Chronic kidney disease itself is a causal risk factor for stroke beyond traditional cardiovascular risk factors: a nationwide cohort study in Taiwan

2024 Guidelines of the Taiwan Society of Cardiology on the Primary Prevention of Atherosclerotic Cardiovascular Disease --- Part I

Atherosclerotic cardiovascular disease (ASCVD) is one of the leading causes of death worldwide and in Taiwan. It is highly prevalent and has a tremendous impact on global health. Therefore, the Taiwan Society of Cardiology developed these best-evidence preventive guidelines for decision-making in clinical practice involving aspects of primordial prevention including national policies, promotion of health education, primary prevention of clinical risk factors, and management and control of clinical risk factors. These guidelines cover the full spectrum of ASCVD, including chronic coronary syndrome, acute coronary syndrome, cerebrovascular disease, peripheral artery disease, and aortic aneurysm. In order to enhance medical education and health promotion not only for physicians but also for the general public, we propose a slogan (2H2L) for the primary prevention of ASCVD on the basis of the essential role of healthy dietary pattern and lifestyles: "Healthy Diet and Healthy Lifestyles to Help Your Life and Save Your Lives". We also propose an acronym of the modifiable risk factors/enhancers and relevant strategies to facilitate memory: " ABC2D2EFG-I'M2 ACE": Adiposity, Blood pressure, Cholesterol and Cigarette smoking, Diabetes mellitus and Dietary pattern, Exercise, Frailty, Gout/hyperuricemia, Inflammation/infection, Metabolic syndrome and Metabolic dysfunction-associated fatty liver disease, Atmosphere (environment), Chronic kidney disease, and Easy life (sleep well and no stress). Some imaging studies can be risk enhancers. Some risk factors/clinical conditions are deemed to be preventable, and healthy dietary pattern, physical activity, and body weight control remain the cornerstone of the preventive strategy.

Epidemiology and Risk Factors for Stroke in Chronic Kidney Disease: A Narrative Review

Patients with chronic kidney disease (CKD) have a higher risk ofboth ischemic and hemorrhagic stroke. This association appears to be partly independent from the higher prevalence of established risk factors for stroke in patients with CKD, including hypertension and atrial fibrillation. In the present review we aim to discuss the impact of CKD on the risk of stroke and stroke-related consequences, and explore the pathophysiology underpinning the increased risk of stroke in patients with CKD. We cover the clinical association between renal dysfunction and cerebrovascular disease including stroke, silent brain infarct, cerebral small vessel disease, microbleeds, and white matter hyperintensity, and discuss the underlying mechanisms.

Kernelized k-Local Hyperplane Distance Nearest-Neighbor Model for Predicting Cerebrovascular Disease in Patients With End-Stage Renal Disease

Detecting and treating cerebrovascular diseases are essential for the survival of patients with chronic kidney disease (CKD). Machine learning algorithms can be used to effectively predict stroke risk in patients with end-stage renal disease (ESRD). An imbalance in the amount of collected data associated with different risk levels can influence the classification task. Therefore, we propose the use of a kernelized k-local hyperplane nearest-neighbor model (KHKNN) for the effective prediction of stroke risk in patients with ESRD. We compared our proposed method with other conventional machine learning methods, which revealed that our method could effectively perform the task of classifying stroke risk.

Chronic and End-Stage Kidney Disease in the Neurological Intensive Care Unit

Patients with renal disease have increased rates of admission to the neurological intensive care unit related to overlapping risk factors for renal and cerebrovascular disease as well as unique risks associated with renal dysfunction alone. Management of acute neurological injury in these patients requires individualized attention to diagnostic and management factors as they relate to coagulopathy, disorders of immune function, encephalopathy and renal replacement modalities. Careful consideration of these brain-kidney interactions is necessary to optimize care for this special patient population and improve neurological and renal outcomes.

Association of lipid profiles with severity and outcome of acute ischemic stroke in patients with and without chronic kidney disease

Background

Contribution of lipid profiles to stroke severity and outcome was inconclusive, whether chronic kidney disease (CKD) (estimated glomerular filtration rate < 60 mL/min/1.73 m²) affects the association has not been investigated. We aim to evaluate this relationship.

Methods

A retrospective study of consecutive acute ischemic stroke patients was performed. We assessed the risk of severe stroke with the National Institutes of Health Stroke Scale (NIHSS) ≥ 5 at admission and poor outcome with the modified Rankin Scale (mRS) ≥ 3 at discharge. Multivariate stepwise logistic regression models were adopted to study interaction and independent association of lipid components with stroke severity and outcome according to lipid level quartiles by CKD stratification.

Results

Among the 875 included patients (mean age 64.9 years, 67.8% males), 213 (24.3%) presented with CKD. Elevated low-density lipoprotein cholesterol (LDL-C) was independently associated with severe stroke in patients with CKD (P for trend = 0.033) than in those without CKD (P for trend = 0.121). The association between the level of LDL-C and stroke severity was appreciably modified by CKD (P_interaction = 0.013). Compared with without CKD patients in the lowest LDL-C quartile, the multivariable-adjusted risk of severe stroke increased significantly by 2.9-fold (95% CI 1.48–5.74) in patients with CKD in the highest LDL-C quartile. No significant association was observed between lipid components and early outcome in patients with and without CKD.

Conclusion

LDL-C levels are positively associated with stroke severity in only patients with CKD, with an interactive impact of LDL-C and CKD on ischemic stroke in the acute phase.

Cerebral blood flow regulation in end-stage kidney disease

Patients with chronic kidney disease (CKD) and end-stage kidney disease (ESKD) experience an increased risk of cerebrovascular disease and cognitive dysfunction. Hemodialysis (HD), a major modality of renal replacement therapy in ESKD, can cause rapid changes in blood pressure, osmolality, and acid-base balance that collectively present a unique stress to the cerebral vasculature. This review presents an update regarding cerebral blood flow (CBF) regulation in CKD and ESKD and how the maintenance of cerebral oxygenation may be compromised during HD. Patients with ESKD exhibit decreased cerebral oxygen delivery due to anemia, despite cerebral hyperperfusion at rest. Cerebral oxygenation further declines during HD due to reductions in CBF, and this may induce cerebral ischemia or "stunning." Intradialytic reductions in CBF are driven by decreases in cerebral perfusion pressure that may be partially opposed by bicarbonate shifts during dialysis. Intradialytic reductions in CBF have been related to several variables that are routinely measured in clinical practice including ultrafiltration rate and blood pressure. However, the role of compensatory cerebrovascular regulatory mechanisms during HD remains relatively unexplored. In particular, cerebral autoregulation can oppose reductions in CBF driven by reductions in systemic blood pressure, while cerebrovascular reactivity to CO₂ may attenuate intradialytic reductions in CBF through promoting cerebral vasodilation. However, whether these mechanisms are effective in ESKD and during HD remain relatively unexplored. Important areas for future work include investigating potential alterations in cerebrovascular regulation in CKD and ESKD and how key regulatory mechanisms are engaged and integrated during HD to modulate intradialytic declines in CBF.

Crosstalk between the nervous system and the kidney

Under physiological states, the nervous system and the kidneys communicate with each other to maintain normal body homeostasis. However, pathological states disrupt this interaction as seen in hypertension, and kidney damage can cause impaired renorenal reflex and sodium handling. In acute kidney injury (AKI) and chronic kidney disease (CKD), damaged kidneys can have a detrimental effect on the central nervous system. CKD is an independent risk factor for cerebrovascular disease and cognitive impairment, and many factors, including retention of uremic toxins and phosphate, have been proposed as CKD-specific factors responsible for structural and functional cerebral changes in patients with CKD. However, more studies are needed to determine the precise pathogenesis. Epidemiological studies have shown that AKI is associated with a subsequent risk for developing stroke and dementia. However, recent animal studies have shown that the renal nerve contributes to kidney inflammation and fibrosis, whereas activation of the cholinergic anti-inflammatory pathway, which involves the vagus nerve, the splenic nerve, and immune cells in the spleen, has a significant renoprotective effect. Therefore, elucidating mechanisms of communication between the nervous system and the kidney enables us not only to develop new strategies to ameliorate neurological conditions associated with kidney disease but also to design safe and effective clinical interventions for kidney disease, using the neural and neuroimmune control of kidney injury and disease.

Effects of Prevalent and Incident Atrial Fibrillation on Renal Outcome, Cardiovascular Events, and Mortality in Patients with Chronic Kidney Disease

BACKGROUND

Little is known about how incident atrial fibrillation (AF) affects the clinical outcomes in chronic kidney disease (CKD) patients and whether there is a different influence between pre-existing and incident AF.

METHODS

Incident CKD patients from 2000 to 2013 were retrieved from the National Health Insurance Research Database (NHIRD) of Taiwan and they were classified as non-AF (n = 15,251), prevalent AF (n = 612), and incident AF (n = 588). The outcomes of interest were end-stage renal disease (ESRD) requiring dialysis, all-cause mortality, cardiovascular (CV) mortality, acute myocardial infarction (AMI), stroke or systemic thromboembolism.

RESULTS

Compared with CKD patients without AF, those with prevalent or incident AF were associated with higher adjusted rates of ESRD (hazard ratio (HR), 1.40; 95% confidence interval (CI), 1.32-1.48; HR, 2.91; 95% CI, 2.74-3.09, respectively), stroke or systemic thromboembolism (HR, 1.89; 95% CI, 1.77-2.03; HR, 1.67; 95% CI, 1.54-1.81, respectively), AMI (HR, 1.24; 95% CI, 1.09-1.41; HR, 1.99; 95% CI, 1.75-2.27, respectively), all-cause mortality (HR, 1.64; 95% CI, 1.56-1.72; HR, 2.17; 95% CI, 2.06-2.29, respectively), and CV mortality (HR, 2.95; 95% CI, 2.62-3.32; HR, 4.61; 95% CI, 4.09-5.20, respectively). Intriguingly, CKD patients with prevalent AF were associated with lower adjusted rates of ESRD, AMI, all-cause mortality, and CV mortality compared with those with incident AF.

CONCLUSION

Both incident and prevalent AF were independently associated with greater risks of AMI, all-cause mortality, CV mortality, ESRD, and stroke or systemic thromboembolism. Our findings are novel in that, compared with prevalent AF, incident AF possessed an even higher risk of some clinical consequences, including ESRD, all-cause mortality, CV mortality, and AMI.

Atherosclerosis in Chronic Kidney Disease: More, Less, or Just Different?

Patients with chronic kidney disease (CKD) are at an increased risk of premature mortality, mainly from cardiovascular causes. The association between CKD on hemodialysis and accelerated atherosclerosis was described >40 years ago. However, more recently, it has been suggested that the increase in atherosclerosis risk is actually observed in early CKD stages, remaining stable thereafter. In this regard, interventions targeting the pathogenesis of atherosclerosis, such as statins, successful in the general population, have failed to benefit patients with very advanced CKD. This raises the issue of the relative contribution of atherosclerosis versus other forms of cardiovascular injury such as arteriosclerosis or myocardial injury to the increased cardiovascular risk in CKD. In this review, the pathophysiogical contributors to atherosclerosis in CKD that are shared with the general population, or specific to CKD, are discussed. The NEFRONA study (Observatorio Nacional de Atherosclerosis en NEFrologia) prospectively assessed the prevalence and progression of subclinical atherosclerosis (plaque in vascular ultrasound), confirming an increased prevalence of atherosclerosis in patients with moderate CKD. However, the adjusted odds ratio for subclinical atherosclerosis increased with CKD stage, suggesting a contribution of CKD itself to subclinical atherosclerosis. Progression of atherosclerosis was closely related to CKD progression as well as to the baseline presence of atheroma plaque, and to higher phosphate, uric acid, and ferritin and lower 25(OH) vitamin D levels. These insights may help design future clinical trials of stratified personalized medicine targeting atherosclerosis in patients with CKD. Future primary prevention trials should enroll patients with evidence of subclinical atherosclerosis and should provide a comprehensive control of all known risk factors in addition to testing any additional intervention or placebo.

Specific risk factors for cerebrovascular disorders in patients with chronic kidney disease in the pre-dialysis period

Cerebral vascular disorders are one of the leading causes of disability and mortality in patients with chronic kidney disease (CKD). The article presents the currently available data on risk factors (RF) for the development of cerebrovascular disorders in pre-dialysis patients with CKD. Two groups of RF are identified: traditional and non-traditional (specific). Traditional RF, which include arterial hypertension, diabetes mellitus and hypercholesterolemia, independently affect the cerebral vascular bed and get worse against the background of CKD. Specific RF is associated with features of the CKD pathogenesis. It includes increased blood levels of homocysteine, β2-microglobulin, impaired calcium-phosphorus metabolism, accumulation of uremic toxins and toxins of intestinal bacteria, anemia and other factors. In the present review, special attention is paid to specific RF and pathogenetic mechanisms of the development of cerebrovascular disorders in predialysis patients with CKD. Timely detection of cerebral risk factors may lead to the improvement of early diagnosis and prevention of cerebral vascular disorders, optimization of therapy for patients with CKD.

Estimated glomerular filtration rate predicts incident stroke among Ghanaians with diabetes and hypertension

Background

Sub-Saharan Africa is currently experiencing a high burden of both chronic kidney disease (CKD) and stroke as a result of a rapid rise in shared common vascular risk factors such as hypertension and diabetes mellitus. However, no previous study has prospectively explored independent associations between CKD and incident stroke occurrence among indigenous Africans. This study sought to fill this knowledge gap.

Methods

A prospective cohort study involving Ghanaians adults with hypertension or type II diabetes mellitus from 5 public hospitals. Patients were followed every 2 months in clinic for 18 months and assessed clinically for first ever stroke by physicians. Serum creatinine derived estimated glomerular filtration rates (eGFR) were determined at baseline for 2631 (81.7%) out of 3296 participants. We assessed associations between eGFR and incident stroke using a multivariate Cox Proportional Hazards regression model.

Results

Stroke incidence rates (95% CI) increased with decreasing eGFR categories of 89, 60–88, 30–59 and <29 ml/min corresponding to incidence rates of 7.58 (3.58–13.51), 14.45 (9.07–21.92), 29.43 (15.95–50.04) and 66.23 (16.85–180.20)/1000 person-years respectively. Adjusted hazard ratios (95%CI) for stroke occurrence according to eGFR were 1.42 (0.63–3.21) for eGFR of 60-89 ml/min, 1.88 (1.17–3.02) for 30-59 ml/min and 1.52 (0.93–2.43) for <30 ml/min compared with eGFR of >89 ml/min. Adjusted HR for stroke occurrence among patients with hypertension with eGFR<60 ml/min was 3.69 (1.49–9.13), p = .0047 and among those with diabetes was 1.50 (0.56–3.98), p = .42.

Conclusion

CKD is dose-dependently associated with occurrence of incident strokes among Ghanaians with hypertension and diabetes mellitus. Further studies are warranted to explore interventions that could attenuate the risk of stroke attributable to renal disease among patients with hypertension in SSA.

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We assessed association between incident stroke and estimated glomerular filtration rate.

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2631 participants stroke-free Ghanaian adults with hypertension or diabetes were followed for 14 months.

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There were 45 incident strokes.

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Incident stroke risk independently increased with declining eGFR.

Short- and long-term outcomes after postsurgical acute kidney injury requiring dialysis

Objective

Prompt assessment of perioperative complications is critical for the comprehensive care of surgical patients. Acute kidney injury requiring dialysis (AKI-D) is associated with high mortality, yet little is known about how long-term outcomes of patients have evolved. The association of AKI-D with postsurgical outcomes has not been well studied.

Methods

We investigated patients from the National Health Insurance Research Database and validated by the multicenter Clinical Trial Consortium for Renal Diseases cohort. All patients with AKI-D 18 years or older undergoing four major surgeries (cardiothoracic, esophagus, intestine, and liver) were retrospectively investigated (N=106,573). Patient demographics, surgery type, comorbidities before admission, and postsurgical outcomes, including the in-hospital, 30-day, and long-term mortality together with dialysis dependence were collected.

Results

AKI-D is the top risk factor for 30-day and long-term mortality after major surgery. Of 1,664 individuals with AKI-D and 6,656 matched controls, AKI-D during the hospital stay was associated with in-hospital (adjusted hazard ratio [aHR]=3.04, 95% CI 2.79–3.31), 30-day (aHR=3.65, 95% CI 3.37–3.94), and long-term (aHR=3.22, 95% CI 3.01–3.44) mortality. Patients undergoing cardiothoracic surgery (CTS) showed less in-hospital (aHR=0.85, 95% CI 0.75–0.97), 30-day (aHR=0.79, 95% CI 0.70–0.89), and long-term (aHR=0.80, 95% CI 0.72–0.90) mortality compared with non-CTS patients with AKI-D. CTS patients had a high risk of 30-day dialysis dependence (subhazard ratio [sHR]=1.67, 95% CI 1.18–2.38), but the risk of long-term dialysis dependence was similar (sHR=1.38, 95% CI 0.96–2.00) after AKI-D by taking mortality as a competing risk. Non-CTS patients had more comorbidities of sepsis, azotemia, hypoalbuminemia, and metabolic acidosis compared with CTS patients.

Conclusion

AKI exhibits paramount effects on postsurgical outcomes that extend well beyond discharge from the hospital. The goal of the perioperative assessment should include the reassurance of enhancing renal function recovery among different surgeries, and optimized follow-up is warranted in attenuating the complications after postsurgical AKI has occurred.

Association of Chronic Kidney Disease with Coronary Heart Disease and Stroke Risks in Patients with Type 2 Diabetes Mellitus: An Observational Cross-sectional Study in Hangzhou, China

Background:

Chronic kidney disease (CKD) is an independent risk factor for cardiovascular disease (CVD). However, the association between CKD and CVD risk in patients with type 2 diabetes mellitus (T2DM) in China has not yet been well investigated. This study aimed to determine the association of CKD with the risks of coronary heart disease (CHD) and stroke in a Chinese population with T2DM.

Methods:

A total of 1401 inpatients with T2DM at the Second Affiliated Hospital of Zhejiang University School of Medicine between April 2008 and November 2013 were included in this study. The CKD-Epidemiology Collaboration equation for Asians was used to classify CKD. The UK Prospective Diabetes Study risk engine was used to estimate the risks of CHD and stroke.

Results:

CHD risk was significantly increased with CKD stage (20.1%, 24.8%, and 34.3% in T2DM patients with no CKD, CKD Stage 1–2, and Stage 3–5, respectively; P < 0.001 for all). The stroke risk was also increased with CKD stage (8.6%, 12.7%, and 25.4% in T2DM patients with no CKD, CKD Stage 1–2, and Stage 3–5, respectively; P < 0.001 for all). Compared with no-CKD group, the odds ratios (ORs) for high CHD risk were 1.7 (P < 0.001) in the CKD Stage 1–2 group and 3.5 (P < 0.001) in the CKD Stage 3–5 group. The corresponding ORs for high stroke risk were 1.9 (P < 0.001) and 8.2 (P < 0.001), respectively.

Conclusion:

In patients with T2DM, advanced CKD stage was associated with the increased risks of CHD and stroke.

A Comparative Study of Neurological Complications in Chronic Kidney Disease with Special Reference to its Stages and Haemodialysis Status

INTRODUCTION

Globally, Chronic Kidney Disease (CKD) is a critical and rapidly growing health problem and also a major cause of mortality and morbidity. Neurological complications occur in all levels of the nervous system. Central nervous system complications include cerebrovascular accidents, posterior reversible encephalopathy syndrome, osmotic demyelization syndrome, cerebral infection and sinus vein thrombosis. Peripheral nervous system complications include polyneuropathy, mononeuropathy and carpal tunnel syndrome. Haemodialysis (HD) related neurological complications include dialysis disequilibrium syndrome, dementia and cerebrovascular accidents.

AIM

To assess the neurological complications of CKD and to compare the various neurological complications in patients on HD with those not on HD.

MATERIALS AND METHODS

Hundred patients with CKD were included in the study. They were categorized into two groups according to the stage of CKD and those with stage 3 or more were considered as cases and stage 2 or less as controls. The cases and controls were followed up during subsequent visits for neurological complications.

RESULTS

This study comprised of 50 cases and 50 controls. Among 50 cases, males were 62% and females were 38% with male: female ratio was 1.6:1 and in controls, male: female ratio was 1.08:1. The maximum patients were in the age group of 51-60 years. The incidence of neurological complications was significantly higher in cases compared to controls and among people who underwent dialysis compared to those who were not. Headache was the most common complication both among cases and controls and as well as in people who were on HD. Stroke, seizures and altered sensorium were significantly associated with later stage of CKD. Cases underwent HD had significant association with headache, altered sensorium and stroke than those without HD but peripheral neuropathy and seizure did not show such association.

CONCLUSION

The chances of development of neurological complications were significantly higher in late stages of CKD compared to early stages of CKD. Those neurological complications were more among people who underwent dialysis when compared to those not on maintenance HD.

Prevalence and risk factors for cardiovascular disease among chronic kidney disease patients: results from the Chinese cohort study of chronic kidney disease (C-STRIDE)

BACKGROUND

Although a high incidence of cardiovascular disease (CVD) is observed among chronic kidney disease (CKD) patients in developed countries, limited information is available about CVD prevalence and risk factors in the Chinese CKD population. The Chinese Cohort of Chronic Kidney Disease (C-STRIDE) was established to investigate the prevalence and risk factors of CVD among Chinese CKD patients.

METHODS

Participants with stage 1-4 CKD (18-74 years of age) were recruited at 39 clinical centers located in 28 cities from 22 provinces of China. At entry, the socio-demographic status, medical history, anthropometric measurements and lifestyle behaviors were documented, and blood and urine samples were collected. Estimated glomerular filtration rate (eGFR) was calculated by the CKD-EPI creatinine equation. CVD diagnosis was based on patient self-report and review of medical records by trained staff. A multivariable logistic regression model was used to estimate the association between risk factors and CVD.

RESULTS

Three thousand four hundred fifty-nine Chinese patients with pre-stage 5 CKD were enrolled, and 3168 finished all required examinations and were included in the study. In total, 40.8% of the cohort was female, with a mean age of 48.21 ± 13.70 years. The prevalence of CVD was 9.8%, and in 69.1% of the CVD cases cerebrovascular disease was observed. Multivariable analysis showed that increasing age, lower eGFR, presence of hypertension, abdominal aorta calcification and diabetes were associated with comorbid CVD among CKD patients. The odds ratios and 95% confidence intervals for these risk factors were 3.78 (2.55-5.59) for age 45-64 years and 6.07 (3.89-9.47) for age ≥65 years compared with age <45 years; 2.07 (1.28-3.34) for CKD stage 3a, 1.66 (1.00-2.62) for stage 3b, and 2.74 (1.72-4.36) for stage 4 compared with stages 1 and 2; 2.57 (1.50-4.41) for hypertension, 1.82 (1.23-2.70) for abdominal aorta calcification, and 1.70 (1.30-2.23) for diabetes, respectively.

CONCLUSIONS

We reported the CVD prevalence among a CKD patient cohort and found age, hypertension, diabetes, abdominal aorta calcification and lower eGFR were independently associated with higher CVD prevalence. Prospective follow-up and longitudinal evaluations of CVD risk among CKD patients are warranted.

The Cerebrovascular-Chronic Kidney Disease Connection: Perspectives and Mechanisms

Chronic kidney disease (CKD) is an independent risk factor for the development of cerebrovascular disease, particularly small vessel disease which can manifest in a variety of phenotypes ranging from lacunes to microbleeds. Small vessel disease likely contributes to cognitive dysfunction in the CKD population. Non-traditional risk factors for vascular injury in uremia include loss of calcification inhibitors, hyperphosphatemia, increased blood pressure variability, elastinolysis, platelet dysfunction, and chronic inflammation. In this review, we discuss the putative pathways by which these mechanisms may promote cerebrovascular disease and thus increase risk of future stroke in CKD patients.

Risk of stroke in patients with newly diagnosed multiple myeloma: a retrospective cohort study

Cerebrovascular events are a common complication among patients with cancer, increasing morbidity and mortality. However, the association between multiple myeloma and cerebrovascular events remains unclear. We therefore investigated multiple myeloma patients' risk factors for stroke to devise a better stroke-prevention strategy. This study includes consecutive patients 20 years and older who were newly diagnosed with symptomatic multiple myeloma at Taipei Veterans General Hospital, a tertiary medical center, between January 1, 2002 and December 31, 2014. The primary outcome was stroke development. Patients with head injuries, brain tumors, brain parenchymal invasions, or antecedent malignancies were excluded. Hazard ratios (HRs) of stroke risk factors for multiple myeloma patients were estimated by Cox proportional regression analysis. Overall, 395 patients with a median age of 70 years were investigated. In the median follow-up period of 18 months, cerebrovascular events occurred in 16 patients, including 10 ischemic strokes and 6 hemorrhagic strokes. The 5-year estimated cumulative incidence rate was 7.45%. In the multivariate analysis, the κ light chain isotype (adjusted HR, 8.37; 95% confidence interval [CI], 1.91-39.8), previous cerebrovascular accidents (adjusted HR, 5.16; 95% CI, 1.48-17.9), and serum creatinine > 2 mg/dL (adjusted HR, 4.21; 95% CI, 1.10-16.0) were identified as independent risk factors for stroke. Subgroup analysis showed that atrial fibrillation (adjusted HR, 8.07) and previous cerebrovascular accident (adjusted HR, 4.89) are significant risk factors for ischemic stroke. Serum creatinine > 2 mg/dL (adjusted HR, 30.6) and previous cerebrovascular accident (adjusted HR, 13.9) are significant for hemorrhagic stroke. Moreover, therapeutic strategies for multiple myeloma were not associated with stroke in our study. This study demonstrates that risk of stroke increases in myeloma patients with a κ light chain isotype, previous cerebrovascular events, and renal impairment. Further prospective clinical studies to clarify the relationship between multiple myeloma and stroke are warranted.

Clinical management of the uraemic syndrome in chronic kidney disease

The clinical picture of the uraemic syndrome is a complex amalgam of accelerated ageing and organ dysfunction, which progress in parallel to chronic kidney disease. The uraemic syndrome is associated with cardiovascular disease, metabolic bone disease, inflammation, protein energy wasting, intestinal dysbiosis, anaemia, and neurological and endocrine dysfunction. In this Review, we summarise specific, modern management options for the uraemic syndrome in chronic kidney disease. Although large randomised controlled trials are scarce, based on data from randomised controlled trials and observational studies, as well as pathophysiological reasoning, a therapeutic algorithm can be developed for this complex and multifactorial condition, with interventions targeting several modifiable factors simultaneously.

Neurological complications in chronic kidney disease patients

Chronic kidney disease (CKD) is associated with a high prevalence of cerebrovascular disorders such as stroke, white matter diseases, intracerebral microbleeds and cognitive impairment. This situation has been observed not only in end-stage renal disease patients but also in patients with mild or moderate CKD. The occurrence of cerebrovascular disorders may be linked to the presence of traditional and non-traditional cardiovascular risk factors in CKD. Here, we review current knowledge on the epidemiological aspects of CKD-associated neurological and cognitive disorders and discuss putative causes and potential treatment. CKD is associated with traditional (hypertension, hypercholesterolaemia, diabetes etc.) and non-traditional cardiovascular risk factors such as elevated levels of oxidative stress, chronic inflammation, endothelial dysfunction, vascular calcification, anaemia and uraemic toxins. Clinical and animal studies indicate that these factors may modify the incidence and/or outcomes of stroke and are associated with white matter diseases and cognitive impairment. However, direct evidence in CKD patients is still lacking. A better understanding of the factors responsible for the elevated prevalence of cerebrovascular diseases in CKD patients may facilitate the development of novel treatments. Very few clinical trials have actually been performed in CKD patients, and the impact of certain treatments is subject to debate. Treatments that lower LDL cholesterol or blood pressure may reduce the incidence of cerebrovascular diseases in CKD patients, whereas treatment with erythropoiesis-stimulating agents may be associated with an increased risk of stroke but a decreased risk of cognitive disorders. The impact of therapeutic approaches that reduce levels of uraemic toxins has yet to be evaluated.

A Taiwanese Nationwide Cohort Study Shows Interferon-Based Therapy for Chronic Hepatitis C Reduces the Risk of Chronic Kidney Disease

Hepatitis C virus (HCV) infection is a risk factor for chronic kidney disease (CKD). However, it remains unclear whether interferon-based therapy (IBT) for HCV was associated with reduced risk of CKD.From the Taiwan National Health Insurance Research Database, we identified 919 patients who received 3 months or more of IBT as our treated cohort. This cohort was propensity score-matched 1:4 with 3676 controls who had never received IBT for HCV infection (untreated cohort). Cumulative incidences of and hazard ratios (HRs) for CKD were calculated after adjusting for competing mortality.In the matched HCV cohort, the risk of CKD was significantly lower in the treated cohort (7-year cumulative incidence, 2.6%; 95% confidence interval [CI], 0.7%-6.9%) than in the untreated cohort (4%; 95% CI, 3.5%-5.2%) (P < 0.001), with an adjusted HR of 0.42 (95% CI, 0.20-0.92; P = 0.03). The results also held in the overall HCV cohort. The number needed to treat for 1 fewer CKD at 7 years was 58. The reduced risk of CKD was greatest (0.35; 0.14-0.87; P = 0.024) in HCV-infected patients who received 6 months or more of IBT. Multivariable stratified analysis verified that greater risk reduction of CKD was present in HCV-infected patients with hyperlipidemia, diabetes, hypertension, and those without coronary heart disease.In conclusion, IBT, especially for 6 or more months, is associated with reduced risk of CKD in HCV-infected patients. Hyperlipidemia, diabetes, hypertension, and coronary heart disease can modify this association.

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.

Tonsillectomy and the risk for deep neck infection-a nationwide cohort study

BACKGROUND

Although the tonsils contribute to first line immunity against foreign pathogens in the upper aero-digestive tract, the association of tonsillectomy with the risk of deep neck infection remains unclear. The aim of this study was to assess the incidence rate and risk of deep neck infection among patients who had undergone a tonsillectomy.

METHODS

This retrospective cohort study evaluated all patients who had undergone tonsillectomy between 2001 and 2009 as identified from the Taiwan National Health Insurance Research Database. For each post-tonsillectomy patient, 10 age-, sex-, and index date-matched controls without a history of tonsillectomy were randomly selected. Cox Proportional hazard model and propensity score model were performed to evaluate the association between tonsillectomy and deep neck infection after adjusting for demographic and clinical data.

RESULTS

There were 34 (71.6 cases per 100,000 person-years) and 174 (36.6 cases per 100,000 person-years) patients that developed deep neck infection in the tonsillectomized and comparison cohorts, respectively. After adjusting for covariates, patients who had undergone a tonsillectomy had a 1.71-fold greater risk of deep neck infection by both Cox proportional hazard model (95% confidence interval, 1.13-2.59) and propensity score model (95% confidence interval, 1.10-2.66). This association was not altered regardless of the indication for tonsillectomy (i.e. chronic/recurrent tonsillitis or sleep apnea/hypertrophy of tonsil) (p = 0.9797).

CONCLUSIONS

Based on our review of a nationwide cohort study we identified that the risk of deep neck infection is significantly increased among patients who have undergone a tonsillectomy. Additional research is needed to explore the possible mechanisms behind these findings.

Sleep apnea and the risk of chronic kidney disease: a nationwide population-based cohort study

STUDY OBJECTIVES

Sleep apnea (SA) is characterized by apnea during sleep and is associated with cardiovascular diseases and an increase in all-cause mortality. Chronic kidney disease (CKD) is a global health problem that has placed a substantial burden on healthcare resources. However, the relationship between SA and the incidence of CKD is not clear. This study aimed to determine whether SA is an independent risk factor for the development of CKD.

DESIGN

Retrospective cohort study.

SETTING

National Health Insurance Research Database (NHIRD) of Taiwan.

PATIENTS OR PARTICIPANTS

A total of 4,674 adult patients (age ≥ 30 y) in whom SA was newly diagnosed from 2000 to 2010 were included, together with 23,370 non-SA patients as the comparison group. The two groups were frequency-matched for sex, age, and year of receiving medical service. Each individual was followed until 2011.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

These two groups were monitored and observed for the occurrence of CKD. Patients with SA experienced a 1.94-fold increase (95% confidence interval [CI], 1.52-2.46; P < 0.001) in the incidence of CKD, which was independent of sex, age, and comorbid medical conditions. Additionally, they showed a 2.2-fold increase (95% CI, 1.31-3.69; P < 0.01) in the incidence of end-stage renal disease (ESRD).

CONCLUSIONS

Patients with sleep apnea are at increased risk for chronic kidney disease and end-stage renal disease compared with the general population. As such, screening renal function and treatment of chronic kidney disease is an important issue in patients with sleep apnea.

Fasting blood glucose, but not 2-h postload blood glucose or HbA1c, is associated with mild decline in estimated glomerular filtration rate in healthy Chinese

BACKGROUND

The association of blood glucose [including fasting blood glucose (FBG), 2-h postload blood glucose, and glycated hemoglobin (HbA1c)] with the risk of a mild decline in the estimated glomerular filtration rate (eGFR) in healthy subjects was unclear. The aim of the study was to investigate this association in middle-aged and elderly healthy Chinese.

METHODS

The study included 1,112 healthy Chinese who were ≥40 years old, and all the subjects were divided into two groups based on FBG value of 5.6 mmol/L. A mildly reduced eGFR was defined as 60-90 mL/min/1.73 m2. Multiple linear or logistic regression analysis was used to estimate the association of blood glucose with eGFR and the risk of a mildly reduced eGFR, respectively. A generalized additive model was used to explore a possible nonlinear relationship between FBG and eGFR.

RESULTS

FBG was significantly associated with decreased eGFR and increased risk of a mildly reduced eGFR independent of age, gender, body mass index, waist circumference, systolic blood pressure (BP), diastolic BP, triglyceride, high-density lipoprotein cholesterol, fasting insulin, smoking, and drinking. Additionally, FBG and eGFR showed a nonlinear association (P<0.001). Interestingly, the group with FBG≥5.6 mmol/L significantly increased the risk of a mildly reduced eGFR (OR 2.06, P=0.001) after multivariable adjustment.

CONCLUSIONS

FBG is closely associated with decreased eGFR and increased risk of a mildly reduced eGFR. The ADA criteria using FBG=5.6 mmol/L instead of 6.1 mmol/L as cutoff point to define prediabetes are more suitable for the prevention of diabetes and related kidney disease.

A nationwide cohort study suggests chronic hepatitis B virus infection increases the risk of end-stage renal disease among patients in Taiwan

The association of chronic hepatitis B virus (HBV) infection with end-stage renal disease (ESRD) is unclear. To help clarify this we conducted a nationwide cohort study to measure the association by analyzing the claims data from the Taiwan National Health Insurance Research Database with ICD-9 codes used to identify diseases. We identified 17,758 adults who had chronic HBV infection and had not taken nucleos(t)ide analogs from 1999 to 2010 and randomly selected 71,032 matched controls without HBV in the same data set. The risk of ESRD was compared between these two cohorts. Cumulative incidences and hazard ratios were calculated after adjusting for competing mortality. The risk of ESRD was significantly higher in the HBV cohort (12-year cumulative incidence, 1.9%) than in the non-HBV cohort (0.49%) with a significant adjusted hazard ratio of 3.85. Multivariable stratified analysis further verified significant associations of ESRD with HBV in men of any age and women under the age of 60 years, but no significant association in women aged ⩾60 years. Thus, a large national cohort study indicates that untreated chronic HBV infection is associated with increased risk of ESRD. Hence, high-risk HBV-infected patients should have targeted monitoring for the development of ESRD.

Triglyceride levels are closely associated with mild declines in estimated glomerular filtration rates in middle-aged and elderly Chinese with normal serum lipid levels

OBJECTIVE

To investigate the relationship between lipid profiles [including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C)] and a mild decline in the estimated glomerular filtration rate (eGFR) in subjects with normal serum lipid levels.

DESIGN AND METHODS

In this study, we included 2647 participants who were ≥ 40 years old and had normal serum lipid levels. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation was used to estimate the GFR. A mildly reduced eGFR was defined as 60-90 mL/min/1.73 m(2). First, multiple linear regression analysis was used to estimate the association of lipid profiles with the eGFR. Then, the levels of each lipid component were divided into four groups, using the 25th, 50th and 75th percentiles as cut-off points. Finally, multiple logistic regression analysis was used to investigate the association of different lipid components with the risk of mildly reduced eGFR.

RESULTS

In the group with a mildly reduced eGFR, TG and LDL-C levels were significantly increased, but HDL-C levels were significantly decreased. After adjusting for age, gender, body mass index (BMI), systolic blood pressure (SBP), glycated hemoglobin (HbA1c), smoking and drinking, only TC and TG were independently related to the eGFR. Additionally, only TG showed a linear relationship with an increased risk of a mildly reduced eGFR, with the highest quartile group (TG: 108-150 mg/dl [1.22-1.70 mmol/L]) having a significantly increased risk after adjusting for the above factors.

CONCLUSIONS

Triglyceride levels are closely associated with a mildly reduced eGFR in subjects with normal serum lipid levels. Dyslipidemia with lower TG levels could be used as new diagnostic criteria for subjects with mildly reduced renal function.

Metabolic abnormalities, but not obesity, contribute to the mildly reduced eGFR in middle-aged and elderly Chinese

BACKGROUND

The role of obesity as a determinant of kidney dysfunction has not reached an agreement and the underlying reason may be due to the heterogeneity of obese phenotypes. The aim of the study was to explore the associations of different obese phenotypes with the change of estimated glomerular filtration rate (eGFR) and the roles of obesity and metabolic abnormalities in this association.

METHODS

eGFR was calculated in 8,586 participants (≥ 40 years old). eGFR 60-90 mL/min/1.73 m(2) was defined as the mildly reduced eGFR. Multiple logistic regression analysis was used to determine odds ratios (ORs) for mildly reduced eGFR in the metabolically healthy obese (MHO), metabolically abnormal non-obese (MANO) and metabolically abnormal obese (MAO) groups, using the metabolically healthy non-obese (MHNO) subjects as the reference group. Meanwhile, the associations of body mass index (BMI), waist circumference (WC) and metabolic abnormalities (including hypertension, hyperglycemia and dyslipidemia) with the risk of mildly reduced eGFR were also investigated.

RESULTS

The proportion of MHNO, MHO, MANO and MAO subjects was 8.3, 17.1, 10.1 and 64.5 %, respectively. Increased ORs were observed in MANO (OR 1.51, P = 0.014) and MAO (OR 1.47, P = 0.015) groups, after adjusting for age, gender, smoking, drinking, BMI and WC. When further adjusting for metabolic abnormalities, MANO (OR 1.24, P = 0.247) and MAO (OR 1.17, P = 0.366) subjects would not present increased risk of mildly reduced eGFR any more. Oppositely, fasting insulin (OR 1.03, P < 0.001), hyperglycemia (OR 1.25, P = 0.002) and dyslipidemia (OR 1.25, P = 0.002), but not hypertension, BMI and WC, significantly increased the risk of mildly reduced eGFR.

CONCLUSIONS

Metabolic abnormalities, but not simple obesity, may contribute to the mildly reduced eGFR in middle-aged and elderly Chinese.

Fluctuation between fasting and 2-H postload glucose state is associated with chronic kidney disease in previously diagnosed type 2 diabetes patients with HbA1c ≥ 7%

Objective

To investigate how the glucose variability between fasting and a 2-h postload glucose state (2-h postload plasma glucose [2hPG]-fasting plasma glucose [FPG]) is associated with chronic kidney disease (CKD) in middle-aged and elderly Chinese patients previously diagnosed with type 2 diabetes.

Design and Methods

This cross-sectional study included 1054 previously diagnosed type 2 diabetes patients who were 40 years of age and older. First, the subjects were divided into two groups based on a glycated hemoglobin (HbA1c) value of 7%. Each group was divided into two subgroups, with or without CKD. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation was used to estimate the glomerular filtration rate (GFR). CKD was defined as eGFR<60 mL/min/1.73 m². Multiple linear regression analysis was used to estimate the association between the 2hPG-FPG and eGFR. The 2hPG-FPG value was divided into four groups increasing in increments of 36 mg/dl (2.0 mmol/L): 0–72, 72–108, 108–144 and ≥144 mg/dl, based on the quartiles of patients with HbA1c levels ≥7%; then, binary logistic regression analysis was used to investigate the association between 2hPG-FPG and the risk of CKD.

Results

In the patients with HbA1c levels ≥7%, the 2hPG-FPG was significantly associated with decreased eGFR and an increased risk of CKD independent of age, gender, body mass index (BMI), systolic blood pressure (BP), diastolic BP, smoking, and drinking, as well as fasting insulin, cholesterol, triglyceride, and HbA1c levels. The patients with 2hPG-FPG values ≥144 mg/dl showed an increased odds ratio (OR) of 2.640 (P = 0.033). Additionally, HbA1c was associated with an increased risk of CKD in patients with HbA1c values ≥7%.

Conclusions

The short-term glucose variability expressed by 2hPG-FPG is closely associated with decreased eGFR and an increased risk of CKD in patients with poor glycemic control (HbA1c≥7%).

Estimating glomerular filtration rate in older people

We aimed at reviewing age-related changes in kidney structure and function, methods for estimating kidney function, and impact of reduced kidney function on geriatric outcomes, as well as the reliability and applicability of equations for estimating glomerular filtration rate (eGFR) in older patients. CKD is associated with different comorbidities and adverse outcomes such as disability and premature death in older populations. Creatinine clearance and other methods for estimating kidney function are not easy to apply in older subjects. Thus, an accurate and reliable method for calculating eGFR would be highly desirable for early detection and management of CKD in this vulnerable population. Equations based on serum creatinine, age, race, and gender have been widely used. However, these equations have their own limitations, and no equation seems better than the other ones in older people. New equations specifically developed for use in older populations, especially those based on serum cystatin C, hold promises. However, further studies are needed to definitely accept them as the reference method to estimate kidney function in older patients in the clinical setting.

The impact of acute kidney injury with temporary dialysis on the risk of fracture

Acute kidney injury (AKI) has a negative impact on long-term renal function and prognosis. However, the association between acute renal dysfunction and long-term effects on bone disorders has not yet been characterized. Using a population-based cohort study, we aimed to evaluate associations between AKI and long-term effects on bone fractures. We identified relevant data of all hospitalized patients aged >18 years with histories of dialysis-requiring AKI, with subsequent recovery and discharge, from the claim records of the Taiwan National Health Insurance database between 2000 and 2008. We determined long-term de novo bone fracture and all-cause mortality after patients' index-hospitalization discharge using propensity score-adjusted Cox proportional hazard model. Varying-time models were used to adjust for long-term effects of end-stage renal disease (ESRD) on main outcomes. Among 448 AKI patients who had dialysis and survived 90 days after index-hospitalization discharge without reentering dialysis, 273 were male (60.9%) with a mean age of 61.4 ± 16.6 years. Controls included 1792 hospitalized patients without AKI, dialysis, or bone fracture history. In the AKI recovery group, bone fracture incidence was 320 per 10,000 person-years and hazard ratio (HR) of long-term bone fracture was 1.25 (p = 0.049) compared with the control group, independent of subsequent ESRD status (HR = 1.55; p = 0.01). Both AKI recovery status (HR = 2.31; p < 0.001) and time varying factor of bone fracture (HR = 1.43; p < 0.001) were independent predictors of mortality compared with controls. In conclusion, AKI requiring temporary dialysis independently increases long-term risk of bone fracture, regardless of subsequent progression to ESRD. Long-term bone fractures may negatively impact patient mortality.

Serum homocysteine level is positively associated with chronic kidney disease in a Taiwan Chinese population

BACKGROUND

Both hyperhomocysteinemia and chronic kidney disease (CKD) increase risk of cardiovascular disease. In this study, we investigated the association between serum homocysteine level and CKD.

MATERIALS AND METHODS

A total of 1,581 participants were recruited from a health check-up center in a tertiary hospital in Taiwan between 2006 and 2008. Two groups were created based on serum homocysteine levels above or below 12.24 μmol/l. Estimated glomerular filtration rate (eGFR) was calculated by the Modification of Diet in Renal Disease equation; we defined CKD as an eGFR below 60 ml/min/1.73 m(2). Multivariate logistic and linear regression analyses were used to estimate the associations between serum homocysteine levels and kidney function.

RESULTS

Subjects with elevated homocysteine levels were older and had higher body mass index, blood pressures, fasting plasma glucose, total cholesterol, triglycerides, and eGFR than those with normal serum homocysteine level. Using multiple logistic regression analyses after adjustment for age, sex, lifestyle habits (smoking, alcohol consumption, and betel nut chewing) and chronic diseases (hypertension, diabetes, dyslipidemia), the odds ratio (95 % confidence interval) of having CKD was 5.76 (2.99-11.1) among subjects with elevated serum homocysteine levels compared to subjects with normal serum homocysteine levels. The significant increase in odds ratios for CKD in progressive homocysteine levels reveals a dose-response effect. After adjustment for confounders, at multiple linear regression analyses serum homocysteine level resulted significantly and negatively correlated to eGFR.

CONCLUSIONS

Elevated serum homocysteine levels appear to be closely associated with CKD. Serum homocysteine levels are negatively associated with eGFR.

Serum cystatin C and cerebral microbleeds in patients with acute cerebral stroke

Recent studies have shown that kidney dysfunction is associated with cerebral microbleeds (CMB). Cystatin C is a more useful measurement than creatinine-based estimating equations for evaluating kidney function. The purpose of this study was to clarify the relationship between cystatin C levels and CMB in patients with acute cerebral stroke. This cross-sectional study included a total of 485 patients with acute ischemic stroke and 129 patients with cerebral hemorrhage. The serum levels of cystatin C were significantly higher in acute cerebral stroke patients with CMB than in those without (p<0.001). Multivariate logistic regression analyses showed that for each single standard deviation increase of cystatin C levels, there was a significant increase in the presence of CMB after adjusting for age and sex, and after additional adjustment for cardiovascular risk factors, silent lacunar infarction, and white matter hyperintensity in patients with acute stroke. The odds ratio (95% confidence interval) in patients with acute cerebral infarction and cerebral hemorrhage were 2.92 (1.81-6.93) and 2.98 (1.76-6.97), respectively. The present study suggests that elevated levels of cystatin C are associated with the presence of CMB in acute stroke patients, independent of conventional risk factors.

Risk of developing severe sepsis after acute kidney injury: a population-based cohort study

Introduction

Sepsis has been a factor of acute kidney injury (AKI); however, little is known about dialysis-requiring AKI and the risk of severe sepsis after survival to discharge.

Methods

We conducted a population-based cohort study based on the Taiwan National Health Insurance Research Database from 1999 to 2009. We identified patients with AKI requiring dialysis during hospitalization and survived for at least 90 days after discharge, and matched them with those without AKI according to age, sex, and concurrent diabetes. The primary outcome was severe sepsis, defined as sepsis with a diagnosis of acute organ dysfunction. Individuals who recovered enough to survive without acute dialysis were further analyzed.

Results

We identified 2983 individuals (mean age, 62 years; median follow-up, 3.96 years) with dialysis-requiring AKI and 11,932 matched controls. The incidence rate of severe sepsis was 6.84 and 2.32 per 100 person-years among individuals with dialysis-requiring AKI and without AKI in the index hospitalization, respectively. Dialysis-requiring AKI patients had a higher risk of developing de novo severe sepsis than the non-AKI group. In subgroup analysis, even individuals with recovery from dialysis-requiring AKI were at high risk of developing severe sepsis.

Conclusions

AKI is an independent risk factor for severe sepsis. Even patients who recovered from AKI had a high risk of long-term severe sepsis.

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.

Epidemiology and risk factors for chronic kidney disease in patients with ischaemic stroke

BACKGROUND

There is growing evidence for an association between chronic renal disease (CKD) and adverse cerebrovascular events because of the overlap of several risk factors. The purpose of this study is to examine the epidemiology of CKD and the characteristics of risk factors for CKD in the population with ischaemic stroke.

METHODS

This retrospective study included 571 patients with ischaemic stroke. Estimated glomerular filtration rate (eGFR) was calculated by the Modification of Diet in Renal Disease (MDRD) study equation. Renal function was assessed according to the Kidney Disease Outcomes Quality Initiative (K/DOQI)-CKD classification.

RESULTS

Study demonstrated that the major factors associated with CKD in the ischaemic stroke patients were age, diabetes mellitus, hypertension, systolic blood pressure, LDL cholesterol and serum uric acid. Diabetes mellitus (OR 4·146, 95% CI 1·047-16·418, P = 0·043), hypertension and diabetes mellitus (OR 3·574, 95% CI 1·248-10·234, P = 0·018), serum uric acid (OR 1·010, 95% CI 1·006-1·013, P < 0·001) and LDL cholesterol (OR 1·431, 95% CI 1·063-1·928, P = 0·018) were independent risk factors associated with CKD in the patients with ischaemic stroke.

CONCLUSIONS

The patients with ischaemic stroke may be considered as a high-risk population for CKD and be aggressively managed for CKD prevention. The high prevalence of CKD in population with ischaemic stroke prompts the need for greater public awareness about risks of CKD.

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.