In focus: perplexing increase of urinary stone disease in children, adolescent and young adult women and its economic impact.

Background: Urinary stone disease (USD) historically has affected older men, but studies suggest recent increases in women, leading to a near identical sex incidence ratio. USD incidence has doubled every 10 years, with disproportionate increases amongst children, adolescent, and young adult (AYA) women. USD stone composition in women is frequently apatite (calcium phosphate), which forms in a higher urine pH, low urinary citrate, and an abundance of urinary uric acid, while men produce more calcium oxalate stones. The reasons for this epidemiological trend are unknown. Methods: This perspective presents the extent of USD with data from a Canadian Province and a North American institution, explanations for these findings and offers potential solutions to decrease this trend. We describe the economic impact of USD. Findings: There was a significant increase of 46% in overall surgical interventions for USD in Ontario. The incidence rose from 47.0/100,000 in 2002 to 68.7/100,000 population in 2016. In a single United States institution, the overall USD annual unique patient count rose from 10,612 to 17,706 from 2015 to 2019, and the proportion of women with USD was much higher than expected. In the 10-17-year-old patients, 50.1% were girls; with 57.5% in the 18-34 age group and 53.6% in the 35-44 age group. The roles of obesity, diet, hormones, environmental factors, infections, and antibiotics, as well as the economic impact, are discussed. Interpretation: We confirm the significant increase in USD among women. We offer potential explanations for this sex disparity, including microbiological and pathophysiological aspects. We also outline innovative solutions - that may require steps beyond typical preventive and treatment recommendations.

Ambulatory hypertension diagnosed by 24-h mean ambulatory versus day and night ambulatory blood pressure thresholds in children: a cross-sectional study.

BACKGROUND: The agreement between the commonly used ambulatory blood pressure (ABP) thresholds to diagnose ambulatory hypertension in children (patient's 24-h mean ABP classified by 24-h 95th ABP percentile threshold, American Heart Association [AHA] threshold, or patient's day and night mean ABP classified by day-night 95th ABP percentile thresholds) is not known. We evaluated the agreement among 24-h ABP threshold, AHA threshold, and day-night ABP thresholds to diagnose ambulatory hypertension, white coat hypertension (WCH) and masked hypertension (MH). METHODS: In a cross-sectional study design, we analyzed ABP recordings from 450 participants with suspected hypertension from a tertiary care outpatient hypertension clinic. The American Academy of Pediatrics thresholds were used to diagnose office hypertension. RESULTS: The 24-h ABP threshold and day-night ABP thresholds classified 19% ABP (95% confidence interval [CI], 0.15-0.23) differently into ambulatory normotension/hypertension (kappa [κ], 0.58; 95% CI, 0.51-0.66). Ambulatory hypertension diagnosed by 24-h ABP threshold in 27% participants (95% CI, 0.22-0.32) was significantly lower than that by day-night ABP thresholds in 44% participants (95% CI, 0.37-0.50; P < 0.001). The AHA threshold had a stronger agreement with 24-h ABP threshold than with day-night ABP thresholds for classifying ABP into ambulatory normotension/hypertension (k 0.94, 95% CI 0.91-0.98 vs. k 0.59, 95% CI 0.52-0.66). The diagnosis of ambulatory hypertension by the AHA threshold (26%; 95% CI, 0.21-0.31) was closer to that by 24-h ABP threshold (27%, P = 0.73) than by day-night ABP thresholds (44%, P < 0.001). Similar agreement pattern persisted among these ABP thresholds for diagnosing WCH and MH. CONCLUSIONS: The 24-h ABP threshold classifies a lower proportion of ABP as ambulatory hypertension than day-night ABP thresholds. The AHA threshold exhibits a stronger agreement with 24-h ABP than with day-night ABP thresholds for diagnosing ambulatory hypertension, WCH and MH. Our findings are relevant for a consistent interpretation of hypertension by these ABP thresholds in clinical practice.

Diagnosis of hypertension: Ambulatory pediatric American Heart Association/European Society of Hypertension versus blood pressure load thresholds.

The agreement between the traditionally-used ambulatory blood pressure (ABP)-load thresholds in children and recently-recommended pediatric American Heart Association (AHA)/European Society of Hypertension (ESH) ABP thresholds for diagnosing ambulatory hypertension (AH), white coat hypertension (WCH), and masked hypertension (MH) has not been evaluated. In this cross-sectional study on 450 outpatient participants, the authors evaluated the agreement between previously used ABP-load 25%, 30%, 40%, 50% thresholds and the AHA/ESH thresholds for diagnosing AH, WCH, and MH. The American Academy of Pediatrics thresholds were used to diagnose office hypertension. The AHA threshold diagnosed ambulatory normotension/hypertension closest to ABP load 50% in 88% (95% CI 0.79, 0.96) participants (k 0.67, 95% CI 0.59, 0.75) and the ESH threshold diagnosed ambulatory normotension/hypertension closest to ABP load 40% in 86% (95% CI 0.77, 0.94) participants (k 0.66, 95% CI 0.59, 0.74). In contrast, the AHA/ESH thresholds had a relatively weaker agreement with ABP load 25%/30%. Therefore, the diagnosis of AH was closest between the AHA threshold and ABP load 50% (difference 3%, 95% CI -2.6%, 8.6%, p = .29) and between the ESH threshold and ABP load 40% (difference 4%, 95% CI -2.1%, 10.1%, p = .19) than between the AHA/ESH and ABP load 25%/30% thresholds. A similar agreement pattern persisted between the AHA/ESH and various ABP load thresholds for diagnosing WCH and MH. The AHA and ESH thresholds diagnosed AH, WCH, and MH closest to ABP load 40%/50% than ABP load 25%/30%. Future outcome-based studies are needed to guide the optimal use of these ABP thresholds in clinical practice.

Diagnosis of Pediatric Hypertension: European Society of Hypertension-Recommended 24-Hour vs. 24-Hour-Day-Night Ambulatory Blood Pressure Thresholds.

BACKGROUND: The impact of diagnosing pediatric hypertension based on all three-24-hour, day and night ambulatory blood pressure (ABP) thresholds (combined ABP threshold) vs. conventionally used 24-hour ABP threshold is not known. METHODS: In this cross-sectional, retrospective study from a tertiary care outpatient clinic, we evaluated the diagnosis of hypertension based on the 24-hour European Society of Hypertension (ESH) and combined ESH ABP thresholds in untreated children with essential hypertension. The American Academy of Pediatrics (AAP) and Fourth Report thresholds were used to classify office blood pressure (OBP). RESULTS: In 159 children, aged 5-18 years, the 24-hour ESH and combined ESH thresholds classified 82% (95th confidence interval (CI) 0.68, 0.97) ABP similarly with the area under the curve (AUC) of 0.86 (95th CI 0.80, 0.91). However, the AUC of the 2 ABP thresholds was significantly higher in the participants with office hypertension than office normotension, with OBP classified by the AAP (AUC 0.93, 95th CI 0.84, 0.98 vs. 0.80, 95th CI 0.71, 0.88) or Fourth Report (AUC 0.93, 95th CI 0.83, 0.98 vs. 0.81, 95th CI 0.73, 0.88) threshold. With OBP classified by the either OBP threshold, the combined ESH threshold diagnosed significantly more masked hypertension (MH) (difference 15%, 95th CI 4.9, 24.7; P = 0.00); however, the diagnosis of white coat hypertension (WCH) by the 2 ABP thresholds did not differ significantly (difference 4%, 95th CI 1.8, 10; P = 0.16). CONCLUSIONS: In children with essential hypertension, the 24-hour and combined ESH thresholds have a stronger agreement for diagnosing WCH than MH.

What to Do With Renal Cysts in Children?

OBJECTIVE: To explore the current practice patterns for the management of renal cysts internationally among pediatric urologists and nephrologists. MATERIALS AND METHODS: A survey composed of 21 questions and 4 clinical scenarios was distributed to pediatric urologists and nephrologists. Survey questions evaluated optimal imaging modality, management, and follow-up period. Interspecialty comparisons were made using chi-square analysis where appropriate. RESULTS: A total of 183 respondents completed the survey (128 pediatric urologists, 37 pediatric nephrologists, and 19 other specialists). Most (57%) respondents agreed or strongly agreed with using an ultrasound based Bosniak classification to categorize renal cysts in children. The most commonly used follow-up intervals were 6-12 months for pediatric urologists and 1-2 years for pediatric nephrologists. Symptomatic mass effect (80.9%), gross hematuria (79.2%), or family history were the most common reasons for escalating surveillance. Pediatric nephrologists were more likely to increase follow-up with development of bilateral simple renal cysts (P = .008) or chronic kidney disease (P = .027) when compared to pediatric urologists. Laparoscopic marsupialization (39.4%) was the most common treatment for a simple renal cyst in a symptomatic child. Modified Bosniak III cysts had more heterogeneity in treatment based on the physician responses. CONCLUSION: There is currently no consensus on the optimal protocol for the surveillance, imaging, or treatment of renal cysts in children. Most respondents agree that using an ultrasound-based Bosniak classification is reasonable. A call to action is therefore necessary for the development of registries and guidelines on the management of pediatric renal cysts and their associated malignancies.

Assessment of glomerular filtration rate in the neonate: is creatinine the best tool?

PURPOSE OF REVIEW: This article answers the question of whether creatinine is the best biomarker for monitoring neonatal glomerular filtration rate (GFR) in view of recent advances in measuring neonatal renal function. RECENT FINDINGS: We rely largely on serum creatinine for the estimation of GFR in the newborn, even though creatinine is freely exchanged through the placenta. During the first few days of life, the serum creatinine reflects maternal renal function or the maternal creatinine. Back filtration of creatinine in preterm newborns is also a serious limitation. This review summarizes current knowledge on the prenatal and postnatal handling of creatinine as well as that of other, more novel biomarkers of GFR, such as cystatin C (CysC) and ß-trace protein (BTP). Only small amounts of CysC cross the placenta, whereas BTP does not cross the placenta at all. However, BTP measurements are not widely available. Recent studies on renal volumetry are also discussed. SUMMARY: Currently, CysC may be the most suitable marker of neonatal renal function, but its availability is still limited, it is more costly, and the best method of reporting acute kidney injury and neonatal estimated GFR remains to be established.

Residual renal function assessment with cystatin C.

Su Jin Kim and coworkers from Korea published an important study on the relationship of residual renal function (RRF) and cystatin in pediatric peritoneal dialysis (PD) patients in this issue of Pediatric Nephrology, both in anuric patients and patients with RRF. Based on a lack of correlation between cystatin C and standard small solute-based dialysis adequacy parameters such as Kt/Vurea but a significant correlation with RRF, the authors concluded that cystatin C may be a good tool to monitor RRF. The editorial reviews the available literature in adults, the different handing between urea and cystatin C, and the determinants of cystatin C clearance in dialysis patients. In adults, cystatin C levels are determined predominantly by RRF, but not exclusively. In anephric hemodialysis and PD patients, there is a correlation with standard weekly Kt/Vurea. Cystatin C levels will also depend on ultrafiltration. Despite these factors that affect cystatin C levels beyond RRF, cystatin C is a useful parameter for monitoring PD patients that may be more closely related to long-term outcomes than small solute adequacy parameters.