Renal function decline in older men and women with advanced chronic kidney disease-results from the EQUAL study

Sex disparities in hypertension prevalence, blood pressure trajectories and the effects of anti-hypertensive treatment

INTRODUCTION

Sex differences in blood pressure (BP), hypertension and hypertension mediated cardiovascular complications have become an increasingly important focus of attention. This narrative review gives an overview of current studies on this topic, with the aim to provide a deeper understanding of the sex-based disparities in hypertension with essential insights for refining prevention and management strategies for both men and women.

METHODS AND RESULTS

We searched Medline, Embase and the Cochrane libray on sex differences in BP-trajectories and hypertension prevalence. In the past decade various population-based studies have revealed substantial sex-disparities in BP-trajectories throughout life with women having a larger increase in hypertension prevalence after 30 years of age and a stronger association between BP and cardiovascular disease (CVD). In general, the effects of antihypertensive treatment appear to be consistent across sexes in different populations, although there remains uncertainty about differences in the efficacy of BP lowering drugs below 55 years of age.

CONCLUSION

The current uniform approach to the diagnosis and management of hypertension in both sexes neglects the distinctions in hypertension, while the differences underscore the need for sex-specific recommendations, particularly for younger individuals. A major limitation hampering insights into sex differences in BP-related outcomes is the lack of sex-stratified analyses or an adequate representation of women. Additional large-scale, longitudinal studies are imperative.

The association of sex differences in ambulatory blood pressure with cardiovascular events and mortality in dialysis patients

Male patients with pre-dialysis chronic kidney disease (CKD) have worse ambulatory blood pressure (BP) control than females; this is associated with higher mortality. Male hemodialysis patients have higher ambulatory BP levels than females. This analysis aimed to investigate the association of sex differences in ambulatory BP with cardiovascular events and mortality in hemodialysis individuals. 129 male and 91 female hemodialysis patients with valid 48-h BP monitoring were followed for 53.4 ± 31.1 months. The primary endpoint was cardiovascular mortality; the secondary endpoint was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, resuscitation after cardiac arrest, heart failure-hospitalization, coronary or peripheral revascularization. Cumulative freedom from the primary endpoint was lower for women (logrank-p = 0.032), while cumulative-freedom from the secondary endpoint did not differ significantly between-groups (logrank-p = 0.644). The crude risk for cardiovascular mortality was significantly higher in women (HR = 1.613, 95% CI [1.037, 2.509]). The crude risk for the combined endpoint was not different between the two groups (HR = 0.918, 95% CI [0.638, 1.320]). After adjusting for major risk factors (age, diabetes, dialysis vintage, coronary disease and hemoglobin) no significant differences in the risk for both the primary and the secondary endpoint were observed between women and men (primary: HR = 1.295 (95% CI [0.808, 2.078]), secondary: HR = 0.763 (95% CI [0.521, 1.118])). After additional adjustment for 44-h systolic BP the above relationships did not alter (primary: HR = 1.329 (95% CI [0.826, 2.137]), secondary: HR = 0.808 (95% CI [0.551, 1.184])). In conclusion, female hemodialysis patients have higher crude but similar adjusted cardiovascular mortality rates compared to male counterparts. In contrast to pre-dialysis CKD, the neutral relationship between gender and adverse cardiovascular outcomes in hemodialysis is not further affected by ambulatory BP.

Approximation of Glomerular Filtration Rate after 1 Year Using Annual Medical Examination Data

Background: This cohort study was conducted to devise an approximation formula for predicting the glomerular filtration rate (GFR) after 1 year using annual medical examination data from the general population. Methods: Consecutive annual medical examination data were obtained for 41,337 inhabitants. Machine learning with the random forest method was used to assess the importance of each clinical parameter in terms of its association with estimated GFR (eGFR) after 1 year. An approximation formula was developed by multiple linear regression analysis based on the four most important clinical parameters. The relationship between the GFR after 1 year approximated by our formula and the eGFR after 1 year was analyzed using Pearson's correlation coefficient. Results: The following approximation formula was obtained by multiple linear regression analysis: approximate GFR after 1 year (mL/min/1.73 m2) = -0.054 × age + 0.162 × hemoglobin - 0.085 × uric acid + 0.849 × eGFR + 11.5. The approximate GFR after 1 year was significantly and strongly correlated with the eGFR at that time (r = 0.884; p < 0.001). Conclusions: An approximation formula including age, hemoglobin, uric acid, and eGFR may be useful for predicting GFR after 1 year among members of the general population.

Age and estimated glomerular filtration rate in Chinese older adults: a cohort study from 2014 to 2020

Objectives

This study aimed to fill the data gap of the course of renal function decline in old age and explore changes in renal function across different health states with increasing age.

Methods

This observational, retrospective, single-center cohort study included 5,112 Chinese older adults (3,321 men and 1,791 women, range 60-104 years). The individual rate of estimated glomerular filtration rate (eGFR) decline was analyzed using linear mixed-effects model to account for repeated measures over the years.

Results

The median age was 66 years, median BMI was 24.56 kg/m2, and median eGFR was 89.86 mL/min.1.73 m2. For every 1-year increase in age, women's eGFR decreased by 1.06 mL/min/1.73 m2 and men's by 0.91 mL/min/1.73 m2. We observed greater age-related eGFR decline in men and women with high systolic blood pressure (SBP). Men with high triglyceride (TG), high low-density lipoprotein cholesterol (LDL-C), and low high-density lipoprotein cholesterol (HDL-C), had greater age-related eGFR decline. In women, different BMI groups showed significant differences in age-related eGFR decline, with the highest decline in those with obesity. Additionally, participants with normal baseline eGFR had a faster age-related decline than those with low baseline eGFR.

Conclusion

The eGFR declined linearly with age in Chinese older adults, with women exhibiting a slightly faster decline than men. Both men and women should be cautious of SBP. Older adults with normal baseline renal function experienced a faster eGFR decline. Men with high TG, LDL-C, and low HDL-C levels, as well as obese women, should be vigilant in monitoring renal function.

Sex disparities in mortality and cardiovascular outcomes in chronic kidney disease

Sex (biologically determined) and gender (socially constructed) modulate manifestations and prognosis of a vast number of diseases, including cardiovascular disease (CVD) and chronic kidney disease (CKD). CVD remains the leading cause of death in CKD patients. Population-based studies indicate that women present a higher prevalence of CKD and experience less CVD than men in all CKD stages, although this is not as clear in patients on dialysis or transplantation. When compared to the general population of the same sex, CKD has a more negative impact on women on kidney replacement therapy. European women on dialysis or recipients of kidney transplants have life expectancy up to 44.8 and 19.8 years lower, respectively, than their counterparts of similar age in the general population. For men, these figures stand at 37.1 and 16.5 years, representing a 21% to 20% difference, respectively. Hormonal, genetic, societal, and cultural influences may contribute to these sex-based disparities. To gain a more comprehensive understanding of these differences and their implications for patient care, well-designed clinical trials that involve a larger representation of women and focus on sex-related variables are urgently needed. This narrative review emphasizes the importance of acknowledging the epidemiology and prognosis of sex disparities in CVD among CKD patients. Such insights can guide research into the underlying pathophysiological mechanisms, leading to optimized treatment strategies and ultimately, improved clinical outcomes.

Reno-protective effect of protocatechuic acid is independent of sex-related differences in murine model of UUO-induced kidney injury

BACKGROUND

Obstructive nephropathy is a condition often caused by urinary tract obstruction either anatomical (e.g., tumors), mechanical (e.g., urolithiasis), or compression (e.g., pregnancy) and can progress to chronic kidney disease (CKD). Studies have shown sexual dimorphism in CKD, where males were found to have a more rapid decline in kidney function following kidney injury compared to age-matched females. Protocatechuic acid (PCA), an anti-oxidant and anti-inflammatory polyphenolic compound, has demonstrated promising effects in mitigating drug-induced kidney injuries. The current study aims to explore sexual dimorphism in kidney injury after unilateral ureteral obstruction (UUO) and assess whether PCA treatment can mitigate kidney injury in both sexes.

METHODS

UUO was induced in 10-12 weeks old male and female C57BL/6J mice. Mice were categorized into four groups (n = 6-8/group); Sham, Sham plus PCA (100 mg/kg, I.P daily), UUO, and UUO plus PCA.

RESULTS

After 2 weeks of induction of UUO, markers of kidney oxidative stress (TBARs), inflammation (IL-1α and IL-6), tubular injury (neutrophil gelatinase-associated lipocalin, NGAL and urinary kidney injury molecule-1, KIM-1), fibrosis (Masson's trichrome staining, collagen IV expression, MMP-2 and MMP-9) and apoptosis (TUNEL+ cells, active caspase-1 and caspase-3) were significantly elevated in both males and females relative to their sham counterparts. Males exhibited significantly greater kidney oxidative stress, inflammation, fibrosis, and apoptosis after induction of UUO when compared to females. PCA treatment significantly attenuated UUO-induced kidney injury, inflammation, fibrosis, and apoptosis in both sexes.

CONCLUSION

Our findings suggest a differential gender response to UUO-induced kidney injury with males being more sensitive to UUO-induced kidney inflammation, fibrosis, and apoptosis than age-matched females. Importantly, PCA treatment reduced UUO-induced kidney injury in a sex-independent manner which might be attributed to its anti-oxidant, anti-inflammatory, anti-fibrotic, and anti-apoptotic properties.

Differences in the epidemiology, management and outcomes of kidney disease in men and women

Improved understanding of differences in kidney disease epidemiology, management and outcomes in men and women could help nephrologists to better meet the needs of their patients from a sex- and gender-specific perspective. Evidence of sex differences in the risk and outcomes of acute kidney injury is mixed and dependent on aetiology. Women have a higher prevalence of chronic kidney disease (CKD) stages 3-5 than men, whereas men have a higher prevalence of albuminuria and hence CKD stages 1-2. Men show a faster decline in kidney function, progress more frequently to kidney failure and have higher mortality and risk of cardiovascular disease than women. However, the protective effect of female sex is reduced with CKD progression. Women are less likely than men to be aware of, screened for and diagnosed with CKD, started on antiproteinuric medication and referred to nephrologist care. They also consistently report a poorer health-related quality of life and a higher symptom burden than men. Women experience greater barriers than men to access the waiting list for kidney transplantation, particularly with respect to older age and obesity. However, women also have longer survival than men after transplantation, which may partly explain the comparable prevalence of transplantation between the sexes.

Incidence of hospital-acquired acute kidney injury and trajectories of glomerular filtration rate in older adults

BACKGROUND

In older adults, epidemiological data on incidence rates (IR) of hospital-acquired acute kidney injury (AKI) are scarce. Also, little is known about trajectories of kidney function before hospitalization with AKI.

METHODS

We used data from biennial face-to-face study visits from the prospective Berlin Initiative Study (BIS) including community-dwelling participants aged 70+ with repeat estimated glomerular filtration rate (eGFR) based on serum creatinine and cystatin C. Primary outcome was first incident of hospital-acquired AKI assessed through linked insurance claims data. In a nested case-control study, kidney function decline prior to hospitalization with and without AKI was investigated using eGFR trajectories estimated with mixed-effects models adjusted for traditional cardiovascular comorbidities.

RESULTS

Out of 2020 study participants (52.9% women; mean age 80.4 years) without prior AKI, 383 developed a first incident AKI, 1518 were hospitalized without AKI, and 119 were never hospitalized during a median follow-up of 8.8 years. IR per 1000 person years for hospital-acquired AKI was 26.8 (95% confidence interval (CI): 24.1-29.6); higher for men than women (33.9 (29.5-38.7) vs. 21.2 (18.1-24.6)). IR (CI) were lowest for persons aged 70-75 (13.1; 10.0-16.8) and highest for ≥ 90 years (54.6; 40.0-72.9). eGFR trajectories declined more steeply in men and women with AKI compared to men and women without AKI years before hospitalization. These differences in eGFR trajectories remained after adjustment for traditional comorbidities.

CONCLUSION

AKI is a frequent in-hospital complication in individuals aged 70 + showing a striking increase of IR with age. eGFR decline was steeper in elderly patients with AKI compared to elderly patients without AKI years prior to hospitalization emphasising the need for long-term kidney function monitoring pre-admission to improve risk stratification.

Kidney and Cardiovascular Effects of Canagliflozin According to Age and Sex: A Post Hoc Analysis of the CREDENCE Randomized Clinical Trial

RATIONALE & OBJECTIVE

It is unclear whether the effect of canagliflozin on adverse kidney and cardiovascular events in those with diabetic kidney disease varies by age and sex. We assessed the effects of canagliflozin among age group categories and between sexes in the Canagliflozin and Renal Endpoints in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE) study.

STUDY DESIGN

Secondary analysis of a randomized controlled trial.

SETTING & PARTICIPANTS

Participants in the CREDENCE trial.

INTERVENTION

Participants were randomly assigned to receive canagliflozin 100mg/d or placebo.

OUTCOMES

Primary composite outcome of kidney failure, doubling of serum creatinine concentration, or death due to kidney or cardiovascular disease. Prespecified secondary and safety outcomes were also analyzed. Outcomes were evaluated by age at baseline (<60, 60-69, and≥70 years) and sex in the intention-to-treat population using Cox regression models.

RESULTS

The mean age of the cohort was 63.0±9.2 years, and 34% were female. Older age and female sex were independently associated with a lower risk of the composite of adverse kidney outcomes. There was no evidence that the effect of canagliflozin on the primary outcome (a composite of kidney failure, a doubling of serum creatinine concentration, or death from kidney or cardiovascular causes) differed between age groups (HRs, 0.67 [95% CI, 0.52-0.87], 0.63 [0.48-0.82], and 0.89 [0.61-1.29] for ages<60, 60-69, and≥70 years, respectively; P=0.3for interaction) or sexes (HRs, 0.71 [95% CI, 0.54-0.95] and 0.69 [0.56-0.84] in women and men, respectively; P=0.8for interaction). No differences in safety outcomes by age group or sex were observed.

LIMITATIONS

This was a post hoc analysis with multiple comparisons.

CONCLUSIONS

Canagliflozin consistently reduced the relative risk of kidney events in people with diabetic kidney disease in both sexes and across age subgroups. As a result of greater background risk, the absolute reduction in adverse kidney outcomes was greater in younger participants.

FUNDING

This post hoc analysis of the CREDENCE trial was not funded. The CREDENCE study was sponsored by Janssen Research and Development and was conducted collaboratively by the sponsor, an academic-led steering committee, and an academic research organization, George Clinical.

TRIAL REGISTRATION

The original CREDENCE trial was registered at ClinicalTrials.gov with study number NCT02065791.

Risk Factors for Incident CKD in Black and White Americans: The REGARDS Study

RATIONALE & OBJECTIVE

Little information exists on the incidence of and risk factors for chronic kidney disease (CKD) in contemporary US cohorts and whether risk factors differ by race, sex, or region in the United States.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

4,198 Black and 7,799 White participants aged at least 45 years, recruited from 2003 through 2007 across the continental United States, with baseline estimated glomerular filtration rate (eGFR)>60mL/min/1.73m2 and eGFR assessed again approximately 9 years later.

EXPOSURES

Age, sex, race (Black or White), region ("stroke belt" or other), education, income, systolic blood pressure, body mass index, diabetes, coronary heart disease, hyperlipidemia, smoking, and albuminuria.

OUTCOMES

(1) eGFR change and (2) incident CKD defined as eGFR<60mL/min/1.73m2 and≥40% decrease from baseline or kidney failure.

ANALYTICAL APPROACH

Linear regression and modified Poisson regression were used to determine the association of risk factors with eGFR change and incident CKD overall and stratified by race, sex, and region.

RESULTS

Mean age of participants was 63±8 (SD) years, 54% were female, and 35% were Black. After 9.4±1.0 years of follow-up, CKD developed in 9%. In an age-, sex-, and race-adjusted model, Black race (β =-0.13; P<0.001) was associated with higher risk of eGFR change, but this was attenuated in the fully adjusted model (β=0.02; P=0.5). Stroke belt residence was independently associated with eGFR change (β =-0.10; P<0.001) and incident CKD (relative risk, 1.14 [95% CI, 1.01-1.30]). Albuminuria was more strongly associated with eGFR change (β of-0.26 vs-0.17; P=0.01 for interaction) in Black compared with White participants. Results were similar for incident CKD.

LIMITATIONS

Persons of Hispanic ethnicity were excluded; unknown duration and/or severity of risk factors.

CONCLUSIONS

Established CKD risk factors accounted for higher risk of incident CKD in Black versus White individuals. Albuminuria was a stronger risk factor for eGFR decrease and incident CKD in Black compared with White individuals. Living in the US stroke belt is a novel risk factor for CKD.

Nutritional status and the risk of malnutrition in older adults with chronic kidney disease - implications for low protein intake and nutritional care: A critical review endorsed by ERN-ERA and ESPEN

Increased life expectancy is posing unprecedented challenges to healthcare systems worldwide. These include a sharp increase in the prevalence of chronic kidney disease (CKD) and of impaired nutritional status with malnutrition-protein-energy wasting (PEW) that portends worse clinical outcomes, including reduced survival. In older adults with CKD, a nutritional dilemma occurs when indications from geriatric nutritional guidelines to maintain the protein intake above 1.0 g/kg/day to prevent malnutrition need to be adapted to the indications from nephrology guidelines, to reduce protein intake in order to prevent or slow CKD progression and improve metabolic abnormalities. To address these issues, the European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Renal Nutrition group of the European Renal Association (ERN-ERA) have prepared this conjoint critical review paper, whose objective is to summarize key concepts related to prevention and treatment of both CKD progression and impaired nutritional status using dietary approaches, and to provide guidance on how to define optimal protein and energy intake in older adults with differing severity of CKD. Overall, the authors support careful assessment to identify the most urgent clinical challenge and the consequent treatment priority. The presence of malnutrition-protein-energy wasting (PEW) suggests the need to avoid or postpone protein restriction, particularly in the presence of stable kidney function and considering the patient's preferences and quality of life. CKD progression and advanced CKD stage support prioritization of protein restriction in the presence of a good nutritional status. Individual risk-benefit assessment and appropriate nutritional monitoring should guide the decision-making process. Higher awareness of the challenges of nutritional care in older adult patients with CKD is needed to improve care and outcomes. Research is advocated to support evidence-based recommendations, which we still lack for this increasingly large patient subgroup.

Ageing meets kidney disease

Chronic kidney disease (CKD) is defined as abnormalities of kidney structure or function, present for ˃3 months, with implications for health. The most used diagnostic criteria are a urinary albumin: creatinine ratio ≥30 mg/g or an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. Either of these diagnostic thresholds is associated with adverse health outcomes. GFR decreases with age and the prevalence of CKD is highest in older adults; moreover, the presence of CKD is associated with an increased risk of all-cause and cardiovascular death related to accelerated ageing in all age ranges, and the absolute increase in risk is highest for those aged ˃75 years. Indeed, premature death is a more common outcome than CKD progression to kidney failure requiring kidney replacement therapy. The progressive ageing of the world population contributes to the projection that CKD will become the second most common cause of death before the end of the century in countries with long life expectancy. The current collection of selected studies on kidney disease and ageing published in Age&Ageing, NDT and CKJ provides an overview of key topics, including cognitive decline, sarcopaenia, wasting and cardiovascular and non-cardiovascular morbidity and mortality, the management of kidney failure and gender differences in CKD progression.

Role of sex hormones in diabetic nephropathy

Diabetic nephropathy (DN) is the most common microvascular complication in diabetes and one of the leading causes of end-stage renal disease. The standard treatments for patients with classic DN focus on blood glucose and blood pressure control, but these treatments can only slow the progression of DN instead of stopping or reversing the disease. In recent years, new drugs targeting the pathological mechanisms of DN (e.g., blocking oxidative stress or inflammation) have emerged, and new therapeutic strategies targeting pathological mechanisms are gaining increasing attention. A growing number of epidemiological and clinical studies suggest that sex hormones play an important role in the onset and progression of DN. Testosterone is the main sex hormone in males and is thought to accelerate the occurrence and progression of DN. Estrogen is the main sex hormone in females and is thought to have renoprotective effects. However, the underlying molecular mechanism by which sex hormones regulate DN has not been fully elucidated and summarized. This review aims to summarize the correlation between sex hormones and DN and evaluate the value of hormonotherapy in DN.

Ageing meets kidney disease

Chronic kidney disease (CKD) is defined as abnormalities of kidney structure or function, present for ˃3 months, with implications for health. The most used diagnostic criteria are a urinary albumin: creatinine ratio ≥30 mg/g or an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. Either of these diagnostic thresholds is associated with adverse health outcomes. GFR decreases with age and the prevalence of CKD is highest in older adults; moreover, the presence of CKD is associated with an increased risk of all-cause and cardiovascular death related to accelerated ageing in all age ranges, and the absolute increase in risk is highest for those aged ˃75 years. Indeed, premature death is a more common outcome than CKD progression to kidney failure requiring kidney replacement therapy. The progressive ageing of the world population contributes to the projection that CKD will become the second most common cause of death before the end of the century in countries with long life expectancy. The current collection of selected studies on kidney disease and ageing published in Age&Ageing, NDT and CKJ provides an overview of key topics, including cognitive decline, sarcopaenia, wasting and cardiovascular and non-cardiovascular morbidity and mortality, the management of kidney failure and gender differences in CKD progression.

Joint exposure to outdoor ambient air pollutants and incident chronic kidney disease: A prospective cohort study with 90,032 older adults

Objectives

There is paucity of studies to investigate the association between combined and long-term exposure to air pollution and the risk of incident chronic kidney disease (CKD) in older adults.

Methods

A prospective cohort of 90,032 older adults who did not have CKD at baseline were followed up from January 1, 2017, to December 31, 2019. Various pollutant data, including particulate matter with diameters ≤ 2.5 mm (PM_2.5), ≤ 10 mm (PM₁₀), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), Ozone (O₃), and carbon monoxide (CO), from all monitoring stations in Binhai New Area, Tianjin were considered in calculating the mean exposure concentration of each pollutant over 2 years. By summing each pollutant concentration weighted by the regression coefficients, we developed an air pollution score that assesses the combined exposure of these air pollutants. Due to the strong correlation between air pollutants, Principal Component Analysis (PCA) score was also developed. The association between air pollutants and incident CKD in the elderly was analyzed.

Results

A total of 90,032 subjects participated in this study with a median follow-up of 545 days. Among them, 22,336 (24.8%) developed CKD. The HR (95% CI) for air pollution score and incidence of CKD was 1.062 (1.060-1.063) and p <0.001 after adjusting for all confounders. The adjusted HRs for the quartile subgroups of combined air pollution score were: Q2: 1.064 (1.013-1.117); Q3: 1.141 (1.088-1.198); and Q4: 3.623 (3.482-3.770), respectively (p for trend <0.001). The adjusted HRs for the quartile subgroups of air quality index (AQI) were: Q2: 1.035 (0.985-1.086); Q3: 1.145 (1.091-1.201); and Q4: 3.603 (3.463-3.748), respectively (p for trend <0.001). When the risk score was over 86.9, it significantly rose in a steep curve. The subgroup analysis showed that male, younger or exercise were more likely to develop CKD.

Conclusion

Combined air pollution score, AQI, and PCA score were associated with an increased risk of CKD in an exposure-response relationship. Our current results might also provide evidence for developing environmental protection policies.

Sex differences in ambulatory blood pressure levels, control and phenotypes of hypertension in hemodialysis patients

BACKGROUND AND AIMS

Ambulatory blood pressure (BP) control is worse in men than women with chronic kidney disease or kidney transplantation. So far, no study investigated possible sex differences in the prevalence, control, and phenotypes of BP according to predialysis and 48-h ambulatory blood pressure monitoring (ABPM) in hemodialysis patients. Further, no study has evaluated the diagnostic accuracy of predialysis BP in male and female hemodialysis patients.

METHOD

One hundred and twenty-nine male and 91 female hemodialysis patients that underwent 48-h ABPM were included in this analysis. Hypertension was defined as: (1) predialysis SBP ≥140 or DBP ≥90 mmHg or use of antihypertensive agents, (2) 48-h SBP ≥130 or DBP ≥80 mmHg or use of antihypertensive agents.

RESULTS

Predialysis SBP did not differ between groups, while DBP was marginally higher in men. 48-h SBP (137.2 ± 17.4 vs. 132.2 ± 19.2 mmHg, P  = 0.045), DBP (81.9 ± 12.1 vs. 75.9 ± 11.7 mmHg, P  < 0.001) and daytime SBP/DBP were higher in men. The prevalence of hypertension was not different between groups with the use of predialysis BP or 48-h ABPM (92.2% vs. 89%, P  = 0.411). However, concordant lack of control was more frequent in men than women (65.3% vs. 49.4%, P  = 0.023). The prevalence of white-coat and masked hypertension did not differ between groups; the misclassification rate with the use of predialysis BP was marginally higher in women. In both sexes, predialysis BP showed low accuracy and poor agreement with ABPM for diagnosing ambulatory hypertension [area-under-the-curve in receiver-operating-curve analyses (SBP/DBP): men, 0.681/0.802, women: 0.586/0.707].

CONCLUSION

Ambulatory BP levels are higher in male than female hemodialysis patients. Although hypertension prevalence is similar between sexes, men have worse rates of control. The diagnostic accuracy of predialysis BP was equally poor in men and women.

Ageing meets kidney disease

Chronic kidney disease (CKD) is defined as abnormalities of kidney structure or function, present for >3 months, with implications for health. The most used diagnostic criteria are a urinary albumin: creatinine ratio ≥30 mg/g or an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. Either of these diagnostic thresholds is associated with adverse health outcomes. GFR decreases with age and the prevalence of CKD is highest in older adults; moreover, the presence of CKD is associated with an increased risk of all-cause and cardiovascular death related to accelerated ageing in all age ranges, and the absolute increase in risk is highest for those aged >75 years. Indeed, premature death is a more common outcome than CKD progression to kidney failure requiring kidney replacement therapy. The progressive ageing of the world population contributes to the projection that CKD will become the second most common cause of death before the end of the century in countries with long life expectancy. The current collection of selected studies on kidney disease and ageing published in Age&Ageing, NDT and CKJ provides an overview of key topics, including cognitive decline, sarcopaenia, wasting and cardiovascular and non-cardiovascular morbidity and mortality, the management of kidney failure and gender differences in CKD progression.

Age and the Course of GFR in Persons Aged 70 and Above

BACKGROUND AND OBJECTIVES

In older adults, data on the age-related course of GFR are scarce, which might lead to misjudgment of the clinical relevance of reduced GFR in old age.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

To describe the course of eGFR in older adults and derive reference values in population-based individuals, we used the longitudinal design of the Berlin Initiative Study (BIS) with a repeated estimation of GFR over a median of 6.1 years of follow-up. In 2069 community-dwelling older individuals (mean inclusion age 80 years, range 70-99), GFR was estimated biennially with the BIS-2 equation, including standardized creatinine and cystatin C levels, sex, and age. We described the crude and adjusted course using a mixed-effects model and analyzed the influence of death on the GFR course applying joint models. GFR slopes were compared using GFR equations on the basis of creatinine and/or cystatin C.

RESULTS

We observed a decreasing, thus nonlinear, eGFR decline with increasing age in a population of old adults. The estimated 1-year slope for ages 75 and 90 diminished for men from -1.67 to -0.99 and for women from -1.52 to -0.97. The modeled mean eGFR for men aged ≥79 and women ≥78 was below 60 ml/min per 1.73 m². Multivariable adjustment attenuated slopes only minimally. Taking death into account by applying joint models did not alter the nonlinear eGFR decline. Using eGFR equations on the basis of creatinine only showed linear slope patterns in contrast to nonlinear patterns for equations including cystatin C.

CONCLUSIONS

The eGFR decline depended on sex and age and changed only marginally after multivariable adjustment but decelerated with increasing age. Equations including cystatin C demonstrated a nonlinear slope challenging the previously assumed linearity of the decline of eGFR in old age.

CKD-MBD Biomarkers and CKD Progression: an Analysis by the Joint Model

BACKGROUND

Biomarkers of the CKD- Bone Mineral Disorder (CKD-BMD have been implicated in CKD progression in follow up studies focusing on single measurements of individual biomarkers made at baseline only. The simultaneous relationship between the time trend of these biomarkers over the course of CKD and renal outcomes has never been tested.

METHODS

We applied the Joint Model (JM) to investigate the longitudinal relationship between repeated measurements of CKD-MBD biomarkers and a combined renal endpoint (eGFR reduction >30%, dialysis or transplantation) in 729 stage 2-5 CKD patients over a 36 months follow up.

RESULTS

In the survival sub-model of the JM the longitudinal series of PTH values was directly and independently related to the risk of renal events [HR (1ln PTH) = 2.0 (from 1.5 to 2.8), p<0.001)] and this was also true for repeated measurements of serum phosphate [HR(1mg/dl) = 1.3924 (from 1.1459 to 1.6918), p = 0.001], serum calcium [HR(1mg/dl) = 0.7487 (from 0.5843 to 0.9593), p = 0.022], baseline FGF23 [HR(1pg/ml) = 1.001 (from 1.00 to 1.002), p = 0.045] and 1,25 dihydroxy Vitamin D [HR (1pg/ml) = 0.9796 (from 0.9652 to 0.9942), p = 0.006].

CONCLUSION

Repeated measurements of serum PTH, calcium and phosphate as well as baseline FGF23 and 1,25 dihydroxy vitamin D are independently related with the progression to kidney failure in a cohort of stage 2-5 CKD patients. This longitudinal study generates the hypothesis that interventions at multiple levels on BMD biomarkers can mitigate renal function loss in this population.

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

BACKGROUND AND OBJECTIVES

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

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

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

RESULTS

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

CONCLUSIONS

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

Sex differences in ambulatory blood pressure levels, control, and phenotypes of hypertension in kidney transplant recipients

OBJECTIVES

Ambulatory blood pressure (BP) control is worse in men compared with women with chronic kidney disease (CKD) and this may partially explain the faster CKD progression in men. This is the first study investigating possible sex differences in prevalence, control and phenotypes of hypertension in kidney transplant recipients (KTRs) with office-BP and 24-h ambulatory BP monitoring (ABPM).

METHODS

This cross-sectional study included 136 male and 69 female stable KTRs who underwent office-BP measurements and 24-h ABPM. Hypertension thresholds for office and ambulatory BP were defined according to the 2017 ACC/AHA and 2021 KDIGO guidelines for KTRs.

RESULTS

Age, time from transplantation, eGFR and history of major comorbidities did not differ between groups. Office SBP/DBP levels were insignificantly higher in men than women (130.3 ± 16.3/77.3 ± 9.4 vs. 126.4 ± 17.8/74.9 ± 11.5 mmHg; P = 0.118/0.104) but daytime SBP/DBP was significantly higher in men (128.5 ± 12.1/83.0 ± 8.2 vs. 124.6 ± 11.9/80.3 ± 9.3 mmHg; P = 0.032/P = 0.044). No significant between-group differences were detected for night-time BP. The prevalence of hypertension was similar by office-BP criteria (93.4 vs. 91.3%; P = 0.589), but higher in men than women with ABPM (100 vs. 95.7%; P = 0.014). The use of ACEIs/ARBs and CCBs was more common in men. Office-BP control was similar (43.3 vs. 44.4%, P = 0.882), but 24-h control was significantly lower in men than women (16.9 vs. 30.3%; P = 0.029). White-coat hypertension was similar (5.1 vs. 7.6%; P = 0.493), whereas masked hypertension was insignificantly more prevalent in men than women (35.3 vs. 24.2%; P = 0.113).

CONCLUSION

BP levels, hypertension prevalence and control are similar by office criteria but significantly different by ABPM criteria between male and female KTRs. Worse ambulatory BP control in male compared with female KTRs may interfere with renal and cardiovascular outcomes.

15-year-change of phenotype and prognosis in non-dialysis CKD patients referred to a nephrology clinic

PURPOSE

Changes over time of phenotype and prognosis in CKD patients starting nephrology care are undefined. This information is critical to correctly plan and optimize healthcare resources and clinical management in tertiary care.

METHODS

We performed a long-term observational cohort study including 2,866 non-dialysis CKD patients newly referred to our nephrology clinic from 2004 to 2018. Three cohorts were constituted based on 5-year calendar intervals (2004-2008, 2009-2013, and 2014-2018). The changes over time of main demographic, clinical and laboratory characteristics were compared among the three cohorts. We also compared between cohorts the risk of renal death (combined endpoint of renal replacement therapy-RRT, or death before RRT) as well as of the single components (RRT or death).

RESULTS

Across the three cohorts, we detected a significant increase in the prevalence of age ≥ 75 years (from 22.0 to 28.4%), male gender (from 53.1 to 62.1%), diabetes (from 32.6 to 39.5%), severe proteinuria ≥ 500 mg/24 h (from 46.9 to 52.4%). Mean eGFR at referral declined from 56.8 ± 27.0 to 49.6 ± 26.1 mL/min/1.73m². Incidence of renal death significantly declined over time (5.36, 3.22 and 4.54/100 pts-year in 2004-2008, 2009-2013 and 2014-2018 cohorts, respectively). As compared with patients referred in 2004-2008, adjusted risk of renal death was lower in patients referred in 2009-2013 (HR 0.49, 95%CI 0.34-0.69) and 2014-2018 (HR 0.61, 95%CI 0.45-0.84). Similar results were obtained for RRT, while mortality did not change over time.

CONCLUSIONS

In the last 15 years, phenotype of newly referred CKD patients has remarkably changed with increasing frequency of older patients and more severe disease; however, renal survival improved suggesting greater efficacy of nephrology care.

Low performance of prognostic tools for predicting dialysis in elderly people with advanced CKD

INTRODUCTION

Clinical decision-making about care plans can be difficult for very elderly people with advanced chronic kidney disease (CKD). Current guidelines propose the use of prognostic tools predicting end stage renal disease (ESRD) to assist in a patient-centered shared decision-making approach. Our objective was to evaluate the existing risk model scores predicting ESRD, from data collected for a French prospective multicenter cohort of mainly octogenarians with advanced CKD.

METHODS

We performed a rapid review to identify the risk model scores predicting ESRD developed from CKD patient cohorts and evaluated them with data from a prospective multicenter French cohort of elderly (> 75 years) patients with advanced CKD (estimated glomerular filtration rate [eGFR] < 20 mL/min/1.75m²), followed up for 5 years. We evaluated these scores (in absolute risk) for discrimination, calibration and the Brier score. For scores using the same time frame, we made a joint calibration curve and compared areas under the curve (AUCs).

RESULTS

The PSPA cohort included 573 patients; their mean age was 83 years and their median eGFR was 13 mL/min/1.73 m². At the end of follow-up, 414 had died and 287 had started renal replacement therapy (RRT). Our rapid review found 12 scores that predicted renal replacement therapy. Five were evaluated: the TANGRI 4-variable, DRAWZ, MARKS, GRAMS, and LANDRAY scores. No score performed well in the PSPA cohort: AUCs ranged from 0.57 to 0.65, and Briers scores from 0.18 to 0.25.

CONCLUSIONS

The low predictiveness for ESRD of the scores tested in a cohort of octogenarian patients with advanced CKD underlines the need to develop new tools for this population.