News in Brief

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Short Takes

Risk Factors for Urgent-Start Dialysis Identified

Investigators have identified factors that put patients with chronic kidney disease (CKD) at increased risk for urgent-start dialysis, according to a recent report in Nephrology Dialysis Transplantation.

In the CKD-REIN prospective cohort study that included 3033 patients seen in 40 French nephrology clinics, Victor Fages, MD, of the Université Paris-Saclay, and colleagues found that low health literacy, living alone, heart failure, and polypharmacy were significantly associated with 2.2-, 2.1-, 2.6-, and 2.1-fold increased odds of urgent-start dialysis.

Single PSA Test Can Predict PCa Death Risk

A low baseline level of PSA and a large fraction of free PSA predict a low risk of dying from prostate cancer (PCa) according to investigators.

The finding is from a prospective cohort study of 1782 men aged 55 to 70 years screened for PCa in 1988 and 1989. After 30 years of followup, men with PSA levels less than 1.0 ng/mL at baseline had a 1.2% risk of dying from PCa, Per-Olof Lundgren, MD, of the Karolinska Institutet and Karolinska University Hospital in Stockholm, Sweden, and colleagues reported in BJU International. A freeto-total PSA ratio of 0.25 or higher extended the low-risk range to a PSA level less than 2.0 ng/mL (1.5% risk). PCa mortality risk increased by 4% for each 1 unit increase in baseline PSA.

Graft Loss Tied to Pre-KT Unintentional Weight Loss

Unintentional weight loss prior to kidney transplantation (KT) results in worse post-transplant outcomes, investigators reported in Nephrology Dialysis Transplantation.

In a study of 919 KT recipients, a team led by Mara McAdams-DeMarco, MD, of Johns Hopkins University School of Medicine in Baltimore, Maryland, and colleagues found that unintentional weight loss of 5% or greater was independently associated with an 80% and 91% increased risk for death-uncensored and death-censored graft loss, respectively, and a 72% increased all-cause mortality risk compared with stable pre-KT weight (weight change of 5% or less).

Hypertension in Pediatric Diabetes

Approximately one-quarter of pediatric patients aged 7 to 20 years with type 2 diabetes have hypertension, according to a recent meta-analysis. The prevalence varies by racial group, as shown below.

26.7% 26.5%

21.0%

19.0% 18.4%

15.1%

Pacific Islander Indigenous White Black Asian Hispanic

Preemptive Therapy May Cut FSGS Recurrence Risk in KTRs

Preemptive therapeutic plasma exchange and rituximab treatment may lower the risk of recurrence of focal segmental glomerulosclerosis (FSGS) in kidney transplant recipients (KTRs), according to study findings presented at the virtual National Kidney Foundation 2021 Spring Clinical Meetings.

Venkata Kishore Mukku, MD, of The University of Texas Medical Branch in Galveston, and colleagues studied 18 KTRs in whom FSGS was the primary cause of end-stage kidney disease. Of these, 8 underwent preemptive TPE/rituximab treatment (group 1) and 10 did not (group 2). The median follow-up duration was 2 years for group 1 and 3 years for group 2. Three patients in group 2 had FSGS recurrence, including a patient who experienced allograft loss, compared with none in group 1, the investigators reported in a poster presentation.

Occult Brain Metastases Found in Advanced RCC

Recent study findings suggest a rationale for brain screening of patients with advanced renal cell carcinoma (RCC), investigators concluded in a paper published in the Journal of the National Comprehensive Cancer Network (2021;19:432-438).

A retrospective study of 1689 patients with metastatic RCC screened for 68 clinical trials identified occult brain metastases in 72 (4.3%), Ritesh R. Kotecha, MD, of Memorial Sloan-Kettering Cancer Center in New York City, and colleagues reported. Of these, 26%, 61%, and 13% had favorable-, intermediate-, and poorrisk disease, respectively, according to International Metastatic RCC Database Consortium criteria. The patients had a median overall survival (OS) time of 10.3 months and a 1-year OS probability of 48%.

“Screening should be considered for patients with high metastatic burden or those who have experienced disease progression after first-line therapy,” the authors concluded.

Pregnancy Tied to Higher Risk of Symptomatic Kidney Stones

Pregnancy is associated with an elevated risk for a first-time symptomatic kidney stone, according to the findings of a case-control study. The risk begins to increase in the second trimester and peaks just after delivery.

Compared with nonpregnant women, women in the second and third trimester of pregnancy have significant 2.0- and 2.7-fold increased odds of forming their first kidney stone, a team led by Andrew D. Rule, MD, of Mayo Clinic in Rochester, Minnesota, reported the American Journal of Kidney Diseases. From 0 to 3 months after delivery, women had a 3.5-fold increased risk of kidney stone formation. Kidney stone risk returned to baseline by 1 year after delivery.

The authors concluded that prenatal counseling of kidney stone risk with pregnancy may be warranted, particularly for women with other risk for kidney stones, such as obesity, diabetes, or family history of kidney stones.

The study included 945 women aged 15 to 45 years who had a first-time symptomatic kidney stone and an age-matched control group of 1890 women.

Race, Ethnicity Affect ADPKD Outcomes

Studies reveal differences in mortality rates and age at onset of end-stage kidney disease

RACE AND ETHNICITY affect the course and outcomes of autosomal dominant polycystic kidney disease (ADPKD), findings from separate studies suggest.

In one study, Greg Mader, PhD, of RTI Health Solutions in Research Triangle Park, North Carolina, and colleagues identified racial differences in mortality rates among older patients with ADPKD.

Using 2014-2016 data from the US Renal Data System, Dr Mader’s team calculated mortality rates for patients aged 65 years and older with ADPKD, including 1551 without end-stage kidney disease (ESKD) who had a mean age of 76.5 and 14,756 with ESKD who had a mean age of 70.8 years. In the cohort without ESKD, age-adjusted mortality was 61.9 per 1000 patientyears overall. Black patients had the highest age-adjusted mortality rate at 82.7 per 1000 patient-years, whereas White, Hispanic, Asian, and patients of other races all had rates below the mean at 59.5, 41.4, 51.2, and 54.2 per 1000 patient-years, respectively.

In the cohort with ESKD, the overall age-adjusted mortality rate was high at 129.6 per 1000 patient-years. This time, White patients had the highest death rate — 136.1 per 1000 patient-years — whereas Black, Hispanic, Asian, and patients of other races had rates below the mean at 123.3, 100.3, 102.9, and 94.2 per 1000 patient-years, respectively.

Only among Black men was mortality higher before kidney failure than after, indicating a possible survivorship effect.

“This would occur if black patients with ADPKD were less likely to receive dialysis or transplant and, therefore, were more likely to die prior to initiation of renal replacement therapy, with those black patients surviving to dialysis or transplant being relatively healthier than their white counterparts,” Dr Mader’s team wrote.

In another study, Teresa N. Harrison, SM, of Kaiser Permanente Research & Evaluation in Pasadena, California, and colleagues demonstrated that onset of ESKD in patients with ADPKD occurs earlier in Hispanic patients than in those of other races. The study, which included 3868 patients, found that the mean age of ESKD onset was 50 years among Hispanic patients compared with 53, 56, and 57 years among Asian, Black, and White patients, respectively.

“To our knowledge, this study is one of the first to include Hispanic and Asian ADPKD patients and to report race/ethnic differences in the onset of ESKD,” the authors concluded.

The investigators defined ESKD onset as the initiation of dialysis or receipt of a kidney transplant.

The racial or ethnic distribution of patients in the cohort was 42% White, 32% Hispanic, 12% Black, and 10% Asian. Patients had a mean baseline estimated glomerular filtration rate of 67.4 mL/min/1.73 m2 . The most common comorbidity was hypertension (53.5%), followed by abdominal pain (37.3%) and hyperlipidemia (32.7%). ESKD developed in 27% of the cohort.

The investigators pointed out that the study was limited by its retrospective design and its findings depended on the availability and accuracy of existing records. In addition, the study analyzed data from patients within a single, integrated healthcare system and therefore may not be generalizable to other settings, Harrison’s team noted. ■

Mortality By Race and Ethnicity

Among patients with autosomal dominant polycystic kidney disease but not end-stage kidney disease, Black patients had the highest age-adjusted mortality rate (per 1000 patient years), a study found.

80

60

40

82.7%

59.5%

51.2%

41.4%

20

0

Black White Asian Hispanic

Source: Mader G, Mladsi D, Zhou X, et al. Racial differences in mortality rates among elderly non-ESRD CKD and ESRD patients with autosomal dominant polycystic kidney disease (ADPKD): study findings using data from the USRDS. Presented at the virtual National Kidney Foundation 2021 Spring Clinical Meetings, April 6-10, 2021. Poster 312.

Renal Denervation Has Positive Effects in HTN Cases

Patients with higher plasma renin activity had significant reductions in systolic blood pressure

RENAL DENERVATION (RDN) is associated with decreased plasma renin activity (PRA) and aldosterone levels in patients with hypertension, according to a recent study.

RDN is thought to interrupt the sympathetic-mediated neurohormonal pathway as part of its mechanism of action to reduce blood pressure (BP), noted study authors Felix Mahfoud, MD, of Saarland University Hospital in Homburg/Saar, Germany, and colleagues.

In a study of patients with hypertension who were not taking antihypertensive medications, RDN was significantly associated with decreased PRA and aldosterone levels at 3 months compared with a control group of patients who received a sham procedure.

The study included 331 patients who participated in the SPYRAL HTN-OFF MED Pivotal trial: 166 in the RDN group and 165 in the control arm. At baseline, the intervention and control groups had similar PRA values

(1.0 and 1.1 ng/mL/h, respectively). At 3 months, the change in PRA from baseline was significantly greater for the RDN than control group (–2.0 vs 0.1 ng/mL/h), Dr Mahfoud’s team reported in the Journal of the American College of Cardiology. The RDN-treated patients also experienced a significantly greater reduction in aldosterone level at 3 months compared with the control arm (–1.2 vs 0.4 ng/mL).

The investigators compared the effect of RDN in patients with a baseline PRA of 0.65 ng/mL/h or higher and those with a PRA less than 0.65 ng/mL/h. Office and ambulatory BP measurements were similar for patients in both groups at baseline. The effect of RDN was stronger in the group with a baseline PRA of 0.65 ng/mL/h or higher. In this group, the 24-hour systolic BP (SBP) at 3 months had decreased by 7.1 mm Hg in the RDN-treated patients compared with a decrease of 1.1 mm Hg in the control arm, a significant difference between the groups. Among patients with PRA less than 0.65 ng/mL/h, both study arms had smaller decreases in PRA (–1.5 and –0.7 mm Hg in the RDN and control groups, respectively), and the betweengroup difference was not significant.

The effect of RDN on office SBP also was more pronounced in the patients with a baseline PRA of 0.65 ng/mL/h or higher. At 3 months, RDN-treated patients had a 12.8 mm Hg reduction in office SBP, whereas those in the control arm had a 2.9 mm Hg reduction, a significant difference between the groups. In the patients with lower PRA, the reductions were 7.1 and 3.7 mm Hg, respectively, a nonsignificant difference.

Dr Mahfoud and colleagues pointed out that they observed reductions in office SBP according to baseline PRA at 2 weeks post-procedure, indicating that RDN impacts renal physiology as early as 2 weeks after treatment. ■