Hypertensive nephrosclerosis: wider kidney biopsy indications may be needed to improve diagnostics

Background Hypertensive nephrosclerosis is the presumed underlying cause in many end‐stage kidney disease (ESKD) patients, but the diagnosis is disputed and based on clinical criteria with low diagnostic accuracy. Objective To evaluate and improve the diagnostic process for nephrosclerosis patients. Methods We included adults from the population‐based HUNT study (n = 50 552), Norwegian CKD patients referred for kidney biopsy 1988–2012 (n = 7261), and unselected nephrology clinic patients (n = 193) used for matching. Decision tree analysis and ROC curve‐based methods of optimal cut‐offs were used to improve clinical nephrosclerosis criteria. Results Nephrosclerosis prevalence was 2.7% in the general population, and eGFR decline and risk for kidney‐related hospital admissions and ESKD were comparable to patients with diabetic kidney disease. In the biopsy cohort, current clinical criteria had very low sensitivity (0.13) but high specificity (0.94) for biopsy‐verified arterionephrosclerosis. A new optimized diagnostic algorithm based on proteinuria (155 mm Hg) and age (>75 years) only marginally improved diagnostic accuracy (sensitivity 0.19, specificity 0.96). Likewise, there were still false‐positive cases with treatable diagnoses like glomerulonephritis, interstitial nephritis and others (40% of all test positive). Decision curve analysis showed that the new criteria can lead to higher clinical utility, especially for patients considering the potential harms to be close to the potential benefits, while the more risk‐tolerant ones (harm:benefit ratio < 1:4) should consider kidney biopsy. Conclusion Further improvements of the current clinical criteria seem difficult, so risks and benefits of kidney biopsy could be more actively discussed with selected patients to reduce misclassification and direct treatment.publishedVersio

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 result

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Nutritional problems, overhydration and the association with quality of life in elderly dialysis patients

Purpose The aim of this pilot study was to describe the hydration and nutritional status of a cohort of elderly dialysis patients and to explore the association between these parameters and the quality of life (QoL). Methods All patients over 75 years of age being in chronic dialysis by January 2008 at 3 dialysis units (n = 34) were asked to participate in this pilot study, 24 patients were entered. Hydration status was assessed by bioimpedance spectroscopy (BIS) and nutritional status by the subjective global assessment (SGA), BIS, anthropometric measures and biochemical parameters. Based on these assessments the patients were classified as being cachectic or not according to newly defined criteria. QoL was measured using the SF-36. Results The results showed cachexia in 6 (25 %), 37.5 % had a body mass index below 24, whereas according to SGA 91 % were malnourished. BIS showed low lean tissue index in 46 % and overhydration in 35 % of the patients. Compared to non-cachectic and normohydrated, cachectic and overhydrated patients reported consistently poorer QoL. For cachectic patients, the differences were clinically significant for all SF-36. BIS was easily applicable when used before dialysis. Conclusions The high frequency of nutritional deficits in this study calls for more attention to nutritional status in elderly dialysis patients. There is a need for a general agreement on how nutritional status should be assessed and reported, both in clinics and in research

Reference limits for chromogranin A, CYFRA 21-1, CA 125, CA 19-9 and carcinoembryonic antigen in patients with chronic kidney disease

Background Patients with chronic kidney disease (CKD) may have increased plasma concentrations of some tumor markers even when no cancer is present. Previous studies have indicated that plasma concentrations of chromogranin A (CGA), cytokeratin 19 fragments (CYFRA 21-1), cancer antigen 125 (CA 125), cancer antigen 19-9 (CA 19-9) and carcinoembryonic antigen (CEA) are higher in patients with CKD but without cancer, than in healthy individuals, and this can make interpretation of results more complicated. The aim of this study was to establish reference limits for these markers in patients with CKD not receiving dialysis and with no clinical evidence of cancer. Methods We measured plasma concentrations in samples from 131 patients with CKD due to various etiologies and studied the association of tumor marker concentrations with estimated glomerular filtration rate (GFR) and other patient characteristics. Results Estimated reference limits for plasma CA 125, CA 19-9 and CEA were approximately the same as for healthy populations. Serum concentrations of CGA and CYFRA 21-1 correlated strongly with estimated GFR, and GFR-dependent reference limits were estimated. Conclusions GFR-dependent reference limits for CGA and CYFRA 21-1 are reported in order to support interpretation of these markers in patients with CKD

Hypertensive nephrosclerosis: wider kidney biopsy indications may be needed to improve diagnostics

Background Hypertensive nephrosclerosis is the presumed underlying cause in many end‐stage kidney disease (ESKD) patients, but the diagnosis is disputed and based on clinical criteria with low diagnostic accuracy. Objective To evaluate and improve the diagnostic process for nephrosclerosis patients. Methods We included adults from the population‐based HUNT study (n = 50 552), Norwegian CKD patients referred for kidney biopsy 1988–2012 (n = 7261), and unselected nephrology clinic patients (n = 193) used for matching. Decision tree analysis and ROC curve‐based methods of optimal cut‐offs were used to improve clinical nephrosclerosis criteria. Results Nephrosclerosis prevalence was 2.7% in the general population, and eGFR decline and risk for kidney‐related hospital admissions and ESKD were comparable to patients with diabetic kidney disease. In the biopsy cohort, current clinical criteria had very low sensitivity (0.13) but high specificity (0.94) for biopsy‐verified arterionephrosclerosis. A new optimized diagnostic algorithm based on proteinuria (155 mm Hg) and age (>75 years) only marginally improved diagnostic accuracy (sensitivity 0.19, specificity 0.96). Likewise, there were still false‐positive cases with treatable diagnoses like glomerulonephritis, interstitial nephritis and others (40% of all test positive). Decision curve analysis showed that the new criteria can lead to higher clinical utility, especially for patients considering the potential harms to be close to the potential benefits, while the more risk‐tolerant ones (harm:benefit ratio < 1:4) should consider kidney biopsy. Conclusion Further improvements of the current clinical criteria seem difficult, so risks and benefits of kidney biopsy could be more actively discussed with selected patients to reduce misclassification and direct treatment

Hypertensive nephrosclerosis: wider kidney biopsy indications may be needed to improve diagnostics

Background. Hypertensive nephrosclerosis is the presumed underlying cause in many end-stage kidney disease (ESKD) patients, but the diagnosis is disputed and based on clinical criteria with low diagnostic accuracy. Objective. To evaluate and improve the diagnostic process for nephrosclerosis patients. Methods. We included adults from the populationbased HUNT study (n = 50 552), Norwegian CKD patients referred for kidney biopsy 1988–2012 (n = 7261), and unselected nephrology clinic patients (n = 193) used for matching. Decision tree analysis and ROC curve-based methods of optimal cut-offs were used to improve clinical nephrosclerosis criteria. Results. Nephrosclerosis prevalence was 2.7% in the general population, and eGFR decline and risk for kidney-related hospital admissions and ESKD were comparable to patients with diabetic kidney disease. In the biopsy cohort, current clinical criteria had very low sensitivity (0.13) but high specificity (0.94) for biopsy-verified arterionephrosclerosis. A new optimized diagnostic algorithm based on proteinuria (<0.75 g d 1 ), systolic blood pressure (>155 mm Hg) and age (>75 years) only marginally improved diagnostic accuracy (sensitivity 0.19, specificity 0.96). Likewise, there were still false-positive cases with treatable diagnoses like glomerulonephritis, interstitial nephritis and others (40% of all test positive). Decision curve analysis showed that the new criteria can lead to higher clinical utility, especially for patients considering the potential harms to be close to the potential benefits, while the more risk-tolerant ones (harm:benefit ratio < 1:4) should consider kidney biopsy. Conclusion. Further improvements of the current clinical criteria seem difficult, so risks and benefits of kidney biopsy could be more actively discussed with selected patients to reduce misclassification and direct treatment

Blood Pressure Treatment in Kidney Transplant Recipients—Can We Improve?

Background. Hypertension in kidney transplant (KTx) recipients is common, affecting both patient and graft survival. Annual data from the Norwegian Renal Registry reveal that 18 y) KTx recipients reach target blood pressure (BP) ≤130/80 mm Hg. The aim of this study was to identify the determinants of failure to achieve BP control. Methods. In conjunction with the 2018 annual data reporting, additional questions were added for recipients with BP >130/80 mm Hg (treating physician´s target BP for each patient, reasons for not achieving target, method of measurement). Results. Annual forms were received from 98% (3407 of 3486) of KTx recipients, with 1787 (52%) reporting a BP >130/80 mm Hg (“above-target” group). These recipients were older, mostly male, with higher body mass index and serum creatinine levels (P 130/80 mm Hg, 51% did not reach these individual targets. The number of antihypertensive drugs was significantly higher in the “above-target” group versus “on-target” group (mean 2.1 ± 1.2 versus 1.8 ± 1.3) and 36% versus 25% used ≥3 antihypertensive drugs (P < 0.05). Automatic attended BP measurement was utilized by 51%. Conclusions. In KTx recipients, a higher BP target achievement seems possible, potentially in the range of 75%-80%