[Show abstract][Hide abstract] ABSTRACT: Reduced kidney function is a risk factor for hyperuricaemia and gout, but limited information on the burden of gout is available from studies of patients with chronic kidney disease (CKD). We therefore examined the prevalence and correlates of gout in the large prospective observational German Chronic Kidney Disease (GCKD) study.
[Show abstract][Hide abstract] ABSTRACT: Mycophenolate mofetil (MMF) side effects often prompt dose reduction or discontinuation, and this MMF dose reduction (MDR) can lead to rejection and possibly graft loss. Unfortunately, little is known about what factors might cause or contribute to MDR. Frailty, a measure of physiologic reserve, is emerging as an important, novel domain of risk in kidney transplantation recipients. We hypothesized that frailty, an inflammatory phenotype, might be associated with MDR.
[Show abstract][Hide abstract] ABSTRACT: Disparities in kidney transplantation remain; one mechanism for disparities in access to transplantation (ATT) may be patient-perceived concerns about pursuing transplantation. This study sought to characterize prevalence of patient-perceived concerns, explore interrelationships between concerns, determine patient characteristics associated with concerns, and assess the effect of concerns on ATT.
Clinical Journal of the American Society of Nephrology 09/2014; · 5.25 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Because informed consent requires discussion of alternative treatments, proper consent for dialysis should incorporate discussion about other renal replacement options including kidney transplantation (KT). Accordingly, dialysis providers are required to indicate KT provision of information (KTPI) on CMS Form-2728; however, provider-reported KTPI does not necessarily imply adequate provision of information. Furthermore, the effect of KTPI on pursuit of KT remains unclear. We compared provider-reported KTPI (Form-2728) with patient-reported KTPI (in-person survey of whether a nephrologist or dialysis staff had discussed KT) in a prospective ancillary study of 388 hemodialysis initiates. KTPI was reported by both patient and provider for 56.2% of participants, by provider only for 27.8%, by patient only for 8.3%, and by neither for 7.7%. Among participants with provider-reported KTPI, older age was associated with lack of patient-reported KTPI. Linkage with the Scientific Registry for Transplant Recipients showed that 20.9% of participants were subsequently listed for KT. Patient-reported KTPI was independently associated with a 2.95-fold (95% confidence interval [95% CI], 1.54 to 5.66; P=0.001) higher likelihood of KT listing, whereas provider-reported KTPI was not associated with listing (hazard ratio, 1.18; 95% CI, 0.60 to 2.32; P=0.62). Our findings suggest that patient perception of KTPI is more important for KT listing than provider-reported KTPI. Patient-reported and provider-reported KTPI should be collected for quality assessment in dialysis centers because factors associated with discordance between these metrics might inform interventions to improve this process.
Journal of the American Society of Nephrology 08/2014; · 9.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Smoking is the leading cause of preventable death in the United States. Studies have shown that smoking status tends to be concordant within spouse pairs. This study aimed to estimate the association of spousal smoking status with quitting smoking in US adults. We analyzed data from 4,500 spouse pairs aged 45-64 years from the Atherosclerosis Risk in Communities Study cohort, sampled from 1986 to 1989 from 4 US communities and followed up every 3 years for a total of 9 years. Logistic regression with generalized estimating equations was used to calculate the odds ratio of quitting smoking given that one's spouse is a former smoker or a current smoker compared to a never smoker. Among men and women, being married to a current smoker decreased the odds of quitting smoking (for men, odds ratio (OR) = 0.37, 95% confidence interval (CI): 0.29, 0.46; for women, OR = 0.54, 95% CI: 0.43, 0.68). Among women only, being married to a former smoker increased the odds of quitting smoking (OR = 1.26, 95% CI: 1.04, 1.53). In conclusion, spouses of current smokers are less likely to quit, whereas women married to former smokers are more likely to quit. Smoking cessation programs and clinical advice should consider targeting couples rather than individuals.
American journal of epidemiology 04/2014; · 4.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Some observational studies have identified elevated uric acid concentration as a risk factor for diabetes, while others have found an inverse relationship. We examined both the association of uric acid level with incident diabetes and the change in uric acid concentration after a diabetes diagnosis. We analyzed data from the Atherosclerosis Risk in Communities (ARIC) Study and quantified the independent association between uric acid level and incident diabetes via Cox proportional hazards models. The association between duration of diabetes and change in uric acid level was examined via linear regression. Among 11,134 participants without diagnosed diabetes at baseline (1987-1989), there were 1,294 incident cases of diabetes during a median of 9 years of follow-up (1987-1998). Uric acid level was associated with diabetes even after adjustment for risk factors (per 1 mg/dL, hazard ratio = 1.18, 95% confidence interval: 1.13, 1.23), and the association remained significant after adjustment for fasting glucose and insulin levels. Among participants with diabetes (n = 1,510), every additional 5 years' duration of diabetes was associated with a 0.10-mg/dL (95% confidence interval: 0.04, 0.15) lower uric acid level after adjustment. We conclude that uric acid concentration rises prior to diagnosis of diabetes and then declines with diabetes duration. Future studies investigating uric acid as a risk factor for cardiovascular disease should adequately account for the impact and timing of diabetes development.
American journal of epidemiology 01/2014; · 4.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We examined racial differences in gout incidence among black and white participants in a longitudinal, population-based cohort and tested whether racial differences were explained by higher levels of serum urate. The Atherosclerosis Risk in Communities Study is a prospective, US population-based cohort study of middle-aged adults enrolled between 1987 and 1989 with ongoing annual follow-up through 2012. We estimated the adjusted hazard ratios and 95% confidence intervals of incident gout by race among 11,963 men and women using adjusted Cox proportional hazards models. The cohort was 23.6% black. The incidence rate of gout was 8.4 per 10,000 person-years (15.5/10,000 person-years for black men, 12.0/10,000 person-years for black women, 9.4/10,000 person-years for white men, and 5.0/10,000 person-years for white women; P < 0.001). Black participants had an increased risk of incident gout (for women, adjusted hazard ratio (HR) = 1.69, 95% confidence interval (CI): 1.29, 2.22; for men, adjusted HR = 1.92, 95% CI: 1.44, 2.56). Upon further adjustment for uric acid levels, there was modest attenuation of the association of race with incident gout (for women, adjusted HR = 1.62, 95% CI: 1.24, 2.22; for men, adjusted HR = 1.49, 95% CI: 1.11, 2.00) compared with white participants. In this US population-based cohort, black women and black men were at increased risk of developing gout during middle and older ages compared with whites, which appears, particularly in men, to be partly related to higher urate levels in middle-aged blacks.
American journal of epidemiology 12/2013; · 4.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Increased serum urate levels are associated with poor outcomes including but not limited to gout. It is unclear whether serum urate levels are the sole predictor of incident hyperuricemia or whether demographic and clinical risk factors also predict the development of hyperuricemia. The goal of this study was to identify risk factors for incident hyperuricemia over 9 years in a population-based study, ARIC.
ARIC recruited individuals from 4 US communities; 8,342 participants who had urate levels <7.0 mg/dL were included in this analysis. Risk factors (including baseline, 3-year, and change in urate level over 3 years) for 9-year incident hyperuricemia (urate level of >7.0 g/dL) were identified using an AIC-based selection approach in a modified Poisson regression model.
The 9-year cumulative incidence of hyperuricemia was 4%; men = 5%; women = 3%; African Americans = 6% and; whites = 3%. The adjusted model included 9 predictors for incident hyperuricemia over 9 years: male sex (RR = 1.73 95% CI:1.36-2.21), African-American race (RR = 1.79 95%CI:1.37-2.33), smoking (RR = 1.27, 95%CI: 0.97-1.67), <HS education (RR = 1.27, 95%CI:0.99-1.63), hypertension (RR = 1.65, 95%CI:1.30-2.09), CHD (RR = 1.57, 95%CI:0.99-2.50), obesity (class I RR = 2.37, 95%CI:1.65-3.41 and >= class II RR = 3.47, 95%CI:2.33-5.18), eGFR < 60 (RR = 2.85, 95%CI:1.62-5.01) and triglycerides (Quartile 4 vs. Quartile 1: RR = 2.00, 95%CI:1.38-2.89). In separate models, urate levels at baseline (RR 1 mg/dL increase = 2.33, 95%CI:1.94-2.80) and 3 years after baseline (RR for a 1 mg/dL increase = 1.92, 95%CI:1.78-2.07) were associated with incident hyperuricemia after accounting for demographic and clinical risk factors.
Demographic and clinical risk factors that are routinely collected as part of regular medical care are jointly associated with the development of hyperuricemia.
[Show abstract][Hide abstract] ABSTRACT: Patients undergoing hemodialysis are at high risk of falls, with subsequent complications including fractures, loss of independence, hospitalization, and institutionalization. Factors associated with falls are poorly understood in this population. We hypothesized that insights derived from studies of the elderly might apply to adults of all ages undergoing hemodialysis; we focused on frailty, a phenotype of physiological decline strongly associated with falls in the elderly.
In this prospective, longitudinal study of 95 patients undergoing hemodialysis (1/2009-3/2010), the association of frailty with future falls was explored using adjusted Poisson regression. Frailty was classified using the criteria established by Fried et al., as a combination of five components: shrinking, weakness, exhaustion, low activity, and slowed walking speed.
Over a median 6.7-month period of longitudinal follow-up, 28.3% of study participants (25.9% of those under 65, 29.3% of those 65 and older) experienced a fall. After adjusting for age, sex, race, comorbidity, disability, number of medications, marital status, and education, frailty independently predicted a 3.09-fold (95% CI: 1.38-6.90, P=0.006) higher number of falls. This relationship between frailty and falls did not differ for younger and older adults (P=0.57).
Frailty, a validated construct in the elderly, was a strong and independent predictor of falls in adults undergoing hemodialysis, regardless of age. Our results may aid in identifying frail hemodialysis patients who could be targeted for multidimensional fall prevention strategies.
[Show abstract][Hide abstract] ABSTRACT: Early hospital readmission (EHR) after kidney transplantation (KT) is associated with increased morbidity and higher costs. Registry-based recipient, transplant and center-level predictors of EHR are limited, and novel predictors are needed. We hypothesized that frailty, a measure of physiologic reserve initially described and validated in geriatrics and recently associated with early KT outcomes, might serve as a novel, independent predictor of EHR in KT recipients of all ages. We measured frailty in 383 KT recipients at Johns Hopkins Hospital. EHR was ascertained from medical records as ≥1 hospitalization within 30 days of initial post-KT discharge. Frail KT recipients were much more likely to experience EHR (45.8% vs. 28.0%, p = 0.005), regardless of age. After adjusting for previously described registry-based risk factors, frailty independently predicted 61% higher risk of EHR (adjusted RR = 1.61, 95% CI: 1.18-2.19, p = 0.002). In addition, frailty improved EHR risk prediction by improving the area under the receiver operating characteristic curve (p = 0.01) as well as the net reclassification index (p = 0.04). Identifying frail KT recipients for targeted outpatient monitoring and intervention may reduce EHR rates.
American Journal of Transplantation 06/2013; · 6.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVES: To quantify the prevalence of frailty in adults of all ages undergoing chronic hemodialysis, its relationship to comorbidity and disability, and its association with adverse outcomes of mortality and hospitalization. DESIGN: Prospective cohort study. SETTING: Single hemodialysis center in Baltimore, Maryland. PARTICIPANTS: One hundred forty-six individuals undergoing hemodialysis enrolled between January 2009 and March 2010 and followed through August 2012. MEASUREMENTS: Frailty, comorbidity, and disability on enrollment in the study and subsequent mortality and hospitalizations. RESULTS: At enrollment, 50.0% of older (≥65) and 35.4% of younger (<65) individuals undergoing hemodialysis were frail; 35.9% and 29.3%, respectively, were intermediately frail. Three-year mortality was 16.2% for nonfrail, 34.4% for intermediately frail, and 40.2% for frail participants. Intermediate frailty and frailty were associated with a 2.7 times (95% confidence interval (CI) = 1.02-7.07, P = .046) and 2.6 times (95% CI = 1.04-6.49, P = .04) greater risk of death independent of age, sex, comorbidity, and disability. In the year after enrollment, median number of hospitalizations was 1 (interquartile range 0-3). The proportion with two or more hospitalizations was 28.2% for nonfrail, 25.5% for intermediately frail, and 42.6% for frail participants. Although intermediate frailty was not associated with number of hospitalizations (relative risk = 0.76, 95% CI = 0.49-1.16, P = .21), frailty was associated with 1.4 times (95% CI = 1.00-2.03, P = .049) more hospitalizations independent of age, sex, comorbidity, and disability. The association between frailty and mortality (interaction P = .64) and hospitalizations (P = .14) did not differ between older and younger participants. CONCLUSIONS: Adults of all ages undergoing hemodialysis have a high prevalence of frailty, more than five times as high as community-dwelling older adults. In this population, regardless of age, frailty is a strong, independent predictor of mortality and number of hospitalizations.
Journal of the American Geriatrics Society 05/2013; · 4.22 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Early hospital readmission (EHR) is associated with increased morbidity, costs and transition-of-care errors. We sought to quantify rates of and risk factors for EHR after kidney transplantation (KT). We studied 32 961 Medicare primary KT recipients (2000-2005) linked to Medicare claims through the United States Renal Data System. EHR was defined as at least one hospitalization within 30 days of initial discharge after KT. The association between EHR and recipient and transplant factors was explored using Poisson regression; hierarchical modeling was used to account for study center-level differences. The overall EHR rate was 31%, and 19 independent patient-level factors associated with EHR were identified: recipient factors included older age, African American race and various comorbidities; transplant factors included ECD, length of stay and lack of induction therapy. The unadjusted rate of EHR by center ranged from 18% to 47%, but conventional center-level factors (percent African American, percent age > 60, percent deceased donor and percent expanded criteria donor) were not associated with EHR. However, intermediate total volume and average length of stay were associated with increased EHR risk. Better identification of patients at risk for early hospital readmission following KT may guide discharge planning and early posttransplant outpatient monitoring.
American Journal of Transplantation 09/2012; · 6.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: INTRODUCTION: There is a growing prevalence of gout in the US and worldwide. Gout is a recognized risk factor for cardiovascular disease (CVD). It is unclear whether other risk factors for CVD are also associated with increased risk of gout. Anemia is one such CVD risk factor. No studies have evaluated the relationship between anemia and gout. We tested whether anemia was associated with incident gout independent of comorbid conditions in Atherosclerosis Risk in the Communities. METHODS: This population-based cohort recruited 15,792 individuals in 1987-1989 from 4 US communities and contained 9-years of follow-up. Anemia was defined as hemoglobin <13.5 g/dL for men and <12 g/dL for women. Using a Cox Proportional Hazards model, we estimated the hazard ratio (HR) and confidence intervals (CI) of incident gout by baseline anemia, adjusted for confounders (sex, race, estimated glomerular filtration rate, body mass index, and alcohol intake) and clinical factors (coronary heart disease, congestive heart failure, diabetes, hypertension, diuretic use and serum urate level). RESULTS: Among the 10,791 participants, 10% had anemia at baseline. There were 271 cases of incident gout. Patients with anemia had a 2-fold increased risk of developing gout over 9 years (HR=2.01, 95% CI: 1.46, 2.76). Anemia was associated with incident gout independent of known gout risk factors, confounders and clinical risk factors (HR=1.73, 95% CI: 1.24, 2.41). This association persisted after additionally adjusting for serum urate level (HR=1.83, 95% CI: 1.30, 2.57). CONCLUSION: We identified anemia as a novel risk factor for gout. Anemia was associated with an approximately 2-fold increased risk of gout independent kidney function and serum urate. These findings suggest that anemia is a risk factor for gout on par with other chronic conditions such as obesity and diabetes. The biological mechanism linking anemia to gout remains unclear.
Arthritis research & therapy 08/2012; 14(4):R193. · 4.12 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE: To test for a urate gene-by-diuretic interaction on incident gout. METHODS: The Atherosclerosis Risk in Communities Study is a prospective population-based cohort of 15 792 participants recruited from four US communities (1987-1989). Participants with hypertension and available single nucleotide polymorphism (SNP) genotype data were included. A genetic urate score (GUS) was created from common urate-associated SNPs for eight genes. Gout incidence was self-reported. Using logistic regression, the authors estimated the adjusted OR of incident gout by diuretic use, stratified by GUS median. RESULTS: Of 3524 participants with hypertension, 33% used a diuretic and 3.1% developed gout. The highest 9-year cumulative incidence of gout was in those with GUS above the median and taking a thiazide or loop diuretic (6.3%). Compared with no thiazide or loop diuretic use, their use was associated with an OR of 0.40 (95% CI 0.14 to 1.15) among those with a GUS below the median and 2.13 (95% CI 1.23 to 3.67) for those with GUS above the median; interaction p=0.006. When investigating the genes separately, SLC22A11 and SLC2A9 showed a significant interaction, consistent with the former encoding an organic anion/dicarboxylate exchanger, which mediates diuretic transport in the kidney. CONCLUSIONS: Participants who were genetically predisposed to hyperuricaemia were susceptible to developing gout when taking thiazide or loop diuretics, an effect not evident among those without a genetic predisposition. These findings argue for a potential benefit of genotyping individuals with hypertension to assess gout risk, relative in part to diuretic use.
Annals of the rheumatic diseases 06/2012; · 9.27 Impact Factor