A Comparative Study of Serum Phosphate and Related Parameters in Chronic Kidney Disease between the USA and Japan.

Introduction: Recent studies have suggested a higher incidence of cardiovascular disease (CVD) among patients with chronic kidney disease (CKD) in the USA than in Japan. Hyperphosphatemia, a possible risk for CVD, may explain this difference; however, international differences in phosphate parameters in CKD have not been well elaborated.

Methods: By using the baseline data from the USA and the Japanese nation-wide, multicenter, CKD cohort studies; the Chronic Renal Insufficiency Cohort Study (CRIC, N = 3,870) and the Chronic Kidney Disease-Japan Cohort Study (CKD-JAC, N = 2,632), we harmonized the measures and compared clinical parameters regarding phosphate metabolism or serum phosphate, fibroblast growth factor-23 (FGF23), and parathyroid hormone (PTH), in the cross-sectional model.

Randomized Controlled-Feeding Study of Dietary Emulsifier Carboxymethylcellulose Reveals Detrimental Impacts on the Gut Microbiota and Metabolome.

Background & Aims: Epidemiologic and murine studies suggest that dietary emulsifiers promote development of diseases associated with microbiota dysbiosis. Although the detrimental impact of these compounds on the intestinal microbiota and intestinal health have been demonstrated in animal and in vitro models, impact of these food additives in healthy humans remains poorly characterized.

Methods: To examine this notion in humans, we performed a double-blind controlled-feeding study of the ubiquitous synthetic emulsifier carboxymethylcellulose (CMC) in which healthy adults consumed only emulsifier-free diets (n = 9) or an identical diet enriched with 15 g per day of CMC (n = 7) for 11 days.

A Randomized Trial Comparing the Specific Carbohydrate Diet to a Mediterranean Diet in Adults With Crohn's Disease.

Background & Aims: This study compared the effectiveness of the Specific Carbohydrate Diet (SCD) to the Mediterranean diet (MD) as treatment for Crohn's disease (CD) with mild to moderate symptoms.

Methods: Adult patients with CD and with mild-to-moderate symptoms were randomly assigned 1:1 to consume the MD or SCD for 12 weeks. For the first 6 weeks, participants received prepared meals and snacks according to their assigned diet.

Cardiovascular disease history and β-blocker prescription patterns among Japanese and American patients with CKD: a cross-sectional study of the CRIC and CKD-JAC studies.

Cardiovascular disease (CVD) is a major complication in individuals with chronic kidney disease (CKD). In Japan, the incidence of CVD among persons with CKD is lower than that in the United States. Although various classes of antihypertensive agents are prescribed to prevent CVD, the proportion varies between the United States and Japan.

Role of dietary fiber in the recovery of the human gut microbiome and its metabolome.

Gut microbiota metabolites may be important for host health, yet few studies investigate the correlation between human gut microbiome and production of fecal metabolites and their impact on the plasma metabolome. Since gut microbiota metabolites are influenced by diet, we performed a longitudinal analysis of the impact of three divergent diets, vegan, omnivore, and a synthetic enteral nutrition (EEN) diet lacking fiber, on the human gut microbiome and its metabolome, including after a microbiota depletion intervention. Omnivore and vegan, but not EEN, diets altered fecal amino acid levels by supporting the growth of Firmicutes capable of amino acid metabolism.

Longitudinal Evolution of Markers of Mineral Metabolism in Patients With CKD: The Chronic Renal Insufficiency Cohort (CRIC) Study.

Rationale & Objective: The pathogenesis of disordered mineral metabolism in chronic kidney disease (CKD) is largely informed by cross-sectional studies of humans and longitudinal animal studies. We sought to characterize the longitudinal evolution of disordered mineral metabolism during the course of CKD.

Study Design: Retrospective analysis nested in a cohort study.

Association of Pulse Wave Velocity With Chronic Kidney Disease Progression and Mortality: Findings From the CRIC Study (Chronic Renal Insufficiency Cohort).

Patients with chronic kidney diseases (CKDs) are at risk for further loss of kidney function and death, which occur despite reasonable blood pressure treatment. To determine whether arterial stiffness influences CKD progression and death, independent of blood pressure, we conducted a prospective cohort study of CKD patients enrolled in the CRIC study (Chronic Renal Insufficiency Cohort). Using carotid-femoral pulse wave velocity (PWV), we examined the relationship between PWV and end-stage kidney disease (ESRD), ESRD or halving of estimated glomerular filtration rate, or death from any cause.

Coronary Artery Calcification and Risk of Cardiovascular Disease and Death Among Patients With Chronic Kidney Disease.

Importance: Coronary artery calcification (CAC) is highly prevalent in dialysis-naive patients with chronic kidney disease (CKD). However, there are sparse data on the association of CAC with subsequent risk of cardiovascular disease and all-cause mortality in this population.

Objective: To study the prospective association of CAC with risk of cardiovascular disease and all-cause mortality among dialysis-naive patients with CKD.

Inflammation and elevated levels of fibroblast growth factor 23 are independent risk factors for death in chronic kidney disease.

Inflammation is a consequence of chronic kidney disease (CKD) and is associated with adverse outcomes in many clinical settings. Inflammation stimulates production of fibroblast growth factor 23 (FGF23), high levels of which are independently associated with mortality in CKD. Few large-scale prospective studies have examined inflammation and mortality in patients with CKD, and none tested the interrelationships among inflammation, FGF23, and risk of death.

International Network of Chronic Kidney Disease cohort studies (iNET-CKD): a global network of chronic kidney disease cohorts.

Background: Chronic kidney disease (CKD) is a global health burden, yet it is still underrepresented within public health agendas in many countries. Studies focusing on the natural history of CKD are challenging to design and conduct, because of the long time-course of disease progression, a wide variation in etiologies, and a large amount of clinical variability among individuals with CKD. With the difference in health-related behaviors, healthcare delivery, genetics, and environmental exposures, this variability is greater across countries than within one locale and may not be captured effectively in a single study.

Ankle Brachial Index and Subsequent Cardiovascular Disease Risk in Patients With Chronic Kidney Disease.

Background: The clinical implications of ankle-brachial index (ABI) cutpoints are not well defined in patients with chronic kidney disease (CKD) despite increased prevalence of high ABI attributed to arterial stiffness. We examined the relationship of ABI with cardiovascular disease (CVD) and all-cause mortality among CKD patients.

Methods And Results: Three thousand six hundred twenty-seven participants without clinical peripheral artery disease (PAD) at baseline from the Chronic Renal Insufficiency Cohort Study were included.

Predictors and Outcomes of Health-Related Quality of Life in Adults with CKD.

Background And Objectives: Low health-related quality of life is associated with increased mortality in patients with ESRD. However, little is known about demographic and clinical factors associated with health-related quality of life or its effect on outcomes in adults with CKD.

Design, Settings, Participants, & Measurements: Data from 3837 adult participants with mild to severe CKD enrolled in the prospective observational Chronic Renal Insufficiency Cohort and Hispanic Chronic Renal Insufficiency Cohort Studies were analyzed.

The Associations between Peripheral Artery Disease and Physical Outcome Measures in Men and Women with Chronic Kidney Disease.

Background: Peripheral artery disease (PAD) is highly prevalent and associated with significant morbidity and mortality, but sex-based differences are incompletely understood. We sought to define the associations between PAD and physical outcome measures and to determine if these associations differed by sex in the Chronic Renal Insufficiency Cohort.

Methods: Among 3,543 participants, we assessed the cross-sectional relationship between PAD severity defined by ankle-brachial index; and (1) physical activity (metabolic equivalent [MET]-hr/wk), (2) walking pace (slow versus medium and/or fast), and (3) physical function (12-item Short Form Health Survey [SF-12]) at baseline.

Genetic African Ancestry and Markers of Mineral Metabolism in CKD.

Background And Objectives: Disorders of mineral metabolism are more common in African Americans with CKD than in European Americans with CKD. Previous studies have focused on the differences in mineral metabolism by self-reported race, making it difficult to delineate the importance of environmental compared with biologic factors.

Design, Setting, Participants, & Measurements: In a cross-sectional analysis of 3013 participants of the Chronic Renal Insufficiency Cohort study with complete data, we compared markers of mineral metabolism (phosphorus, calcium, alkaline phosphatase, parathyroid hormone, fibroblast growth factor 23, and urine calcium and phosphorus excretion) in European Americans versus African Americans and separately, across quartiles of genetic African ancestry in African Americans (n=1490).

Sex Differences in the Incidence of Peripheral Artery Disease in the Chronic Renal Insufficiency Cohort.

Background: To define how the incidence of peripheral artery disease (PAD) in chronic kidney disease differs according to sex and age.

Methods And Results: The Chronic Renal Insufficiency Cohort (CRIC) is a multicenter, prospective cohort study of chronic kidney disease participants. Fine and Gray methods were used to determine the cumulative incidence of PAD, defined by an ankle brachial index <0.

Traditional and non-traditional risk factors for incident peripheral arterial disease among patients with chronic kidney disease.

Background: The risk of peripheral arterial disease (PAD) is higher in patients with chronic kidney disease (CKD) compared with those without. However, reasons for this increased risk are not fully understood.

Methods: We studied risk factors for incident PAD among 3169 participants in the Chronic Renal Insufficiency Cohort (CRIC) Study.

Inflammation, Antibiotics, and Diet as Environmental Stressors of the Gut Microbiome in Pediatric Crohn's Disease.

Abnormal composition of intestinal bacteria--"dysbiosis"-is characteristic of Crohn's disease. Disease treatments include dietary changes and immunosuppressive anti-TNFα antibodies as well as ancillary antibiotic therapy, but their effects on microbiota composition are undetermined. Using shotgun metagenomic sequencing, we analyzed fecal samples from a prospective cohort of pediatric Crohn's disease patients starting therapy with enteral nutrition or anti-TNFα antibodies and reveal the full complement and dynamics of bacteria, fungi, archaea, and viruses during treatment.

Burden of chronic kidney disease in resource-limited settings from Peru: a population-based study.

Background: The silent progression of chronic kidney diseases (CKD) and its association with other chronic diseases, and high treatment costs make it a great public health concern worldwide. The population burden of CKD in Peru has yet to be fully described.

Methods: We completed a cross sectional study of CKD prevalence among 404 participants (total study population median age 54.

Pioglitazone Use and Risk of Bladder Cancer and Other Common Cancers in Persons With Diabetes.

Importance: Studies suggest pioglitazone use may increase risk of cancers.

Objective: To examine whether pioglitazone use for diabetes is associated with risk of bladder and 10 additional cancers.

Design, Setting, And Participants: Cohort and nested case-control analyses among persons with diabetes.

Proteinuria, but Not eGFR, Predicts Stroke Risk in Chronic Kidney Disease: Chronic Renal Insufficiency Cohort Study.

Background And Purpose: Chronic kidney disease is associated with an increased risk of cardiovascular events. However, the impact of chronic kidney disease on cerebrovascular disease is less well understood. We hypothesized that renal function severity would be predictive of stroke risk, independent of other vascular risk factors.

Comparative Effectiveness of Nutritional and Biological Therapy in North American Children with Active Crohn's Disease.

Background: Therapeutic targets in pediatric Crohn's disease include symptoms, quality of life (QOL), and mucosal healing. Although partial enteral nutrition (PEN), exclusive enteral nutritional (EEN), and anti-tumor necrosis factor alpha (anti-TNF) therapy all improve symptoms, the comparative effectiveness of these approaches to improve QOL and achieve mucosal healing has not been assessed prospectively.

Methods: In a prospective study of children initiating PEN, EEN, or anti-TNF therapy for Crohn's disease, we compared clinical outcomes using the Pediatric Crohn's Disease Activity Index (PCDAI), QOL (IMPACT score), and mucosal healing as estimated by fecal calprotectin (FCP).