Prevalence and determinants of chronic kidney disease in community-dwelling elderly by various estimating equations

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.

Comorbidity, life-style factors and healthcare utilization in incident chronic kidney disease: sex-specific analyses of claims data

BACKGROUND

Chronic kidney disease (CKD) is common in aging men and women. In contrast to other European countries, Germany lacks CKD registries. The aim of this study was to determine the incidence of CKD stages 2-5 in men and women in Germany. Furthermore, differences between the sexes in terms of comorbidities, potentially inappropriate medications (PIM), and healthcare utilization were examined.

METHODS

In this retrospective observational study, claims data from members of a statutory health insurance fund aged 18 years or older with incident CKD between 2011 and 2018 were analyzed. Incident CKD was defined as having two confirmed diagnoses of CKD stages 2-5 from outpatient care or one primary or secondary diagnosis from inpatient care.

RESULTS

The age- and sex-standardized incidence of all CKD stages was 945/100 000 persons between 2011 and 2018. Incident CKD, especially stages 3 and 4, occurred more frequently in women, while the incidence of stages 2 and 5 was higher in men. While women visited their GP more frequently and were prescribed PIMs more often, men were more likely to visit a nephrologist and were more often hospitalized after the incident CKD diagnosis.

CONCLUSION

More awareness needs to be raised towards the early detection of CKD and the use of PIMs, especially in women. Improved care coordination is needed to avoid an overprovision of patients with uncomplicated incident stages and ensure that patients with advanced CKD stages get timely access to specialist care.

Malnutrition Risk and Kidney Function and Decline in Community-Dwelling Older Adults

OBJECTIVES

The association of malnutrition with chronic kidney disease (CKD) is well established. However, there is a paucity of studies of the effect of malnutrition risk (MR) on kidney function decline among older persons who do not have end-stage or dialyzable CKD. This study aimed to examine the association between MR status and kidney function, and future risks of kidney function decline and CKD progression in community-dwelling older adults.

DESIGN AND METHODS

Nutrition Screening Initiative's DETERMINE Your Nutritional Health Checklist and estimated glomerular filtration rate (eGFR) were assessed at baseline among 5,122 participants free of end-stage renal failure or dialyzed CKD in the Singapore Longitudinal Aging Studies (SLAS-1 and SLAS-2). Follow-up eGFR was assessed in a subcohort of SLAS-2 participants without CKD (eGFR > 60 mL/min/1.73 m²) at baseline (N = 786) who were followed up at 3-5 years.

RESULTS

In baseline cross-sectional analyses adjusting for other risk factors, low, moderate, and high MR was significantly associated with decreasing eGFR coefficients of -1.5, -3.3, and -5.0 mL/min/1.73 m² respectively, and increasing CKD odds ratios of 1.81, 2.18, and 3.11 respectively. In longitudinal analysis, low, moderate, and high MR was significantly associated with increased risk of eGFR (>25%) decline (odds ratio of 2.37, 3.34, and 2.18 respectively).

CONCLUSIONS

Among older adults without advanced kidney disease, MR is associated with poor kidney function and increased risk of kidney function decline and CKD. Preventive interventions to modify MR may help to reduce the deterioration of renal function in older people.

Low testosterone concentrations and prediction of future heart failure in men and in women: evidence from the large FINRISK97 study

Aims

The increased incidence of heart failure in men suggests that endogenous sex hormones might play a role in the development of heart failure, but epidemiological data remain sparse. Here, we evaluated the predictive value of low testosterone levels on future heart failure in the large population‐based FINRISK97 study.

Methods and results

Baseline serum testosterone concentrations were measured in 7855 subjects (3865 men and 3990 women) of the FINRISK97 study. During a median follow‐up (FU) of 13.8 years, a total of 564 heart failure events were recorded. The age‐adjusted baseline testosterone levels did not differ significantly between subjects developing incident heart failure during FU and those without incident events during FU (men: 16.6 vs. 17.1 nmol/L, P = 0.75; women: 1.15 vs. 1.17 nmol/L, P = 0.32). Relevant statistically significant correlations of testosterone levels were found with high‐density lipoprotein cholesterol levels (R = 0.22; P < 0.001), body mass index (R = −0.23; P < 0.001), and waist‐to‐hip ratio (R = −0.21; P < 0.001) in men, while statistically significant correlations in women were negligible in effect size. In sex‐stratified Cox regression analyses, taking age into account, a quite strong association between low testosterone and incident heart failure was found in men [hazard ratio (HR) 1.51 (95% confidence interval, CI: 1.09–2.10); P = 0.020 for lowest vs. highest quarter], but not in women [HR 0.70 (95% CI: 0.49–0.98); P = 0.086 for lowest vs. highest quarter]. Nevertheless, this association turned non‐significant after full adjustment including body mass index and waist‐to‐hip ratio, and testosterone levels were no longer predictive for incident heart failure—neither in men [HR 0.99 (95% CI: 0.70–1.42); P = 0.77 for lowest vs. highest quarter] nor in women [HR 0.92 (95% CI: 0.64–1.33); P = 0.99 for lowest vs. highest quarter]. Accordingly, Kaplan–Meier analyses did not reveal significant association of testosterone levels with heart failure.

Conclusions

Low levels of testosterone do not independently predict future heart failure.

Contribution of cystatin C- and creatinine-based definitions of chronic kidney disease to cardiovascular risk assessment in 20 population-based and 3 disease cohorts: the BiomarCaRE project

BACKGROUND

Chronic kidney disease has emerged as a strong cardiovascular risk factor, and in many current guidelines, it is already considered as a coronary heart disease (CHD) equivalent. Routinely, creatinine has been used as the main marker of renal function, but recently, cystatin C emerged as a more promising marker. The aim of this study was to assess the comparative cardiovascular and mortality risk of chronic kidney disease (CKD) using cystatin C-based and creatinine-based equations of the estimated glomerular filtration rate (eGFR) in participants of population-based and disease cohorts.

METHODS

The present study has been conducted within the BiomarCaRE project, with harmonized data from 20 population-based cohorts (n = 76,954) from 6 European countries and 3 cardiovascular disease (CVD) cohorts (n = 4982) from Germany. Cox proportional hazards models were used to assess hazard ratios (HRs) for the various CKD definitions with adverse outcomes and mortality after adjustment for the Systematic COronary Risk Evaluation (SCORE) variables and study center. Main outcome measures were cardiovascular diseases, cardiovascular death, and all-cause mortality.

RESULTS

The overall prevalence of CKD stage 3-5 by creatinine- and cystatin C-based eGFR, respectively, was 3.3% and 7.4% in the population-based cohorts and 13.9% and 14.4% in the disease cohorts. CKD was an important independent risk factor for subsequent CVD events and mortality. For example, in the population-based cohorts, the HR for CVD mortality was 1.72 (95% CI 1.53 to 1.92) with creatinine-based CKD and it was 2.14 (95% CI 1.90 to 2.40) based on cystatin-based CKD compared to participants without CKD. In general, the HRs were higher for cystatin C-based CKD compared to creatinine-based CKD, for all three outcomes and risk increased clearly below the conventional threshold for CKD, also in older adults. Net reclassification indices were larger for a cystatin-C based CKD definition. Differences in HRs (between the two CKD measures) in the disease cohorts were less pronounced than in the population-based cohorts.

CONCLUSION

CKD is an important risk factor for subsequent CVD events and total mortality. However, point estimates of creatinine- and cystatin C-based CKD differed considerably between low- and high-risk populations. Especially in low-risk settings, the use of cystatin C-based CKD may result in more accurate risk estimates and have better prognostic value.

Association of lung function with overall mortality is independent of inflammatory, cardiac, and functional biomarkers in older adults: the ActiFE-study

Reduced lung function is associated with overall and cardiovascular mortality. Chronic low grade systemic inflammation is linked to impaired lung function and cardiovascular outcomes. We assessed the association of lung function with overall 8-year mortality in 867 individuals of the Activity and Function in the Elderly study using confounder-adjusted Cox proportional hazards models (including gait speed and daily walking time as measures of physical function) without and with adjustment for inflammatory and cardiac markers. Forced expiratory volume in 1 s/forced vital capacity (FEV₁/FVC) but not FVC was related to mortality after adjustment for physical function and other confounders. Additional adjustment for inflammatory and cardiac markers did not change the hazard ratios (HR) markedly, e.g. for a FEV₁/FVC below 0.7 from 1.55 [95% confidence-interval (CI) 1.14-2.11] to 1.49 (95% CI 1.09-2.03). These independent associations were also observed in the apparently lung healthy subpopulation with even higher HRs up to 2.76 (95% CI 1.52-4.93). A measure of airflow limitation but not vital capacity was associated with overall mortality in this community-dwelling older population and in the subgroup classified as lung healthy. These associations were independent of adjustment for inflammatory and cardiac markers and support the role of airflow limitation as independent predictor of mortality in older adults.

Estrogen-related mechanisms in sex differences of hypertension and target organ damage

Hypertension (HTN) is a primary risk factor for cardiovascular (CV) events, target organ damage (TOD), premature death and disability worldwide. The pathophysiology of HTN is complex and influenced by many factors including biological sex. Studies show that the prevalence of HTN is higher among adults aged 60 and over, highlighting the increase of HTN after menopause in women. Estrogen (E2) plays an important role in the development of systemic HTN and TOD, exerting several modulatory effects. The influence of E2 leads to alterations in mechanisms regulating the sympathetic nervous system, renin-angiotensin-aldosterone system, body mass, oxidative stress, endothelial function and salt sensitivity; all associated with a crucial inflammatory state and influenced by genetic factors, ultimately resulting in cardiac, vascular and renal damage in HTN. In the present article, we discuss the role of E2 in mechanisms accounting for the development of HTN and TOD in a sex-specific manner. The identification of targets with therapeutic potential would contribute to the development of more efficient treatments according to individual needs.

Uraemic symptom burden and clinical condition in women and men of ≥65 years of age with advanced chronic kidney disease: results from the EQUAL study

BACKGROUND

The epidemiology and prognosis of chronic kidney disease (CKD) differ by sex. We aimed to compare symptom prevalence and the clinical state in women and men of ≥65 years of age with advanced CKD receiving routine nephrology care.

METHODS

The European QUALity study on treatment in advanced chronic kidney disease (EQUAL) study follows patients from six European countries of ≥65 years of age  years whose estimated glomerular filtration rate (eGFR) dropped to ≤20 mL/min/1.73 m2 for the first time during the last 6 months. The Dialysis Symptom Index was used to assess the prevalence and severity of 33 uraemic symptoms. Data on the clinical state at baseline were collected from medical records. Prevalence was standardized using the age distribution of women as the reference.

RESULTS

The results in women (n = 512) and men (n = 967) did not differ with age (77.0 versus 75.7 years) or eGFR (19.0 versus 18.5). The median number of symptoms was 14 [interquartile range (IQR) 9-19] in women, and 11 (IQR 7-16) in men. Women most frequently reported fatigue {39% [95% confidence interval (CI) 34-45]} and bone/joint pain [37% (95% CI 32-42)] as severe symptoms, whereas more men reported difficulty in becoming sexually aroused [32% (95% CI 28-35)] and a decreased interest in sex [31% (95% CI 28-35)]. Anaemia [73% (95% CI 69-77) versus 85% (95% CI 82-87)] was less common in women than in men, as were smoking history and cardiovascular comorbidity. However, a diagnosis of liver disease other than cirrhosis, psychiatric disease and mild malnutrition were more common among women.

CONCLUSIONS

Women in secondary care with an incident eGFR ≤20 mL/min/1.73 m2 reported a higher symptom burden, while their clinical state was considered similar or even more favourable as compared with men.

Creatinine versus cystatin C for renal function-based mortality prediction in an elderly cohort: The Northern Manhattan Study

Background

Estimated glomerular filtration rate (eGFR) is routinely utilized as a measure of renal function. While creatinine-based eGFR (eGFRcr) is widely used in clinical practice, the use of cystatin-C to estimate GFR (eGFRcys) has demonstrated superior risk prediction in various populations. Prior studies that derived eGFR formulas have infrequently included high proportions of elderly, African-Americans, and Hispanics.

Objective

Our objective as to compare mortality risk prediction using eGFRcr and eGFRcys in an elderly, race/ethnically diverse population.

Design

The Northern Manhattan Study (NOMAS) is a multiethnic prospective cohort of elderly stroke-free individuals consisting of a total of 3,298 participants recruited between 1993 and 2001, with a median follow-up of 18 years.

Participants

We included all Northern Manhattan Study (NOMAS) participants with concurrent measured creatinine and cystatin-C.

Main measures

The eGFRcr was calculated using the CKD-EPI 2009 equation. eGFRcys was calculated using the CKD-EPI 2012 equations. The performance of each eGFR formula in predicting mortality risk was tested using receiver-operating characteristics, calibration and reclassification. Net reclassification improvement (NRI) was calculated based on the Reynolds 10 year risk score from adjusted Cox models with mortality as an outcome. The primary hypothesis was that eGFRcys would better predict mortality than eGFRcr.

Results

Participants (n = 2988) had a mean age of 69±10.2 years and were predominantly Hispanic (53%), overweight (69%), and current or former smokers (53% combined). The mean eGFRcr (74.68±18.8 ml/min/1.73m²) was higher than eGFRcys (51.72±17.2 ml/min/1.73m²). During a mean of 13.0±5.6 years of follow-up, 53% of the cohort had died. The AUC of eGFRcys (0.73) was greater than for eGFRcr (0.67, p for difference<0.0001). The proportions of correct reclassification (NRI) based on 10 year mortality for the model with eGFRcys compared to the model with eGFRcr were 4.2% (p = 0.002).

Conclusions

In an elderly, race/ethnically diverse cohort low eGFR is associated with risk of all-cause mortality. Estimated GFR based on serum cystatin-C, in comparison to serum creatinine, was a better predictor of all-cause mortality.

Prevalence of kidney damage in Chinese elderly: a large-scale population-based study

Background

In China, both population aging and kidney damage has become emerging public health challenges. Despite the number of elders is huge, data on kidney damage in this population are scarce. The present study aimed to describe the prevalence of kidney damage among older adults in Wuhan, China.

Methods

To describe the prevalence of kidney damage among Chinese elderly, the health screening data of 350,881 adults older than 65 years in Wuhan, China were collected and analyzed. Kidney damage was defined as eGFR less than 60 mL/min per 1·73 m² or the presence of proteinuria. Decreased renal function was defined as an eGFR < 60 mL/min/1.73 m². Proteinuria was defined as urine protein ≥1+ and without urine WBC or nitrite positive. The associated risk factors of eGFR decline and kidney damage were analyzed by multivariate logistic regression.

Results

The age-standardized prevalence of kidney damage, decreased renal function and proteinuria was 17.2, 13.5 and 5.3%. Among the patients, up to 74.4% was stage 3. The prevalence of kidney damage and eGFR decline were higher in suburbs than in urban (18.3% vs 16.0 and 14.6% vs 12.4%). Factors independently associated with kidney damage were age, female, BMI, abdominal circumference, hypertension, diabetes, stroke and coronary heart disease.

Conclusions

Kidney damage has become an important public health problem in Chinese elderly. More attention should be paid to elderly lived in suburbs or rural area in our further work.

Predictive value of low testosterone concentrations regarding coronary heart disease and mortality in men and women - evidence from the FINRISK97 study

INTRODUCTION

The relevance of low testosterone concentrations for incident coronary heart disease (CHD) and mortality has been discussed in various studies. Here, we evaluate the predictive value of low baseline testosterone levels in a large population-based cohort.

METHODS

We measured the serum levels of testosterone in 7671 subjects (3710 male, 3961 female) of the population-based FINRISK97 study.

RESULTS

The median follow-up (FU) was 13.8 years. During the FU, a total of 779 deaths from any cause, and 395 incident CHD events were recorded. The age-adjusted baseline testosterone levels were similar in subjects suffering incident events during FU and those without incident events during FU (men: 15.80 vs. 17.01 nmol L-1 ; P = 0.69, women: 1.14 vs. 1.15 nmol L-1 ; P = 0.92). Weak correlations of testosterone levels were found with smoking (R = 0.09; P < 0.001), HDL cholesterol levels (R = 0.22, P < 0.001), systolic blood pressure (R = -0.05; P = 0.011), BMI (R = -0.23; P < 0.001) and waist-hip-ratio (R = -0.21; P < 0.001) in men, and with eGFR (R = -0.05; P = 0.009) in women. Kaplan-Meier analyses did not reveal a positive association of testosterone levels with incident CHD or mortality. Accordingly, also in Cox regression analyses, testosterone levels were not predictive for incident CHD or mortality - neither in men (HR 1.02 [95%CI: 0.70-1.51]; P = 0.79 for lowest versus highest quarter regarding CHD and HR 1.06 [95%CI: 0.80-1.39]; P = 0.67 regarding mortality), nor in women (HR 1.13 [95%CI: 0.69-1.85]; P = 0.56 for lowest versus highest quarter regarding CHD and HR 0.99 [95%CI: 0.71-1.39]; P = 0.80 regarding mortality).

CONCLUSIONS

Low levels of testosterone are not predictive regarding future CHD or mortality - neither in men, nor in women.

Comparison of MDRD, CKD-EPI, and Cockcroft-Gault equation in relation to measured glomerular filtration rate among a large cohort with diabetes

AIMS

To analyze the performance of Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Cockcroft-Gault (CG), and CG calculated with ideal bodyweight (CG-IBW) equations to estimate glomerular filtration rate (eGFR) based on serum creatinine in a large diabetic population.

METHODS

24,516 adults with type-1-diabetes or type-2-diabetes from the multicenter diabetes prospective follow-up registry DPV were analyzed. We compared eGFR and measured GFR (mGFR) based on 24-h urine collection by calculating mean bias (difference), precision (SD of this difference), accuracy (proportion of eGFR within ±10% of mGFR), Bland-Altman-plots.

RESULTS

CG overestimates, whereas MDRD, CKD-EPI, and CG-IBW underestimate. Smallest mean bias and highest accuracy (75.3%) were observed for MDRD compared to the other equations (p<0.0001). MDRD and CKD-EPI estimated most accurately in stages 1 (MDRD:57.7%, CKD-EPI:57.3%) and 2 (MDRD:80.2%, CKD-EPI:80.7%). In stages 3 to 5, highest accuracy was observed for the MDRD (stage 3:82.3%, stage 4:77.8%, stage 5:71.0%). Among younger subjects, accuracy was higher using the CKD-EPI (18-<40years:63.7%, 40-<60years:72.8%). Above age 60years, MDRD estimated most accurately (60-<70years:77.3%, ≥70years:78.8%). In males and females, MDRD estimated most accurately (males:75.3%, females:75.3%).

CONCLUSION

In this large diabetic cohort, smallest bias and highest accuracy were observed for the MDRD.

The global burden of chronic kidney disease: estimates, variability and pitfalls

Chronic kidney disease (CKD) is currently defined by abnormalities of kidney structure or function assessed using a matrix of variables - including glomerular filtration rate (GFR), thresholds of albuminuria and duration of injury - and is considered by many to be a common disorder globally. However, estimates of CKD prevalence vary widely, both within and between countries. The reasons for these variations are manifold, and include true regional differences in CKD prevalence, vagaries of using estimated GFR (eGFR) for identifying CKD, issues relating to the use of set GFR thresholds to define CKD in elderly populations, and concerns regarding the use of one-off testing for assessment of eGFR or albuminuria to define the prevalence of CKD in large-scale epidemiological studies. Although CKD is common, the suggestion that its prevalence is increasing in many countries might not be correct. Here, we discuss the possible origins of differences in estimates of CKD prevalence, and present possible solutions for tackling the factors responsible for the reported variations in GFR measurements. The strategies we discuss include approaches to improve testing methodologies for more accurate assessment of GFR, to improve awareness of factors that can alter GFR readouts, and to more accurately stage CKD in certain populations, including the elderly.

Global Prevalence of Chronic Kidney Disease - A Systematic Review and Meta-Analysis

Chronic kidney disease (CKD) is a global health burden with a high economic cost to health systems and is an independent risk factor for cardiovascular disease (CVD). All stages of CKD are associated with increased risks of cardiovascular morbidity, premature mortality, and/or decreased quality of life. CKD is usually asymptomatic until later stages and accurate prevalence data are lacking. Thus we sought to determine the prevalence of CKD globally, by stage, geographical location, gender and age. A systematic review and meta-analysis of observational studies estimating CKD prevalence in general populations was conducted through literature searches in 8 databases. We assessed pooled data using a random effects model. Of 5,842 potential articles, 100 studies of diverse quality were included, comprising 6,908,440 patients. Global mean(95%CI) CKD prevalence of 5 stages 13·4%(11·7-15·1%), and stages 3-5 was 10·6%(9·2-12·2%). Weighting by study quality did not affect prevalence estimates. CKD prevalence by stage was Stage-1 (eGFR>90+ACR>30): 3·5% (2·8-4·2%); Stage-2 (eGFR 60-89+ACR>30): 3·9% (2·7-5·3%); Stage-3 (eGFR 30-59): 7·6% (6·4-8·9%); Stage-4 = (eGFR 29-15): 0·4% (0·3-0·5%); and Stage-5 (eGFR<15): 0·1% (0·1-0·1%). CKD has a high global prevalence with a consistent estimated global CKD prevalence of between 11 to 13% with the majority stage 3. Future research should evaluate intervention strategies deliverable at scale to delay the progression of CKD and improve CVD outcomes.

Methodology used in studies reporting chronic kidney disease prevalence: a systematic literature review

Background

Many publications report the prevalence of chronic kidney disease (CKD) in the general population. Comparisons across studies are hampered as CKD prevalence estimations are influenced by study population characteristics and laboratory methods.

Methods

For this systematic review, two researchers independently searched PubMed, MEDLINE and EMBASE to identify all original research articles that were published between 1 January 2003 and 1 November 2014 reporting the prevalence of CKD in the European adult general population. Data on study methodology and reporting of CKD prevalence results were independently extracted by two researchers.

Results

We identified 82 eligible publications and included 48 publications of individual studies for the data extraction. There was considerable variation in population sample selection. The majority of studies did not report the sampling frame used, and the response ranged from 10 to 87%. With regard to the assessment of kidney function, 67% used a Jaffe assay, whereas 13% used the enzymatic assay for creatinine determination. Isotope dilution mass spectrometry calibration was used in 29%. The CKD-EPI (52%) and MDRD (75%) equations were most often used to estimate glomerular filtration rate (GFR). CKD was defined as estimated GFR (eGFR) <60 mL/min/1.73 m² in 92% of studies. Urinary markers of CKD were assessed in 60% of the studies. CKD prevalence was reported by sex and age strata in 54 and 50% of the studies, respectively. In publications with a primary objective of reporting CKD prevalence, 39% reported a 95% confidence interval.

Conclusions

The findings from this systematic review showed considerable variation in methods for sampling the general population and assessment of kidney function across studies reporting CKD prevalence. These results are utilized to provide recommendations to help optimize both the design and the reporting of future CKD prevalence studies, which will enhance comparability of study results.

Assessment of kidney dysfunction with cystatin C- and creatinine-based estimated glomerular filtration rate and predicting type 2 diabetes: Toranomon Hospital Health Management Center Study 21

OBJECTIVE

Whether early stages of kidney dysfunction assessed by the estimated glomerular filtration rate from cystatin C measurements (eGFRCysC) rather than from creatinine measurements (eGFRCr) would more precisely reflect the risk of developing type 2 diabetes (T2D) has not been clarified. We compared the risk of developing T2D associated with renal dysfunction indicated by eGFRCysC or eGFRCr measurements.

METHODS

Studied were 2131 Japanese individuals without diabetes. Hazard ratios (HRs) for the development of T2D over 3-5 y were calculated across categories of eGFRCysC and eGFRCr, respectively.

RESULTS

Reduced levels of eGFRCysC were associated with a step-wise increase in the cumulative incidence rate of T2D (p=0.007). In comparison with the eGFRCysC >85th percentile group (≥ 117.4 ml/min/1.73 m(2)), the lowest group, which was the eGFRCysC <15th percentile group (<86.2 ml/min/1.73 m(2)), had an adjusted HR of 2.30 (95% CI 1.13, 4.68) for T2D. Compared with the eGFRCr >85th percentile group, the lowest eGFRCr group (<15th percentile) had an HR of 1.19 (0.63, 2.24) for T2D. However, individuals with eGFRCr <60 ml/min/1.73 m(2) had a significantly increased risk of T2D. Clustering of both low eGFRCysC and low eGFRCr further elevated the HR for T2D compared with the presence of either.

CONCLUSIONS

Although eGFRCr in ranges indicating chronic kidney disease reflected an elevated risk of developing diabetes, earlier stages of kidney dysfunction indicated by reduced eGFRCysC, which could not be captured by reduced eGFRCr, would be a marker for an elevated risk of developing T2D.

Association of Metabolic Syndrome with Chronic Kidney Disease in Elderly Japanese Women: Comparison by Estimation of Glomerular Filtration Rate from Creatinine, Cystatin C, and Both

BACKGROUND

Associations between metabolic syndrome (MetS) and chronic kidney disease (CKD) has not been extensively studied in elderly Asians, who in general have lower body mass index (BMI) than European populations.

METHODS

A cross-sectional analysis was conducted including 159 community-living elderly Japanese women. MetS was defined by the modified National Cholesterol Education Program Adult Treatment Panel III criteria, but using a BMI ≥25 kg/m(2) instead of waist circumference and renal function was assessed according to the Kidney Disease Outcomes Quality Initiative CKD classification. Creatinine-based and cystatin C-based estimated glomerular filtration rate (eGFR) and the average of the two eGFRS were used.

RESULTS

Prevalence of CKD was much higher when creatinine-based eGFR was used than the prevalence obtained when cystatin-C based equations were used (46.5% vs. 12.6%, P < 0.001). Eighteen (11.3%) women met MetS criteria. Both the presence of MetS and the number of MetS components were associated with higher prevalence of CKD using the average eGFR (all P < 0.05) but not using creatinine-based (P = 0.86) and cystatin C-based (P = 0.12) eGFR alone. Lower average eGFR and higher prevalence of CKD using average eGFR were evident in even women with only one MetS component, 89% of whom had elevated blood pressure.

CONCLUSIONS

Prevalence of CKD varied substantially depending on the used equation. In nonobese, elderly Japanese women, both the presence of MetS and the number of MetS components were associated with higher prevalence of CKD and elevated blood pressure may play an important role in these associations. These findings should be confirmed in studies employing more participants with MetS diagnosed using standard criteria (waist circumference instead of BMI).

Prospective evaluation of renal function, serum vitamin D level, and risk of fall and fracture in community-dwelling elderly subjects

SUMMARY

This prospective study in elderly showed that kidney function plays a minor role in explaining the high prevalence of vitamin D deficiency seen in noninstitutionalized elderly subjects. However, 25-hydroxyvitamin D levels were clearly inversely associated with risk for first fall, which was especially seen in subjects with calcium levels above median.

INTRODUCTION

Few prospective studies in elderly exist that have investigated the association of renal dysfunction and vitamin D status on risk of falls. The aim of this study is to evaluate the association of renal function with 25-hydroxyvitamin D (25-OH-D) levels and, secondly, to assess the role of both factors on the risk of falls and subsequent bone fractures.

METHODS

This is a prospective population-based cohort study among noninstitutionalized elderly subjects during a 1-year follow-up. 25-OH-D levels and renal function were estimated, the latter by cystatin C-based equations. Information on falls was assessed prospectively.

RESULTS

Overall, 1,385 subjects aged 65 and older were included in the study (mean age 75.6 years), of whom 9.2 % had a 25-OH-D serum level above 75 nmol/L (US units 30 ng/mL); 41.4 %, between 50 and 75 nmol/L (US units 20 to 29 ng/mL, insufficiency); and 49.4 %, <50 nmol/L (US units <20 ng/mL, deficiency). We found no association of chronic kidney disease with risk of first fall. In contrast, 25-OH-D serum categories were clearly associated with risk of first fall and we found evidence of effect modification with calcium levels. In the group with a calcium level above the median (≥ 9.6 mg/dL), subjects with 25-OH-D serum level between 50 and 75 nmol/L and with concentrations <50 nmol/L had a hazard rate ratio (HRR) of 1.75 (1.03-2.87) and 1.93 (1.10-3.37) for risk of first fall. 25-OH-D serum levels were also associated with several markers of inflammation and hemodynamic stress.

CONCLUSIONS

We demonstrated an association of 25-OH-D serum levels and risk of first fall, which was especially evident in subjects with serum calcium in upper normal, independent of renal function.

Assessment of glomerular filtration rate in elderly patients with chronic kidney disease

PURPOSE

We sought to evaluate various glomerular filtration rate (GFR) estimating equations in elderly patients with chronic kidney disease (CKD).

METHODS

A total of 332 Chinese elderly patients with CKD who had undergone technetium-99m diethylenetriaminepentaacetic acid ((99m)Tc-DTPA) renal dynamic imaging were enrolled. The MDRD equation, the re-expressed MDRD equation, the Chinese equation, the Ruijin equation, the previously Japanese equation, the new Japanese equation, the CKD-EPI equation, and the BIS1 equation were compared.

RESULTS

The median of difference between estimated GFR and standard GFR ranged from -9.78 to 1.79 ml/min/1.73 m(2). The interquartile range of difference ranged from 12.38 to 20.87 ml/min/1.73 m(2). Accuracy with a deviation <30 % ranged from 44.9 to 66.3 %. However, none of the equations had accuracy up to the 70 % level. Bland-Altman analysis demonstrated that the precision ranged from 50.5-87.6 ml/min/1.73 m(2). The slopes of regression line ranged from -0.26 to 0.55 and the intercepts ranged from -18.71 to 11.07. In both the overall performance and the performances in different stage of CKD, GFR estimated by the BIS1 equation performed better results.

CONCLUSION

None of the GFR estimating equations are suitable for the specific Chinese population tested. At present, the BIS1 equation may be the optimal one for elderly Chinese CKD patients.

Seasonality of vitamin D status in older people in Southern Germany: implications for assessment

BACKGROUND

from a clinical and public health perspective, it is important to understand the influence of seasonality on the serum vitamin D level to adequately assess and interpret an individual measurement. Therefore, the aim of this study was to analyse the effects of seasonal conditions on 25-hydroxyvitamin D (25(OH)D) serum levels in a population-based cohort of older people.

METHODS

between March 2009 and April 2010 the 25(OH)D serum level was assessed in 1,418 community-dwelling individuals living in Germany aged ≥65 years (56.7% men) with no subscribed vitamin D supplementation. Least-square means of monthly 25(OH)D serum levels with 95% confidence intervals (CI) were estimated, adjusted for gender, age and body mass index. Additionally, the proportion of vitamin deficiency (<20 ng/ml), insufficiency (20-<30 ng/ml) and sufficiency (30 ng/ml or higher) were estimated for each month. Finally, mean values of daily total global solar radiation and daylight were calculated for each month.

RESULTS

the minimum 25(OH)D serum level was observed in March with 15.4 ng/ml (SD = 6.56 ng/ml) and the maximum in August with 25.6 ng/ml (SD = 6.59 ng/ml). Compared with daylight and global solar radiation the progression over the year was similar but delayed by ∼2 months. The proportion of vitamin D deficiency, insufficiency and sufficiency were 78.8, 19.2 and 1.9% in March and 16.1, 63.4 and 20.5% in August, respectively.

CONCLUSION

vitamin D insufficiency was very common in this cohort and showed a strong seasonal effect with lowest values in March.

Prevalence of chronic kidney disease and its related risk factors in elderly of southern iran: a population-based study

Aim. The prevalence of chronic kidney disease (CKD) as a serious public health problem is growing in the elderly. This study aimed to assess CKD prevalence and its related risk factors in elderly population of Fars province. Methods. In this cross sectional study a total of 1190 elderly people are enrolled, and demographic and medical data were obtained. Data were analyzed by SPSS, and P of less than 0.05 was considered as statistically significant. Results. Prevalence of CKD stages III–V was 27.5% in the 60–69 years age group, 36.5% in the 70–79 years age group, and 40% in the ≥80 years age group. The prevalence of CKD increased with ageing in both men and women. Female gender was the strongest risk factor for CKD. Conclusions. Prevalence of CKD in elderly is high in Southern Iran, which has become an important health problem while it can be prevented or delayed in progression.

Aging and ESRD demographics: consequences for the practice of dialysis

The disproportionate increase in the prevalence of chronic kidney disease (CKD) and end-stage renal disease (ESRD) in the elderly is now recognized as a national and global reality. Among the major contributing factors are the aging of the population, a growing prevalence of CKD, greater access to care, and increased comorbidities. The utilization of renal replacement therapy in the geriatric population has concomitantly increased. It is imposing enormous challenges to the practice of ESRD care, the largest of which may be to determine the best application of clinical performance targets to a population with limitations in life expectancy. Concurrently, increased focus on quality of life will be required. The effective dialysis practitioner will need to adapt to the aging ESRD demographics with an increased focus on physical and mental well-being of the geriatric patient.