Background A low rate of blood pressure control has been reported among patients with chronic kidney disease (CKD). These data were derived from population-based samples with a low rate of CKD awareness. Study Design Cross-sectional Setting & Participants Data from the baseline visit of the Chronic Renal Insufficiency Cohort (CRIC) study (n=3612) were analyzed. Participants with an estimated glomerular filtration rate of 20 to 70 ml/min/1.73m2 were identified from physician offices and review of laboratory databases. Outcomes Prevalence and awareness of hypertension, treatment patterns, control rates and factors associated with hypertension control. Measurements Following a standardized protocol, blood pressure was measured three times by trained staff and hypertension was defined as systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg and/or self-reported antihypertensive medication use. Patients’ awareness and treatment of hypertension were defined using self-report and two levels of hypertension control were evaluated: systolic/diastolic blood pressure <140/90 mmHg and <130/80 mmHg. Results The prevalence of hypertension was 85.7%, and 98.9% of CRIC participants were aware of this diagnosis, 98.3% were treated with medications while 67.1% and 46.1% had their hypertension controlled to <140/90 mmHg and <130/80 mmHg, respectively. Of CRIC participants with hypertension, 15%, 25%, 26% and 32% were taking one, two, three and four or more antihypertensive medications, respectively. After multivariable adjustment, older patients, blacks, those with higher urinary albumin excretion were less likely while participants taking ACE-inhibitors and angiotensin receptor blockers were more likely to have controlled their hypertension to <140/90 mmHg and <130/80 mmHg. Limitations Data were derived from a single study visit. Conclusions Despite almost universal hypertension awareness and treatment in this cohort of patients with CKD, rates of hypertension control were sub-optimal.

Background Aortic PWV is a measure of arterial stiffness and has proved useful in predicting cardiovascular morbidity and mortality in several populations of patients, including the healthy elderly, hypertensives and those with end stage renal disease receiving hemodialysis. Little data exist characterizing aortic stiffness in patients with chronic kidney disease who are not receiving dialysis, and in particular the effect of reduced kidney function on aortic PWV. Methods We performed measurements of aortic PWV in a cross-sectional cohort of participants enrolled in the Chronic Renal Insufficiency Cohort (CRIC) study to determine factors which predict increased aortic PWV in chronic kidney disease. Results PWV measurements were obtained in 2564 participants. The tertiles of aortic PWV (adjusted for waist circumference) were < 7.7 m/sec, 7.7–10.2 m/sec and > 10.2 m/sec with an overall mean (± S.D.) value of 9.48 ± 3.03 m/sec [95% CI = 9.35–9.61 m/sec]. Multivariable regression identified significant independent positive associations of age, blood glucose concentrations, race, waist circumference, mean arterial blood pressure, gender, and presence of diabetes with aortic PWV and a significant negative association with the level of kidney function. Conclusions The large size of this unique cohort, and the targeted enrollment of chronic kidney disease participants provides an ideal situation to study the role of reduced kidney function as a determinant of arterial stiffness. Arterial stiffness may be a significant component of the enhanced cardiovascular risk associated with kidney failure.

Growth differentiation factor-15 (GDF-15) is a member of the TGF- cytokine superfamily that is widely expressed and may be induced in response to tissue injury. Elevations in GDF-15 may identify a novel pathway involved in loss of kidney function among patients with CKD. Among participants in the Clinical Phenotyping and Resource Biobank (C-PROBE) study and the Seattle Kidney Study (SKS), we tested whether kidney tissue expression of mRNA correlates with circulating levels of GDF-15 and whether elevations in circulating GDF-15 are associated with decline in kidney function. In matching samples of 24 patients with CKD from the C-PROBE study, circulating GDF-15 levels significantly correlated with intrarenal transcript levels (=0.54, =0.01). Among the 224 C-PROBE and 297 SKS participants, 72 (32.1%) and 94 (32.0%) patients, respectively, reached a composite end point of 30% decline in eGFR or progression to ESRD over a median of 1.8 and 2.0 years of follow up, respectively. In multivariable models, after adjusting for potential confounders, every doubling of GDF-15 level associated with a 72% higher (95% confidence interval, 1.21 to 4.45;=0.003) and 65% higher (95% confidence interval, 1.08 to 2.50; =0.02) risk of progression of kidney disease in C-PROBE and SKS participants, respectively. These results show that circulating GDF-15 levels strongly correlated with intrarenal expression of and significantly associated with increased risk of CKD progression in two independent cohorts. Circulating GDF-15 may be a marker for intrarenal -related signaling pathways associated with CKD and CKD progression.

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2018_02_20_CJASNPodcast_18_3_T.mp3.

Background and objectives This analysis from the Nephrotic Syndrome Study Network (NEPTUNE) assessed the phenotypic and pathology characteristics of proteinuric patients undergoing kidney biopsy and defined the frequency and factors associated with complete proteinuria remission (CRever).Design, setting, participants, & measurements We enrolled adults and children with proteinuria $0.5 g/d at the time of first clinically indicated renal biopsy at 21 sites in North America from April 2010 to June 2014 into a prospective cohort study. NEPTUNE central pathologists assigned participants to minimal-change disease (MCD), FSGS, membranous nephropathy, or other glomerulopathy cohorts. Outcome measures for this analysis were (1) CRever with urine protein-to-creatinine ratio (UPC) ,0.3 g/g with preserved native kidney function and (2) ESRD. Continuous variables are reported as median and interquartile range (IQR; 25th, 75th percentile). Cox proportional hazards modeling was used to assess factors associated with CRever.Results We enrolled 441 patients: 116 (27%) had MCD, 142 (32%) had FSGS, 66 (15%) had membranous nephropathy, and 117 (27%) had other glomerulopathy. The baseline UPC was 4.1 g/g (IQR, 1.9, 7.7) and the eGFR was 81 ml/min per 1.73 m 2 (IQR, 50, 105). Median duration of observation was 19 months (IQR,11, 30). CRever occurred in 46% of patients, and 4.6% progressed to ESRD. Multivariate analysis demonstrated that higher prebiopsy proteinuria (hazard ratio, 0.3; 95% confidence interval, 0.2 to 0.5) and pathology diagnosis (FSGS versus MCD; hazard ratio, 0.2; 95% confidence interval, 0.1 to 0.5) were inversely associated with CRever. The effect of immunosuppressive therapy on remission varied by pathology diagnosis.Conclusions In NEPTUNE, the high frequency of other pathology in proteinuric patients affirms the value of the diagnostic kidney biopsy. Clinical factors, including level of proteinuria before biopsy, pathology diagnosis, and immunosuppression, are associated with complete remission.