Prevalence of anaemia, iron, and vitamin deficiencies in the health system in the Republic of Ireland: a retrospective cohort study.

BACKGROUND: Anaemia is a common but treatable condition that predicts adverse clinical outcomes. However, standards of anaemia management vary considerably. AIM: To estimate the prevalence of anaemia and extent of screening for common underlying causes in the healthcare system in the Republic of Ireland. DESIGN & SETTING: We conducted a retrospective cohort study of 112 181 adult patients, aged ≥18 years, who had a full blood count performed in 2013, using data from the National Kidney Disease Surveillance System. METHOD: The prevalence of anaemia was determined across demographic and clinical subgroups, according to World Health Organization (WHO) definitions. The proportion screened for iron, vitamin B12, and folate deficiency was determined within a 3-month follow-up period and the corresponding prevalence for each deficiency determined. RESULTS: The overall prevalence of anaemia was 12.0% (95% confidence interval [CI] = 11.8% to 12.2%) and was higher in women than men (13.2% versus 10.5%, P<0.001). Anaemia increased with advancing age (33.4% for those aged >75 years) and worsening kidney function (8.2%, 10.9%, 33.2%, and 63.8% for each estimated glomerular filtration rate [eGFR] categories >90, 60-89, 30-59 and <30 ml/min/1.73 m², respectively, P<0.001). After 3-months' follow-up, the proportion screened for iron deficiency was 11.2% based on transferrin saturation and 33.7% using serum ferritin. Screening for folate and B12 deficiency was 17.6% and 19.8%, respectively. Among screened patients, the prevalence of iron deficiency, B12, and folate deficiency was 37.0%, 6.3%, and 5.8%, respectively. CONCLUSION: The burden of anaemia in the healthcare system is substantial especially for older patients and those with advanced kidney disease. Low screening rates for iron, B12, and folate deficiency are common and warrant quality improvement initiatives.

Impact of serum sodium concentrations, and effect modifiers on mortality in the Irish Health System.

BACKGROUND: Abnormalities of serum sodium are associated with increased mortality risk in hospitalised patients, but it is unclear whether, and to what extent other factors influence this relationship. We investigated the impact of dysnatraemia on total and cause-specific mortality in the Irish health system while exploring the concurrent impact of age, kidney function and designated clinical work-based settings. METHODS: A retrospective cohort study of 32,666 participants was conducted using data from the National Kidney Disease Surveillance System. Hyponatraemia was defined as < 135 mmol/L and hypernatraemia as > 145 mmol/L with normal range 135-145 mmol/L. Multivariable Cox proportional hazards regression was used to estimate hazard ratios (HR's) and 95% Confidence Intervals (CIs) while penalised spline models further examined patterns of risk. RESULTS: There were 5,114 deaths (15.7%) over a median follow up of 5.5 years. Dysnatraemia was present in 8.5% of patients overall. In multivariable analysis, both baseline and time-dependent serum sodium concentrations exhibited a U-shaped association with mortality. Hyponatremia was significantly associated with increased risk for cardiovascular [HR 1.38 (1.18-1.61)], malignant [HR: 2.49 (2.23-2.78)] and non-cardiovascular/non-malignant causes of death [1.36 (1.17-1.58)], while hypernatremia was significantly associated with cardiovascular [HR: 2.16 (1.58-2.96)] and non-cardiovascular/ non-malignant deaths respectively [HR: 3.60 (2.87-4.52)]. The sodium-mortality relationship was significantly influenced by age, level of kidney function and the clinical setting at baseline (P < 0.001). For hyponatraemia, relative mortality risks were significantly higher for younger patients (interaction term P < 0.001), for patients with better kidney function, and for patients attending general practice [HR 2.70 (2.15-3.36)] than other clinical settings. For hypernatraemia, age and kidney function remained significant effect modifiers, with patients attending outpatient departments experiencing the greatest risk [HR 9.84 (4.88-18.62)] than patients who attended other clinical locations. Optimal serum sodium thresholds for mortality varied by level of kidney function with a flattening of mortality curve observed for patients with poorer kidney function. CONCLUSION: Serum sodium concentrations outside the standard normal range adversly impact mortality and are associated with specific causes of death. The thresholds at which these risks appear to vary by age, level of kidney function, and are modified in specific clinical settings within the health system.

Ferric Carboxymaltose in Iron-Deficient Patients with Hospitalized Heart Failure and Reduced Kidney Function.

BACKGROUND: Reduced kidney function is common among patients with heart failure. In patients with heart failure and/or kidney disease, iron deficiency is an independent predictor of adverse outcomes. In the AFFIRM-AHF trial, patients with acute heart failure with iron deficiency treated with intravenous ferric carboxymaltose demonstrated reduced risk of heart failure hospitalization, with improved quality of life. We aimed to further characterize the impact of ferric carboxymaltose among patients with coexisting kidney impairment. METHODS: The double-blind, placebo-controlled AFFIRM-AHF trial randomized 1132 stabilized adults with acute heart failure (left ventricular ejection fraction <50%) and iron deficiency. Patients on dialysis were excluded. The primary end point was a composite of total heart failure hospitalizations and cardiovascular death during the 52-week follow-up period. Additional end points included cardiovascular hospitalizations, total heart failure hospitalizations, and days lost to heart failure hospitalizations or cardiovascular death. For this subgroup analysis, patients were stratified according to baseline eGFR. RESULTS: Overall, 60% of patients had an eGFR <60 ml/min per 1.73 m 2 (the lower eGFR subgroup). These patients were significantly older, more likely to be female and to have ischemic heart failure, and had higher baseline serum phosphate levels and higher rates of anemia. For all end points, event rates were higher in the lower eGFR group. In the lower eGFR group, the annualized event rates for the primary composite outcome were 68.96 and 86.30 per 100 patient-years in the ferric carboxymaltose and placebo arms, respectively (rate ratio, 0.76; 95% confidence interval, 0.54 to 1.06). The treatment effect was similar in the higher eGFR subgroup (rate ratio, 0.65; 95% confidence interval, 0.42 to 1.02; Pinteraction = 0.60). A similar pattern was observed for all end points ( Pinteraction > 0.05). CONCLUSIONS: In a cohort of patients with acute heart failure, left ventricular ejection fraction <50%, and iron deficiency, the safety and efficacy of ferric carboxymaltose were consistent across a range of eGFR values. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Study to Compare Ferric Carboxymaltose With Placebo in Patients With Acute Heart Failure and Iron Deficiency (Affirm-AHF), NCT02937454 .

Rationale, design, demographics and baseline characteristics of the randomized, controlled, Phase 2b SAPPHIRE study of verinurad plus allopurinol in patients with chronic kidney disease and hyperuricaemia.

BACKGROUND: Verinurad is a human uric acid (UA) transporter (URAT1) inhibitor known to decrease serum UA (sUA) levels and that may reduce albuminuria. In a Phase 2a study (NCT03118739), treatment with verinurad + febuxostat lowered urine albumin-to-creatinine ratio (UACR) at 12 weeks by 39% (90% confidence interval 4-62%) among patients with Type 2 diabetes mellitus, hyperuricaemia and albuminuria. The Phase 2b, randomized, placebo-controlled Study of verinurAd and alloPurinol in Patients with cHronic kIdney disease and hyperuRicaEmia (SAPPHIRE; NCT03990363) will examine the effect of verinurad + allopurinol on albuminuria and estimated glomerular filtration rate (eGFR) slope among patients with chronic kidney disease (CKD) and hyperuricaemia. METHODS: Adults (≥18 years of age) with CKD, eGFR ≥25 mL/min/1.73 m2, UACR 30-5000 mg/g and sUA ≥6.0 mg/dL will be enrolled. Approximately 725 patients will be randomized 1:1:1:1:1 to 12, 7.5 or 3 mg verinurad + allopurinol, allopurinol or placebo. An 8-week dose-titration period will precede a 12-month treatment period; verinurad dose will be increased to 24 mg at Month 9 in a subset of patients in the 3 mg verinurad + allopurinol arm. The primary efficacy endpoint the is change from baseline in UACR at 6 months. Secondary efficacy endpoints include changes in UACR, eGFR and sUA from baseline at 6 and 12 months. CONCLUSIONS: This study will assess the combined clinical effect of verinurad + allopurinol on kidney function in patients with CKD, hyperuricaemia and albuminuria, and whether this combination confers renoprotection beyond standard-of-care.

Iron Deficiency in CKD Without Concomitant Anemia.

The physiological role of iron extends well beyond hematopoiesis. Likewise, the pathophysiological effects of iron deficiency (ID) extend beyond anemia. Although inextricably interrelated, ID and anemia of chronic kidney disease (CKD) are distinct clinical entities. For more than 3 decades, however, nephrologists have focused primarily on the correction of anemia. The achievement of target hemoglobin (Hgb) concentrations is prioritized over repletion of iron stores, and iron status is generally a secondary consideration only assessed in those patients with anemia. Historically, the correction of ID independent of anemia has not been a primary focus in the management of CKD. In contrast, ID is a key therapeutic target in the setting of heart failure (HF) with reduced ejection fraction (HFrEF); correction of ID in this population improves functional status and quality of life and may improve cardiovascular (CV) outcomes. Given the strong interrelationships between HF and CKD, it is reasonable to consider whether iron therapy alone may benefit those with CKD and evidence of ID irrespective of Hgb concentration. In this review, we differentiate anemia from ID by considering both epidemiologic and pathophysiological perspectives and by reviewing the evidence linking correction of ID to outcomes in patients with HF and/or CKD. Furthermore, we discuss existing gaps in evidence and provide proposals for future research and practical considerations for clinicians.

Effect of Intensive Urate Lowering With Combined Verinurad and Febuxostat on Albuminuria in Patients With Type 2 Diabetes: A Randomized Trial.

RATIONALE & OBJECTIVE: Hyperuricemia has been implicated in the development and progression of chronic kidney disease. Verinurad is a novel, potent, specific urate reabsorption inhibitor. We evaluated the effects on albuminuria of intensive urate-lowering therapy with verinurad combined with the xanthine oxidase inhibitor febuxostat in patients with hyperuricemia and type 2 diabetes mellitus (T2DM). STUDY DESIGN: Phase 2, multicenter, prospective, randomized, double-blind, parallel-group, placebo-controlled trial. SETTING & PARTICIPANTS: Patients 18 years or older with hyperuricemia, albuminuria, and T2DM. INTERVENTION: Patients randomly assigned 1:1 to verinurad (9mg) plus febuxostat (80mg) or matched placebo once daily for 24 weeks. OUTCOMES: The primary end point was change in urinary albumin-creatinine ratio (UACR) from baseline after 12 weeks' treatment. Secondary end points included safety and tolerability and effect on glomerular filtration. RESULTS: 60 patients were enrolled (n=32, verinurad and febuxostat; n=28, placebo). UACRs after treatment with verinurad plus febuxostat were lower than after placebo at 1, 12, and 24 weeks: -38.6% (90% CI, -60.9% to-3.6%), -39.4% (90% CI, -61.8% to-3.8%), and-49.3% (90% CI, -68.2% to-19.0%), respectively. Serum urate levels after treatment with verinurad plus febuxostat were 59.6% and 63.7% lower than after placebo at 12 and 24 weeks, respectively. No clinically meaningful changes were observed in estimated glomerular filtration rate or serum creatinine or serum cystatin C concentrations. Verinurad plus febuxostat was well tolerated. LIMITATIONS: Sample size and study duration were insufficient to evaluate definitive effects of verinurad plus febuxostat on UACR and glomerular filtration. Generalizability was limited by exclusion of patients with stages 4 and 5 chronic kidney disease. CONCLUSIONS: Verinurad plus febuxostat reduced albuminuria and lowered serum urate concentrations in patients with T2DM, albuminuria, and hyperuricemia. Definitive assessment of their combined impact on preservation of kidney function awaits larger clinical studies. FUNDING: This study was supported by AstraZeneca. TRIAL REGISTRATION: Registered at ClinicalTrials.gov with study number NCT03118739.

Gout and the risk of advanced chronic kidney disease in the UK health system: a national cohort study.

OBJECTIVE: Evaluate the association between gout and risk of advanced chronic kidney disease (CKD). DESIGN: Retrospective matched cohort study. SETTING: UK Clinical Practice Research Datalink. PARTICIPANTS: The analysis included data for 68 897 patients with gout and 554 964 matched patients without gout. Patients were aged ≥18 years, registered at UK practices, had ≥12 months of clinical data and had data linked with Hospital Episode Statistics. Patients were excluded for history of advanced CKD, juvenile gout, cancer, HIV, tumour lysis syndrome, Lesch-Nyhan syndrome or familial Mediterranean fever. PRIMARY AND SECONDARY OUTCOME MEASURES: Advanced CKD was defined as first occurrence of: (1) dialysis, kidney transplant, diagnosis of end-stage kidney disease (ESKD) or stage 5 CKD (diagnostic codes in Read system or International Classification of Diseases, Tenth Revision); (2) estimated glomerular filtration rate (eGFR) <10 mL/min/1.73 m²; (3) doubling of serum creatinine from baseline and (4) death associated with CKD. RESULTS: Advanced CKD incidence was higher for patients with gout (8.54 per 1000 patient-years; 95% CI 8.26 to 8.83) versus without gout (4.08; 95% CI 4.00 to 4.16). Gout was associated with higher advanced CKD risk in both unadjusted analysis (HR, 2.00; 95% CI 1.92 to 2.07) and after adjustment (HR, 1.29; 95% CI 1.23 to 1.35). Association was strongest for ESKD (HR, 2.13; 95% CI 1.73 to 2.61) and was present for eGFR <10 mL/min/1.73 m² (HR, 1.45; 95% CI 1.30 to 1.61) and serum creatinine doubling (HR, 1.13; 95% CI 1.08 to 1.19) but not CKD-associated death (HR, 1.14; 95% CI 0.99 to 1.31). Association of gout with advanced CKD was replicated in propensity-score matched analysis (HR, 1.23; 95% CI 1.17 to 1.29) and analysis limited to patients with incident gout (HR, 1.28; 95% CI 1.22 to 1.35). CONCLUSIONS: Gout is associated with elevated risk of CKD progression. Future studies should investigate whether controlling gout is protective and reduces CKD risk.

Prevalence and treatment of gout among patients with chronic kidney disease in the Irish health system: A national study.

BACKGROUND: Gout is a common inflammatory arthritis associated with adverse clinical outcomes. Under treatment is common in the general population. The aim of this study was to determine the prevalence of gout and its treatment among patients with chronic kidney disease (CKD). METHODS: We conducted a multi-centre cross sectional study of patients (n = 522) who attended specialist nephrology clinics in Ireland. Standardized data collection tool recorded clinical characteristics and medication use at clinic visits and kidney function was assessed with standardised creatinine measurements and Estimated Glomerular Filtration Rate (eGFR). The prevalence of gout and the corresponding use of urate lowering therapies (ULT) were determined. Multivariate logistic regression explored correlates of gout expressed as Odds Ratios (OR) and 95% Confidence Intervals (CI) adjusting for demographic and clinical characteristics. RESULTS: Overall prevalence of gout was 16.6% and increased significantly from 7.5% in Stage 1-2 CKD to 22.8% in stage 4-5 CKD, P< 0.005. Prevalence increased with age (P < 0.005) and was higher in men than women (19.1% versus 10.3% P< 0.005). Overall, 67.9% of gout patients with CKD were treated with ULT, and the percentage increased with advancing stage of CKD from 55.6% in Stage 1-2 to 77.4% in Stage 4-5, P<0.005. Multivariable modelling identified men (vs women), OR, 1.95 (0.95-4.03), serum albumin, OR 1.09 (1.02-1.16) per 1 g/L lower, poorer kidney function, OR 1.11 (1.01-1.22) per 5 ml/min/1.73m2 lower, and rising parathyroid hormone levels, OR 1.38 (1.08-1.77) per 50 pg/ml higher as disease correlates. CONCLUSIONS: Gout is common in CKD and increases with worsening kidney function in the Irish health system. Over two thirds of patients with gout were receiving ULT, increasing to 77% of patients with advanced CKD. Greater awareness of gout in CKD, its treatment and the effectiveness of treatment strategies should be vigorously monitored to improve patient outcomes.

Sweet syndrome: a rare feature of ANCA-associated vasculitis or unusual consequence of azathioprine-induced treatment.

BACKGROUND: Sweet syndrome is a rare skin condition characterised by fever, neutrophilia, and tender erythematous skin lesions and has been reported to occur in association with anti-neutrophil cytoplasmic antibodies (ANCA) as well as complicate treatment with azathioprine therapy. Azathioprine, a relatively safe immunosuppressive, is frequently used to maintain disease remission in the treatment of ANCA-associated vasculitis. The occurrence of Sweet syndrome in a patient with ANCA-positive vasculitis and following treatment with azathioprine prompted us to present this clinical case and share this unusually rare occurrence. In doing so, we also wish to discuss current understanding of the disease and plausible associations. CASE PRESENTATION: Herein, we discuss the case of a 54-year old white male, who presented with features of ANCA vasculitis with haemoptysis, arthralgia, abnormal kidney function with active urine sediment and a positive p-ANCA titre. Standard immunosuppressive treatment with corticosteroids and intravenous rituximab resulted in disease remission. Due to significant steroid side effects, his steroid treatment was gradually tapered and switched to azathioprine over a 6-month period. Two weeks following initiation of azathioprine, he developed a painful maculo-papular erythematous skin rash and fever. A skin biopsy confirmed classical features consistent with Sweet syndrome. Withdrawal of azathioprine and treatment with oral corticosteroids and colchicine therapy resulted in complete resolution of the rash, although he continued to have high titres of MPO positive ANCA. CONCLUSION: Sweet syndrome is a rare adverse reaction to azathioprine but has also been reported to occur in association with ANCA vasculitis. The temporal association with azathioprine in our case and the relatively rapid resolution of the skin vasculitis upon its withdrawal suggested a primarily drug-induced reaction rather than an associated feature of ANCA vasculitis.

Prevalence and correlates of central venous catheter use among haemodialysis patients in the Irish health system - a national study.

BACKGROUND: Central venous catheters (CVC) are associated with substantial morbidity and mortality among patients undergoing haemodialysis (HD), yet they are frequently used as the primary vascular access for many patients on HD. The goal of this study was to determine the prevalence and variation in CVC use across centres in the Irish health system. METHODS: Data from the National Kidney Disease Clinical Patient Management System (KDCPMS) was used to determine CVC use and patterns across centres. Data on demographic characteristics, primary cause of end-stage kidney disease (ESKD), comorbid conditions, laboratory values and centre affiliation were extracted for adult HD patients (n = 1, 196) who were on dialysis for at least three months up to end of December 2016. Correlates of CVC use were explored using multivariable logistic regression. RESULTS: Overall prevalence of CVC use was 54% and varied significantly across clinical sites from 43% to 73%, P < 0.001. In multivariate analysis, the likelihood of CVC use was lower with increasing dialysis vintage, OR 0.40 (0.26-0.60) for 4 years vs 1 year vintage, rising serum albumin, OR 0.73 (0.59-0.90) per 5 g/L), and with cystic disease as a cause of ESKD, OR 0.38 (95% CI 0.21-0.6). In contrast, catheter use was greater for women than men, OR 1.77 (1.34-2.34) and for 2 out of 10 regional dialysis centres, OR 1.98 (1.02-3.84) and OR 2.86 (1.67-4.90) respectively compared to referent group). CONCLUSIONS: Catheters are the predominant type of vascular access in patients undergoing HD in the Irish health system. Substantial centre variation exists which is not explained by patient-level characteristics.

Erectile Dysfunction and Ischaemic Heart Disease.

Erectile dysfunction (ED) is a common disorder that affects the quality of life of many patients. It is prevalent in more than half of males aged over 60 years. Increasing evidence suggests that ED is predominantly a vascular disorder. Endothelial dysfunction seems to be the common pathological process causing ED. Many common risk factors for atherosclerosis such as diabetes, hypertension, smoking, obesity and hyperlipidaemia are prevalent in patients with ED and so management of these common cardiovascular risk factors can potentially prevent ED. Phosphodiesterase type 5 inhibitors provide short-term change of haemodynamic factors to help initiate and maintain penile erection. They have been shown to be an effective and safe treatment strategy for ED in patients with heart disease, including those with ischaemic heart disease and hypertension.

The real-world use of different anti-tumor necrosis factor agents in a Northern European population of patients with Behçet's disease.

OBJECTIVE: The aim of this study was to evaluate prescription practices, treatment responses, and serious adverse events of anti-tumor necrosis factor (anti-TNF) therapies in Behçet's disease (BD). MATERIAL AND METHODS: Patients with BD satisfying the International Study Group for Behçet's Disease or the International Criteria for Behçet's Disease criteria were recruited from a regional rheumatology program. The choice of anti-TNF, treatment response, and adverse events were specified. Response to treatment was evaluated by the detection of new, worsening, or improving clinical features, and management was benchmarked against current The European League against Rheumatism recommendations published in 2008. RESULTS: Out of the total of 22 patients, 18 (81.9%) received anti-TNF therapies, resulting in 14 (77.8%) complete and 4 (22.2%) partial remissions. Eleven (61.1%) patients switched to a second anti-TNF, seven patients (38.9%) required three different anti-TNFs, and one required a fourth anti-TNF to achieve remission. Two patients required retrials before their disease was controlled. Anti-TNF therapy included infliximab (IFX): n=15, 83.3%; adalimumab (ADA): n=9, 50%; golimumab: n=6, 33.3%; etanercept: n=5, 27.8%; and certolizumab pegol: n=2, 11.1%. Secondary failure was observed with IFX (4/15; 26.7%) and ADA (2/9; 22.2%), and these (100%) were manifested after at least 2 years of treatment. Five patients with potentially life-threatening laryngeal involvement received anti-TNFs successfully halting disease progression. Five allergic reactions were encountered, and five serious infections were documented involving three patients aged ≥ 50 years, all with the use of IFX. CONCLUSION: Anti-TNF therapy induced a clinical response in 100% patients and achieved complete remission in 78% patients. It provides an effective alternative option for first-line therapy in severe BD where many conventional immunosuppressive therapies fail. Patients with BD who do not respond to one or more anti-TNFs because of intolerance, ineffectiveness, or secondary failure might benefit from switching to another drug from this group or even a retrial of a previously administered anti-TNF because unsatisfactory results with one biologic is not predictive of response to another anti-TNF. For those with potentially life-threatening destructive laryngeal manifestation, anti-TNF as a first choice may be considered.

Differential impact of smoking on mortality and kidney transplantation among adult Men and Women undergoing dialysis.

BACKGROUND: The extent to which smoking contributes to adverse outcomes among men and women of all ages undergoing dialysis is uncertain. The objective of this study was to determine the differential impact of smoking on risks of mortality and kidney transplantation by age and by sex at dialysis initiation. METHODS: We conducted a population-based cohort of incident U.S dialysis patients (n = 1, 220, 000) from 1995-2010. Age- and sex-specific mortality and kidney transplantation rates were determined for patients with and without a history of cardiovascular disease. Multivariable Cox regression evaluated relative hazard ratios (HR) for death and kidney transplantation at 2 years stratified by atherosclerotic condition, smoking status and age. Analyses were adjusted for demographic characteristics, non-cardiovascular conditions, laboratory variables, socioeconomic and lifestyle factors. RESULTS: The average age was 62.8 (±15) years old, 54 % were male, and the majority was white. During 2-year follow-up, 40.5 % died and 5.7 % were transplanted. Age- and sex-specific mortality rates were significantly higher while transplantation rates were significantly lower for smokers with atherosclerotic conditions than non-smokers (P < 0.01). The adjusted mortality hazards were significantly higher for smokers with pre-existing coronary disease (HR 1.15, 95 % CI (1.11-1.18), stroke (HR 1.21, 1.16-1.27) and peripheral vascular disease (HR = 1.21, 1.17-1.25) compared to non-smokers without these conditions (HR 1.00, referent group). The magnitude of effect was greatest for younger patients than older patients. Contrastingly, the adjusted risks of kidney transplantation were significantly lower for smokers with coronary disease: (HR 0.60, 0.52-0.69), stroke; (HR 0.47, 0.37-0.60), and peripheral arterial disease (HR 0.55, 0.46-0.66) respectively compared to non-smokers without these conditions. CONCLUSIONS: We provide compelling evidence that smoking is associated with adverse clinical outcomes and reduced lifespans among dialysis patients of all ages and sexes. The adverse impact is greatest for younger men and women.

Spatial and Temporal Clustering of Anti-Glomerular Basement Membrane Disease.

BACKGROUND AND OBJECTIVES: An environmental trigger has been proposed as an inciting factor in the development of anti-GBM disease. This multicenter, observational study sought to define the national incidence of anti-GBM disease during an 11-year period (2003-2014) in Ireland, investigate clustering of cases in time and space, and assess the effect of spatial variability in incidence on outcome. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We ascertained cases by screening immunology laboratories for instances of positivity for anti-GBM antibody and the national renal histopathology registry for biopsy-proven cases. The population at risk was defined from national census data. We used a variable-window scan statistic to detect temporal clustering. A Bayesian spatial model was used to calculate standardized incidence ratios (SIRs) for each of the 26 counties. RESULTS: Seventy-nine cases were included. National incidence was 1.64 (95% confidence interval [95% CI], 0.82 to 3.35) per million population per year. A temporal cluster (n=10) was identified during a 3-month period; six cases were resident in four rural counties in the southeast. Spatial analysis revealed wide regional variation in SIRs and a cluster (n=7) in the northwest (SIR, 1.71; 95% CI, 1.02 to 3.06). There were 29 deaths and 57 cases of ESRD during a mean follow-up of 2.9 years. Greater distance from diagnosis site to treating center, stratified by median distance traveled, did not significantly affect patient (hazard ratio, 1.80; 95% CI, 0.87 to 3.77) or renal (hazard ratio, 0.76; 95% CI, 0.40 to 1.13) survival. CONCLUSIONS: To our knowledge, this is the first study to report national incidence rates of anti-GBM disease and formally investigate patterns of incidence. Clustering of cases in time and space supports the hypothesis of an environmental trigger for disease onset. The substantial variability in regional incidence highlights the need for comprehensive country-wide studies to improve our understanding of the etiology of anti-GBM disease.

The impact of chronic obstructive pulmonary disease and smoking on mortality and kidney transplantation in end-stage kidney disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) and tobacco use are leading causes of morbidity and mortality. The prevalence and clinical impact of COPD on mortality and kidney transplantation among patients who begin dialysis therapy is unclear. METHODS: We explored the clinical impact of COPD and continued tobacco use on overall mortality and kidney transplantation in a national cohort study of US dialysis patients. National data on all dialysis patients (n = 769,984), incident between May 1995 and December 2004 and followed until October 31, 2006, were analyzed from the United States Renal Data System. Prevalence and period trends were determined while multivariable Cox regression evaluated relative hazard ratios (RR) for death and kidney transplantation. RESULTS: The prevalence of COPD was 7.5% overall and increased from 6.7 to 8.1% from 1995-2004. COPD correlated significantly with older age, cardiovascular conditions, cancer, malnutrition, poor functional status, and tobacco use. Adjusted mortality risks were significantly higher for patients with COPD (RR = 1.20, 95% CI 1.18-1.21), especially among current smokers (RR = 1.28, 95% CI 1.25-1.32), and varied inversely with advancing age. In contrast, the adjusted risks of kidney transplantation were significantly lower for patients with COPD (RR = 0.47, 95% CI 0.41-0.54, for smokers and RR = 0.54, 95% CI 0.50-0.58, for non-smokers) than without COPD [RR = 0.72, 95% CI 0.70-0.75, for smokers and RR = 1.00 for non-smokers (referent category)]. CONCLUSIONS: Patients with COPD who begin dialysis therapy in the US experience higher mortality and lower rates of kidney transplantation, outcomes that are far worse among current smokers.

Cigarette use and cardiovascular risk in chronic kidney disease: an unappreciated modifiable lifestyle risk factor.

Tobacco use is a major modifiable cardiovascular risk factor in the general population and contributes to excess cardiovascular risk. Emerging evidence from large-scale observational studies suggests that continued tobacco use is also an independent cardiovascular risk factor among patients with chronic kidney disease (CKD). The benefits of smoking cessation programs on improving the heath status of patients and reducing mortality are unequivocal in the general population. Despite this, there has been little effort in pursuing tobacco cessation programs in dialysis cohorts or those with lesser degrees of kidney impairment. Most of our attention to date has focused on the development of "kidney-specific" interventions that reduce rates of renal disease progression and improve dialysis outcomes. The purpose of this current review is to describe the epidemiology of tobacco use among patients with CKD, draw attention to its negative impact on cardiovascular morbidity and mortality, and finally highlight potential strategies for successful intervention. We hope that this study heightens the importance of tobacco use in CKD, stimulates renewed interest in the barriers and challenges that exist in achieving smoking cessation, and endorses the efficacy of intervention strategies and the immeasurable benefits of quitting on cardiovascular and noncardiovascular outcomes.

Determinants and prognostic importance of cardiomegaly among new ESRD patients in the United States.

PURPOSE: Cardiomegaly is a radiographic abnormality of major prognostic importance in the general population. We explored the clinical correlations and mortality impact of cardiomegaly in new end-stage renal disease (ESRD) patients from the Dialysis Morbidity and Mortality Study Wave 2. METHODS: Radiographic data denoting the presence or absence of cardiomegaly were available for 97% (n=3908) of the entire cohort. Multivariate logistic regression explored relationships between potential uremic factors and known traditional cardiovascular disease (CVD) factors with cardiomegaly and Cox regression estimated the mortality risk associations over 2 years. RESULTS: The prevalence of cardiomegaly was 26%. Multivariate analysis identified: age (adjusted odds ratio [OR]=1.30 per 10 years older), black race (OR=1.33) diabetes (OR=1.26), hypertension (OR=1.28), tobacco use (OR=1.17), serum albumin (OR=1.36 per 1 g/dL lower), and extremes of body mass index (BMI) (OR=1.24 for BMI<21.1 and OR=1.10 for BMI>30.0 compared with referent [21.1-23.3 Kg/m2]) as significant correlates. The impact of cardiomegaly on mortality was greatest in the first 12 months (RR=1.56; CI, 1.33-1.83) and persisted for up to 2 years (RR=1.44; CI, 1.27-1.62). Interestingly, the likelihood of cardiomegaly was significantly lower for patients who received regular care during the pre-ESRD period (erythropoietin use [OR=0.79] and nephrology visits [OR=0.80 for > or =2 vs. less]). CONCLUSIONS: Traditional CVD risk factors were the predominant correlates of cardiomegaly in new ESRD patients. Vigorous CVD risk factor reduction strategies and frequent specialist care during the pre-ESRD period may be beneficial in reducing the prevalence of cardiomegaly and attenuating its impact on survival.

Clinical correlates and mortality impact of left ventricular hypertrophy among new ESRD patients in the United States.

BACKGROUND: Left ventricular hypertrophy (LVH) is common among patients with end-stage renal disease (ESRD), but few population-based studies exist. Here, we describe clinical correlations and mortality impact of LVH in new patients with ESRD from the Dialysis Morbidity and Mortality Study Wave 2. METHODS: Echocardiographic data denoting the presence or absence of LVH were available for 64% (n = 2,584) of the entire cohort. Multivariate logistic regression identified significant correlates of LVH, and Cox proportional hazards regression estimated the mortality risk (risk ratio [RR]) for LVH at 6, 12, and 24 months. RESULTS: The prevalence of LVH was 16.4%. Multivariate analysis identified age (adjusted odds ratio [OR], 1.15 per 10 years older), hypertension (OR, 1.39), diabetes (OR, 1.47), tobacco use (OR, 1.42), serum calcium level (OR, 1.17 per 1 mg/dL [0.25 mmol/L] higher), parathyroid hormone level greater than versus less than 157 pg/mL (157 ng/L; OR, 1.53), serum albumin level (OR, 1.38 per 1 g/dL [10 g/L] lower), and presence of pericarditis (OR, 2.55) as significant disease correlates. The impact of LVH on subsequent mortality was greatest in the first 6 months of follow-up (RR, 1.61; confidence interval [CI], 1.17 to 2.22) and became less pronounced thereafter (RR, 1.36; CI, 1.07 to 1.89; RR, 1.29; CI, 1.07 to 1.56 at the end of 1 and 2 years, respectively). CONCLUSION: This study identifies known coronary risk factors and markers of uremia as independent correlates of LVH presence in new patients with ESRD. It also highlights the adverse impact of pre-ESRD LVH on short-term patient survival. Given the clinical consequences of LVH on morbidity and mortality, greater efforts are required to reduce known risk factors for LVH in the pre-ESRD period.

Prevalence and clinical correlates of coronary artery disease among new dialysis patients in the United States: a cross-sectional study.

Despite the high prevalence of coronary artery disease (CAD) among patients with end-stage renal disease (ESRD), few studies have identified clinical correlates using national data. The purpose of this study was to determine the prevalence and clinical associations of CAD in a national random sample of new ESRD in the United States in 1996/1997 (n = 4025). Data on demographic characteristics and comorbidities were obtained from the Dialysis Morbidity and Mortality Study, Wave 2. The principal outcome was CAD, defined as the presence of a previous history of CAD, myocardial infarction, or angina, coronary artery bypass surgery, coronary angioplasty, or abnormal coronary angiographic findings. Multivariate logistic regression analysis was used to assess the relationship of conventional factors and proposed uremic factors to the presence of CAD. CAD was present in 38% of patients. Of the total cohort, 17% had a history of myocardial infarction and 23% had angina. Several conventional risk factors, including advancing age, male gender, diabetes mellitus, and smoking, were significantly associated with CAD. Of the proposed uremic factors, lower serum albumin levels but higher residual renal function and higher hematocrit values were significantly associated with the presence of CAD. Vascular comorbid conditions, structural cardiac abnormalities, white race, and geographic location were also strongly correlated with the presence of CAD. This national study suggests that several conventional CAD risk factors may also be risk factors for CAD among the ESRD population. This study identifies nonconventional factors such as serum albumin levels, vascular comorbid conditions, and structural cardiac abnormalities as important disease correlates. Future logitudinal studies are required to explore the relative importance of the relationships observed here.