ANALYTICAL APPROACH

Incidence was described and standardized mortality ratios (SMR) calculated for infection-related death. Fine-Gray subdistribution hazards models were fitted, with non-infection-related death and kidney transplantation treated as competing events.

RESULTS

The study comprised 46,074 patients who received hemodialysis and 20,653 who were treated with peritoneal dialysis who were followed for 164,536 and 69,846 person-years, respectively. There were 38,463 deaths during the follow-up period, 12% of which were ascribed to infection. The overall rate of mortality from infection (per 10,000 person-years) was 185 and 232 for patients treated with hemodialysis and peritoneal dialysis, respectively. The rates were 184 and 219 for males and females, respectively; and 99, 181, 255, and 292 for patients aged 18-44, 45-64, 65-74, 75 years and over, respectively. The rates were 224 and 163 for those commencing dialysis in years 1980-2005 and 2006-2018, respectively. The overall SMR declined over time, from 37.1 (95% CI, 35.5-38.8) in years 1980-2005 to 19.3 (95% CI, 18.4-20.3) in years 2006-2018, consistent with the declining 5-year SMR trend (P<0.001). Infection-related mortality was associated with being female, older age, and Aboriginal and/or a Torres Strait Islander or Māori.

LIMITATIONS

Mediation analyses defining the causal relationships between infection type and infection-related death could not be undertaken as disaggregating the data was not feasible.

CONCLUSIONS

The excess risk of infection-related death in patients on dialysis has improved substantially over time but remains more than 20 times higher than in the general population.

Sex Disparity in Cause-Specific and All-Cause Mortality Among Incident Dialysis Patients

RATIONALE & OBJECTIVE

Early mortality rates of female patients receiving dialysis have been, at times, observed to be higher than rates among male patients. The differences in cause-specific mortality between male and female incident dialysis patients with kidney failure are not well understood and were the focus of this study.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Incident patients who had initiated dialysis in Australia and New Zealand in 1998-2018.

EXPOSURE

Sex.

OUTCOMES

Cause-specific and all-cause mortality while receiving dialysis, censored for kidney transplant.

ANALYTICAL APPROACH

Adjusted cause-specific proportional hazards models, focusing on the first 5 years following initiation of dialysis.

RESULTS

Among 53,414 patients (20,876 [39%] female) followed for a median period of 2.8 (IQR, 1.3-5.2) years, 27,137 (51%) died, with the predominant cause of death attributed to cardiovascular disease (18%), followed by dialysis withdrawal (16%). Compared with male patients, female patients were more likely to die in the first 5 years after dialysis initiation (adjusted hazard ratio [AHR], 1.08 [95% CI, 1.05-1.11]). Even though female patients experienced a lower risk of cardiovascular disease-related mortality (AHR, 0.93 [95% CI, 0.89-0.98]) than male patients, they experienced a greater risk of infection-related (AHR, 1.20 [95% CI, 1.10-1.32]) and dialysis withdrawal-related (AHR, 1.19 [95% CI, 1.13-1.26]) mortality.

LIMITATIONS

Possibility of residual and unmeasured confounders.

CONCLUSIONS

Compared with male patients, female patients had a higher risk of all-cause mortality in the first 5 years after dialysis initiation, a difference driven by higher rates of mortality from infections and dialysis withdrawals. These findings may inform the study of sex differences in mortality in other geographic settings.

Sex and Racial/Ethnic Differences in Home Hemodialysis Mortality

Key Points

Women on home hemodialysis have higher 1-year mortality than men, and women and men have comparable survival on long-term follow-up. Compared with White patients on home hemodialysis, there was no difference in all-cause mortality for Black patients, Hispanics, or Native Americans. Among patients undergoing home hemodialysis, Asians had a lower risk of all-cause mortality than White patients.

Background

Women and minorities constitute substantial portions of the prevalent population of patients with kidney failure. Little is known about sex and racial/ethnic differences in mortality among patients with kidney failure on home hemodialysis in the United States.

Methods

Using the United States Renal Data System, we retrospectively evaluated a cohort of 42,849 patients who started home hemodialysis between January 1, 2005, and December 31, 2015. We examined the association of sex and race/ethnicity with the outcome of all-cause mortality using adjusted Cox proportional hazard models and logistic regression models.

Results

In the study cohort, 40.4% were women, and 57.4% were White. Women on home hemodialysis had higher unadjusted death rates (26.9 versus 22.4 per 100 person-years) compared with men. There was no difference in adjusted all-cause mortality between men and women, but women had an 8% higher adjusted risk of all-cause mortality at 1 year after initiating home hemodialysis (odds ratio 1.08, 95% confidence interval [CI], 1.01 to 1.15). Regarding race/ethnicity, Hispanic, White, and Black patients had higher unadjusted death rates compared with Asians and Native Americans (25.1 versus 24.8 versus 23.2 versus 17.4 versus 16.6 per 100 person-years). There was no difference in adjusted all-cause mortality in Black, Hispanic, and Native Americans compared with White patients, while Asians had a lower risk of all-cause mortality than did White patients (hazard ratio, 0.81; 95% CI, 0.72 to 0.92). There was no difference in adjusted 1-year mortality for Asian, Black, Hispanic, and Native American patients compared with White patients.

Conclusions

Among patients undergoing home hemodialysis, women have higher 1-year mortality than men, and women and men have comparable survival on long-term follow-up after adjusting for other covariates. Compared with White patients, there was no difference in adjusted survival on long-term follow-up for Black patients, Hispanics, or Native Americans, while Asians had better survival. Our results suggest the need for population-wide strategies to overcome differences in home hemodialysis care.

All-Cause Standardized Mortality Ratio in Hemodialysis and Peritoneal Dialysis Patients: A Nationwide Population-Based Cohort Study

Patients with end-stage renal disease (ESRD) are at a higher mortality risk compared with the general population. Previous studies have described a relationship between mortality and patients with ESRD, but the data on standardized mortality ratio (SMR) corresponding to different causes of death in patients undergoing hemodialysis (HD) and peritoneal dialysis (PD) are limited. This study was designed as a nationwide population-based retrospective cohort study. Incident dialysis patients between January 2000 and December 2015 in Taiwan were included. Using data acquired from the Taiwan Death Registry, SMR values were calculated and compared with the overall survival. The results showed there were a total of 128,966 patients enrolled, including 117,376 incident HD patients and 11,590 incident PD patients. It was found that 75,297 patients (58.4%) died during the period of 2000-2017. The overall SMR was 5.21. The neoplasms SMR was 2.11; the endocrine, nutritional, metabolic, and immunity disorders SMR was 13.53; the circulatory system SMR was 4.31; the respiratory system SMR was 2.59; the digestive system SMR was 6.1; and the genitourinary system SMR was 27.22. Therefore, more attention should be paid to these diseases in clinical care.

Years of Potential Life Lost on Renal Replacement Therapy: Retrospective Study Cohort

BACKGROUND

Chronic kidney disease is the non-communicable disease with the highest growth in morbidity and mortality. Renal transplantation (RT) is the first option of renal replacement in end-stage kidney disease (ESKD) and dialysis is an alternative. However, there is no objective quantification of the impact of both options on a patient's overall survival. The purpose of our study is to assess the potential years of life lost by patients on renal replacement therapy.

METHODS

Retrospective study cohort conducted from 2008 to 2018 based on autonomic data registry.

RESULTS

11,551 patients included who received renal replacement therapy (RRT) in a range of age from 15 to 94 years. The mean age at the time of onset was 62.7 years, 95% confidence interval (95% CI) (62.4; 63.0). The mortality rate of RRT patients was 42.2%, 95% CI (41.5; 43.3) and the mean age at death was 72.7 years, 95% CI (72.4; 73.1). The number of patients with ESKD treated with RT was 3776, 32.7% of the total, 95% CI (31.8; 33.5). The total amount of years of potential life lost (YPLL) in the entire cohort was 77,831.3 years, 48,010.1 years in men, and 29,821.2 years in women. The mean number of YPLL per patient with RRT was 6.74 years in both sexes, 6.95 years in women, and 6.61 years in men. The mean number of potential years of life lost in dialysis patients was 9.0 years in both sexes, 8.8 years in men, and 9.2 years in women, while among kidney transplant recipients this figure decreased to 2.2 years in both men and women.

CONCLUSIONS

End-stage chronic kidney disease in renal replacement therapy by dialysis causes an average of 9.0 years of life potentially lost for each patient on dialysis treatment, while having received a kidney transplant reduces this figure by 75.6%.

Sex disparities in mortality among patients with kidney failure receiving dialysis

Females are known to have a better survival rate than males in the general population, but previous studies have shown that this superior survival is diminished in patients on dialysis. This study aimed to investigate the risk of mortality in relation to sex among Korean patients undergoing hemodialysis (HD) or peritoneal dialysis (PD). A total of 4994 patients with kidney failure who were receiving dialysis were included for a prospective nationwide cohort study. Cox multivariate proportional hazard models were used to determine the association between sex and the risk of cause-specific mortality according to dialysis modality. During a median follow-up of 5.8 years, the death rate per 100 person-years was 6.4 and 8.3 in females and males, respectively. The female-to-male mortality rate in patients on dialysis was 0.77, compared to 0.85 in the general population. In adjusted analyses, the risk of all-cause mortality was significantly lower for females than males in the entire population (hazard ratio [HR] 0.79, 95% confidence interval [CI] 0.71-0.87, P < 0.001). No significant differences in the risk of cardiovascular and infection-related deaths were observed according to sex. The risk of mortality due to sudden death, cancer, other, or unknown causes was significantly lower for females than males in the entire population (HR 0.66, 95% CI 0.56-0.78, P < 0.001), in patients on HD (HR 0.75, 95% CI 0.62-0.90, P = 0.003), and in patients on PD (HR 0.49, 95% CI 0.34-0.70, P < 0.001). The survival advantage of females in the general population was maintained in Korean dialysis patients, which was attributed to a lower risk of noncardiovascular and noninfectious death.Trial registration: ClinicalTrials.gov Identifier: NCT00931970.

Excess all-cause and cause-specific mortality for people with diabetes and end-stage kidney disease

AIMS

Excess mortality is high in the setting of diabetes and end-stage kidney disease (ESKD), but the effects of ESKD beyond diabetes itself remains incompletely understood. We examined excess mortality in people with diabetes with versus without ESKD, and variation by age, sex and diabetes type.

METHODS

This study included 63,599 people with type 1 (aged 20-69 years; 56% men) and 1,172,160 people with type 2 diabetes (aged 30+ years; 54% men), from the Australian National Diabetes Services Scheme. Initiation of renal replacement therapy and mortality outcomes were obtained via linkage to the Australia and New Zealand Dialysis and Transplant Registry and the National Death Index, respectively. Excess mortality was measured by calculating the mortality rate ratio (MRR) for people with versus without ESKD via indirect standardisation.

RESULTS

A total of 9027 people developed ESKD during 8,601,522 person-years of follow-up. Among people with type 1 diabetes, the MRR was 34.9 (95%CI: 16.6-73.1) in men and 41.5 (20.8-83.1) in women aged 20-29 years and was 5.6 (4.5-7.0) and 7.4 (5.5-10.1) in men and women aged 60-69 years, respectively. In type 2 diabetes, MRRs were 16.6 (8.6-31.8) and 35.8 (17.0-75.2) at age 30-39 years and were 2.8 (2.6-3.1) and 3.6 (3.2-4.1) at age 80+ years in men and women, respectively. Excess cause-specific mortality was highest for peripheral artery disease, cardiac arrest, and infections, and lowest for cancer.

CONCLUSIONS

Among people with diabetes, excess mortality in ESKD is much higher at younger ages and is higher for women compared with men.

County-Level Characteristics Associated with Variation in ESKD Mortality in the United States, 2010-2018

Background

Geographic and neighborhood-level factors, such as poverty and education, have been associated with an increased risk for incident ESKD, likelihood of receiving pre-ESKD care, and likelihood of receiving a transplant. However, few studies have examined whether these same factors are associated with ESKD mortality. In this study, we examined county-level variation in ESKD mortality and identified county-level characteristics associated with this variation.

Methods

We identified 1,515,986 individuals (aged 18-84 years) initiating RRT (dialysis or transplant) between 2010 and 2018 using the United States Renal Data System. Among 2781 counties, we estimated county-level, all-cause, age-standardized mortality rates (ASMR) among patients with ESKD. We then identified county-level demographic (e.g., percent female), socioeconomic (e.g., percent unemployed), healthcare (e.g., percent without health insurance), and health behavior (e.g., percent current smokers) characteristics associated with ASMR using multivariable hierarchic linear mixed models and quantified the percentage of ASMR variation explained by county-level characteristics.

Results

County-level ESKD ASMR ranged from 45 to 1022 per 1000 person-years (PY) (mean, 119 per 1000 PY). ASMRs were highest in counties located in the Tennessee Valley and Appalachia regions, and lowest in counties located in New England, the Pacific Northwest, and Southern California. In fully adjusted models, county-level characteristics significantly associated with higher ESKD mortality included a lower percentage of Black residents (-4.94 per 1000 PY), lower transplant rate (-4.08 per 1000 PY), and higher healthcare expenditures (5.21 per 1000 PY). Overall, county-level characteristics explained 19% of variation in ESKD mortality.

Conclusions

Counties with high ESKD-related mortality may benefit from targeted and multilevel interventions that combine knowledge from a growing evidence base on the interplay between individual and community-level factors associated with ESKD mortality.

Accessing hemodialysis clinics during the COVID-19 pandemic

Transportation is a key element of access to healthcare. The COVID-19 pandemic posed unique and unforeseen challenges to patients receiving hemodialysis who rely on three times weekly transportation to receive their life-saving treatments, but there is little data on the problems they faced. This study explores the attitudes, fears, and concerns of hemodialysis patients during the pandemic with a focus on their travel to/from dialysis treatments. A mixed methods travel survey was distributed to hemodialysis patients from three urban centers in Montréal, Canada, during the pandemic (n = 43). The survey included closed questions that were analysed through descriptive statistics as well as open-ended questions that were assessed through thematic analysis. Descriptive statistics show that hemodialysis patients are more fearful of contracting COVID-19 in transit than they are at the treatment center. Patients taking paratransit, public transportation, and taxis are more fearful of COVID-19 while traveling than those who drive, who are driven, or who walk to the clinic. In the open-ended questions, patients reported struggling with confusing COVID-19 protocols in public transport, including conflicting information on whether paratransit taxis allowed one or multiple passengers. Paratransit was the most used travel mode to access treatment (n = 30), with problems identified in the open-ended questions, such as long and unreliable pickup windows, and extended travel times. To limit COVID-19 exposure and stress for paratransit users, agencies should consider sitting one patient per paratransit taxi, clearly communicating COVID-19 protocols online and in the vehicles, and tracking vehicles for more efficient pickups.

The Other Way Around: Living With Chronic Kidney Disease From the Perspective of Men

A wealth of evidence has suggested sex (biological) and gender (sociocultural) differences in the prevalence, progression, and outcomes of persons with chronic kidney disease. Much of this evidence tends to emphasize differences in which women are disadvantaged, and less attention is paid to findings in which women are better off or similar to men. However, gender medicine recognizes that men and women have different disease determinants, presentation, and attitudes, and it pertains to both sexes. In this review, we revisit chronic kidney disease through the perspective of men, and illustrate a population segment at need of stringent preventative and management strategies.

Sex-Based Differences in Risk Factors and Complications of Chronic Kidney Disease

Globally, females are ∼30% more likely to have pre-dialysis chronic kidney disease (CKD) than males for reasons that are not fully understood. CKD is associated with numerous adverse health outcomes which makes understanding and working to eradicating sex based disparities in CKD prevalence essential. This review maps both what is known, and what is unknown, about the way sex and gender impacts (1) the epidemiology and risk factors for CKD including age, diabetes, hypertension, obesity, smoking, and cerebrovascular disease, and (2) the complications from CKD including kidney disease progression, cardiovascular disease, CKD mineral and bone disorders, anaemia, quality-of-life, cancer and mortality. This mapping can be used to guide future research.

Sex differences in the 10-year survival of patients undergoing maintenance hemodialysis in the Q-Cohort Study

Women have a longer life expectancy than men in the general population. However, it has remained unclear whether this advantage is maintained in patients undergoing maintenance hemodialysis. The aim of this study was to compare the risk of mortality, especially infection-related mortality, between male and female hemodialysis patients. A total of 3065 Japanese hemodialysis patients aged ≥ 18 years old were followed up for 10 years. The primary outcomes were all-cause and infection-related mortality. The associations between sex and these outcomes were examined using Cox proportional hazards models. During the median follow-up of 8.8 years, 1498 patients died of any cause, 387 of whom died of infection. Compared with men, the multivariable-adjusted hazard ratios (95% confidence interval) for all-cause and infection-related mortality in women were 0.51 (0.45–0.58, P < 0.05) and 0.36 (0.27–0.47, P < 0.05), respectively. These findings remained significant even when propensity score-matching or inverse probability of treatment weighting adjustment methods were employed. Furthermore, even when the non-infection-related mortality was considered a competing risk, the infection-related mortality rate in women was still significantly lower than that in men. Regarding all-cause and infection-related deaths, women have a survival advantage compared with men among Japanese patients undergoing maintenance hemodialysis.

Sex differences in mortality among binational cohort of people with chronic kidney disease: population based data linkage study

OBJECTIVE

To evaluate sex differences in mortality among people with kidney failure compared with the general population.

DESIGN

Population based cohort study using data linkage.

SETTING

The Australian and New Zealand Dialysis and Transplant Registry (ANZDATA), which includes all patients receiving kidney replacement therapy in Australia (1980-2019) and New Zealand (1988-2019). Data were linked to national death registers to determine deaths and their causes, with additional details obtained from ANZDATA.

PARTICIPANTS

Of 82 844 people with kidney failure, 33 329 were female (40%) and 49 555 were male (60%); 49 376 deaths (20 099 in female patients; 29 277 in male patients) were recorded over a total of 536 602 person years of follow-up.

MAIN OUTCOME MEASURES

Relative measures of survival, including standardised mortality ratios, relative survival, and years of life lost, using general population data to account for background mortality (adjusting for country, age, sex, and year). Estimates were stratified by dialysis modality (haemodialysis or peritoneal dialysis) and for the subpopulation of kidney transplant recipients.

RESULTS

Few differences in outcomes were found between male and female patients with kidney failure. However, compared with the general population, female patients with kidney failure had greater excess all cause deaths than male patients (female patients: standardised mortality ratio 11.3, 95% confidence interval 11.2 to 11.5, expected deaths 1781, observed deaths 20 099; male patients: 6.9, 6.8 to 6.9, expected deaths 4272, observed deaths 29 277). The greatest difference was observed among younger patients and those who died from cardiovascular disease. Relative survival was also consistently lower in female patients, with adjusted excess mortality 11% higher (95% confidence interval 8% to 13%). Average years of life lost was 3.6 years (95% confidence interval 3.6 to 3.7) greater in female patients with kidney failure compared with male patients across all ages. No major differences were found in mortality by sex for haemodialysis or peritoneal dialysis. Kidney transplantation reduced but did not entirely remove the sex difference in excess mortality, with similar relative survival (P=0.83) and years of life lost difference reduced to 2.3 years (95% confidence interval 2.2 to 2.3) between female and male patients.

CONCLUSIONS

Compared with the general population, female patients had greater excess deaths, worse relative survival, and more years of life lost than male patients, however kidney transplantation reduced these differences. Future research should investigate whether systematic differences exist in access to care and possible strategies to mitigate excess mortality among female patients.

Changes in excess mortality among adults with diabetes-related end-stage kidney disease: a comparison between the USA and Australia

BACKGROUND

The number of people with diabetes-related end-stage kidney disease (ESKD-DM) has doubled in the last two decades. We examined changes in excess mortality for people with ESKD-DM in the USA and Australia.

METHODS

In this retrospective cohort study, we included adults (ages 20-84 years) receiving renal replacement therapy (RRT) for ESKD-DM in the USA (n = 1 178 860 from the United States Renal Data System, 2002-17) and Australia (n = 10 381 from the Australia and New Zealand Dialysis and Transplant Registry, 2002-13). ESKD-DM was defined as those with diagnosed diabetes at time of RRT initiation and mortality status was captured from national death registries. Annual standardized mortality ratios (SMR) were stratified by treatment modality, and age, sex and race (USA only). Trends were assessed using join point regression and annual percent change (APC) was reported.

RESULTS

Overall, in the dialysis population SMR decreased from 2006 to 2014 in the USA (from 12.0 to 10.1; APC -2.1) and from 2002 to 2013 in Australia (from 12.0 to 9.4; APC -3.4). In the transplant population, SMR decreased from 6.2 to 4.0 from 2002 to 2013 in the USA, and did not significantly change from 2002 to 2013 in Australia. By subgroup, excess mortality was higher in women (versus men), younger (versus older) adults, dialysis (versus transplant) patients, and in Asian or Pacific Islanders and American Indian or Alaskan Natives (AI/AN) (versus Whites and Blacks). SMRs declined similarly across all subgroups excluding AI/AN (USA) and transplant patients (Australia), where relative declines were smaller.

CONCLUSIONS

Excess mortality for people with ESKD-DM treated with dialysis or transplant has decreased in the USA and Australia, but progress has stalled from ∼2013 in the USA. Nevertheless, mortality remains more than nine times higher in ESKD-DM versus the general population, with important variations by subgroups. Given the increasing burden of diabetes in the population, a focus on reducing excess mortality risk in the ESKD-DM population is needed.

The Effect of Cardiovascular Comorbidities on Women Compared to Men: Longitudinal Retrospective Analysis

Background

Although men are more prone to developing cardiovascular disease (CVD) than women, risk factors for CVD, such as nicotine abuse and diabetes mellitus, have been shown to be more detrimental in women than in men.

Objective

We developed a method to systematically investigate population-wide electronic health records for all possible associations between risk factors for CVD and other diagnoses. The developed structured approach allows an exploratory and comprehensive screening of all possible comorbidities of CVD, which are more connected to CVD in either men or women.

Methods

Based on a population-wide medical claims dataset comprising 44 million records of inpatient stays in Austria from 2003 to 2014, we determined comorbidities of acute myocardial infarction (AMI; International Classification of Diseases, Tenth Revision [ICD-10] code I21) and chronic ischemic heart disease (CHD; ICD-10 code I25) with a significantly different prevalence in men and women. We introduced a measure of sex difference as a measure of differences in logarithmic odds ratios (ORs) between male and female patients in units of pooled standard errors.

Results

Except for lipid metabolism disorders (OR for females [ORf]=6.68, 95% confidence interval [CI]=6.57-6.79, OR for males [ORm]=8.31, 95% CI=8.21-8.41), all identified comorbidities were more likely to be associated with AMI and CHD in females than in males: nicotine dependence (ORf=6.16, 95% CI=5.96-6.36, ORm=4.43, 95% CI=4.35-4.5), diabetes mellitus (ORf=3.52, 95% CI=3.45-3.59, ORm=3.13, 95% CI=3.07-3.19), obesity (ORf=3.64, 95% CI=3.56-3.72, ORm=3.33, 95% CI=3.27-3.39), renal disorders (ORf=4.27, 95% CI=4.11-4.44, ORm=3.74, 95% CI=3.67-3.81), asthma (ORf=2.09, 95% CI=1.96-2.23, ORm=1.59, 95% CI=1.5-1.68), and COPD (ORf=2.09, 95% CI 1.96-2.23, ORm=1.59, 95% CI 1.5-1.68). Similar results could be observed for AMI.

Conclusions

Although AMI and CHD are more prevalent in men, women appear to be more affected by certain comorbidities of AMI and CHD in their risk for developing CVD.

Comparison of long-term outcomes between Chinese peritoneal dialysis patients with and without diabetes: A 10-year cohort study

AIMS

This study aimed to evaluate the long-term outcomes of peritoneal dialysis (PD) patients with and without diabetes in southern China.

METHODS

This retrospective and observational cohort study included all adult patients with end-stage renal disease (ESRD) who received PD in our center from January 2009 to December 2017 and were followed until December 2019. Clinical outcomes were compared by Kaplan-Meier survival analysis and cumulative incidence function, and risk factors were estimated using Cox regression analyses and competing risk models.

RESULTS

Of 401 patients receiving PD, 120 (29.9%) had type 2 diabetes mellitus (DM), and 281 (70.1%) did not have diabetes mellitus (NDM). Patients with DM were older and had more cardiovascular disease (CVD) morbidities than patients without DM. Kaplan-Meier analysis showed that patients with DM had shorter survival (Log-rank 3.215, P < 0.0001) compared with patients without DM. Patients with DM had a lower death-censored technique survival (Log-rank 2.029, P = 0.0180), however, there was no significant difference in peritonitis-free period (Log rank 1.375, P = 0.1133). These results were reproduced after taking competing events into account. Both on multivariate Cox analysis and on multivariate competing risk regression, diabetes was an independent predictor for increased mortality and technique failure, but not for peritonitis-free survival.

CONCLUSIONS

Patients undergoing PD with DM had increased risk of mortality and technique failure, and closer monitoring and additional focus in patients with DM treated by PD are, therefore, warranted.

Emergency department use by patients with end-stage renal disease in the United States

Background

We sought to describe the national characteristics of ED visits by patients with end-stage renal disease (ESRD) in the United States in order to improve the emergency treatment and screening of ESRD patients.

Methods

We analyzed data from 2014 to 2016 ED visits provided by the National Hospital Ambulatory Medical Care Survey. We sampled adult (age ≥ 18 years) ED patients with ESRD. By proportion or means of weighted sample variables, we quantified annual ED visits by patients with ESRD. We investigated demographics, ED resource utilization, clinical characteristics, and disposition of patients with ESRD and compared these to those of patients without ESRD. Logistic regression models were used to estimate the association between these characteristics and ESRD ED visits.

Results

Approximately 722,692 (7.78%) out of 92,899,685 annual ED visits represented ESRD patients. Males were more likely to be ESRD patients than females (aOR: 1.34; 95% CI: 1.09–1.66). Compare to whites, non-Hispanic Blacks were 2.55 times more likely to have ESRD (aOR: 2.55; 95% CI: 1.97–3.30), and Hispanics were 2.68 times more likely to have ESRD (95% CI: 1.95–3.69). ED patients with ESRD were more likely to be admitted to the hospital (aOR: 2.70; 95% CI: 2.13–3.41) and intensive care unit (ICU) (aOR: 2.21; 95% CI: 1.45–3.38) than patients without ESRD. ED patients with ESRD were more likely to receive blood tests and get radiology tests.

Conclusion

We described the unique demographic, socioeconomic, and clinical characteristics of ED patients with ESRD, using the most comprehensive, nationally representative study to date. These patients’ higher hospital and ICU admission rates indicate that patients with ESRD require a higher level of emergency care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-021-00420-8.

Impact of Pretransplant and New-Onset Diabetes After Transplantation on the Risk of Major Adverse Cardiovascular Events in Kidney Transplant Recipients: a Population-Based Cohort Study

BACKGROUND

Pretransplant diabetes and new onset diabetes after transplant (NODAT) are known risk factors for vascular events after kidney transplantation but the incidence and magnitude of the risk of major adverse cardiovascular events (MACE) and cardiac deaths remains uncertain in recent era.

METHODS

A population cohort study of kidney transplant recipients identified using data from linked administrative healthcare databases from Ontario, Canada. The incidence rates of MACE (expressed as events with 95% confidence interval (95%CI) per 1000-person-years were reported according to diabetes status of pretransplant diabetes, NODAT or no diabetes. Extended Cox regression model was used to examine the association between diabetes status, MACE and cardiac death.

RESULTS

Of 5248 recipients, 1973 (38%) had pretransplant diabetes and 799 (15%) developed NODAT with a median follow-up of 5.5 years. The incidence rates (95%CI) of MACE for recipients with pretransplant diabetes, NODAT and no diabetes between 1-3 years posttransplant were 38.1 (32.1-45.3), 12.6 (6.3-25.2) and 11.8 (9.2-15.0) per 1000-person-years, respectively. Compared to recipients with pretransplant diabetes, recipients with NODAT experienced a lower risk of MACE (adjusted hazard ratio [HR]0.59, 95%CI 0.47-0.74]), but not cardiac death [0.97(0.61-1.55)]. The rate of MACE and cardiac death was lowest in patients without diabetes.

CONCLUSIONS

Patients with pretransplant diabetes incur the greatest rate of MACE and cardiac deaths after transplantation. Having NODAT also bear high burden of vascular events compared to those without diabetes, but the magnitude of the increased rate remains lower than recipients with pretransplant diabetes.

Impact of clinical, sociodemographic and quality of life factors on dialysis patient survival: a nine-year follow-up cohort study

Although renal replacement therapy has contributed to the survival of chronic kidney failure (CKF) patients, mortality remains a major concern. This study aimed to identify the factors associated with mortality in a prospective cohort of CKF patients. Sociodemographic, clinical, nutritional, lifestyle and quality of life data were collected from 712 patients. The instruments used were the Short-Form Health Survey (SF-36), Global Subjective Assessment (GSA) and Charlson Comorbidity Index (CCI) questionnaires. A total of 444 patients died during the study. After five years of follow-up, factors such as not being married (hazard ratio - HR = 1.289, 95%CI: 1.001; 1.660), a low frequency of leisure activities (HR = 1.321; 95%CI: 1.010; 1.727) and not being transplanted (HR = 7.246; 95%CI: 3.359; 15.630) remained independently associated with the risk of mortality. At the end of the follow-up period, factors such as not being married (HR = 1.337, 95%CI: 1.019; 1.756), not being transplanted (HR = 7.341, 95%CI: 3.829; 14.075) and having a worse nutritional status (HR = 1.363, 95%CI: 1.002; 1.853) remained independently associated with an increased risk of mortality, whereas a high schooling level (10 to 12 years, HR = 0.578, 95%CI: 0.344; 0.972; and over 12 years, HR = 0.561, 95%CI: 0.329; 0.956) and a better SF-36 physical functioning score (HR = 0.992, 95%CI: 0.987; 0.998) were protective factors associated with survival. The survival of patients with CKF is associated with factors not restricted to the clinical spectrum. The following factors were associated with high mortality: not being married, low schooling level, a limited social routine, a longer time on dialysis, worse nutritional status, and worse physical functioning.

Two decades of the Eurotransplant Senior Program: the gender gap in mortality impacts patient survival after kidney transplantation

BACKGROUND

Long-term outcomes of the Eurotransplant Senior Program (ESP) are urgently needed to improve selection criteria and allocation policies in the elderly.

METHODS

We analysed patient and allograft outcomes of 244 ESP-kidney transplant recipients (KTRs) between 1999 and 2019 and assessed quality of living compared with 82 ESP-waitlisted dialysis patients using standardized short form-8.

RESULTS

We observed 1-, 5- and 10-year patient survival of 91.7, 66.3 and 38.0%, respectively. Mortality risk factors included male gender (P = 0.006) and T-cell-mediated rejection (P < 0.001). Median patient survival of male ESP-KTRs was 80 versus 131 months for female ESP-KTRs (P = 0.006). 1-, 5- and 10-year death-censored allograft survival was 93.3, 82.6 and 70.4%. Risk factors included high body mass index (P < 0.001) and T-cell-mediated rejection (P < 0.001). After re-initiation of dialysis median patient survival was 58 months. Change of estimated glomerular filtration rate showed a mean decline of 2.3 and 6.8 mL/min at 5 and 10 years. Median physical and mental component scores of ESP-KTRs were 40.2 and 48.3, significantly higher compared with dialysis patients (P < 0.05). Of ESP-KTRs, 97.5% who underwent transplantation would again do so.

CONCLUSIONS

Long-term outcomes of ESP-KTRs ultimately support the effectiveness of an age-matched allocation system. Our data suggest that the survival advantage of women is maintained after kidney transplantation and calls for gender-specific care.

DyeVert™ PLUS EZ System for Preventing Contrast-Induced Acute Kidney Injury in Patients Undergoing Diagnostic Coronary Angiography and/or Percutaneous Coronary Intervention: A UK-Based Cost-Utility Analysis

BACKGROUND

Contrast-induced acute kidney injury (CI-AKI) is a complication commonly associated with invasive angiographic procedures and is considered the leading cause of hospital-acquired acute kidney injury. CI-AKI can lead to a prolonged hospital stay, with a substantial economic impact, and increased mortality. The DyeVert™ PLUS EZ system (FDA approved and CE marked) is a device that has been developed to divert a portion of the theoretical injected contrast media volume (CMV), reducing the overall volume of contrast media injected and aortic reflux, and potentially improving long-term health outcomes.

OBJECTIVES

To assess the long-term costs and health outcomes associated with the introduction of the DyeVert™ PLUS EZ system into the UK health care service for the prevention of CI-AKI in a cohort of patients with chronic kidney disease (CKD) stage 3-4 undergoing diagnostic coronary angiography (DAG) and/or percutaneous coronary intervention (PCI), and to compare these costs and outcomes with those of the current practice.

METHODS

A de novo economic model was developed based on the current pathway of managing patients undergoing DAG and/or PCI and on evidence related to the clinical effectiveness of DyeVert™ in terms of its impact on relevant clinical outcomes and health service resource use. Clinical data used to populate the model were derived from the literature or were based on assumptions informed by expert clinical input. Costs included in the model were from the NHS and personal social services perspective and obtained from the literature and UK-based routine sources. Probabilistic distributions were assigned to the majority of model parameters so that a probabilistic analysis could be undertaken, while deterministic sensitivity analyses were also carried out to explore the impact of key parameter variation on the model results.

RESULTS

Base-case results indicate that the intervention leads to cost savings (- £435) and improved effectiveness (+ 0.028 QALYs) over the patient's lifetime compared with current practice. Output from the probabilistic analysis points to a high likelihood of the intervention being cost-effective across presented willingness-to-pay (WTP) thresholds. The overall long-term cost saving for the NHS associated with the introduction of the DyeVert™ PLUS EZ system is over £19.7 million for each annual cohort of patients. The cost savings are mainly driven by a lower risk of subsequent diseases and their associated costs.

CONCLUSIONS

The introduction of the DyeVert™ PLUS EZ system has the potential to reduce costs for the health care service and yield improved clinical outcomes for patients with CKD stage 3-4 undergoing angiographic procedures.

The current and future landscape of dialysis

The development of dialysis by early pioneers such as Willem Kolff and Belding Scribner set in motion several dramatic changes in the epidemiology, economics and ethical frameworks for the treatment of kidney failure. However, despite a rapid expansion in the provision of dialysis — particularly haemodialysis and most notably in high-income countries (HICs) — the rate of true patient-centred innovation has slowed. Current trends are particularly concerning from a global perspective: current costs are not sustainable, even for HICs, and globally, most people who develop kidney failure forego treatment, resulting in millions of deaths every year. Thus, there is an urgent need to develop new approaches and dialysis modalities that are cost-effective, accessible and offer improved patient outcomes. Nephrology researchers are increasingly engaging with patients to determine their priorities for meaningful outcomes that should be used to measure progress. The overarching message from this engagement is that while patients value longevity, reducing symptom burden and achieving maximal functional and social rehabilitation are prioritized more highly. In response, patients, payors, regulators and health-care systems are increasingly demanding improved value, which can only come about through true patient-centred innovation that supports high-quality, high-value care. Substantial efforts are now underway to support requisite transformative changes. These efforts need to be catalysed, promoted and fostered through international collaboration and harmonization.

Dialysis is a life-saving therapy; however, costs of dialysis are high, access is inequitable and outcomes are inadequate. This Review describes the current landscape of dialysis therapy from an epidemiological, economic, ethical and patient-centred framework, and describes initiatives that are aimed at stimulating innovations in the field to one that supports high-quality, high-value care.

The global dialysis population is growing rapidly, especially in low-income and middle-income countries; however, worldwide, a substantial number of people lack access to kidney replacement therapy, and millions of people die of kidney failure each year, often without supportive care.

The costs of dialysis care are high and will likely continue to rise as a result of increased life expectancy and improved therapies for causes of kidney failure such as diabetes mellitus and cardiovascular disease.

Patients on dialysis continue to bear a high burden of disease, shortened life expectancy and report a high symptom burden and a low health-related quality of life.

Patient-focused research has identified fatigue, insomnia, cramps, depression, anxiety and frustration as key symptoms contributing to unsatisfactory outcomes for patients on dialysis.

Initiatives to transform dialysis outcomes for patients require both top-down efforts (that is, efforts that promote incentives based on systems level policy, regulations, macroeconomic and organizational changes) and bottom-up efforts (that is, patient-led and patient-centred advocacy efforts as well as efforts led by individual teams of innovators).

Patients, payors, regulators and health-care systems increasingly demand improved value in dialysis care, which can only come about through true patient-centred innovation that supports high-quality, high-value care.

Effects of surrounding environment on incidence of end stage renal disease

The rising prevalence and incidence of end-stage renal disease (ESRD) have been noted around the world. However, no study has been conducted to examine the effect of surrounding environment on incidence of ESRD. This study assessed the associations of exposure to PM2.5 level and surrounding green spaces, separately, with incidence of ESRD in Taiwan. Demographic and clinical data used in this study was retrieved from the National Health Insurance Research Database from 2003 to 2012. PM2.5 data collected from the Environmental Protection Administration of Taiwan and a hybrid land-use regression model was used to approximate long-term exposure to PM2.5. Percentage of exposure to surrounding green spaces was used to determine individual exposure level. Cox proportional hazards models with a generalized estimating equation were applied to investigate the effect of surrounding environment on incidence of ESRD. The results showed significant positive association between exposure to PM2.5 level and incidence of ESRD; but inverse association between exposure to surrounding green spaces and incidence of ESRD (adjusted hazard ratio (AHR) = 1.08, 95% CI: 1.00-1.15 for exposure to PM2.5 level; AHR = 0.90, 95%CI: 0.84-0.98 for surrounding green spaces). Together, the findings from this study have added suggestive evidence on the adverse effect of exposure to PM2.5 level and the beneficial effect of exposure to surrounding green spaces on the incidence of ESRD in a general population in Taiwan.

Associations between diabetes and sex with peritoneal dialysis technique and patient survival: Results from the Australia and New Zealand Dialysis and Transplant Registry cohort study

BACKGROUND

A differential association between mortality and cause of end-stage kidney disease in patients with type 2 diabetes mellitus (T2DM) has been shown. Sex-specific differences in diabetes-related complications have been described. It is unclear whether sex affects the associations between diabetes and peritoneal dialysis (PD) technique and patient survival.

METHODS

Using the Australia and New Zealand Dialysis and Transplant Registry, we examined a two-way interaction between sex and diabetes status (no diabetes, T2DM and non-diabetic nephropathy [T2DM + non-DN] and T2DM and diabetic nephropathy [T2DM + DN]) for PD technique failure (including death), all-cause mortality and cause-specific mortality in incident adult PD patients between 1996 and 2016 using adjusted Cox regression. Mediation analysis was conducted to determine whether peritonitis was a mediator in these associations.

RESULTS

In 8279 PD patients, those with T2DM + DN had the greatest risks in technique failure, all-cause mortality and cause-specific mortality followed by patients with T2DM + non-DN, then patients without diabetes. Sex modified the association with diabetes status in technique failure (p _interaction = 0.001) and cardiac mortality (p _interaction = 0.008). In women with T2DM + DN, the adjusted hazard ratio (HR) for technique failure was 1.45 (1.30-1.62) and was higher than men with T2DM + DN (1.17 [1.08-1.28]; referent: no diabetes). In women with T2DM + DN, the adjusted HR for cardiac mortality was 2.12 (1.73-2.61) and was also higher than men with T2DM + DN (1.66 [1.43-1.95]). Less than 10 % of the effect between diabetes and PD technique failure or mortality was mediated by peritonitis.

CONCLUSIONS

PD patients with diabetic nephropathy had increased risk of PD technique failure and mortality, with the magnitude of these risks greater in women.

Sex-specific analysis of haemodialysis prevalence, practices and mortality over time: the Austrian Dialysis Registry from 1965 to 2014

BACKGROUND

Despite a higher prevalence of chronic kidney disease among women, more men than women start renal replacement therapy (RRT). We hypothesized that gender differences in health care access exist and therefore aimed at determining whether characteristics and outcomes of haemodialysis patients over time differ by sex.

METHODS

We studied all 28 323 adults who began haemodialysis during 1965-2014 in the Austrian Dialysis Registry, analysing trends in patient characteristics by sex and decade with mortality (via Cox regression), which was compared with the mortality of the Austrian general population.

RESULTS

More men than women started haemodialysis (60.1% men versus 39.9% women overall), with minor differences among decades and age groups. The male:female mortality rate ratio in the general population ranged from 1.2 to 2.4 for age groups >18 years and in haemodialysis patients ranged from 0.80 to 1.3 (closer to 1 than in the general population, but consistently >1 in Decades 3-5). In recent decades, diabetes and hypertension replaced glomerulonephritis as the primary cause of end-stage renal disease in both men and women. Interaction analyses showed the mortality risk associated with haemodialysis access (only recorded in Decade 5) was significantly lower for men than for women.

CONCLUSIONS

The male:female mortality rate ratio and the proportion of women starting haemodialysis were remarkably stable, which does not support the hypothesis of gender differences in health care/haemodialysis access or could imply that such differences might have persisted over decades. Future research should expand to other countries and other forms of RRT.

Sex Differences in Diabetic Kidney Disease

While the global prevalence of both type 1 and type 2 diabetes mellitus is similar in men and women, the consequences of diabetes on associated end-organ complications, including diabetic kidney disease appear to be more sex-specific. Particularly, women with diabetes have higher mortality rates for diabetes-related deaths, and higher prevalence of diabetic kidney disease risk factors such as hypertension, hyperglycemia, obesity, and dyslipidemia. However, the evidence for the impact of sex on diabetic kidney disease prevalence and disease progression is limited and inconsistent. Although most studies agree that the protective effect of the female sex against the development of kidney disease is diminished in the setting of diabetes, the reasons for this observation are unclear. Whether or not sex differences exist in the risk of diabetic kidney disease is also unclear, with studies reporting either higher risk in men, women, or no sex differences. Despite the remaining controversies, some of the factors that associate with sex differences in the risk of diabetic kidney disease are age at onset, and type and duration of diabetes. There is growing appreciation of the importance of sex hormones in the regulation of renal function, with estrogens generally considered to be renoprotective. Although some progress has been made towards better understanding of the mechanisms by which sex hormones play a role in the pathophysiology of diabetic kidney disease, the translational potential of this knowledge is still underappreciated. A better understanding of sex differences in diabetic kidney disease may provide basis for personalized and sex-specific treatment of diabetic kidney disease.

Metabolic Surgery to Treat Obesity in Diabetic Kidney Disease, Chronic Kidney Disease, and End-Stage Kidney Disease; What Are the Unanswered Questions?

Obesity is a major factor in contemporary clinical practice in nephrology. Obesity accelerates the progression of both diabetic and non-diabetic chronic kidney disease and, in renal transplantation, both recipient and donor obesity increase the risk of allograft complications. Obesity is thus a major driver of renal disease progression and a barrier to deceased and living donor kidney transplantation. Large observational studies have highlighted that metabolic surgery reduces the incidence of albuminuria, slows chronic kidney disease progression, and reduces the incidence of end-stage kidney disease over extended follow-up in people with and without type 2 diabetes. The surgical treatment of obesity and its metabolic sequelae has therefore the potential to improve management of diabetic and non-diabetic chronic kidney disease and aid in the slowing of renal decline toward end-stage kidney disease. In the context of patients with end-stage kidney disease, although complications of metabolic surgery are higher, absolute event rates are low and it remains a safe intervention in this population. Pre-transplant metabolic surgery increases access to kidney transplantation in people with obesity and end-stage kidney disease. Metabolic surgery also improves management of metabolic complications post-kidney transplantation, including new-onset diabetes. Procedure selection may be critical to mitigate the risks of oxalate nephropathy and disruption to immunosuppressant pharmacokinetics. Metabolic surgery may also have a role in the treatment of donor obesity, which could increase the living kidney donor pool with potential downstream impact on kidney paired exchange programmes. The present paper provides a comprehensive coverage of the literature concerning renal outcomes in clinical studies of metabolic surgery and integrates findings from relevant mechanistic pre-clinical studies. In so doing the key unanswered questions for the field are brought to the fore for discussion.

Diabetes mellitus and other cardiovascular risk factors in lower-extremity peripheral artery disease versus coronary artery disease: an analysis of 1,121,359 cases from the nationwide databases

BACKGROUND

Lower-extremity peripheral artery disease (LE-PAD) and coronary artery disease (CAD) are both pathologically rooted in atherosclerosis, and their shared clinical features regarding the exposure to cardiovascular risk factors have been emphasized. However, comparative data of the two cardiovascular diseases (CVDs) were so far lacking. The purpose of this study was to directly compare the clinical profile between cases undergoing endovascular therapy (EVT) for LE-PAD and those undergoing percutaneous coronary intervention (PCI).

METHODS

Data were extracted from the nationwide procedural databases of EVT and PCI in Japan (J-EVT and J-PCI) between 2012 and 2017. A total of 1,121,359 cases (103,887 EVT cases for critical limb ischemia [CLI] or intermittent claudication and 1,017,472 PCI cases for acute coronary syndrome [ACS] or stable angina) were analyzed. Heterogeneity in clinical profile between CVDs was evaluated using the C statistic of the logistic regression model for which dependent variable was one CVD versus another, and explanatory variables were clinical profile. When two CVDs were completely discriminated from each other by the developed model, the C statistic (discrimination ability) of the model would be equal to 1, indicating that the two CVDs were completely different in clinical profile. On the other hand, when two CVDs were identical in clinical profile, the developed model would not discriminate them at all, with the C statistic equal to 0.5.

RESULTS

Mean age was 73.5 ± 9.3 years in LE-PAD patients versus 70.0 ± 11.2 years in CAD patients (P < 0.001). The prevalence of diabetes mellitus and end-stage renal disease was 1.96- and 6.39-times higher in LE-PAD patients than in CAD patients (both P < 0.001). The higher prevalence was observed irrespective of age group. The exposure to other cardiovascular risk factors and the likelihood of cardiovascular risk clustering also varied between the diseases. The between-disease heterogeneity in patient profile was particularly evident between CLI and ACS, with the C statistic equal to 0.833 (95% CI 0.831-0.836).

CONCLUSIONS

The current study, an analysis based on nationwide procedural databases, confirmed that patient profiles were not identical but rather considerably different between clinically significant LE-PAD and CAD warranting revascularization.

Sex Differences in Kidney Replacement Therapy Initiation and Maintenance

BACKGROUND AND OBJECTIVES

More men than women undergo kidney replacement therapy (KRT) despite a larger number of women being affected by CKD. The aim of this multinational European study was to explore whether there might be historic and geographic trends in sex-specific incidence and prevalence of various KRT modalities.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We assessed sex-specific differences in KRT incidence and prevalence using data from nine countries reporting to the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry for at least 40 years, during the period 1965-2015. Sex distribution data were compared with the European general population (Eurostat). Statistical methodology included basic descriptive statistics, incidence and prevalence calculations per million population (pmp), as well as their male-to-female ratios. Analyses were stratified by age group and diabetic status.

RESULTS

We analyzed data from 230,378 patients receiving KRT (38% women). For all KRT modalities, the incidence and prevalence rates were consistently higher in men than women. For example, the KRT incidence increased from 8 pmp in 1965-1974 to 98 pmp in 2005-2015 in women, whereas it rose from 12 to 173 pmp in men during the same period. Male-to-female ratios, calculated for incident and prevalent KRT patients, increased with age (range 1.2-2.4), showing consistency over decades and for individual countries, despite marked changes in primary kidney disease (diabetes more prevalent than glomerulonephritis in recent decades). The proportion of kidney transplants decreased less with age in incident and prevalent men compared with women on KRT. Stratified analysis of patients who were diabetic versus nondiabetic revealed that the male-to-female ratio was markedly higher for kidney transplantation in patients with diabetes.

CONCLUSIONS

Since the beginning of KRT programs reporting to the ERA-EDTA Registry since the 1960s, fewer women than men have received KRT. The relative difference between men and women initiating and undergoing KRT has remained consistent over the last five decades and in all studied countries.

Factors affecting mortality during the waiting time for kidney transplantation: A nationwide population-based cohort study using the Korean Network for Organ Sharing (KONOS) database

BACKGROUND

Long waiting time for deceased donor kidney transplant is inevitable due to the scarcity of donor, resulting in highlighting the importance of waiting time care. We analyzed the Korean Network for Organ Sharing (KONOS) database to assess the impact of waiting time on post-transplant survival outcomes and investigate risk factors for mortality by waiting time based on a complete enumeration survey in Korea.

METHODS

We analyzed all persons aged over 18 years in deceased donor kidney transplant cases enrolled in the Korean Network for Organ Sharing (KONOS) database from January 2000 to January 2015. The primary end point was all-cause mortality after enrollment.

RESULTS

Of the 24,296 wait-listed subjects on dialysis, 5,255 patients received kidney transplants from deceased donors, with a median waiting time of 4.5 years. Longer waiting times had distinct deleterious effects on overall survival after transplantation. While waiting for a transplant, patients with diabetes were more likely to die before transplantation (HR 1.515, 95% CI 1.388-1.653, p<0.001). Age was another significant risk factor for mortality. Only 56% of people aged 65 years survived after 10 years of waiting, whereas 86% of people aged 35 years survived after 10 years. Moreover, women on the waiting list were more likely to live longer than men on the list.

CONCLUSIONS

More attention should be focused on patients with a higher risk of mortality while waiting for a deceased donor kidney transplant, such as patients with diabetes, those of advanced age, and those who are male.

Gender-specific discrepancy in subjective global assessment for mortality in hemodialysis patients

Although subjective global assessment (SGA) is a widely used representative tool for nutritional investigations even among dialysis patients, no studies have examined gender-specific differences in the ability of SGA to predict mortality in hemodialysis (HD) patients. A total of 2,798 dialysis patients were enrolled from clinical research center for end-stage renal disease (CRC for ESRD) between 2009 and 2015. The cohort was divided into two groups based on nutritional status as evaluated by SGA: 'good nutrition' and 'mild to severe malnutrition'. Multivariate Cox proportional regression analyses were performed to investigate gender-specific differences in SGA for mortality among incident and prevalent HD patients. 'Mild to severe malnutrition' was significantly correlated with increased mortality compared with 'good nutrition' for all HD, incident and prevalent HD patients. Compared with 'good nutrition', 'mild to severe malnutrition' was also more significantly associated with increased mortality in male patients in the incident and prevalent HD groups. However, no significant associations between nutritional status evaluated by SGA and mortality were observed for female patients. SGA of HD patients can be useful for predicting mortality, especially in male HD patients. However, SGA alone might not reflect adverse outcomes in female patients.

Mortality due to bleeding, myocardial infarction and stroke in dialysis patients

Essentials Mortality due to bleeding vs. arterial thrombosis in dialysis patients is unknown. We compared death causes of 201 918 dialysis patients with the general population. Dialysis was associated with increased mortality risks of bleeding and arterial thrombosis. Clinicians should be aware of the increased bleeding and thrombosis risks.

SUMMARY

Background Dialysis has been associated with both bleeding and thrombotic events. However, there is limited information on bleeding as a cause of death versus arterial thrombosis as a cause of death. Objectives To investigate the occurrence of bleeding, myocardial infarction and stroke as causes of death in the dialysis population as compared with the general population. Methods We included 201 918 patients from 11 countries providing data to the ERA-EDTA Registry who started dialysis treatment between 1994 and 2011, and followed them for 3 years. Age-standardized and sex-standardized mortality rate ratios for bleeding, myocardial infarction and stroke as causes of death were calculated in dialysis patients as compared with the European general population. Associations between potential risk factors and these causes of death in dialysis patients were investigated by calculating hazard ratios (HRs) with 95% confidence intervals (CIs) by the use of Cox proportional-hazards regression. Results As compared with the general population, the age-standardized and sex-standardized mortality rate ratios in dialysis patients were 12.8 (95% CI 11.9-13.7) for bleeding as a cause of death (6.2 per 1000 person-years among dialysis patients versus 0.3 per 1000 person-years in the general population), 13.4 (95% CI 13.0-13.9) for myocardial infarction (22.5 versus 0.9 per 1000 person-years), and 12.4 (95% CI 11.9-12.9) for stroke (14.3 versus 0.7 per 1000 person-years). Conclusion Dialysis patients have highly increased risks of death caused by bleeding and arterial thrombosis as compared with the general population. Clinicians should be aware of the increased mortality risks caused by these conditions.

Plasma Protein Carbonylation in Haemodialysed Patients: Focus on Diabetes and Gender

Patients with end-stage renal disease (ESRD) undergoing haemodialysis (HD) experience oxidative/carbonyl stress, which is postulated to increase after the HD session. The influence of diabetes mellitus and sex on oxidation of plasma proteins in ESRD has not yet been clarified despite that diabetic nephropathy is the most common cause of ESRD in developed and developing countries and despite the increasingly emerging differences between males and females in epidemiology, pathophysiology, clinical manifestations, and outcomes for several diseases. Therefore, this study aimed to evaluate the possible effect of type 2 diabetes mellitus, gender, and dialysis filter on plasma level of protein carbonyls (PCO) in ESRD patients at the beginning and at the end of a single HD session. Results show that mean post-HD plasma PCO levels are significantly higher than mean pre-HD plasma PCO levels and that the type of dialysis filter and dialysis technique are unrelated to plasma PCO levels. The mean level of plasma PCO after a HD session increases slightly but significantly in nondiabetic ESRD patients compared to diabetic ones, whereas it increases more markedly in women than in men. These novel findings suggest that women with ESRD are more susceptible than men to oxidative/carbonyl stress induced by HD.

Inflammatory Mechanisms as New Biomarkers and Therapeutic Targets for Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the leading cause of CKD and end-stage kidney disease (ESKD) worldwide. Approximately 30-40% of people with diabetes develop this microvascular complication, placing them at high risk of losing kidney function as well as of cardiovascular events, infections, and death. Current therapies are ineffective for arresting kidney disease progression and mitigating risks of comorbidities and death among patients with DKD. As the global count of people with diabetes will soon exceed 400 million, the need for effective and safe treatment options for complications such as DKD becomes ever more urgent. Recently, the understanding of DKD pathogenesis has evolved to recognize inflammation as a major underlying mechanism of kidney damage. In turn, inflammatory mediators have emerged as potential biomarkers and therapeutic targets for DKD. Phase 2 clinical trials testing inhibitors of monocyte-chemotactic protein-1 chemokine C-C motif-ligand 2 and the Janus kinase/signal transducer and activator of transcription pathway, in particular, have produced promising results.

Diabetic kidney disease in the elderly: prevalence and clinical correlates

BACKGROUND

Diabetic kidney disease (DKD) is a major burden in elderly patients with type 2 diabetes (T2DM). Low estimated glomerular filtration rate (eGFR+, < 60 mL/min/1.73 m2) and albuminuria (Alb+) are essential for the diagnosis of DKD, but their association with clinical variables and quality of care may be influenced by ageing.

METHODS

Here we investigated the association of clinical variables and quality of care measures with eGFR+ and Alb+ in 157,595 T2DM individuals participating to the Italian Association of Clinical Diabetologists (AMD) Annals Initiative, stratified by age.

RESULTS

The prevalence of eGFR+ and Alb+ increased with ageing, although this increment was more pronounced for low eGFR. Irrespective of age, both the eGFR+ and Alb + groups had the worst risk factors profile when compared to subjects without renal disease, showing a higher prevalence of out-of target values of HbA1c, BMI, triglycerides, HDL-C, blood pressure and more complex cardiovascular (CVD) and anti-diabetic therapies, including a larger use of insulin In all age groups, these associations differed according to the specific renal outcome examined: male sex and smoking were positively associated with Alb+ and negatively with eGFR+; age and anti-hypertensive therapies were more strongly associated with eGFR+, glucose control with Alb+, whereas BMI, and lipid-related variables with both abnormalities. All these associations were attenuated in the older (> 75 years) as compared to the younger groups (< 65 years; 65-75 years), and they were confirmed by multivariate analysis. Notably, Q-score values < 15, indicating a low quality of care, were strongly associated with Alb+ (OR 8.54; P < 0.001), but not with eGFR+.

CONCLUSIONS

In T2DM patients, the prevalence of both eGFR and Albuminuria increase with age. DKD is associated with poor cardiovascular risk profile and a lower quality of care, although these associations are influenced by the type of renal abnormality and by ageing. These data indicate that clinical surveillance of DKD should not be unerestimated in old T2DM patients.

Hospitalization Among Individuals Waitlisted For Kidney Transplant

BACKGROUND

For patients waitlisted for a deceased-donor kidney, hospitalization is associated with a lower likelihood of transplantation and worse posttransplant outcomes. However, individual-, neighborhood-, and regional-level risk factors for hospitalization throughout the waitlist period and specific causes of hospitalization in this population are unknown.

METHODS

We used United States Renal Data System Medicare-linked data on patients waitlisted between 2005 and 2013 with continuous enrollment in Medicare parts A and B (n = 53 810) to examine the association between annual hospitalization rate and a variety of demographic, clinical, and social factors. We used multilevel multivariable ordinal logistic regression to estimate odds ratios.

RESULTS

Factors associated with significantly increased hospitalization rates among waitlisted individuals included older age, female sex, more years on dialysis before waitlisting, tobacco use, panel-reactive antibody greater than 0, public insurance or no insurance at end-stage renal disease diagnosis, more regional acute care hospital beds, and urban residence (all P < 0.05). Among patients dialysis-dependent when waitlisted, individuals with arteriovenous fistulas were significantly less likely than individuals with indwelling catheters or grafts to be hospitalized (odds ratios, 0.79 and 0.82, respectively, both P < 0.001). The most common causes of hospitalization were complications related to devices, implants, and grafts; hypertension; and sepsis.

CONCLUSIONS

Individual- and regional-level variables were significantly associated with hospitalization while waitlisted, suggesting that personal, health system, and geographic factors may impact patients' risk. Conditions related to dialysis access and comorbidities were common hospitalization causes, underscoring the importance proper access management and care for additional chronic health conditions.

Restricted mean survival time over 15 years for patients starting renal replacement therapy

Background

The restricted mean survival time (RMST) estimates life expectancy up to a given time horizon and can thus express the impact of a disease. The aim of this study was to estimate the 15-year RMST of a hypothetical cohort of incident patients starting renal replacement therapy (RRT), according to their age, gender and diabetes status, and to compare it with the expected RMST of the general population.

Methods

Using data from 67 258 adult patients in the French Renal Epidemiology and Information Network (REIN) registry, we estimated the RMST of a hypothetical patient cohort (and its subgroups) for the first 15 years after starting RRT (cRMST) and used the general population mortality tables to estimate the expected RMST (pRMST). Results were expressed in three different ways: the cRMST, which calculates the years of life gained under the hypothesis of 100% death without RRT treatment, the difference between the pRMST and the cRMST (the years lost), and a ratio expressing the percentage reduction of the expected RMST: (pRMST - cRMST)/pRMST.

Results

Over their first 15 years of RRT, the RMST of end-stage renal disease (ESRD) patients decreased with age, ranging from 14.3 years in patients without diabetes aged 18 years at ESRD to 1.8 years for those aged 90 years, and from 12.7 to 1.6 years, respectively, for those with diabetes; expected RMST varied from 15.0 to 4.1 years between 18 and 90 years. The number of years lost in all subgroups followed a bell curve that was highest for patients aged 70 years. After the age of 55 years in patients with and 70 years in patients without diabetes, the reduction of the expected RMST was >50%.

Conclusion

While neither a clinician nor a survival curve can predict with absolute certainty how long a patient will live, providing estimates on years gained or lost, or percentage reduction of expected RMST, may improve the accuracy of the prognostic estimates that influence clinical decisions and information given to patients.

Sex and gender differences in chronic kidney disease: progression to end-stage renal disease and haemodialysis

Sex and gender differences are of fundamental importance in most diseases, including chronic kidney disease (CKD). Men and women with CKD differ with regard to the underlying pathophysiology of the disease and its complications, present different symptoms and signs, respond differently to therapy and tolerate/cope with the disease differently. Yet an approach using gender in the prevention and treatment of CKD, implementation of clinical practice guidelines and in research has been largely neglected. The present review highlights some sex- and gender-specific evidence in the field of CKD, starting with a critical appraisal of the lack of inclusion of women in randomized clinical trials in nephrology, and thereafter revisits sex/gender differences in kidney pathophysiology, kidney disease progression, outcomes and management of haemodialysis care. In each case we critically consider whether apparent discrepancies are likely to be explained by biological or psycho-socioeconomic factors. In some cases (a few), these findings have resulted in the discovery of disease pathways and/or therapeutic opportunities for improvement. In most cases, they have been reported as merely anecdotal findings. The aim of the present review is to expose some of the stimulating hypotheses arising from these observations as a preamble for stricter approaches using gender for the prevention and treatment of CKD and its complications.

Gender-Specific Differences in Peritoneal Dialysis

BACKGROUND/AIMS

Gender-specific differences between patients on renal replacement therapy have so far rarely been investigated. In the present study we aimed to describe gender-specific differences in a large cohort of peritoneal dialysis (PD) patients.

METHODS

Clinical information for all patients who started PD at our center has been collected since the start of the PD-program in 1979. We used Cox regression to examine associations between technique failure and gender. We estimated hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

A total of 745 patients (315 women and 430 men with a median age of 57 years; IQR 43-67) started PD between 1979 and 2015 in our center. Women were significantly younger at PD start 54 (40-65) years vs. 58 (47-68) years, p<0.001. Within the last almost 15 years, more man than women started PD, but technical survival rates were significantly better in female compared to men (HR=0.662, CI 95% (0.496-0.885) P=0.005). Cardiovascular events were the main cause of death over the study period in both sexes, but decreased over time. Additionally, death due to PD-associated peritonitis decreased significantly over the three decades in both sexes.

CONCLUSIONS

Our data suggest that technical survival rates were significantly better in female compared to men over three decades and death due to cardiovascular events and PD-associated peritonitis decreased significantly over the three decades in both sexes.

Nutritional parameters as mortality predictors in haemodialysis: Differences between genders

BACKGROUND

Malnutrition is common in patients undergoing haemodialysis (HD). Several studies have described different nutritional parameters as mortality predictors but few have studied whether there are differences between genders. This study aimed to evaluate which nutrition parameters may be associated with mortality in patients undergoing long-term HD depending on their gender.

METHODS

Longitudinal prospective multicentre study with 12 months of follow-up. Anthropometric and laboratory measures were obtained from 697 patients.

RESULTS

Men who died were older, had lower dry weight, body mass index, potassium, phosphorus and albumin, compared with male patients who survived. Female patients who died had lower albumin and nPCR compared with survivors. Kaplan-Meier analysis displayed a significantly worse survival in patients with albumin <3.5 g/dl in both genders and with body mass index <23 kg/m² in men. In the Cox regression analysis patients overall mortality was related to body mass index <23 kg/m² , potassium ≤5.5 mEq/l and phosphorus <3.0 mg/dl for male patients and albumin <3.5 g/dl and normalised protein catabolic rate (nPCR) <0.8 g/kg/day for both genders. Associations between albumin, body mass index and mortality risk continued to be significant after adjustments for age, length of time on dialysis and diabetes for males. However, in women, only albumin persisted as an independent predictor of death.

CONCLUSION

Depending on the gender, different parameters such as protein intake, potassium, phosphorus, body mass index and albumin are associated with mortality in patients undergoing HD. Albumin <3.5 g/dl is an independent mortality predictor in both genders, whereas a body mass index <23 kg/m² is an independent predictor of death, but only in men.