Factors associated with CKD in the elderly and nonelderly population

Global forecasting of chronic kidney disease mortality rates and numbers with the generalized additive model

BACKGROUND

Chronic kidney disease (CKD) is an important public health problem worldwide; therefore, forecasting CKD mortality rates and death numbers globally is vital for planning CKD prevention programs. This study aimed to characterize the temporal trends in CKD mortality at the international level from 1990 to 2019 and predict CKD mortality rates and numbers until 2030.

METHODS

Data were obtained from the Global Burden of Disease 2019 Study. A joinpoint regression model was used to estimate the average annual percentage change in CKD mortality rates and numbers. Finally, we used a generalized additive model to predict CKD mortality through 2030.

RESULTS

The number of CKD-related deaths worldwide increased from 591.80 thousand in 1990 to 1425.67 thousand in 2019. The CKD age-adjusted mortality rate increased from 15.95 per 100,000 people to 18.35 per 100,000 people during the same period. Between 2020 and 2030, the number of CKD deaths is forecasted to increase further to 1812.85 thousand by 2030. The CKD age-adjusted mortality rate is expected to decrease slightly to 17.76 per 100,000 people (95% credible interval (CrI): 13.84 to 21.68). Globally, it is predicted that in the next decade, the CKD mortality rate will decrease in men, women, all subgroups of disease etiology except glomerulonephritis, people younger than 40 years old, and all groupings of countries based on the sociodemographic index (SDI) except high-middle-SDI countries.

CONCLUSIONS

The CKD mortality rate is predicted to decrease in the next decade. However, more attention should be given to people with glomerulonephritis, people over 40 years old, and people in high- to middle-income countries because the mortality rate due to CKD in these subgroups is expected to increase until 2030.

Hepatitis B virus infection as a risk factor for chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

Currently, several studies have observed that chronic hepatitis B virus infection is associated with the pathogenesis of kidney disease. However, the extent of the correlation between hepatitis B virus infection and the chronic kidney disease risk remains controversial.

METHODS

In the present study, we searched all eligible literature in seven databases in English and Chinese. The random effects model was used to conduct a meta-analysis. Quality of included studies was assessed using the Newcastle-Ottawa Quality Scale.

RESULTS

In this analysis, a total of 31 studies reporting the association between hepatitis B virus infection and chronic kidney disease risk were included. The results showed a significant positive association between hepatitis B virus infection and the risk of chronic kidney disease (pooled OR, 1.20; 95% CI, 1.12-1.29), which means that hepatitis B virus increases the risk of developing chronic kidney disease.

CONCLUSION

This study found that hepatitis B virus infection was associated with a significantly increased risk of chronic kidney disease. However, the current study still cannot directly determine this causal relationship. Thus, more comprehensive prospective longitudinal studies are needed in the future to provide further exploration and explanation of the association between hepatitis B virus and the risk of developing chronic kidney disease.

Application of creatinine-based eGFR equations in Chinese septuagenarians and octogenarians

PURPOSE

The utilization of creatinine-based estimated glomerular filtration rate (eGFR) equations in the adult population is acknowledged. Nevertheless, the appropriateness of creatinine-based eGFR in septuagenarians and octogenarians is debatable. This study evaluates the creatinine-based equations in Chinese septuagenarians and octogenarians cohorts.

PATIENTS AND METHODS

This study employed a retrospective design, utilizing a review of the hospital medical records system to identify 347 hospitalized participants within the Division of Geriatrics or the Division of Nephrology. These participants underwent renal dynamic imaging with 99 m Tc-DTPA and serum creatinine testing. Comparison of the equations was performed, including the full age-spectrum equation (FAS-Cr equation), European Kidney Function Consortium equation (EKFC equation), Chronic Kidney Disease Epidemiology Collaboration equation for Asian (Asian CKD-EPI equation), Xiangya equation, and Lund-Malmö revised equation (LMR equation).

RESULTS

Most equations tended to underestimate GFR. The FAS-Cr equation had the smallest interquartile range (IQR), while the Asian CKD-EPI equation (mGFR ≥ 30) and Xiangya equation (mGFR < 30) had the biggest IQRs. The FAS-Cr equation had the highest overall P30 of 63.98%, while the Asian CKD-EPI equation had the highest P30 of 75.64% in mGFR ≥ 60. The Xiangya equation, on the other hand, reported the lowest P30 of 36.36% in mGFR < 30. We discovered similar patterns in root-mean-square error (RMSE) as P30. GFR category misclassification rates in the entire cohort ranged from 46.11 to 49.86% for all equations. The FAS-Cr equation exhibited an advantage in octogenarians over other equations in the GFR category misclassification with mGFR lower than 60 ml/min/1.73 m2.

CONCLUSION

None of the creatinine-based equations in this study could perform well regarding precision, accuracy, and CKD stages' classification for the Chinese elderly. Nevertheless, the FAS-Cr equation should be suitable for octogenarians with mGFR lower than 60 ml/min/1.73 m2.

The Relationship Between Sleep and Brain Function in Older Adults With Chronic Kidney Disease and Self-Identified Cognitive Impairment

Older adults with chronic kidney disease (CKD) are at risk for cognitive impairment and sleep disturbances. The purpose of the current study was to investigate the relationship between sleep and brain structure/function in older adults with CKD and self-identified cognitive impairment. The sample (N = 37) had a mean age of 68 years (SD = 4.9 years), estimated glomerular filtration rate of 43.7 mL/min/1.73m2 (SD = 10.98), median sleep time of 7.4 hours, and was 70% female. Sleeping <7.4 hours, compared to ≥7.4 hours, was associated with better attention/information processing (β = 11.46, 95% confidence interval [CI] [3.85, 19.06]) and better learning/memory (β = 2.06, 95% CI [0.37, 3.75]). Better sleep efficiency was associated with better global cerebral blood flow (β = 3.30, 95% CI [0.65, 5.95]). Longer awake length after sleep onset was associated with worse fractional anisotropy of the cingulum (β = -0.01, 95% CI [-0.02, -0.003]). Sleep duration and continuity may be related to brain function in older adults with CKD and self-identified cognitive impairment. [Journal of Gerontological Nursing, 49(7), 31-39.].

A nomogram for predicting the 4-year risk of chronic kidney disease among Chinese elderly adults

BACKGROUND

Chronic kidney disease (CKD) has become a major public health problem across the globe, leading to various complications. This study aimed to construct a nomogram to predict the 4-year risk of CKD among Chinese adults.

METHODS

The study was based on the China Health and Retirement Longitudinal Study (CHARLS). A total of 3562 participants with complete information in CHARLS2011 and CHARLS2015 were included, and further divided into the training cohort and the validation cohort by a ratio of 7:3. Univariate and multivariate logistic regression analyses were used to select variables of the nomogram. The nomogram was evaluated by receiver-operating characteristic curve, calibration plots, and decision curve analysis (DCA).

RESULTS

In all, 2494 and 1068 participants were included in the training cohort and the validation cohort, respectively. A total of 413 participants developed CKD in the following 4 years. Five variables selected by multivariate logistic regression were incorporated in the nomogram, consisting of gender, hypertension, the estimated glomerular filtration rate (eGFR), hemoglobin, and Cystatin C. The area under curve was 0.809 and 0.837 in the training cohort and the validation cohort, respectively. The calibration plots showed agreement between the nomogram-predicted probability and the observed probability. DCA indicated that the nomogram had potential clinical use.

CONCLUSIONS

A predictive nomogram was established and internally validated in aid of identifying individuals at increased risk of CKD.

Exposure to ambient air pollutants with kidney function decline in chronic kidney disease patients

Chronic kidney disease (CKD) has been a global public health problem with many adverse outcomes, but data are lacking regarding the relationship between air pollutants and risk of renal progression in patients with CKD. This study was to investigate whether 1-year average exposure to ambient air pollutants -CO, NO, NO₂, SO₂, O₃, PM_2.5, and PM₁₀-is related to renal function deterioration among patients with CKD. A total of 5301 CKD patients were included in this study between October 2008 and February 2016. To estimate each patient's exposure to ambient air pollution, we used the 24-h ambient air pollution concentration monitoring data collected one year prior to renal progression or their last renal function assessment. Renal progression was considered when estimated glomerular filtration rate (eGFR) decreased more than 25% from the baseline eGFR. Cox proportional hazard regression was performed to calculate hazard ratios (HRs). Among 5301 patients with CKD, 1813 (34.20%) developed renal progression during the 30.48 ± 14.99-month follow-up. Patients with the highest quartile exposure to CO [HR = 1.53 (95% CI: 1.24, 1.88)], NO [HR = 1.38 (95% CI: 1.11, 1.71)], NO₂ [HR = 1.63 (95% CI: 1.36, 1.97)], SO₂ [HR = 2.27 (95% CI: 1.83, 2.82)], PM_2.5 [HR = 7.58 (95% CI: 5.97, 9.62)], and PM₁₀ [HR = 3.68 (95% CI: 2.84, 4.78)] had a significantly higher risk of renal progression than those with the lowest quartile exposure. In the multipollutant model, the analyses yielded to similar results. These results reinforce the importance of measures to mitigate air pollution and strategies to prevent worsening of kidney function in patients with CKD. One-year high exposure to ambient CO, NO, NO₂, SO₂, PM_2.5, and PM₁₀ is significantly associated with deteriorated kidney function in patients with CKD among Taiwanese adults.

Hepatitis Status and its Effect upon the Progression of Chronic Kidney Disease: Presentations, Associations and Complications

Chronic kidney disease (CKD), hepatitis B virus (HBV), and hepatitis C virus (HCV) have a high prevalence in Oman. This study aimed to examine the association between CKD and viral hepatitis through an observational cohort study conducted at the Royal Hospital of the Sultanate of Oman to evaluate the relationship of HBV and HCV with CKD. During the study, 233 patients were identified, 112 with chronic HBV (Group 1), 112 with chronic HCV (Group 2), and nine with HBV and HCV coinfection (Group 3). The population was predominantly male, especially in Groups 1 and 3. The difference in age between Groups 1 and 2 was significant, with the mean age being 48 ± 14.6 years and 55 ± 12.6 years, respectively (P <0.05). This study revealed that the prevalence of CKD in Group 1 is 51%, in Group 2 was 78%, and in Group 3 was 56%. The mean estimated glomerular filtration rate (eGFR) was 79.7 mL/min/1.73 m2 in Group 1, 73.2 mL/min/1.73 m2 in Group 2, and 57.6 mL/min/1.73 m2 in Group 3. CKD had the highest prevalence in Group 2. The lowest eGFR was found in Group 3. Group 2 showed the highest rate of declining renal function over time despite treatment. This study found a significant and independent association between viral hepatitis and the risk of CKD, especially in cases of coinfection and HCV infection. This warrants close monitoring of kidney function during screening and follow-up. Patients with CKD should be screened for viral hepatitis.

HBV infection is a risk factor for chronic kidney disease: Systematic review and meta-analysis

BACKGROUND

The activity of hepatitis B virus (HBV) as a risk factor for the incidence and progression of chronic kidney disease (CKD) has not been clarified.

AIM

We evaluated the impact of infection with HBV on the risk of CKD in the general population.

MATERIAL AND METHODS

We carried out a systematic review of the published medical literature to assess whether a relationship between hepatitis B infection and an increased risk of CKD in the adult general population occurs. We adopted the random effects model of DerSimonian and Laird to provide a summary estimate of the risk of chronic kidney disease (defined by lowered glomerular filtration rate and/or detectable proteinuria) with HBV infection across the published studies. Meta-regression and stratified analyses were also performed.

RESULTS

We retrieved 33 studies (n = 7,849,849 patients) published in 26 different articles, and separate meta-analyses were performed according to the outcome. Pooling results from cohort studies (11 studies, n = 1,056,645 patients) demonstrated a relationship between positive HBV serologic status and increased incidence of CKD, the summary estimate for adjusted HR with HBV across the surveys, 1.40 (95% CI, 1.16-1.69) (P < .001). Between-study heterogeneity was noted (Q value, 49.5, P < .0001). No relationship between HBV and prevalence of CKD was noted in the subset of cross-sectional studies (10 studies; n = 3,222,545 patients), adjusted OR, 1.04 (95% IC 0.90-1.218; P = .5). Meta-regression analysis reported a relationship between positive HBsAg status and incidence of CKD in the general population (P < .015).

CONCLUSIONS

It appears that exposure to HBV infection seems to be associated with an increased risk of developing CKD in the adult general population. Studies aimed to understand the mechanisms responsible of such association are under way.

Hyperuricemia, urate-lowering therapy, and kidney outcomes: a systematic review and meta-analysis

BACKGROUND

Contradictory evidence exists for association of hyperuricemia and kidney function. To investigate the association of hyperuricemia and kidney function decline (hyperuricemia question) and effect of urate-lowering therapies (ULTs) on kidney function (ULT question), we performed a systematic review and meta-analysis.

METHODS

MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and CINAHL were searched from inception to July 2020. We selected observational studies for the hyperuricemia question and controlled trials for the ULT question. Two investigators independently assessed study eligibility and abstracted the data. Risk of bias was assessed using the Newcastle-Ottawa Scale and Cochrane risk of bias tool. Meta-analysis was done using the inverse variance method and random effect model. We estimated odds ratio (OR), hazard ratio (HR), risk ratio (RR), and the mean difference (MD). Evidence certainty was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

RESULTS

Of 12,037 studies screened, 131 studies with 3,414,226 patients were included. Hyperuricemia was associated with a significant risk of rapid estimated glomerula filtration rate (eGFR) decline ⩾3 ml/min per 1.73 m2 per year (OR 1.38, 95% CI 1.20-1.59; low certainty), albuminuria (OR/HR 1.94, 95% CI 1.34-2.79; very low certainty), chronic kidney disease (OR/HR 2.13, 95% CI 1.74-2.61; very low certainty), and kidney failure (HR 1.53, 95% CI 1.18-1.99; very low certainty). Compared with control, ULT use for ⩾1 year was associated with significantly more improved eGFR (MD 1.81 ml/min per 1.73 m2, 95% CI 0.26-3.35; very low certainty), serum creatinine (MD -0.33 mg/dl, 95% CI -0.47 to -0.19; low certainty), and proteinuria (MD -5.44 mg/day, 95% CI -8.49 to -2.39; low certainty), but no difference in kidney failure.

CONCLUSION

Hyperuricemia is associated with worsening eGFR, albuminuria, chronic kidney disease, and kidney failure. ULT use for ⩾1 year may improve kidney function.

REGISTRATION

The protocol was registered at PROSPERO database, CRD42015013859.

Correlation of Indoleamine-2,3-Dioxygenase and Chronic Kidney Disease: A Pilot Study

Objective

To explore the correlation of indoleamine-2,3-dioxygenase (IDO) and chronic kidney disease (CKD).

Methods

A total of 154 CKD patients and 42 non-CKD patients were recruited. Patients were grouped into ACR1~ACR3 (<30 mg/g, 30-300 mg/g, and >300 mg/g). Biomarkers in different groups were compared by ANOVA. Correlation was calculated by Pearson or Spearman analysis and binary logistic regression. The ROC curve was also performed.

Results

The levels of albumin, serum creatinine (sCr), and IDO in non-CKD patients were significantly different from those in CKD3-CKD5 stages (p < 0.05). IDO was correlated with age, proteinuria, ACR, and eGFR (p < 0.01). After adjusting for CKD-related indices, ln(IDO) was an independent risk factor for CKD (3.48, p < 0.05). The analysis of ROC curve revealed a best cut­off for IDO was 0.0466 and yielded a sensitivity of 83.8% and a specificity of 75%. Hemoglobin, total protein, and albumin in the ACR1 group were significantly higher than those in the ACR2 and ACR3 groups (p < 0.01), while sCr and IDO levels were significantly lower than those in the ACR2 and ACR3 groups (p < 0.01 or p < 0.05). After adjusting for CKD-related indices, ln(IDO) was still an independent risk factor for ACR (OR = 2.7, p < 0.05). The analysis of ROC curve revealed a best cut­off for IDO was 0.075 and yielded a sensitivity of 71.9% and a specificity of 72.2%.

Conclusion

IDO may be a promising biomarker to predict CKD and assess kidney function.

PhysIOpathology of NEuromuscular function rElated to fatigue in chronic Renal disease in the elderly (PIONEER): study protocol

BACKGROUND

Chronic Kidney Disease (CKD) is associated with reduced muscular strength resulting in profound fatigue. The physiopathology of these changes, their prevalence and evolution are still debated. Moreover, we have little data on elderly CKD patients. The present study protocol aims to 1) quantify the prevalence of low muscle strength (dynapenia) in a cohort of elderly patients with advanced CKD and to 2) characterize their force production coupled with electromyographic features and the symptoms of fatigue compared to a matched control group.

METHODS

This is a case-control, prospective, interventional study.

INCLUSION CRITERIA

age ≥ 60 years; CKD Stage 3b-5; clinical stability (i.e. no hospitalization and ≤ 25% in creatinine increase in the previous 3 months). Controls with normal kidney function will be matched in terms of age, gender and diabetes mellitus (requisite: estimated glomerular filtration rate ≥ 60 ml/min/1.73m² available in the last 6 months). Exclusion criteria for cases and controls: neuromuscular disease, life expectancy < 3 months. The handgrip strength protocol is an intermittent test consisting in 6 series of 9 repetitions of 3-s sub-maximum contractions at 40% of the maximum voluntary contraction (MVC) and 2 s of resting time between contractions. Each series is separated by one fast sub-maximum contraction and one MVC. Strength is assessed with a high-frequency handgrip dynamometer paired with surface electromyography. Symptoms of fatigue are assessed using MFI-20 and FACIT-F questionnaires. In order to reach a statistical power of 96%, we plan to enroll 110 subjects in each group.

DISCUSSION

The novelty of this study resides in the application of an already validated set of tests in a population in which this combination (dynamometer, electromyography and questionnaires) has not previously been explored. We expect a high prevalence of dynapenia and a higher fatigability in CKD patients. A positive correlation is expected between reported fatigue and fatigability. Better appreciation of the prevalence and the relationship between fatigability and a sensation of fatigue can help us target interventions in CKD patients to improve quality of life and survival.

TRIAL REGISTRATION

The study was approved by Ethical Committee EST III n°20.03.01 and was recorded as a Clinical Trial (NCT04330807) on April 2, 2020.

HBV infection is a risk factor for chronic kidney disease: Systematic review and meta-analysis

BACKGROUND

The activity of hepatitis B virus (HBV) as a risk factor for the incidence and progression of chronic kidney disease (CKD) has not been clarified.

AIM

We evaluated the impact of infection with HBV on the risk of CKD in the general population.

MATERIAL AND METHODS

We carried out a systematic review of the published medical literature to assess whether a relationship between hepatitis B infection and an increased risk of CKD in the adult general population occurs. We adopted the random effects model of DerSimonian and Laird to provide a summary estimate of the risk of chronic kidney disease (defined by lowered glomerular filtration rate and/or detectable proteinuria) with HBV infection across the published studies. Meta-regression and stratified analyses were also performed.

RESULTS

We retrieved 33 studies (n=7,849,849 patients) published in 26 different articles, and separate meta-analyses were performed according to the outcome. Pooling results from cohort studies (11 studies, n=1,056,645 patients) demonstrated a relationship between positive HBV serologic status and increased incidence of CKD, the summary estimate for adjusted HR with HBV across the surveys, 1.40 (95% CI, 1.16-1.69) (P<.001). Between-study heterogeneity was noted (Q value, 49.5, P<.0001). No relationship between HBV and prevalence of CKD was noted in the subset of cross-sectional studies (10 studies; n=3,222,545 patients), adjusted OR, 1.04 (95% IC 0.90-1.218; P=.5). Meta-regression analysis reported a relationship between positive HBsAg status and incidence of CKD in the general population (P<.015).

CONCLUSIONS

It appears that exposure to HBV infection seems to be associated with an increased risk of developing CKD in the adult general population. Studies aimed to understand the mechanisms responsible of such association are under way.

Association Between Hepatitis C Virus and Chronic Kidney Disease: A Systematic Review and Meta-Analysis

INTRODUCTION AND AIM

The role of hepatitis C virus infection as a risk factor for the development and progression of chronic kidney disease in the general population remains unclear.

MATERIAL AND METHODS

A systematic review of the published medical literature was performed to assess whether positive anti-HCV serologic status is associated with higher frequency of chronic kidney disease in the adult general population. We used a random-effects model to generate a summary estimate of the relative risk of chronic kidney disease (defined by lowered glomerular filtration rate or detectable proteinuria) with HCV across the published studies. Meta-regression and stratified analysis were also carried out.

RESULTS

Forty studies were eligible (n = 4,072,867 patients), and separate meta-analyses were conducted according to the outcome. Pooling results of longitudinal studies (n = 15 studies, n = 2,299,134 unique patients) demonstrated an association between positive anti-HCV serologic status and increased incidence of CKD, the summary estimate for adjusted HR with HCV across the surveys, 1.54 (95% CI, 1.26; 1.87) (P &lt; 0.001). Between-study heterogeneity was observed (Q value by Chi-squared [χ2] test 500.3, P &lt; 0.0001). The risk of chronic kidney disease related to HCV, in the subset of surveys from Asia was 1.45 (1.27; 1.65) (P &lt; 0.001) (no heterogeneity). According to our meta-regression, ageing (P &lt; 0.0001) and duration of follow-up (P &lt; 0.0001) increased the risk of chronic kidney disease among HCV-positive subjects. We observed a relationship between anti-HCV positive serologic status and frequency of proteinuria, adjusted effect estimate of proteinuria with HCV among surveys was 1.633 (95% CI, 1,29; 2.05) (P &lt; 0.001) (n = 10 studies; 315,404 unique patients). However, between-studies heterogeneity was noted (P value by Q test &lt; 0.0001).

CONCLUSION

An association between HCV infection and increased risk of chronic kidney disease in the general population exists. The mechanisms underlying such association are currently under active investigation.

Associations between Water Quality Measures and Chronic Kidney Disease Prevalence in Taiwan

To determine the relationships between exposure to environmental contaminants in water and chronic kidney disease (CKD), we investigated the associations of 61 water attributes with the prevalence of CKD and End-Stage Renal Disease (ESRD) using data from 2005 to 2011 from all 22 counties and cities in the main island of Taiwan. We acquired patient information from the Taiwan Longitudinal Health Insurance Database to calculate the age-standardized CKD and ESRD prevalence rates and linked the patients’ residences to the water quality monitoring data, which were sampled periodically for a total of over 45,000 observations obtained from the Taiwan Environmental Water Quality Information Database. The association analysis adjusting for gender, age, and annual effects showed that the zinc (Zn), ammonia, chemical oxygen demand (COD), and dissolved oxygen in rivers were weakly correlated with CKD (τ = 0.268/0.250/0.238/−0.267, p = 6.01×10⁻⁶/2.52×10⁻⁵/6.05×10⁻⁵/3.30×10⁻⁵, respectively), but none for ESRD. The importances of Zn and COD in rivers were also demonstrated in a CKD regression model. Moreover, an unusually high CKD prevalence was related to arsenic contamination in groundwater. A further prospective cohort study would improve our understanding of what level of environmental water with risky properties could affect the development of CKD.

Prognostic value of plasma NT-proBNP levels in very old patients with moderate renal insufficiency in China

BACKGROUND

The N‑terminal pro-brain natriuretic peptide (NT-proBNP) has an important prognostic value in chronic renal insufficiency; however, most studies have been conducted in patients with end-stage renal disease (ESRD). In this study we evaluated the prognostic significance of NT-proBNP in very old patients with stage 3 chronic kidney disease (CKD) and compared its prognostic value in CKD3a versus CKD3b patients.

METHODS

Patients (age ≥80 years old) hospitalized with stage 3 CKD from 2007 to 2010 who were eligible for this prospective study underwent follow-up examinations in 2015. The examinations included measurements of anthropometric characteristics, blood pressure, plasma NT-proBNP, creatinine, and lipids. End-point events were all-cause death and major adverse cardiac events (MACEs).

RESULTS

A total of 168 patients (mean age 87.4 ± 2.9 years, range 80-99 years) were included in the analysis (CKD3a, n = 117; CKD3b, n = 51). The results showed that CKD3b was associated with lower hemoglobin levels, higher NT-proBNP levels and a higher rate of hypertension compared with CKD3a. After a median follow-up of 3.8 years (interquartile range 1.5-6.1 years), a higher NT-proBNP level was associated with a higher risk of all-cause death (hazard ratio HR 1.986, 95% confidence interval CI 1.276-2.819, p = 0.028) and MACEs (HR 2.872, 95% CI 1.241-6.644, p = 0.014) after adjusting for age, sex, and traditional risk factors; however, a subgroup comparison showed that elevated NT-proBNP levels were associated with a higher risk of all-cause death (HR 2.350, 95% CI 1.906-6.091, p = 0.039) and MACEs (HR 3.025, 95% CI 1.024-8.940, p = 0.045) in CKD3a but not CKD3b.

CONCLUSION

Levels of NT-proBNP increased with decreased renal function in very old patients with stage 3 CKD; therefore, NT-proBNP is an independent predictor for all-cause death and MACEs in these patients but has a greater prognostic value in CKD3a than in CKD3b.

Age Modifies the Association of Dietary Protein Intake with All-Cause Mortality in Patients with Chronic Kidney Disease

Whether the effect of a low-protein diet on progression to end-stage renal disease (ESRD) and mortality risk differs between young and elderly adults with chronic kidney disease (CKD) is unclear. We conducted a retrospective CKD cohort study to investigate the association between protein intake and mortality or renal outcomes and whether age affects this association. The cohort comprised 352 patients with stage G3-5 CKD who had been followed up for a median 4.2 years, had undergone educational hospitalization, and for whom baseline protein intake was estimated from 24-h urine samples. We classified the patients into a very low protein intake (VLPI) group (<0.6 g/kg ideal body weight/day), a low protein intake (LPI) group (0.6⁻0.8 g), and a moderate protein intake (MPI) group (>0.8 g). Compared with the LPI group, the MPI group had a significantly lower risk of all-cause mortality (hazard ratio: 0.29; 95% confidence interval: 0.07 to 0.94) but a similar risk of ESRD, although relatively high protein intake was related to a faster decline in the estimated glomerular filtration rate. When examined per age group, these results were observed only among the elderly patients, suggesting that the association between baseline dietary protein intake and all-cause mortality in patients with CKD is age-dependent.

Chronic Hepatitis B Infection Is Significantly Associated with Chronic Kidney Disease: a Population-based, Matched Case-control Study

BACKGROUND

Hepatitis B virus (HBV) infection leads to hepatic and extrahepatic manifestations including chronic kidney disease (CKD). However, the association between HBV and CKD is not clear. This study investigated the association between chronic HBV infection and CKD in a nationwide multicenter study.

METHODS

A total of 265,086 subjects who underwent health-check examinations in 33 hospitals from January 2015 to December 2015 were enrolled. HBV surface antigen (HBsAg) positive cases (n = 10,048), and age- and gender-matched HBsAg negative controls (n = 40,192) were identified. CKD was defined as a glomerular filtration rate (GFR) < 60 mL/min/1.73 m² or proteinuria as at least grade 2+ of urine protein.

RESULTS

HBsAg positive cases showed a significantly higher prevalence of GFR < 60 mL/min/1.73 m² (3.3%), and proteinuria (18.9%) than that of the controls (2.6%, P < 0.001, and 14.1%, P < 0.001, respectively). In the multivariate analysis, HBsAg positivity was an independent factor associated with GFR < 60 mL/min/1.73 m² along with age, blood levels of albumin, bilirubin, anemia, and hemoglobin A1c (HbA1c). Likewise, HBsAg positivity was an independent factor for proteinuria along with age, male, blood levels of bilirubin, protein, albumin, and HbA1c. A subgroup analysis showed that HBsAg positive men but not women had a significantly increased risk for GFR < 60 mL/min/1.73 m².

CONCLUSION

Chronic HBV infection was significantly associated with a GFR < 60 mL/min/1.73 m² and proteinuria (≥ 2+). Therefore, clinical concern about CKD in chronic HBV infected patients, especially in male, is warranted.

Associations between socioeconomic status and chronic kidney disease: a meta-analysis

BACKGROUND

Socioeconomic status (SES) has long been conjectured to be associated with the incidence and progression of chronic kidney disease (CKD), but few studies have examined this quantitatively. This meta-analysis aims to fill this gap.

METHODS

A systematic literature review was performed using Medline and EMBASE to identify observational studies on associations between SES and incidence and progression of CKD, published between 1974 and March 2017. Individual results were meta-analysed using a random effects model, in line with Meta-analysis of Observational Studies in Epidemiology guidelines.

RESULTS

In total, 43 articles met our inclusion criteria. CKD prevalence was associated with several indicators of SES, particularly lower income (OR 1.34, 95% CI (1.18 to 1.53), P<0.001; I²=73.0%, P=0.05); lower education (OR 1.21, 95% CI (1.11 to 1.32), P<0.001; I²=45.20%, P=0.034); and lower combined SES (OR 2.18, 95% CI (1.64 to 2.89), P<0.001; I²=0.0%, P=0.326). Lower levels of income, occupation and combined SES were also significantly associated with progression to end-stage renal disease (risk ratio (RR) 1.24, 95% CI (1.12 to 1.37), P<0.001; I²=66.6%, P=0.006; RR 1.05, 95% CI (1.01 to 1.09), P=0.012; I²=0.0%, P=0.796; and RR 1.39, 95% CI (1.09 to 1.79), P=0.009; I²=74.2%, P=0.009). Subgroup analyses generally confirmed these results, except in a few cases, such as an inverse association related to particular socioeconomic backgrounds and where results were adjusted by more disease-related risk factors.

CONCLUSION

Lower income was most closely associated with prevalence and progression of CKD, and lower education was significantly associated with its prevalence. Evidence for other indicators was inconclusive.

Spectrum (characteristics) of patients with chronic kidney disease (CKD) with increasing age in a major metropolitan renal service

Background

Aim of our study is to describe, in people with CKD, the demographic and clinical characteristics and outcomes with increasing age. The prevalence of CKD in Western populations, where longevity is the norm, is about 10–15%, but how age influence different characteristics of patients with CKD is largely not known.

Methods

One thousand two hundred sixty-five patients enrolled in the CKD.QLD registry at the Royal Brisbane and Women’s Hospital were grouped according to age at consent i.e. <35, 35–44, 45–54, 55–64, 65–74, 75–84, 85+ years age groups, and were followed till start of renal replacement therapy (RRT), death, discharge or the censor date of September 2015.

Results

Age ranged from 17.6 to 98.5 years with medians of 70.1 and 69.9 years for males and females respectively: 7% were <35 years of age, with the majority (63%) >65 years old. The leading renal diagnoses changed from genetic real disease (GRD) and glomerulonephritis (GN) in the younger patients to renovascular disease (RVD) and hypertension (HTN) in older patients. With increasing age, there were often multiple renal disease diagnoses, more advanced stages of CKD, greater number of comorbidities, more frequent and more costly hospitalizations, and higher death rates. The rates of initiation of renal replacement therapy (RRT) rose from 4.5 per 100 person years in those age < 35 years to a maximum of 5.5 per 100 person years in 45–54 years age group and were lowest, at 0.5 per 100 person years in those >85 years. Mortality rates increased by age group from 1.3 to 17.0 per 100 person years in 35–44 year and 85+ year age groups respectively. Rates of hospitalization, length of stay and cost progressively increased from the youngest to eldest groups. Patients with diabetic nephropathy had highest incidence rate of RRT and death. The proportion of patients who lost more than 5mls/min/1.73m² of eGFR during at least 12 months follow up increased from 13.3% in the youngest age group to 29.2% in the eldest.

Conclusion

This is the first comprehensive view, with no exclusions, of CKD patients seen in a public renal specialty referral practice, in Australia. The age distribution of patients encompasses the whole of adult life, with a broader range and higher median value than patients receiving RRT. Health status ranged from a single system (renal) disease in young adults through, with advancing age, renal impairment as a component of, or accompanying multisystem diseases, to demands and complexities of support of frail or elderly people approaching end of life. This great spectrum demands a broad understanding and capacity of renal health care providers, and dictates a need for a wider scope of health services provision incorporating multiple models of care.

Association between hepatitis B virus and chronic kidney disease: a systematic review and meta-analysis

 Background. Hepatitis B virus infection and chronic kidney disease are prevalent and remain a major public health problem worldwide. It remains unclear how infection with hepatitis B virus impacts on the development and progression of chronic kidney disease.

AIM

To evaluate the effect of infection with HBV on the risk of chronic kidney disease in the general population.

MATERIAL AND METHODS

We conducted a systematic review of the published medical literature to determine if hepatitis B infection is associated with increased likelihood of chronic kidney disease. We used the random effects model of DerSimonian and Laird to generate a summary estimate of the relative risk for chronic kidney disease (defined by reduced glomerular filtration rate and/or detectable proteinuria) with hepatitis B virus across the published studies. Meta-regression and stratified analysis were also conducted.

RESULTS

We identified 16 studies (n = 394,664 patients) and separate meta-analyses were performed according to the outcome. The subset of longitudinal studies addressing ESRD (n = 2; n = 91,656) gave a pooled aHR 3.87 (95% CI, 1.48; 6.25, P < 0.0001) among HBV-infected patients and no heterogeneity was recorded. In meta-regression, we noted the impact of male (P = 0.006) and duration of follow- up (P = 0.007) upon the adjusted hazard ratio of incidence of chronic kidney disease (including end-stage renal disease). No relationship occurred between HBV positive status and prevalent chronic disease (n = 7, n = 109,889 unique patients); adjusted odds ratio, were 1.07 (95% CI, 0.89; 1.25) and 0.93 (95% CI, 0.76; 1.10), respectively.

CONCLUSIONS

HBV infection is possibly associated with a risk of developing reduced glomerular filtration rate in the general population; no link between HBV sero-positive status and frequency of chronic kidney disease or proteinuria was noted in cross-sectional surveys.

Simultaneous control of glycemic, blood pressure, and lipid significantly reduce the risk of renal progression in diabetes patients

BACKGROUND AND AIM

Hyperglycemic, hypertension, and lipid abnormalities are risk factors for diabetic kidney disease However, no study has discussed the association of the simultaneous control of glycemic, blood pressure, and lipids with renal function among diabetes patients. Thus, this study examined the interactive effects of the intensive control of all 3 conditions on the progression of renal function.

MATERIALS AND METHODS

The study population was derived from eight hospitals in Taiwan from October 2008 to April 2015. Demographic characteristics were collected using structured questionnaires. Clinical variables were obtained from medical chart review. The renal progression was defined as a decline in the eGFR by more than 25% according to the baseline eGFR.

RESULTS

Total of 1602 diabetes patients were included in the study analysis, the mean age was 63.03±10.98years, 55.56% were men. Compared to the simultaneous control of glycemic, blood pressure and lipid group, the poor control of all three diseases had the highest risk of renal progression, with an adjusted OR of 2.21 (95% CI, 1.26-3.86). Even if the patients with an intensive control of lipid, the result showed that the poor control of both glycemic and hypertension was associated with the increased risk of renal progression than the reference group.

CONCLUSION

This study demonstrated that the simultaneous poor control of glycemic, blood pressure, and lipid had the highest risk of renal progression. Thus, patients with type 2 diabetes should not only control glycemic but also manage their blood pressure and lipid.

Determinants and burden of chronic kidney disease in a high-risk population in Korea: results from a cross-sectional study

BACKGROUND/AIMS

This study aimed to investigate the prevalence of chronic kidney disease (CKD) and associated risk factors in a high-risk population in Korea.

METHODS

A total of 6,045 participants aged ≥ 65 years (mean age, 73.0 ± 5.5) with diabetes or hypertension were enrolled. Participants were screened for CKD, which was defined as the presence of albuminuria (urine albumin-to-creatinine ratio ≥ 30 mg/g) or an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m(2).

RESULTS

The prevalence of CKD was 39.6% (women, 40.3%; men, 38.4%). Albuminuria was detected in 22.6% of participants, whereas eGFR < 60 mL/min/1.73 m(2) was found in 24.6% of participants. The prevalence of CKD by stage was 4.4% for stage 1, 10.4% for stage 2, 23.4% for stage 3, 0.9% for stage 4, and 0.3% for stage 5. Older age, concomitant diabetes and hypertension, higher body mass index, higher systolic and diastolic blood pressure, and higher hemoglobin A1c levels were independently associated with the presence of CKD in multivariate-adjusted analyses that included with age, sex, body mass index, hypertension, diabetes, and smoking.

CONCLUSIONS

The prevalence of CKD was very high in the present high-risk Korean population. Our results suggest that a screening method for early detection of CKD in high-risk populations is needed in Korea.

Relationship between occult hepatitis B virus infection and chronic kidney disease in a Chinese population-based cohort

OBJECTIVE

Previous studies have revealed inconsistent results regarding the association between occult hepatitis B virus (HBV) infection and chronic kidney disease (CKD). Therefore, we conducted a prospective cohort study to evaluate the association between occult HBV infection and CKD.

METHODS

A total of 4329 adults, aged 46.2 ± 13.7 years, without CKD at baseline were enrolled while undergoing physical examinations. Occult HBV infection was defined as seropositivity for antibody to HBV core antigen. CKD was defined as decreased estimated glomerular filtration rate (eGFR < 60 ml·min^-1·1.73 m^-2) or presence of proteinuria ≥1+, assessed using a repeated dipstick method. eGFR was computed using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.

RESULTS

The prevalence of occult HBV infection was 8.1% (352/4329). During 5 years of follow-up, 165 patients (3.8%) developed CKD. Univariate Logistic regression analysis showed that occult HBV infection was positively associated with decreased eGFR, with an odds ratio (OR) of 2.15 (95% confidence interval (CI): 1.05-4.11). In contrast, occult HBV infection was not associated with either proteinuria or CKD (P > 0.05). After adjustment for potential confounders in the multivariate Logistic regression analysis, age, hypertension, diabetes, and the highest quartile of uric acid were associated with CKD, with ORs of 1.04 (95% CI: 1.02-1.05), 2.1 (95% CI: 1.46-3.01), 2.02 (95% CI: 1.36-2.99), and 1.86 (95% CI: 1.17-2.95), respectively. However, occult HBV infection was not associated with CKD, with an OR of 1.12 (95% CI: 0.65-1.95).

CONCLUSIONS

This study did not find an association between occult HBV infection and CKD. However, high-risk patients infected with HBV should still be targeted for monitoring for the development of CKD.

Risk factors of gender for renal progression in patients with early chronic kidney disease

Risk factors for chronic kidney disease (CKD), such as hypertension, hyperglycemia, albuminuria, renal structure, and sex hormones, have been reported to have different effects on males and females. Thus, CKD progression may differ depending on sex. In addition to CKD management, treatment at earlier stages can reduce complications and prevent disease progression as well as high medical expenses at late stages. We examined the differences in predictive risk factors for renal progression between male and female patients with early CKD.This case-cohort study recruited patients aged 18 years or older treated in the outpatient departments of 8 hospitals in Taiwan between August 2008 and September 2014. In total, 1530 patients were included in the analysis. Renal progression was defined as ≥25% decline based on baseline estimated glomerular filtration rate. To examine the predictive risk factors for renal progression, we constructed a subset multivariate logistic model with stepwise variable selection by using P < 0.10 for variable retention.The numbers of male and female patients with CKD exhibiting renal progression were 100 (11.64%) and 84 (12.52%), respectively. After adjusting for all the potential confounders, stepwise logistic regression analysis showed that main independent predictive risk factors for the male patients- (C statistic = 0.72) were proteinuria (odds ratio [OR] 2.20; 95% confidence interval [CI] 1.26-3.84), age (OR 1.04; 95% CI 1.02-1.06), anemia (OR 2.75; 95% CI 1.20-6.30), and poor control of blood pressure (OR 1.84; 95% CI 1.05-3.22). However, the main independent predictive factors for the female patients were (C statistic = 0.75) poor glycemic control (OR 2.28; 95% CI 1.22-4.25), poor blood pressure control (OR 1.93; 95% CI 1.06-3.50), and family income (OR 2.51; 95% CI 1.01-6.20).In conclusion, this study demonstrated that proteinuria was the most crucial risk factor for male patients, whereas poor glycemic control was the main risk factor for female patients. Poor blood pressure control was a shared risk factor for male and female patients.

Hepatitis C Virus Infection Increases the Risk of Developing Chronic Kidney Disease: A Systematic Review and Meta-Analysis

BACKGROUND AND RATIONALE

Chronic kidney disease and hepatitis C virus are prevalent in the general population worldwide, and controversy exists about the impact of HCV infection on the development and progression of kidney disease.

DESIGN

A systematic review of the published medical literature was made to assess whether positive anti-HCV serologic status plays an independent impact on the development of chronic kidney disease in the adult general population. We used a random-effects model to generate a summary estimate of the relative risk of chronic kidney disease (defined by reduced glomerular filtration rate or detectable proteinuria) with HCV across the published studies. Meta-regression and stratified analysis were also conducted.

RESULTS

Twenty-three studies (n = 2,842,421 patients) were eligible, and separate meta-analyses were performed according to the outcome. Pooling results of longitudinal studies (n = 9; 1,947,034 unique patients) demonstrated a relationship between positive HCV serologic status and increased incidence of chronic kidney disease, the summary estimate for adjusted hazard ratio was 1.43 (95% confidence interval 1.23; 1.63, P = 0.0001), and between-studies heterogeneity was noted (P value by Q test <0.0001). The risk of the incidence of chronic kidney disease associated with HCV, in the subset of Asian surveys, was 1.31 (95% confidence interval 1.16; 1.45) without heterogeneity (P value by Q test = 0.6). HCV positive serology was an independent risk factor for proteinuria; adjusted odds ratio, 1.508 (95% confidence intervals 1.19; 1.89, P = 0.0001) (n = 6 studies; 107,356 unique patients).

CONCLUSIONS

HCV infection is associated with an increased risk of developing chronic kidney disease in the adult general population.

Association of herbal and dietary supplements with progression and complications of chronic kidney disease: A prospective cohort study

AIM

To determine associations between herbal and dietary supplement (HDS) use and the progression of chronic kidney disease (CKD), and associations of HDS with uncontrolled hyperphosphataemia in patients with CKD.

METHOD

The cohort study recruited 406 Thai outpatients with stage 3-5 CKD from two kidney clinics of which 357 were followed up over 12 months. Patients receiving renal replacement therapy prior to recruitment were excluded. Participants were interviewed regarding their HDS use, dietary intake and conventional medication adherence using a questionnaire. The primary outcome was a composite of a decline of at least 5 mL/min per 1.73 m² per year of estimated glomerular filtration rate and end stage renal disease. Serum creatinine, serum levels of potassium and phosphate were extracted from their medical notes over the 12 months. χ² tests and multiple logistic regression analyses were performed to ascertain any associations.

RESULTS

Despite no association between HDS and the progression of CKD over a one-year period (adjusted odds ratio (OR) 1.16, 95% confidence interval (CI) 0.66-2.03), two patients had acute kidney injury, which may be related to an unknown Chinese herbal medicine, or river spiderwort combined with diclofenac reported in the medical notes. The use of HDS was associated with uncontrolled hyperphosphataemia (adjusted OR 3.53, 95%CI 1.20-10.43).

CONCLUSIONS

The findings suggest that HDS are likely to be related to acute kidney injury rather than the progression of CKD in Thai patients with CKD. The products were associated with uncontrolled hyperphosphataemia. Patients who have CKD and use HDS should be closely monitored regarding their kidney function and electrolytes.

13-year nationwide cohort study of chronic kidney disease risk among treatment-naïve patients with chronic hepatitis B in Taiwan

Background

Chronic hepatitis B virus (HBV) infection and chronic kidney disease (CKD) have high prevalences in Taiwan and worldwide. However, the association of untreated chronic hepatitis B virus (HBV) infection with chronic kidney disease (CKD) remains unclear.

Methods

This cohort study used claims data in the Taiwan National Health Insurance Research Database in 1996–2010, in which all diseases were classified by ICD-9-CM codes. We identified 17796 adults who had chronic HBV infection and did not take nucleos(t)ide analogues from 1998 to 2010 and also randomly selected 71184 matched controls without HBV in the same dataset. Cumulative incidences and adjusted hazard ratio (aHR) of incident CKD were evaluated through the end of 2010 after adjusting for competing mortality.

Results

The risk of CKD was significantly higher in the HBV cohort (13-year cumulative incidence, 6.2 %; 95 % confidence interval [CI], 5.4–7.1 %) than in the non-HBV cohort (2.7 %; 95 % CI, 2.5–3.0 %) (p < 0.001), and the aHR was 2.58 (95 % CI, 1.95-3.42; p < 0.001). Multivariable stratified analysis further verified significant associations of CKD with HBV in men of any age (aHR, 2.98; 95 % CI, 2.32–3.83, p < 0.001 for men aged <50 years; aHR, 1.58; 95 % CI, 1.31–1.91, p < 0.001 for men aged ≧50 years) and women under the age of 50 (aHR, 2.99; 95 % CI, 2.04–4.42, p < 0.001), but no significant association in women aged 50 or over.

Conclusion

Untreated chronic HBV infection is associated with increased risk of CKD. Hence, high-risk HBV-infected subjects should have targeted monitoring for the development of CKD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0106-5) contains supplementary material, which is available to authorized users.

Gout and risk of chronic kidney disease and nephrolithiasis: meta-analysis of observational studies

Introduction

To determine the prevalence of chronic kidney disease and nephrolithiasis in people with gout, and the association between gout and prevalent or incident chronic kidney disease and nephrolithiasis.

Methods

Systematic review and meta-analysis of epidemiological studies. Data sources; MEDLINE, EMBASE and CINAHL databases, hand-searched reference lists, citation history and contact with authors. Eligibility criteria: cohort, case–control or cross-sectional studies which examined the occurrence of chronic kidney disease or nephrolithiasis amongst adults with gout (with or without a non-gout comparator group) in primary care or general population samples. Prevalence and risk estimate meta-analyses were performed using a random-effects model.

Results

Seventeen studies were included in the meta-analysis (chronic kidney disease n = 7, nephrolithiasis n = 8, both n = 2). Pooled prevalence estimates of chronic kidney disease stage ≥3 and self-reported lifetime nephrolithiasis in people with gout were 24% (95% confidence interval 19% to 28%) and 14% (95% CI 12% to 17%) respectively. Gout was associated with both chronic kidney disease (pooled adjusted odds ratio 2.41, 95% confidence interval 1.86 to 3.11) and self-reported lifetime nephrolithiasis (1.77, 1.43 to 2.19).

Conclusions

Chronic kidney disease and nephrolithiasis are commonly found amongst patients with gout. Gout is independently associated with both chronic kidney disease and nephrolithiasis. Patients with gout should be actively screened for chronic kidney disease and its consequences.

Addressing health disparities in chronic kidney disease

According to the official health statistics, Taiwan has the highest prevalence of end stage renal disease (ESRD) in the world. Each year, around 60,000 ESRD patients in Taiwan consume 6% of the national insurance budget for dialysis treatment. The prevalence of chronic kidney disease (CKD) has been climbing during 2008–2012. However, the spatial disparities and clustering of CKD at the public health level have rarely been discussed. The aims of this study are to explore the possible population level risk factors and identify any clusters of CKD, using the national health insurance database. The results show that the ESRD prevalence in females is higher than that in males. ESRD medical expenditure constitutes 87% of total CKD medical expenditure. Pre-CKD and pre-ESRD disease management might slow the progression from CKD to ESRD. After applying ordinary least-squares regression, the percentages of high education status and the elderly in the townships are positively correlated with CKD prevalence. Geographically weighted regression and Local Moran’s I are used for identifying the clusters in southern Taiwan. The findings can be important evidence for earlier and targeted community interventions and reducing the health disparities of CKD.

The Unravelled Link between Chronic Kidney Disease and Hepatitis C Infection

The 2011 report of the World Health Organization General Assembly on noncommunicable diseases identified chronic kidney disease as a worldwide health issue posing a heavy economic burden. Hepatitis C virus infection, which is responsible for over 1 million deaths resulting from cirrhosis and liver cancer, is linked to chronic kidney disease in several ways; some forms of renal disease are precipitated by hepatitis C and patients with end-stage chronic renal disease are at increased risk for acquiring HCV. The aim of this review is to update the evidence on the relationship between hepatitis C infection and chronic kidney disease. Information has been accumulated in the last decade indicating that HCV plays an adverse effect on the incidence and progression of chronic kidney disease; a novel meta-analysis of observational studies (seven longitudinal studies; 890,560 unique individuals) found a relationship between hepatitis C seropositivity and incidence of reduced estimated glomerular filtration rate (adjusted relative risk, 1.70; 95% CI, 1.20; 2.39; P=0.002) in the adult general population. In addition to conventional risk factors, hepatitis C may be an additional factor for the development of chronic kidney disease, and an atheromasic activity of hepatitis C virus has been mentioned. The link between hepatitis C and atherosclerosis could also explain the excess risk of cardiovascular mortality that has been observed among hepatitis C virus seropositive patients undergoing maintenance dialysis. A number of biologically plausible mechanisms related to hepatitis C virus have been hypothesized to contribute to atherosclerosis. Implementation of effective treatment intervention towards hepatitis C is required to decrease the healthcare burden of hepatitis C and to prevent the progression of chronic renal disease.

Hepatitis C virus itself is a causal risk factor for chronic kidney disease beyond traditional risk factors: a 6-year nationwide cohort study across Taiwan

Background

Hepatitis C virus (HCV) infection and chronic kidney disease (CKD) have high prevalences in Taiwan and worldwide, but the role of HCV infection in causing CKD remains uncertain. This cohort study aimed to explore this association.

Methods

This nationwide cohort study examined the association of HCV with CKD by analysis of sampled claims data from Taiwan National Health Insurance Research Database from 1998 to 2004. ICD-9 diagnosis codes were used to identify diseases. We extracted data of 3182 subjects who had newly identified HCV infection and no traditional CKD risk factors and data of randomly selected 12728 matched HCV-uninfected control subjects. Each subject was tracked for 6 years from the index date to identify incident CKD cases. Cox proportional hazard regression was used to determine the risk of CKD in the HCV-infected and control groups.

Results

The mean follow-up durations were 5.88 years and 5.92 years for the HCV-infected and control groups, respectively. Among the sample of 15910 subjects, 251 subjects (1.6%) developed CKD during the 6-year follow-up period, 64 subjects (2.0%) from the HCV-infected group and 187 subjects (1.5%) from the control group. The incidence rate of CKD was significantly higher in the HCV-infected group than in the control group (3.42 vs. 2.48 per 1000 person-years, p = 0.02). Multivariate analysis indicated that the HCV-infected group had significantly greater risk for CKD (adjusted hazard ratio: 1.75, 95% CI: 1.25-2.43, p = 0.0009). This relationship also held for a comparison of HCV-infected and HCV-uninfected subjects who were younger than 70 years and had none of traditional CKD risk factors.

Conclusions

HCV infection is associated with increased risk for CKD beyond the well-known traditional CKD risk factors. HCV patients should be informed of their increased risk for development of CKD and should be more closely monitored.