Search

Background and Objectives: There have been limited studies regarding the association between glomerular hyperfiltration (GHF) and restrictive spirometry pattern (RSP) in Korean adults., Methods: We used data of 23,189 adults from the Korea National Health and Nutritional Examination Survey 2009-2015 with a complete data set including spirometry, serum creatinine, and anthropometric measurements. Spirometry data included the forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). We defined GHF as the >90th percentile of age & sex adjusted estimated glomerular filtration rate (eGFR), and RSP was defined as an FVC <80%-predicted value and an FEV1/FVC ratio ≥0.7., Results: Participants with RSP showed higher blood pressure, fasting glucose, and triglyceride, reduced high density lipoprotein cholesterol, and central obesity, which resulted in a higher prevalence of metabolic syndrome (MetS) compared to those without RSP. Multivariate logistic regression revealed that the odds for RSP were significantly increased with an increased number of MetS components. In addition, increased eGFR was associated with decreased FVC, showing an inverted J-shaped relationship in a multivariate generalized additive model analysis. In the multivariate logistic regression analysis, the adjusted odds ratio and 95% confidence interval of GHF for RSP was 1.184 (1.026-1.368, P = 0.021), which was evident in groups without metabolic disorders., Conclusions: We concluded that GHF was associated with increased odds for RSP, particularly in groups without metabolic disorders. Further prospective studies are needed to confirm our study results., Competing Interests: The authors have declared that no competing interests exist.

Background: Urine osmolality indicates the ability of the kidney to concentrate the urine and reflects the antidiuretic action of vasopressin. However, results about the association between urine osmolality and adverse renal outcomes in chronic kidney disease (CKD) are conflicting. We investigated the association between urine osmolality and adverse renal outcomes in a nationwide prospective CKD cohort., Methods: A total of 1,999 CKD patients were categorized into 3 groups according to their urine osmolality tertiles. Primary outcome was a composite of 50% decline in the estimated glomerular filtration rate (eGFR), initiation of dialysis, or kidney transplantation., Results: During a mean follow-up of 35.2 ± 19.0 months, primary outcome occurred in 432 (21.6%) patients; 240 (36.4%), 162 (24.3%), and 30 (4.5%) in the lowest, middle, and highest tertiles, respectively. Low urine osmolality was independently associated with a greater risk of CKD progression (hazard ratio [HR], 1.71; 95% confidence interval [CI], 1.12-2.59). This association was particularly evident in patients with CKD stages 3-4 (per 10 mosm/kg decrease; HR, 1.02; 95% CI, 1.00-1.03). Adding urine osmolality to a base model with conventional factors significantly increased the ability to predict CKD progression (C-statistics, 0.86; integrated discrimination improvement [IDI], 0.021; both p < 0.001). However, adding both urine osmolality and eGFR did not further improve the predictive ability compared with the addition of eGFR only (C-statistics, p = 0.29; IDI, p = 0.09)., Conclusions: Low urine osmolality was an independent risk factor for adverse renal outcomes in CKD patients, but its predictive ability did not surpass eGFR. Thus, kidney function should be considered while interpreting the clinical significance of urine osmolality., (© 2019 The Author(s) Published by S. Karger AG, Basel.)

Background: The estimated glomerular filtration rate (eGFR) is an important parameter in the management of patients with kidney diseases, yet eGFR quality goals are lacking. We examined the uncertainties in eGFR determinations and assessed their impact on patient classifications, aiming to set eGFR quality goals., Methods: Adult patients undergoing creatinine concentration assessments at our hospital, between June 2014 and October 2016, were included (N=285,982). Using 7 eGFR equations, we calculated the imprecisions in the eGFR, based on the imprecisions in determining creatinine and/or cystatin C concentrations. The uncertainties in the eGFR were expressed as functions of creatinine and/or cystatin C concentration uncertainties. Subsequently, the number of ambiguous cases was assessed, based on the calculated uncertainty in the eGFR., Results: Uncertainties in the eGFRs varied according to the eGFR calculation equation used. Although a 0.8% expanded uncertainty in the eGFR caused a 3.5% ambiguous case rate, a 10% expanded uncertainty resulted in a 42.3% rate of ambiguous cases. To meet minimal quality requirements, creatinine imprecision should be ≤3.0%., Conclusions: Even a low level of uncertainty in the eGFR may cause noticeable impacts on patient classifications. Laboratory physicians should be aware, and cautious, of the uncertainties in eGFR calculations., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background The relationship between orthostatic blood pressure (BP) changes and incident chronic kidney disease (CKD) has not been explored in Asian populations. Methods We reviewed the data of 7,039 participants from the Ansung-Ansan cohort study. BP was measured in the supine position and 2 minutes after standing. The change in BP from the supine to upright position was defined as orthostatic BP change. Orthostatic systolic BP (SBP) decline was defined as an orthostatic SBP change of <−2 mm Hg. The primary outcome was the development of CKD, defined as the first event of an estimated glomerular filtration rate <60 ml/min/1.73 m2 at least twice during the follow-up period. Results Of 7,039 participants, 949 (13.5 %) developed incident CKD over a mean of 11.9 years. Although orthostatic diastolic BP change was not associated with incident CKD, every 1 mm Hg increase in orthostatic SBP change was associated with a decreased risk of incident CKD (HR, 0.989; 95% CI, 0.982–0.995; P = 0.001). Orthostatic SBP decline was associated with an increased risk of incident CKD (HR, 1.337; 95% CI, 1.163–1.537; P < 0.001). Older age and diabetes were associated with increased odds of orthostatic SBP decline, whereas male sex and high body mass index were associated with decreased odds of orthostatic SBP decline. Subgroup analysis revealed that orthostatic SBP decline was associated with incident CKD only in non-diabetic participants. Conclusions Orthostatic SBP decline was independently associated with an increased risk of future incident CKD, whereas orthostatic DBP decline was not. [ABSTRACT FROM AUTHOR]

Introduction: The renal hazard of polypharmacy has never been evaluated in predialysis chronic kidney disease (CKD) patients. Objective: We aimed to analyze the renal hazard of polypharmacy in predialysis CKD patients with stage 1–5. Method: The data of 2,238 patients from a large-scale multicenter prospective Korean study (2011–2016), excluding 325 patients with various missing data, were reviewed. Polypharmacy was defined as taking 6 or more medications at the time of enrollment; renal events were defined as a ≥50% decrease in kidney function from baseline values, doubling of the serum creatinine levels, or initiation of renal replacement treatment. Hazard ratio (HR) and 95% confidence interval (CI) were calculated using Cox proportional-hazard regression analysis. Results: Of the 1,913 patients, the mean estimated glomerular filtration rate was 53.6 mL/min/1.73 m2. The mean medication count was 4.1, and the prevalence of polypharmacy was 27.1%. During the average period of 3.6 years, 520 patients developed renal events (27.2%). Although increased medication counts were associated with increased renal hazard with HR (95% CI) of 1.056 (1.007–1.107, p = 0.025), even after adjusting for various confounders, adding comorbidity score and kidney function nullified the statistical significance. In mediation analysis, 55.6% (p = 0.016) of renal hazard in increased medication counts was mediated by the kidney function, and there was no direct effect of medication counts on renal event development. In subgroup analysis, the renal hazard of the medication counts was evident only in stage 1–3 of CKD patients (p for interaction = 0.014). Conclusions: We cannot identify the direct renal hazard of multiple medications, and most of the potential renal hazard was derived from intimate relationship with disease burden and kidney function. [ABSTRACT FROM AUTHOR]

Introduction: Thyroid function is evaluated by thyroid stimulating hormone (TSH) and free thyroxine (fT4). Although many studies have indicated an intimate relationship between thyroid hormones and kidney functions, reports about the simultaneous evaluation of TSH and fT4 are rare. Objective: We aimed to analyze the association between TSH and kidney function, with emphasis on a potential nonlinear relationship, and identify an independent relationship between fT4 and kidney function. Methods: We reviewed the data of 7,061 subjects in the Korea National Health and Nutrition Examination Surveys who were randomly subsampled for thyroid function evaluation between 2013 and 2015. A total of 5,578 subjects were included in the final analysis, after excluding people <18 years old, and those with a short fasting time, abnormal fT4 levels, and thyroid disease or related medications. Creatinine-based estimated glomerular filtration rate (eGFR) was used to define kidney function. Results: A 1 mmol/L increase of logarithmic TSH was associated with decreased eGFR (β: –1.8; 95% CI –2.3 to –1.2; p < 0.001), according to multivariate linear regression analysis. On the multivariate generalized additive model plot, TSH demonstrated an L-shaped relationship with eGFR, showing a steeper slope for 0–4 mIU/L of TSH. A 1 µg/dL increase of fT4 was also associated with decreased eGFR (β: –7.0; 95% CI –0.94 to –4.7; p < 0.001) on the multivariate linear regression analysis; this association was reversed after adjusting for age. On the mediation analysis, the indirect effect via age and direct effect per 1 µg/dL increase of fT4 on eGFR was 9.9 (8.1 to 11.7, p < 0.001) and –7.1 (–9.3 to –4.8, p < 0.001), respectively. Conclusions: Increased TSH was associated with decreased eGFR, particularly in the reference range. The direct effect of increased fT4 was decreased eGFR, which may be affected indirectly by age. [ABSTRACT FROM AUTHOR]

Background: Development of acute kidney injury (AKI) is common and is associated with poor outcomes. We aimed to determine whether hypoalbuminemia (HA) at admission could be a risk factor for the development of AKI and mortality in hospitalized patients. Methods: We enrolled patients who were admitted to Seoul National University Bundang Hospital from January 2013 to December 2013. HA at admission was defined as a serum albumin level < 3.4 mg/dL measured within two days after admission. AKI was defined as an increase in the serum creatinine level by ≥0.3 mg/dL or ≥1.5 times of the baseline value during the hospital stay. Results: A total of 19,472 patients were enrolled and divided into HA and normoalbuminemia (NA) groups at admission. The incidence of AKI was 10.7% (340/3179) in the HA group and 4.1% (662/16293) in the NA group (adjusted odds ratio [OR], 1.243; 95% confidence interval [CI], 1.069–1.445; P = 0.005). The hazard ratios for the 30-day, 90-day, and 1-year mortality were 1.873 (95% CI, 1.383–2.537; P < 0.001), 1.710 (95% CI, 1.410–2.072; P < 0.001), and 1.372 (95% CI, 1.214–1.551; P < 0.001), compared to the NA group. In patients with AKI, albumin replacement improved renal recovery (OR, 2.605; 95% CI, 1.450–4.681; P = 0.001). The mortality rate was not different according to albumin replacement. Conclusions: HA is associated with the development of AKI and high mortality in hospitalized patients. Replacement of albumin after the development of AKI may contribute to renal recovery. Further clinical trials are warranted. [ABSTRACT FROM AUTHOR]

Background and Objectives: Cardiovascular outcomes and mortality rates are poor in advanced chronic kidney disease (CKD) patients. Novel risk factors related to clinical outcomes should be identified. Methods: A retrospective analysis of data from a randomized controlled study was performed in 440 CKD patients aged > 18 years, with estimated glomerular filtration rate 15–60 mL/min/1.73m2. Clinical data were available, and the albumin-adjusted serum anion gap (A-SAG) could be calculated. The outcome analyzed was all-cause mortality. Results: Of 440 participants, the median (interquartile range, IQR) follow-up duration was 5.1 (3.0–5.5) years. During the follow-up duration, 29 participants died (all-cause mortality 6.6%). The area under the receiver operating characteristic curve of A-SAG for all-cause mortality was 0.616 (95% CI 0.520–0.712, P = 0.037). The best threshold of A-SAG for all-cause mortality was 9.48 mmol/L, with sensitivity 0.793 and specificity 0.431. After adjusting for confounders, A-SAG above 9.48 mmol/L was independently associated with increased risk of all-cause mortality, with hazard ratio 2.968 (95% CI 1.143–7.708, P = 0.025). In our study, serum levels of beta-2 microglobulin and blood urea nitrogen (BUN) were positively associated with A-SAG. Conclusions: A-SAG is an independent risk factor for all-cause mortality in advanced CKD patients. The positive correlation between A-SAG and serum beta-2 microglobulin or BUN might be a potential reason. Future study is needed. Trial Registration: Clinicaltrials.gov [ABSTRACT FROM AUTHOR]

Background and Objectives: There has been little published information on risk factors for poor long-term outcome in adult biopsy-proven minimal change disease (MCD). Methods: Data from sixty-three adult, biopsy-proven primary MCD patients treated at a tertiary university hospital between 2003 and 2013 were analyzed. Baseline clinical and pathologic factors were assessed for the associations with composite outcome of creatinine doubling, end stage renal disease, or all-cause mortality. Results: During a median (interquartile) 5.0 (2.8–5.0) years, the composite outcome occurred in 11.1% (7/63) of patients. The rate of glomerular immune deposits was 23.8% (15/63). Patients with glomerular immune deposits showed a significantly lower urine protein creatinine ratio than those without deposits (P = 0.033). The rate of non-responders was significantly higher in patients with glomerular immune deposits than in those without deposits (P = 0.033). In patients with deposits, 26.7% (4/15) developed the composite outcome, while only 6.3% (3/48) developed the composite outcome among those without deposits (P = 0.049). In multivariate Cox proportional hazards regression analysis, the presence of glomerular immune deposits was the only factor associated with development of the composite outcome (hazard ratio: 2.310, 95% confidence interval: 1.031–98.579, P = 0.047). Conclusion: Glomerular immune deposits were associated with increased risk of a composite outcome in adult MCD patients. The higher rate of non-responders in patients with deposits might be related to the poor outcome. Future study is needed. [ABSTRACT FROM AUTHOR]