Chronic kidney disease and end-stage renal disease in the elderly population: current prevalence, future projections, and clinical significance

Presepsin (sCD14-ST) in emergency department: the need for adapted threshold values?

Presepsin is elevated in patients developing infections and increases in a severity-dependent manner. We aimed to evaluate circulating values of this new biomarker in a population free of any acute infectious disorder. We recruited 144 consecutive patients presenting at the emergency department (ED) without acute infection or acute/unstable disorder, and 54 healthy participants. Presepsin plasmatic concentrations were measured on the PATHFAST point-of-care analyzer. The 95th percentile of presepsin values in the ED population is 750ng/L. Presepsin was significantly increased in patients aged ≥70years vs. younger patients (470 [380-601] ng/L vs. 300 [201-457] ng/L, p<0.001). Prevalence of elevated presepsin values was increased in patients in comparison to controls (80% vs.13%, p<0.001), and in patients aged ≥70years in comparison to younger patients (87% vs. 47%, p<0.001). Presepsin concentrations were significantly increased in patients with kidney dysfunction. Aging was an independent predictor of an elevated presepsin value. In conclusion, presepsin concentrations increase with age and kidney dysfunction. Therefore interpretation of presepsin concentrations might be altered in the elderly or in patients with impaired renal function. Adapted thresholds are needed for specific populations.

The prevalence of chronic kidney disease in a primary care setting: a Swiss cross-sectional study

Chronic kidney disease (CKD) often remains clinically silent and therefore undiagnosed until a progressed stage is reached. Our aim was to estimate the prevalence of CKD in a primary care setting in Switzerland. A multicenter, cross-sectional study with randomly selected general practitioners was performed. Adults visiting their general physician’s cabinet during defined periods were asked to participate. Baseline information was reported on a questionnaire, urine and blood samples were analyzed in a central laboratory. Renal status was assessed using the Kidney Disease: Improving Global Outcomes (KDIGO) classification. Extrapolation of results to national level was adjusted for age and gender. One thousand individuals (57% females) with a mean age of 57±17 years were included. Overall, 41% of the patients had normal estimated glomerular filtration rate (eGFR) and albumin creatinine ratio (ACR), whereas 36% of the subjects had slightly reduced excretory renal function with physiological albuminuria based on normal ACR. Almost one fourth of the subjects (23%) had either a substantially reduced eGFR or high levels of ACR. About 10% of the patients had a substantially reduced eGFR of <60 ml/min/1.73 m², and 17% showed relevant proteinuria (ACR >30 mg/g creatinine). Extrapolation to national level suggests that about 18% of primary care patients may suffer from CKD. CKD prevalence in a primary care population is therefore high, and preventive interventions may be advisable, in particular as CKD prevalence is likely to rise over the next decades.

Non-alcoholic Fatty Liver Disease and Chronic Kidney Disease in Koreans Aged 50 Years or Older

Background

Non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) share common pathogenic mechanisms and many risk factors, and both are linked to an increased risk of cardiovascular diseases. The aim of this study was to assess the association between NAFLD and CKD according to the presence of hypertension and diabetes mellitus in Koreans aged 50 years or older.

Methods

A cross-sectional study of 1,706 subjects who received their routine health examination was conducted between May 2008 and April 2010 at Konkuk University medical center. Biochemical tests for liver and abdominal ultrasonography were performed. CKD was defined as either proteinuria or glomerular filtration rate ≤60 mL/min per 1.73 m².

Results

Among the 1,706 subjects, There were 545 (31.9%) with non-alcoholic fatty liver disease and 424 (24.9%) with chronic kidney disease. In univariate logistic regression analysis, NAFLD was significantly associated with CKD (odds ratio [OR], 1.69; 95% confidence interval [CI], 1.34 to 2.12). In multivariate logistic regression analysis adjusted for age, sex, current smoking, abdominal obesity, aspartate aminotransferases, alanine aminotransferases, γ-glutamyltransferase, hypertension, diabetes mellitus, hypertriglyceridemia, and low high-density lipoprotein cholesterol, NAFLD was associated with CKD (adjusted OR, 1.68; 95% CI, 1.27 to 2.24). This relationship remained significant after classification according to the presence of hypertension or diabetes mellitus.

Conclusion

NAFLD diagnosed by ultrasonography was significantly associated with CKD in Koreans aged 50 years or older.

Estimated GFR reporting is associated with decreased nonsteroidal anti-inflammatory drug prescribing and increased renal function

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used; however, they are also nephrotoxic with both acute and chronic effects on kidney function. Here we determined NSAID prescribing before and after estimated GFR (eGFR) reporting and evaluate renal function in patients who used NSAIDs but stopped these after their first eGFR report. A population-based longitudinal analysis using a record-linkage database was conducted with the GFR estimated using the four-variable equation from the MDRD study and analyzed by trend test, paired t-test, and logistic regression modeling. Prescriptions for NSAIDs significantly decreased from 39,459 to 35,415 after implementation of eGFR reporting from the second quarter of 2005 compared with the first quarter of 2007. Reporting eGFR was associated with reduced NSAID prescriptions (adjusted odds ratio, 0.78). NSAID prescription rates in the 6 months before April 2006 were 18.8, 15.4, and 7.0% in patients with CKD stages 3, 4, and 5 and 15.5, 10.7, and 6.3%, respectively, after eGFR reporting commenced. In patients who stopped NSAID treatment, eGFR significantly increased from 45.9 to 46.9, 23.9 to 27.1, and 12.4 to 26.4 ml/min per 1.73 m² in 1340 stage 3 patients, 162 stage 4 patients, and 9 stage 5 patients, respectively. Thus, NSAID prescribing decreased after the implementation of eGFR reporting, and there were significant improvements in estimated renal function in patients who stopped taking NSAIDs. Hence, eGFR reporting may result in safer prescribing.

Diagnostic value of screening instruments for identifying obstructive sleep apnea in kidney failure

BACKGROUND

Patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) have a high prevalence of obstructive sleep apnea (OSA) that can have significant clinical implications. An accurate clinical screening tool for OSA that identifies patients for further diagnostic testing would assist in the identification of this comorbidity. The Berlin Questionnaire (BQ), Adjusted Neck Circumference (ANC), and STOP-BANG questionnaire are 3 such instruments that have been validated in patients with normal kidney function.

OBJECTIVE

The objective of this study was to determine the validity of these screening instruments in patients with CKD and ESRD, using overnight cardiopulmonary monitoring to diagnose OSA.

METHODS

One hundred seventy-two patients were recruited from nephrology clinics and hemodialysis units (CKD: n = 109; ESRD: n = 63). All patients completed the BQ, ANC, STOP-BANG, and overnight cardiopulmonary monitoring to diagnose OSA (respiratory disturbance index [RDI] ≥ 15). Sensitivity, specificity, positive and negative predictive values, and accuracy were calculated for the BQ, ANC, and STOP-BANG.

RESULTS

Obstructive sleep apnea was present in 41 CKD patients (38%) and 32 ESRD patients (51%). All screening instruments had satisfactory sensitivity (56% to 94%) but poor specificity (29% to 77%) and low accuracy (51% to 69%) in both CKD and ESRD patients with RDI ≥ 15. Using an RDI ≥ 30 yielded similar results.

CONCLUSIONS

Current screening questionnaires do not accurately identify patients at high risk for OSA or rule out the presence of OSA in patients with CKD and ESRD. Consequently, objective monitoring during sleep is required to reliably identify sleep apnea in these patient populations.

Retinopathy and cognitive impairment in adults with CKD

BACKGROUND

Retinal microvascular abnormalities have been associated with cognitive impairment, possibly serving as a marker of cerebral small-vessel disease. This relationship has not been evaluated in persons with chronic kidney disease (CKD), a condition associated with increased risk of both retinal pathology and cognitive impairment.

STUDY DESIGN

Cross-sectional study.

SETTING & PARTICIPANTS

588 participants 52 years or older with CKD in the Chronic Renal Insufficiency Cohort (CRIC) Study.

PREDICTOR

Retinopathy graded using the Early Treatment Diabetic Retinopathy Study severity scale and diameters of retinal vessels.

OUTCOMES

Neuropsychological battery of 6 cognitive tests.

MEASUREMENTS

Logistic regression models were used to evaluate the association of retinopathy, individual retinopathy features, and retinal vessel diameters with cognitive impairment (≤1 SD from the mean), and linear regression models were used to compare cognitive test scores across levels of retinopathy, adjusting for age, race, sex, education, and medical comorbid conditions.

RESULTS

The mean age of the cohort was 65.3±5.6 (SD) years, 51.9% were nonwhite, and 52.6% were men. The prevalence of retinopathy was 30.1%, and the prevalence of cognitive impairment was 14.3%. Compared with those without retinopathy, participants with retinopathy had an increased likelihood of cognitive impairment on executive function (35.1% vs 11.5%; OR, 3.4 [95% CI, 2.0-6.0]), attention (26.7% vs 7.3%; OR, 3.0 [95% CI, 1.8-4.9]), and naming (26.0% vs 10.0%; OR, 2.1 [95% CI, 1.2-3.4]) after multivariable adjustment. Increased level of retinopathy also was associated with lower cognitive performance on executive function and attention. Microaneurysms were associated with cognitive impairment on some domains, but there were no significant associations with other retinal measures after multivariable adjustment.

LIMITATIONS

Unknown temporal relationship between retinopathy and impairment.

CONCLUSIONS

In adults with CKD, retinopathy is associated with poor performance on several cognitive domains, including executive function and attention. Evaluation of retinal microvascular abnormalities may be a promising tool for identifying patients with CKD who are at increased risk of cognitive impairment.

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.

How to improve drug dosing for patients with renal impairment in primary care - a cluster-randomized controlled trial

Background

Patients with chronic kidney disease (CKD) are at increased risk for inappropriate or potentially harmful prescribing. The aim of this study was to examine whether a multifaceted intervention including the use of a software programme for the estimation of creatinine clearance and recommendation of individual dosage requirements may improve correct dosage adjustment of relevant medications for patients with CKD in primary care.

Methods

A cluster-randomized controlled trial was conducted between January and December 2007 in small primary care practices in Germany. Practices were randomly allocated to intervention or control groups. In each practice, we included patients with known CKD and elderly patients (≥70 years) suffering from hypertension. The practices in the intervention group received interactive training and were provided a software programme to assist with individual dose adjustment. The control group performed usual care. Data were collected at baseline and at 6 months. The outcome measures, analyzed across individual patients, included prescriptions exceeding recommended maximum daily doses, with the primary outcome being prescriptions exceeding recommended standard daily doses by more than 30%.

Results

Data from 44 general practitioners and 404 patients are included. The intervention was effective in reducing prescriptions exceeding the maximum daily dose per patients, with a trend in reducing prescriptions exceeding the standard daily dose by more than 30%.

Conclusions

A multifaceted intervention including the use of a software program effectively reduced inappropriately high doses of renally excreted medications in patients with CKD in the setting of small primary care practices.

Trial registration

Current Controlled Trials ISRCTN02900734

Geriatric assessment and chronic kidney disease in the oldest old: the Octabaix study

BACKGROUND

The prevalence of chronic kidney disease (CKD) in older people is increasing. We determine the proportion of CKD in a sample of 321, 85-year-old community-dwelling subjects, and assess the association of socio-demographic data, global geriatric assessment data and comorbidity with CKD according to the estimated glomerular filtration rate (eGFR) of subjects.

METHODS

Serum creatinine, eGFR (derived in ml/min/1.73 m(2) using the Modification of Diet in Renal Disease formula), socio-demographic variables, the Barthel Index (BI), the Spanish version of the Mini-Mental State Examination (MEC), the Mini Nutritional Assessment (MNA), the Charlson Index, the Gait Rating Scale, social risk, quality of life and prevalent chronic diseases were collected.

RESULTS

CKD prevalence was 56.7% for eGFR < 60 ml/min/1.73 m(2), 19.9% for eGFR < 45 ml/min/1.73 m(2) and 6.6% for GFR < 30 ml/min/1.73 m(2). Multiple logistic regression analysis showed that a prior diagnosis of hypertension was associated with an eGFR < 60 ml/min/1.73 m(2) (p<0.008, OR 2.134, 95% CI 1.216-3.744). A diagnosis of heart failure (p<0.001, OR 3.610, 95% CI 1.677-7.771) and a poor score on the quality of life measure (p<0.008, OR 0.9660, 95% CI 0.966-0.995) were associated with an eGFR < 45 ml/min/1.73 m(2).

CONCLUSIONS

More than half of the oldest old in this study had an eGFR < 60 ml/min/1.73 m(2). A history of hypertension was associated with CKD. The group of patients with an eGFR < 45 ml/min/1.73 m(2) was associated with a diagnosis of heart failure and a worse quality of life.

Predictors and prevalence of latent tuberculosis infection in patients receiving long-term hemodialysis and peritoneal dialysis

Background

Tuberculosis is a common infectious disease in long-term dialysis patients. The prevalence of latent tuberculosis infection (LTBI) in this population is unclear, particularly in those receiving peritoneal dialysis (PD). This study investigated the prevalence of LTBI in patients receiving either hemodialysis (HD) or PD to determine predictors of LTBI and indeterminate results of interferon-gamma release assay.

Methods

Patients receiving long-term (≥3 months) HD or PD from March 2011 to February 2012 in two medical centers were prospectively enrolled. QuantiFERON-Gold in tube (QFT) test was used to determine the status of LTBI after excluding active tuberculosis. The LTBI prevalence was determined in patients receiving different dialysis modes to obtain predictors of LTBI and QFT-indeterminate results.

Results

Of 427 patients enrolled (124 PD and 303 HD), 91 (21.3%) were QFT-positive, 316 (74.0%) QFT-negative, and 20 (4.7%) QFT-indeterminate. The prevalence of LTBI was similar in the PD and HD groups. Independent predictors of LTBI were old age (OR: 1.034 [1.013–1.056] per year increment), TB history (OR: 6.467 [1.985–21.066]), and current smoker (OR: 2.675 [1.061–6.747]). Factors associated with indeterminate QFT results were HD (OR: 10.535 [1.336–83.093]), dialysis duration (OR: 1.113 [1.015–1.221] per year increment), anemia (OR: 8.760 [1.014–75.651]), and serum albumin level (OR: 0.244 [0.086–0.693] per 1 g/dL increment).

Conclusion

More than one-fifth of dialysis patients have LTBI. The LTBI prevalence is similar in PD and HD patients but is higher in the elderly, current smokers, and those with prior TB history. Such patients require closer follow-up. Repeated or alternative test may be required for malnutrition patients who received long length of HD.

Short-term change in kidney function and risk of end-stage renal disease

BACKGROUND

It is unclear what degree of change in the eGFR over a 1-year period indicates clinically significant progression, and whether this change adds additional information beyond that obtained by a single eGFR measure alone.

METHODS

We included 598 397 adults who had at least two outpatient eGFR measurements (at least 6 months apart) during 1-year accrual period in Alberta, Canada. Change in kidney function (using the first and last eGFR) was defined by change in kidney function category with confirmation based on percent (%) change in eGFR [(last eGFR - first eGFR)/first eGFR × 100]. The groups for change in kidney function were thus defined as: 'certain drop' (drop in CKD category with ≥25% decrease in the eGFR); 'uncertain drop' (drop in CKD category with <25% decrease in the eGFR); 'stable' (no change in CKD category); 'uncertain rise' (rise in CKD category with <25% rise in the eGFR) and 'certain rise' (rise in CKD category with ≥25% increase in the eGFR). Adjusted end-stage renal disease (ESRD) rates (per 1000 person-years) for each group of change in kidney function were calculated using Poisson regression. Adjusted risks of ESRD associated with change in kidney function, in reference to stable kidney function, were estimated.

RESULTS

Among the 598 397 participants, 74.8% (n = 447 570) had stable (no change in CKD category), 3.3% (n = 19 591) had a certain drop and 3.7% (n = 22 171) had a certain rise in kidney function. Participants who experienced a certain change in kidney function (both drop and rise) were older, more likely to be female, and had a higher prevalence of comorbidities, in comparison with those with stable kidney function. There were 1966 (0.3%) ESRD events over a median follow-up of 3.5 years. Compared with participants with stable kidney function, after adjustment for covariates, and the first eGFR measurement, those with certain drop had 5-fold increased risk of ESRD (HR: 5.11; 95% CI: 4.56-5.71), whereas those with an uncertain drop had 2-fold increased risk (HR: 2.13; 95% CI: 1.84-2.47). After adjustment for the eGFR and covariates at the last visit, neither a certain nor uncertain drop in the eGFR was associated with an increased ESRD risk. The ESRD risk associated with the last eGFR level, adjusted for the slope over time, were 2.89 (95% CI: 2.35-3.55), 10.98 (95% CI: 8.69-13.87), 35.20 (95% CI: 27.95-44.32) and 147.96 (116.92-187.23) for categories 2, 3a, 3b and 4, respectively, in reference to category 1.

CONCLUSIONS

A change in eGFR category accompanied by ≥25% decline (certain drop) is associated with increased ESRD risk. However, this elevated risk is captured by patient characteristics and eGFR at the last visit, suggesting that eGFR trajectories based on more than two serum creatinine measurements over a period longer than 1 year are required to determine ESRD risk and allow more reliable risk prediction.

Decisional procalcitonin thresholds are not adapted to elderly patients admitted to the emergency room

CONTEXT

Diagnosis of sepsis in elderly is challenging.

OBJECTIVES

We investigated whether procalcitonin concentrations in elderly differed from values for the general population.

METHODS

Procalcitonin measurement was assessed prospectively in 307 apyretic patients ≥75 years visiting the emergency department.

RESULTS

Median age was 86 years [IQR81-90] and 222 (72%) were female. Procalcitonin concentration was 0.057 µg/L [0.040-0.092]; 99th percentile was 0.661 µg/L. Patients with procalcitonin concentrations above decisional thresholds had lower glomerular filtration rate and higher C-reactive protein concentrations.

CONCLUSIONS

Baseline procalcitonin levels are increased in elderly. Elevated values are common and associated to low-grade inflammation and lower eGFR.

Complications and characteristics of patients referred to a joint diabetes renal clinic in Ireland

BACKGROUND AND METHODS

Joint diabetes renal (JDR) clinics are recommended as the appropriate model of care to manage advanced diabetic-associated renal failure. We performed a retrospective review of clinical data and records of the first 60 patients who attended our service and their follow-up at 12 months.

RESULTS

Of the patients, 88 % had type 2 diabetes. At the first visit, 43 % had retinopathy, 56 % had neuropathy, 48 % had overt cardiovascular disease, 13 % had a previous history of stroke and 36 % peripheral arterial disease. Ten percent had lower limb amputation and 33 % had never previously seen a diabetologist. Fifteen percent were still on metformin despite significant renal impairment, while 43 % were on three or more different antihypertensives. Sixty-eight percent were either on an ACE inhibitor or angiotensin receptor blocker. At 12 months, a trend towards a reduction in HbA1c (7.6 ± 2.0 vs. 7.0 ± 1.6 %, p = 0.14) and systolic (159.4 ± 30.8 vs. 141.8 ± 35.5 mmHg, p = 0.13) and diastolic blood pressure (73.2 ± 9.3 vs. 69.2 ± 9.4 mmHg, p = 0.075) was observed. No significant differences were found in the lipid profile or creatinine clearance within the group.

CONCLUSION

Thirty-three percent of patients with advanced diabetic nephropathy had never previously seen a diabetes consultant and a significant proportion had other diabetes-related complications. Patients with diabetic nephropathy may therefore benefit from having a multidisciplinary input at a joint diabetes renal clinic.

The kidney disease quality of life cognitive function subscale and cognitive performance in maintenance hemodialysis patients

BACKGROUND

Cognitive impairment is common but often undiagnosed in patients with end-stage renal disease, in part reflecting limited validated and easily administered tools to assess cognitive function in dialysis patients. Accordingly, we assessed the utility of the Kidney Disease Quality of Life Cognitive Function (KDQOL-CF) scale in comparison to an extensive neuropsychological battery, building on a prior assessment of this potential cognitive screen.

STUDY DESIGN

Cross-sectional cohort.

SETTING & PARTICIPANTS

Maintenance hemodialysis patients at 6 Boston area dialysis units were administered an extensive neurocognitive battery and the KDQOL-CF at the beginning of a hemodialysis session.

PREDICTORS

KDQOL-CF score, depression symptom burden, and demographic and clinical characteristics.

OUTCOMES

Neurocognitive performance classified into executive function and memory domains, determined using principal components analysis.

MEASUREMENTS

Univariate and multivariable linear regression models adjusting for age, sex, race, and end-stage renal disease cause were used to evaluate the association between KDQOL-CF score and cognitive performance, and test metrics were determined for a KDQOL-CF cutoff score of 60 or less from a maximum score of 100.

RESULTS

For 168 prevalent hemodialysis patients, KDQOL-CF score was 76 ± 19 and 40 (24%) had scores of 60 or less, consistent with self-identified worse cognitive performance. There was no significant correlation between KDQOL-CF score and either memory (P = 0.2 and P = 0.3) or executive function (P = 0.1 and P = 0.4) in univariate and multivariable models, respectively. There was a strong correlation between higher KDQOL-CF score and fewer depression symptoms (P < 0.001). Sensitivity of the KDQOL-CF was poor (range, 0.28-0.36), with modest specificity (range, 0.77-0.81) for identifying worse executive function and memory.

LIMITATIONS

Cross-sectional study, modest population size, and abbreviated gold-standard cognitive battery.

CONCLUSIONS

The KDQOL-CF is a poor determinant of neurocognitive performance in hemodialysis patients, with limited sensitivity. To assess cognitive impairment in hemodialysis patients, better screening tests are essential.

The inflammatory cytokines TWEAK and TNFα reduce renal klotho expression through NFκB

Proinflammatory cytokines contribute to renal injury, but the downstream effectors within kidney cells are not well understood. One candidate effector is Klotho, a protein expressed by renal cells that has antiaging properties; Klotho-deficient mice have an accelerated aging-like phenotype, including vascular injury and renal injury. Whether proinflammatory cytokines, such as TNF and TNF-like weak inducer of apoptosis (TWEAK), modulate Klotho is unknown. In mice, exogenous administration of TWEAK decreased expression of Klotho in the kidney. In the setting of acute kidney injury induced by folic acid, the blockade or absence of TWEAK abrogated the injury-related decrease in renal and plasma Klotho levels. TWEAK, TNFα, and siRNA-mediated knockdown of IκBα all activated NFκB and reduced Klotho expression in the MCT tubular cell line. Furthermore, inhibition of NFκB with parthenolide prevented TWEAK- or TNFα-induced downregulation of Klotho. Inhibition of histone deacetylase reversed TWEAK-induced downregulation of Klotho, and chromatin immunoprecipitation showed that TWEAK promotes RelA binding to the Klotho promoter, inducing its deacetylation. In conclusion, inflammatory cytokines, such as TWEAK and TNFα, downregulate Klotho expression through an NFκB-dependent mechanism. These results may partially explain the relationship between inflammation and diseases characterized by accelerated aging of organs, including CKD.