A 6-Month clinical practice pilot study of sucroferric oxyhydroxide on nutritional status in patients on peritoneal dialysis.

BACKGROUND: Hyperphosphatemia is common in patients on peritoneal dialysis (PD). Restricting dietary phosphorus often leads to a decrease in protein intake, which may result in hypoalbuminemia. The high pill burden of phosphate binders may also contribute to compromised appetite and dietary intake. Hypoalbuminemia is associated with an increased risk of morbidity and mortality in PD patients. The goal of this study was to determine if sucroferric oxyhydroxide improves albumin and self-reported measures of appetite in PD patients. METHODS: We performed a prospective, open-label, 6-month, pilot study of 17 adult PD patients from the Denver Metro Area. Patients had to use automated peritoneal dialysis for ≥ 3 months, have a serum albumin ≤ 3.8 g/dL, and have serum phosphate ≥ 5.5 mg/dL or ≤ 5.5 mg/dL on a binder other than SO. SO was titrated to a goal serum phosphate of < 5.5 mg/dL. The primary outcome was change in serum phosphate, albumin, and phosphorus-attuned albumin (defined as albumin divided by phosphorus) over 6 months. RESULTS: The mean (SD) age and dialysis vintage was 55 ± 13 years and 3.8 ± 2.7 years, respectively. Participants' serum phosphate significantly decreased with fewer phosphate binder pills/day after switching to SO. There was no change in serum albumin, appetite, or dietary intake. However, participants had significant improvements in phosphorus-attuned albumin. CONCLUSION: The transition to SO improved phosphorus control, phosphorus-attuned albumin, and pill burden. There were no significant changes in self-reported appetite or dietary intake during the study. These findings suggest that PD patients maintained nutritional status with SO therapy. TRIAL REGISTRATION: First registered at ClinicalTrials.gov ( NCT04046263 ) on 06/08/2019.

Curcumin Therapy to Treat Vascular Dysfunction in Children and Young Adults with ADPKD: A Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: Clinical manifestations of autosomal dominant polycystic kidney disease (ADPKD), including evidence of vascular dysfunction, can begin in childhood. Curcumin is a polyphenol found in turmeric that reduces vascular dysfunction in rodent models and humans without ADPKD. It also slows kidney cystic progression in a murine model of ADPKD. We hypothesized that oral curcumin therapy would reduce vascular endothelial dysfunction and arterial stiffness in children/young adults with ADPKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In a randomized, placebo-controlled, double-blind trial, 68 children/young adults 6-25 years of age with ADPKD and eGFR>80 ml/min per 1.73 m2 were randomized to either curcumin supplementation (25 mg/kg body weight per day) or placebo administered in powder form for 12 months. The coprimary outcomes were brachial artery flow-mediated dilation and aortic pulse-wave velocity. We also assessed change in circulating/urine biomarkers of oxidative stress/inflammation and kidney growth (height-adjusted total kidney volume) by magnetic resonance imaging. In a subgroup of participants ≥18 years, vascular oxidative stress was measured as the change in brachial artery flow-mediated dilation following an acute infusion of ascorbic acid. RESULTS: Enrolled participants were 18±5 (mean ± SD) years, 54% were girls, baseline brachial artery flow-mediated dilation was 9.3±4.1% change, and baseline aortic pulse-wave velocity was 512±94 cm/s. Fifty-seven participants completed the trial. Neither coprimary end point changed with curcumin (estimated change [95% confidence interval] for brachial artery flow-mediated dilation [percentage change]: curcumin: 1.14; 95% confidence interval, -0.84 to 3.13; placebo: 0.33; 95% confidence interval, -1.34 to 2.00; estimated difference for change: 0.81; 95% confidence interval, -1.21 to 2.84; P=0.48; aortic pulse-wave velocity [centimeters per second]: curcumin: 0.6; 95% confidence interval, -25.7 to 26.9; placebo: 6.5; 95% confidence interval, -20.4 to 33.5; estimated difference for change: -5.9; 95% confidence interval, -35.8 to 24.0; P=0.67; intent to treat). There was no curcumin-specific reduction in vascular oxidative stress or changes in mechanistic biomarkers. Height-adjusted total kidney volume also did not change as compared with placebo. CONCLUSIONS: Curcumin supplementation does not improve vascular function or slow kidney growth in children/young adults with ADPKD. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Curcumin Therapy to Treat Vascular Dysfunction in Children and Young Adults with ADPKD, NCT02494141. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2022_02_07_CJN08950621.mp3.

Time-Efficient Inspiratory Muscle Strength Training Lowers Blood Pressure and Improves Endothelial Function, NO Bioavailability, and Oxidative Stress in Midlife/Older Adults With Above-Normal Blood Pressure.

Background High-resistance inspiratory muscle strength training (IMST) is a novel, time-efficient physical training modality. Methods and Results We performed a double-blind, randomized, sham-controlled trial to investigate whether 6 weeks of IMST (30 breaths/day, 6 days/week) improves blood pressure, endothelial function, and arterial stiffness in midlife/older adults (aged 50-79 years) with systolic blood pressure ≥120 mm Hg, while also investigating potential mechanisms and long-lasting effects. Thirty-six participants completed high-resistance IMST (75% maximal inspiratory pressure, n=18) or low-resistance sham training (15% maximal inspiratory pressure, n=18). IMST was safe, well tolerated, and had excellent adherence (≈95% of training sessions completed). Casual systolic blood pressure decreased from 135±2 mm Hg to 126±3 mm Hg (P<0.01) with IMST, which was ≈75% sustained 6 weeks after IMST (P<0.01), whereas IMST modestly decreased casual diastolic blood pressure (79±2 mm Hg to 77±2 mm Hg, P=0.03); blood pressure was unaffected by sham training (all P>0.05). Twenty-four hour systolic blood pressure was lower after IMST versus sham training (P=0.01). Brachial artery flow-mediated dilation improved ≈45% with IMST (P<0.01) but was unchanged with sham training (P=0.73). Human umbilical vein endothelial cells cultured with subject serum sampled after versus before IMST exhibited increased NO bioavailability, greater endothelial NO synthase activation, and lower reactive oxygen species bioactivity (P<0.05). IMST decreased C-reactive protein (P=0.05) and altered select circulating metabolites (targeted plasma metabolomics) associated with cardiovascular function. Neither IMST nor sham training influenced arterial stiffness (P>0.05). Conclusions High-resistance IMST is a safe, highly adherable lifestyle intervention for improving blood pressure and endothelial function in midlife/older adults with above-normal initial systolic blood pressure. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03266510.

Curcumin therapy to treat vascular dysfunction in children and young adults with autosomal dominant polycystic kidney disease: Design and baseline characteristics of participants.

Although often considered to be a disease of adults, complications of autosomal dominant polycystic kidney disease (ADPKD) begin in childhood. While the hallmark of ADPKD is the development and continued growth of multiple renal cysts that ultimately result in loss of kidney function, cardiovascular complications are the leading cause of death among affected patients. Vascular dysfunction (endothelial dysfunction and large elastic artery stiffness) is evident very early in the course of the disease and appears to involve increased oxidative stress and inflammation. Treatment options to prevent cardiovascular disease in adults with ADPKD are limited, thus childhood may represent a key therapeutic window. Curcumin is a safe, naturally occurring polyphenol found in the Indian spice turmeric. This spice has a unique ability to activate transcription of key antioxidants, suppress inflammation, and reduce proliferation. Here we describe our ongoing randomized, placebo-controlled, double-blind clinical trial to assess the effect of curcumin therapy on vascular function and kidney growth in 68 children and young adults age 6-25 years with ADPKD. Baseline demographic, vascular, and kidney volume data are provided. This study has the potential to establish a novel, safe, and facile therapy for the treatment of arterial dysfunction, and possibly renal cystic disease, in an understudied population of children and young adults with ADPKD.

Incident infection following acute kidney injury with recovery to baseline creatinine: A propensity score matched analysis.

BACKGROUND: Severe acute kidney injury (AKI) is associated with subsequent infection. Whether AKI followed by a return to baseline creatinine is associated with incident infection is unknown. OBJECTIVE: We hypothesized that risk of both short and long term infection would be higher among patients with AKI and return to baseline creatinine than in propensity score matched peers without AKI in the year following a non-infectious hospital admission. DESIGN: Retrospective, propensity score matched cohort study. PARTICIPANTS: We identified 494 patients who were hospitalized between January 1, 1999 and December 31, 2009 and had AKI followed by return to baseline creatinine. These were propensity score matched to controls without AKI. MAIN MEASURES: The predictor variable was AKI defined by International Classification of Diseases, Ninth Revision (ICD-9) codes and by the Kidney Disease Improving Global Outcomes definition, with return to baseline creatinine defined as a decrease in serum creatinine level to within 10% of the baseline value within 7 days of hospital discharge. The outcome variable was incident infection defined by ICD-9 code within 1 year of hospital discharge. RESULTS: AKI followed by return to baseline creatinine was associated with a 4.5-fold increased odds ratio for infection (odds ratio 4.53 [95% CI, 2.43-8.45]; p<0.0001) within 30 days following discharge. The association between AKI and subsequent infection remained significant at 31-60 days and 91 to 365 days but not during 61-90 days following discharge. CONCLUSION: Among patients from an integrated health care delivery system, non-infectious AKI followed by return to baseline creatinine was associated with an increased odds ratio for infection in the year following discharge.

Fibroblast Growth Factor 23 Trajectories in Chronic Hemodialysis Patients: Lessons from the HEMO Study.

BACKGROUND: Long-term patterns of fibroblast growth factor 23 (FGF23) are poorly characterized among dialysis patients. OBJECTIVES: To identify different FGF23 trajectories and determine clinical factors that predict distinct FGF23 trajectories and whether FGF23 trajectories differ in regard to their associations with all-cause mortality among prevalent hemodialysis patients. METHODS: The HEMO study was a randomized multicenter study evaluating the effects of high-dose vs. standard-dose and high-flux vs. low-flux hemodialysis on mortality. We measured intact FGF23 levels in stored serum samples at baseline and annually among 919 HEMO participants and identified FGF23 trajectories using group-based modeling. Logistic regression determined predictors of trajectories. Cox regression models evaluated the association between trajectory and all-cause mortality. RESULTS: We identified 5 distinct FGF23 trajectory groups during the initial 24 months: low stable, low increasing, elevated increasing, elevated decreasing, and elevated stable. In multivariable models, diabetes, high dose dialysis, no venous catheter, low serum calcium, phosphorus, and interleukin-6, no vitamin D analog use, and greater residual kidney function were associated with the low stable trajectory group compared to the elevated stable group. High flux dialysis, no venous catheter, and low serum phosphorus and 25-hydroxyvitamin D were associated with the elevated decreasing trajectory group compared to the elevated stable group. After full adjustment, the low stable trajectory group was associated with reduced mortality (hazard ratio [HR] 0.61; 95% CI -0.41-0.91) compared to the elevated stable trajectory group. CONCLUSIONS: We identified 5 distinct FGF23 trajectories over 24 months among HEMO study participants including a decreasing trajectory. The low stable FGF23 trajectory was associated with a reduced HR of all-cause mortality.

Risk of adverse maternal and fetal outcomes during pregnancy in living kidney donors: A matched cohort study.

BACKGROUND: We examined the risk of adverse pregnancy outcomes in primiparous kidney donors compared to matched controls. METHODS: Fifty-nine women with a history of kidney donation prior to their first pregnancy with normal renal function and no history of kidney disease, diabetes or chronic hypertension were matched 1:4 by age (within 2 years) and race to women with two kidneys using data from an integrated healthcare delivery system. Adverse pregnancy outcomes were defined as preterm delivery (delivery <37 weeks), delivery via cesarean section, gestational hypertension, preeclampsia/eclampsia, gestational diabetes, length of stay in the hospital >3 days, infant death/transfer to acute facility and low birthweight (<2500 g). RESULTS: Living kidney donors did not have a higher risk of adverse outcomes compared to matched controls. There was a trend toward an increased risk of preeclampsia/eclampsia in kidney donors but it did not reach statistical significance (Odds ratio [OR]: 2.96, 95% CI: 0.98-8.94, P = 0.06). However, in kidney donors ≤30 years of age, there was a fourfold increased risk of preeclampsia/eclampsia (OR: 4.09, 95% CI: 1.07-15.59, P = 0.04). CONCLUSION: Overall, the risk of pregnancy-associated complications following kidney donation is small but potential female kidney donors should be counseled on the possible increased risk of preeclampsia.

Cholecalciferol, Calcitriol, and Vascular Function in CKD: A Randomized, Double-Blind Trial.

BACKGROUND AND OBJECTIVES: High circulating vitamin D levels are associated with lower cardiovascular mortality in CKD, possibly by modifying endothelial function. We examined the effect of calcitriol versus cholecalciferol supplementation on vascular endothelial function in patients with CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We performed a prospective, double-blind, randomized trial of 128 adult patients with eGFR=15-44 ml/min per 1.73 m2and serum 25-hydroxyvitamin D level <30 ng/ml at the University of Colorado. Participants were randomly assigned to oral cholecalciferol (2000 IU daily) or calcitriol (0.5 µg) daily for 6 months. The primary end point was change in brachial artery flow-mediated dilation. Secondary end points included changes in circulating markers of mineral metabolism and circulating and cellular markers of inflammation. RESULTS: One hundred and fifteen patients completed the study. The mean (SD) age and eGFR of participants were 58±12 years old and 33.0±10.2 ml/min per 1.73 m2, respectively. There were no significant differences between groups at baseline. After 6 months, neither calcitriol nor cholecalciferol treatment resulted in a significant improvement in flow-mediated dilation (mean±SD percentage flow-mediated dilation; calcitriol: baseline 4.8±3.1%, end of study 5.1±3.6%; cholecalciferol: baseline 5.2±5.2%, end of study 4.7±3.6%); 25-hydroxyvitamin D levels increased significantly in the cholecalciferol group compared with the calcitriol group (cholecalciferol: 11.0±9.5 ng/ml; calcitriol: -0.8±4.8 ng/ml; P<0.001). Parathyroid hormone levels decreased significantly in the calcitriol group compared with the cholecalciferol group (median [interquartile range]; calcitriol: -22.1 [-48.7-3.5] pg/ml; cholecalciferol: -0.3 [-22.6-16.9] pg/ml; P=0.004). CONCLUSIONS: Six months of therapy with calcitriol or cholecalciferol did not improve vascular endothelial function or improve inflammation in patients with CKD.

Potent DNA strand annealing activity associated with mouse Mcm2∼7 heterohexameric complex.

Mini-chromosome maintenance (Mcm) is a central component for DNA unwinding reaction during eukaryotic DNA replication. Mcm2∼7, each containing a conserved ATPase motif, form a six subunit-heterohexamer. Although the reconstituted Mcm2∼7-Cdc45-GINS (CMG) complex displays DNA unwinding activity, the Mcm2∼7 complex does not generally exhibit helicase activity under a normal assay condition. We detected a strong DNA strand annealing activity in the purified mouse Mcm2∼7 heterohexamer, which promotes rapid reassociation of displaced complementary single-stranded DNAs, suggesting a potential cause for its inability to exhibit DNA helicase activity. Indeed, DNA unwinding activity of Mcm2∼7 could be detected in the presence of a single-stranded DNA that is complementary to the displaced strand, which would prevent its reannealing to the template. ATPase-deficient mutations in Mcm2, 4, 5 and 6 subunits inactivated the annealing activity, while those in Mcm2 and 5 subunits alone did not. The annealing activity of Mcm2∼7 does not require Mg2+ and ATP, and is adversely inhibited by the presence of high concentration of Mg2+ and ATP while activated by similar concentrations of ADP. Our findings show that the DNA helicase activity of Mcm2∼7 may be masked by its unexpectedly strong annealing activity, and suggest potential physiological roles of strand annealing activity of Mcm during replication stress responses.

Association of Unilateral Renal Agenesis With Adverse Outcomes in Pregnancy: A Matched Cohort Study.

BACKGROUND: Data regarding the effect of a solitary kidney during pregnancy have come from studies of living kidney donors. We evaluated the risk for adverse pregnancy outcomes in women with a single kidney from renal agenesis. STUDY DESIGN: Matched cohort study. SETTING & PARTICIPANTS: Using data from 7,079 childbirths from an integrated health care delivery system from 1996 through 2015, we identified births from women with renal agenesis. Only first pregnancies and singleton births were included. After excluding those with diabetes and kidney disease, 200 women with renal agenesis were matched 1:4 by age (within 2 years), race, and history of hypertension to women with 2 kidneys. PREDICTOR: Renal agenesis defined by International Classification of Diseases, Ninth Revision (ICD-9) codes prior to pregnancy. OUTCOMES: The primary outcome was adverse maternal outcomes, including preterm delivery, delivery by cesarean section, preeclampsia/eclampsia, and hospital length of stay. Adverse neonatal end points were considered as a secondary outcome and included low birth weight (<2,500g) and infant death/transfer to acute inpatient facility. RESULTS: Mean gestational age at delivery was 37.9±2.1 weeks for women with renal agenesis compared to 38.6±1.8 weeks for women with 2 kidneys. Compared with women with 2 kidneys, those with renal agenesis had increased risk for preterm delivery (OR, 2.88; 95% CI, 1.86-4.45), delivery by cesarean section (OR, 2.11; 95% CI, 1.49-2.99), preeclampsia/eclampsia (OR, 2.41; 95% CI, 1.23-4.72), and length of stay longer than 3 days (OR, 1.81; 95% CI, 1.18-2.78). Renal agenesis was not significantly associated with increased risk for infant death/transfer to acute facility (OR, 2.60; 95% CI, 0.57-11.89) or low birth weight after accounting for preterm delivery (OR, 2.11; 95% CI, 0.76-5.88). LIMITATIONS: Renal agenesis was identified by ICD-9 code, not by imaging of the abdomen. CONCLUSION: Women with unilateral renal agenesis have a higher risk for adverse outcomes in pregnancy.

Changes in plasma FGF23 in growth hormone deficient children during rhGH therapy.

BACKGROUND: Children with growth hormone deficiency (GHD) have increased renal phosphorus reabsorption during rhGH therapy, Fibroblast growth factor 23 (FGF23) is a known regulator of serum phosphorus and may be responsible for this effect. METHODS: Prospective study in GHD children investigating changes in plasma C-terminal FGF23 (C-FGF23), markers of mineral metabolism, and insulin-like growth factor (IGF-1) in the first year of rhGH therapy. Normal stature children served as baseline controls. RESULTS: The two groups at baseline were similar, except GHD patients had lower baseline TmP/GFR vs. controls (p < 0.05). C-FGF23 in GHD patients trended upward at follow-up 1 (p = 0.058) and significantly increased at follow-up 2 (p = 0.0005) compared to baseline. TmP/GFR also rose at follow-up 1 (p = 0.002) and follow-up 2 (p = 0.027). The C-FGF23 rise persisted after adjusting for age, gender, sex, total calcium, and phosphorus (p < 0.01) but attenuated after adjusting for TmP/GFR or IGF-1. CONCLUSIONS: C-FGF23 rises during rhGH therapy in spite of increased Tmp/GFR, an unanticipated observation given the role of FGF23 as a phosphaturic factor. The C-FGF23 rise may be a secondary response during rhGH therapy.