Renal function and systolic blood pressure in very-low-birth-weight infants 1–3?years of age

Background

Preterm very-low-birth-weight (PT-VLBW) infants are at risk of an elevated systolic blood pressure (SBP) in infancy and adulthood; however, the pathogenesis remains unclear. Altered renal development or function may be associated with increased SBP, but their contribution in PT-VLBW is unknown.

Methods

We determined renal function and its relationship to SBP in three groups of PT-VLBW at 1, 2, and 3?years of age, using serum cystatin-C to calculate the estimated glomerular filtration rate (eGFR).

Results

Cystatin-C levels decreased from 0.84?±?0.2 (SD) within the 1-year group to 0.70?±?0.1?mg/l (±SD; P?<?0.001) at 3?years and were unrelated to gender, fetal growth, and neonatal indomethacin exposure. eGFR rose from 121?±?59 in the 1-year group to 138?±?21?ml/min·1.73?m² (P?<?0.001) at 3?years. At 1?year, cystatin-C levels decreased with increasing SBP (P?<?0.007), and infants with SBP ≥?90th% had lower cystatin-C and higher eGFR (P?<?0.05). At 3?years, infants with lower birth weight (P?<?0.03) and gestational age (P?=?0.06) had reduced eGFR.

Conclusions

Preterm very-low-birth-weight infants demonstrate increasing renal function with advancing age. An elevated SBP and eGFR at 1?year suggests dysfunctional renal autoregulation and hyperfiltration, which may alter subsequent renal function and contribute to the lower eGFR seen at 3?years in infants with the lowest birth weight and gestational age.     

Birth weight is more important for peak bone mineral content than for bone density: the PEAK-25 study of 1,061 young adult women

Summary

Lower birth weight has a negative association with adult BMC and body composition in young adult Swedish women.

Introduction

The aim of this study was to evaluate the influence of birth weight on peak bone mass and body composition in a cohort of 25-year-old women.

Methods

One thousand sixty-one women participated in this cross-sectional population-based study using dual energy X-ray absorptiometry (DXA) to assess bone mineral content (BMC), bone mineral density (BMD), and body composition (total body (TB), femoral neck (FN), total hip (TH), lumbar spine L1–L4 (LS), and lean and fat mass). Birth weight data was available for 1,047 women and was categorized into tertiles of low (≤3,180 g), intermediate (3,181–3,620 g), and high (≥3,621 g) birth weight.

Results

Significant correlations were observed between birth weight and TB-BMC (r?=?0.159, p?<?0.001), FN-BMC (r?=?0.096, p?<?0.001), TH-BMC (r?=?0.102, p?=?0.001), LS-BMC (r?=?0.095, p?=?0.002), and lean mass (r?=?0.215, p?<?0.001). No correlation was observed between birth weight and BMD. The estimated magnitude of effect was equivalent to a 0.3–0.5 SD difference in BMC for every 1 kg difference in birth weight (151 g (TB); 0.22 g (FN); 1.5 g (TH), 2.5 kg TB lean mass). The strongest correlations between birth weight and BMC occurred in women with lowest birth weights, although excluding women who weighed <2,500 g at birth, and the correlation remained significant although slightly weaker.

Conclusions

Women with lower birth weight have lower BMC and less lean and fat mass at the age of 25, independent of current body weight. Lower birth weight has a greater negative influence on bone mass than the positive influence of higher birth weight.     

Disparities in antihypertensive medication adherence in adolescents

Background

Hypertension affects up to 5 % of all children, but little is known about the role of medication adherence on blood pressure (BP) control. In this study we examined the association between adolescents’ antihypertensive medication adherence and BP control, investigating for racial disparities.

Methods

A total of 21 adolescents with essential hypertension [mean age 14.7 ± 2.0 years, 57 % male, 52 % African American] were recruited from a pediatric nephrology clinic. Objective medication adherence measures were obtained with Medication Event Monitoring System (MEMS) caps and pharmacy refill records to determine medication possession ratios (MPRs).

Results

The African Americans adolescents had lower medication adherence than non-African Americans adolescents based on the MPR over the past 12 months (mean 0.54?±?0.21 vs. 0.85?±?0.16, respectively; p?<?0.001) and a trend for less adherence measured by MEMS caps over the last 28 days (mean 0.75 ±0.26 vs. 0.91?±?0.04, respectively; p?<?0.07). Seven of the eight participants with low adherence (MPR?<0.65) had uncontrolled BP (systolic and/or diastolic BPs?≥95th percentile), and no participants with high adherence according to the MPR had uncontrolled BP (p?<?0.001). There was no difference in BP control by race.

Conclusions

Antihypertensive medication adherence measured by pharmacy refills was associated with BP control. AAs were more likely to have lower medication adherence. Targeting medication adherence through the use of electronic medical records may be a potential mechanism to reduce health disparities.     

Comparison of functional outcomes of robotic and open partial nephrectomy in patients with pre-existing chronic kidney disease: a multicenter study

Background

We compared renal functional outcomes of robotic (RPN) and open partial nephrectomy (OPN) in patients with chronic kidney disease (CKD), a definite indication for nephron-sparing surgery.

Methods

A multicenter retrospective analysis of OPN and RPN in patients with baseline ≥?CKD Stage III [estimated glomerular filtration rate (eGFR) <?60 mL/min/1.73 m²] was performed. Primary outcome was change in eGFR (ΔeGFR, mL/min/1.73 m²) between preoperative and last follow-up with respect to RENAL nephrometry score group [simple (4–6), intermediate (7–9), complex (10–12)]. Secondary outcomes included eGFR decline >?50%.

Results

728 patients (426 OPN, 302 RPN, mean follow-up 33.3 months) were analyzed. Similar RENAL score distribution (p?=?0.148) was noted between groups. RPN had lower median estimated blood loss (p?<?0.001), and hospital stay (3 vs. 5 days, p?<?0.001). Median ischemia time (OPN 23.7 vs. RPN 21.5 min, p?=?0.089), positive margin (p?=?0.256), transfusion (p?=?0.166), and 30-day complications (p?=?0.208) were similar. For OPN vs. RPN, mean ΔeGFR demonstrated no significant difference for simple (0.5 vs. 0.3, p?=?0.328), intermediate (2.1 vs. 2.1, p?=?0.384), and complex (4.9 vs. 6.1, p?=?0.108). Cox regression analysis demonstrated that decreasing preoperative eGFR (OR 1.10, p?=?0.001) and complex RENAL score (OR 5.61, p?=?0.03) were independent predictors for eGFR decline >?50%. Kaplan–Meier analysis demonstrated 5-year freedom from eGFR decline >?50% of 88.6% for OPN and 88.3% for RPN (p?=?0.724).

Conclusions

RPN and OPN demonstrated similar renal functional outcomes when stratified by tumor complexity group. Increasing tumor age and tumor complexity were primary drivers associated with functional decline. RPN provides similar renal functional outcomes to OPN in appropriately selected patients.

     

Extra-uterine renal growth in preterm infants: Oligonephropathy and prematurity

Background

Nephron number in humans is determined during fetal life. The objective of this study was to investigate the effects of preterm birth on nephron number using renal volume as a surrogate for nephron number.

Methods

This observational study was conducted over 12 months in a tertiary perinatal center. Preterm babies less than 32 weeks of gestation were recruited and followed until discharge. Term infants were recruited for comparison. The babies underwent renal sonography and renal function measurements at 32 and 38 weeks corrected age. The primary outcome measurement was total kidney volume at 38 weeks and the secondary outcome was estimated glomerular filtration rate (eGFR).

Results

Forty-four preterm infants and 24 term infants were recruited. At 38 weeks corrected age, premature infants had lower total kidney volume than term infants (21.6?±?5.7 vs. 25.2?±?5.7 ml; p?=?0.02) and a significantly lower eGFR (73.6 [IQR 68.1–77.6] vs. 79.3 [IQR 72.5–86.6] ml·min^?1·1.73 m^?2; p?=?0.03). There was a significant correlation between total kidney volume and eGFR in premature and term babies.

Conclusions

Premature infants have smaller kidney volume and likely decreased nephron number and lower estimated glomerulofiltration rate relative to infants born at term.     

Renal impairment in children with posterior urethral valves

Background

Posterior urethral valves (PUV) are a common cause of end-stage renal failure in childhood. Our aim was to describe a cohort of patients with PUV and to investigate the predictors of renal impairment.

Methods

We performed a retrospective chart review of children with PUV who were followed at King Abdulaziz University hospital between 2002 and 2011.

Results

The cohort comprised 68 boys. There was a significant difference in the duration of follow-up (p?=?0.024), nadir serum creatinine (p?<?0.001), and last known serum creatinine level (p?=?0.001) between the patients with and without renal impairment. The duration of follow-up appeared to be a significant predictor for serum creatinine doubling (p?=?0.003; odds ratio, 1.8). There was no difference in the age of presentation, age at the time of the study, and first or last serum creatinine between children who initially had vesicostomy and children who had ablation.

Conclusions

Ablation of PUV or vesicostomy did not influence kidney function in our study cohort. Children with a normal nadir serum creatinine who presented early had a better outcome.     

Urethral closure pressures among primiparous women with and without levator ani muscle defects

Introduction and hypothesis

Vaginal birth is an established risk factor for levator ani (LA) defects and incontinence. We hypothesized an association between urethral pressure profiles and LA defects.

Methods

One hundred sixty primiparous women, 9?C12?months postpartum, were assessed with MRI for LA defects, urodynamic testing, and instrumented speculum for vaginal closure force. Urodynamic testing included resting maximal urethral closure pressure (MUCP) and urethral closure pressure with a pelvic floor contraction or Kegel (KUCP). We examined the relationships between MUCP, KUCP, LA defect status, and vaginal closure force.

Results

There was no significant association between MUCP or KUCP in women with and without LA defects (p?=?0.94, p?=?0.95). Additionally, there was no correlation between MUCP and vaginal closure force (r?=?0.06, p?=?0.41), and a weak correlation between KUCP and vaginal closure force (r?=?0.20, p?=?0.01).

Conclusions

In this population, urethral pressure profiles are unrelated to LA defect status after vaginal birth, indicating that the mechanism responsible for LA damage spares the urethra.     

Birth parameters and parental height predict growth outcome in children with chronic kidney disease

Background

We analyzed the impact of birth parameters and parental height on long-term growth outcome in children with chronic kidney disease (CKD) stage 3–5.

Methods

Linear growth was prospectively investigated in 509 children, with a mean follow-up of 4.1 years. Growth outcome was categorized in (i) poor growth (PG): height standard deviation score (SDS) during follow-up <??2.0 and/or actual or previous growth hormone (GH) treatment, and (ii) good growth (GG): height SDS ≥??2.0 and no need for GH. A multivariate binary logistic regression model was constructed for predictors of PG outcome.

Results

PG was observed in 55 % of patients. The rate of pre-term and small for gestational age birth was significantly higher in children with PG compared to GG (43.2 vs. 25.6 % and 36.8 vs. 18.9 %; p?<?0.001). Children with PG had significantly lower average values for gestational age, birth weight, length, and head circumference, umbilical cord pH, Apgar scores, and parental height than children with GG. Birth length, umbilical cord pH, and parental height were significant independent predictors of PG outcome (sensitivity 72.8 %, specificity 69.3 %).

Conclusions

Birth parameters and parental height are independent predictors of growth outcome in children with CKD.     

Laparoscopic and robotic partial nephrectomy without renal ischaemia for tumours larger than 4?cm: perioperative and functional outcomes

Purpose

To evaluate the technical feasibility, safety and functional outcomes of zero ischaemia laparoscopic and robotic partial nephrectomy with controlled hypotension for renal tumours larger than 4?cm.

Methods

We evaluated 121 consecutive patients with American Society of Anaesthesiologists (ASA) scores 1–2 who underwent laparoscopic (n?=?70) or robotic (n?=?51) partial nephrectomy with controlled hypotension with either tumour size ≤4?cm (group 1, n?=?78) or tumour size >4 cm (group 2, n?=?43) performed by a single surgeon from December 2010 to December 2011. Operative data, complications, serum creatinine, estimated glomerular filtration rates and effective renal plasma flow calculated from 99mTc-mercaptoacetyltriglycine renal scintigraphy were compared. Differences between groups were evaluated by the Chi-square test and the Student’s t test.

Results

A significant difference in mean intraoperative blood loss and postoperative complications was found between the two groups: 168?ml (range: 10–600?ml in group 1) and 205?ml (range: 90–700?ml in group 2); p?=?0.005, and 6.4?% versus 18.6?%; p?=?0.004, respectively. The mean percentage decrease of ERPF of the operated kidney was 1.8?% in group 1 and 4.1?% in group 2.

Conclusions

Laparoscopic and robotic partial nephrectomy with controlled hypotension for tumours >4?cm in ASA 1–2 patients was feasible with significant higher intraoperative blood loss and postoperative complications compared to smaller renal masses. The benefits of avoiding hilar clamping to preserve kidney function seem excellent.     

Racial differences in restless legs symptoms and serum ferritin in an incident dialysis patient cohort

Purpose

Restless legs syndrome (RLS), a debilitating sleep disorder that is frequently reported by CKD patients on dialysis, may be more common in whites than in non-whites. Iron deficiency is associated with RLS, and serum ferritin is higher among African Americans compared to Caucasians in the general population. No prior studies have compared restless legs symptoms and serum ferritin levels of African-American and those of the Caucasian patients on dialysis.

Methods

In a multicenter observational study that included in-person interviews and medical chart review, we studied 210 patients who had recently started renal dialysis. Predictors of restless legs symptoms were examined in a multivariable logistic regression model.

Results

African Americans had a reduced risk of restless legs complaint compared to Caucasian patients (OR, 0.44 [95% CI 0.21?C0.93]; P?=?0.03). African-American patients were also less likely than Caucasian patients to have low serum ferritin values (<100?ng/ml), and among patients with serum ferritin ??100?ng/ml, the average serum ferritin of African-American patients was higher than that of Caucasian patients.

Conclusions

Further study of racial and iron status relationships could advance the understanding of RLS pathophysiology, and RLS is an important patient outcome to monitor, as revised anemia and iron protocols are implemented in the clinical setting.     

Post-transplant hypertension in pediatric kidney transplant recipients

Background

The aim of the study was to investigate the prevalence of post-transplant hypertension (HT) and to assess the blood pressure (BP) of transplanted children with possible risk factors.

Methods

Office and ambulatory blood pressure measurements were performed for each patient.

Results

Twenty-nine patients were included in the study, including 13 patients with newly diagnosed untreated HT according to the results of ambulatory blood pressure monitoring (ABPM). Fourteen patients were on antihypertensive medication, but only in five of these patients was the HT under control; nine patients receiving antihypertensive drugs had uncontrolled HT. Of the 29 patients, two had normotension without any antihypertensive drug(s). Standard deviation scores (SDS) of the nocturnal diastolic BP of the ABPM were positively correlated with the prednisolone dosage per kilogram (p?=?0.013, r?=?0.45) and negatively correlated with the time period after transplantation (p?=?0.024, r?= ?0.41). Similarly, the SDS of the 24-h diastolic BP was positively correlated with the prednisolone dosage per kilogram (p?=?0.006, r?=?0.50) and negatively correlated with the time period after transplantation (p?=?0.016, r?= ?0.44). Patients with alternate-day steroid treatment had lower nocturnal systolic (p?=?0.016), nocturnal diastolic (p?=?0.001) and 24-h diastolic (p?=?0.008) SDS when compared to those receiving daily steroid medication.

Conclusion

The prevalence of HT among children after renal transplantation was high among our patient cohort, and steroids had direct impact on nocturnal and diastolic BP.     

Obesity, But Not High-Fat Diet, Promotes Murine Pancreatic Cancer Growth

Background

Obesity accelerates pancreatic cancer growth; the mechanisms underlying this association are poorly understood. This study evaluated the hypothesis that obesity, rather than high-fat diet, is responsible for accelerated pancreatic cancer growth.

Methods

Male C57BL/6J mice were studied after 19?weeks of high-fat (60?% fat; n?=?20) or low-fat (10?% fat; n?=?10) diet and 5?weeks of Pan02 murine pancreatic cancer growth (flank).

Results

By two-way ANOVA, diet did not (p?=?0.58), but body weight, significantly influenced tumor weight (p?=?0.01). Tumor weight correlated positively with body weight (R ²?=?0.562; p?<?0.001). Tumors in overweight mice were twice as large as those growing in lean mice (1.2?±?0.2?g vs. 0.6?±?.01?g, p?<?0.01), had significantly fewer apoptotic cells than those in lean mice (0.8?±?0.4 vs 2.4?±?0.5; p?<?0.05), and greater adipocyte volume (3.7 vs. 2.2?%, p?<?0.05). Apoptosis (R ²?=?0.472; p?=?0.008) and serum adiponectin correlated negatively with tumor weight (R?=?0.45; p?<?0.05).

Conclusions

These data suggest that body weight, and not high-fat diet, is responsible for accelerated murine pancreatic cancer growth observed in this model of diet-induced obesity. Decreased tumor apoptosis appears to play an important mechanistic role in this process. The concept that decreased apoptosis is potentiated by hypoadiponectinemia (seen in obesity) deserves further investigation.     

Growth and function in childhood of a normal solitary kidney from birth or from early infancy

Background

Children with a solitary kidney (SK) have an increased long-term risk of hypertension, albuminuria and glomerulosclerosis. In this study, we assessed the early signs of impaired glomerular filtration in children with a SK from birth or from early infancy.

Methods

Renal growth and function at ages 4–15.5 years were studied in 38 children with SK and 40 matched control subjects in terms of accelerated growth.

Results

The systolic/diastolic blood pressure Z-scores (p?=?0.01/<0.05) and the resistance index (RI) of the arcuate arteries (p?=?0.05) were higher in the children with SK. Creatinine clearance and 24-h protein and albumin urinary excretion showed no difference. All but seven children with SK had 99mTc diethylene-triamine pentaacetic acid glomerular filtration rate values of >80 ml/min/1.73 m². An independent positive correlation was found between length of the follow-up time and 24-h albumin urinary excretion (β?=?0.54, p?<?0.01). Accelerated postnatal growth was positively related with kidney volume (β?=?0.35, p?<?0.05).

Conclusions

Among our patient cohort, renal function was well preserved at ages 4–15.5 years in children who were born with a SK. However, both their higher blood pressure and RI and the correlation of 24-h albumin urinary excretion with length of follow-up time underline the need for monitoring to detect early signs of glomerular hyperfiltration and, if necessary, implement timely intervention. SK hypertrophy was found to be correlated with postnatal growth.     

Growth of children with end-stage renal disease undergoing daily hemodialysis

Background

The aim of this report is to describe the effect of daily hemodialysis on the growth of children with end-stage renal disease (ESRD).

Methods

We performed a prospective, observational study on 24 children with ESRD undergoing daily hemodialysis (DHD). The control group comprised 26 children on concurrent conventional hemodialysis (CHD), and the follow-up for both groups was 9.3?±?3.0 months. No patient received growth hormone (GH) therapy.

Results

At the onset of the study, the height-for-age Z-score was ?2.12?±?1.54 in the CHD group and ?2.84?±?2.27 in the DHD group (p?=?0.313). Assuming an increase of 0.5 standard deviation scores (SDS) of the height-for-age parameter as an improvement of growth, there were 33 % of patients in the DHD group and 8 % in the CHD group (p?=?0.035). The cumulative probability of gain in height for age at 12 months was 40 % in the DHD group versus 15 % in the CHD group (p?=?0.047). Also, 98 % of patients in the DHD group had an adequate total caloric intake, whereas 38 % in the CHD group reached this goal (p?<?0.001). No patient left the study due to intensification of the dialysis modality.

Conclusions

Our data show that the DHD favored a 0.5 SDS height gain in a third of patients without GH treatment. Dialysis intensification was not a cause for treatment dropouts, and DHD should be considered as a treatment for selected cases, especially small children.     

Race/Ethnicity Is Predictive of Lymph Node Status in Patients with Early Gastric Cancer

Background

Race/ethnicity has long been suspected to affect survival in patients with gastric adenocarcinoma. However, the clinicohistopathological impact of race or ethnicity on early gastric cancer (EGC) is not known.

Methods

From 2000 to 2013, 286 patients underwent gastrectomy and 104 patients had pathological confirmation of EGC. A retrospective analysis of pathological and clinical prognostic indicators was performed.

Results

The study population consisted of 38 (37 %) Asian Americans and 66 (63 %) non-Asian Americans. Of these, 2 (5.3 %) Asian Americans and 19 (28.8 %) non-Asian Americans had pathological confirmation of lymph node metastasis (LNM) (p?=?0.004). Univariate analysis comparing the clinicohistopathological characteristics in each group did not reveal significant difference regarding histotype, tumor size, grade, location, morphology, or lymphovascular invasion, except for the LNM rate and mean body mass index (23.2 versus 26.6, p?p?=?0.038), younger age (OR, 1.11; 95 % CI, 1.01–1.12; p?=?0.046), and lymphovascular invasion (OR, 13.9; 95 % CI, 2.40–79.99; p?=?0.003) were significant predictors for LNM.

Conclusions

This study demonstrated that Asian American race in EGC is associated with a significantly decreased rate of LNM in comparison to non-Asian Americans, despite similar histopathological characteristics of each group.     

Physical activity, calcium intake and childhood bone mineral: a population-based cross-sectional study

Summary

In a free-living cohort of 4-year old children, mean daily time in moderate?Cvigorous physical activity and daily calcium intake at 3?years, were positively related to hip bone size and density. Relationships between physical activity and bone indices were stronger when calcium intake was above compared with below median (966?mg/day).

Introduction

We examined the cross-sectional relationships between childhood physical activity, dietary calcium intake and bone size and density.

Methods

Children aged 4?years were recruited from the Southampton Women's Survey. They underwent measurement of bone mass by DXA (Hologic Discovery). Physical activity was assessed by accelerometry (Actiheart, Cambridge Neurotechnology Ltd, Cambridge, UK) for seven continuous days.

Results

Four hundred twenty-two children (212 boys) participated. In a cross-sectional analysis, after adjusting for gender, daily mean time(minutes per day) spent in moderate to very vigorous activity (MVPA) was positively related to hip BA (R ²?=?3%, p?<?0.001), BMC (R ²?=?4%, p?<?0.001), aBMD (R ²?=?3%, p?=?0.001) and estimated vBMD (R ²?=?2%, p?=?0.01), but not height (r _s?=?0.04, p?=?0.42) or weight (r _s?=?0.01, p?=?0.76). Mean daily calcium intake (assessed at 3?years old) positively predicted bone indices in those with a calcium intake below the median (966?mg/day), but there was a much attenuated relationship in those above this. These associations persisted after inclusion of total energy, protein and phosphorus in multivariate models. The relationships between MVPA and bone indices were stronger in children with calcium intakes above the median. Thus, for aBMD, the variance explained by MVPA when daily calcium intake was below the median was 2% (p?=?0.1) and above median was 6% (p?=?0.001).

Conclusions

These results support the notion that adequate calcium intake may be required for optimal action of physical activity on bone development and that improving levels of physical activity and calcium intake in childhood may help to optimise accrual of bone mass.     

The impact of serum uric acid reduction on renal function and blood pressure in chronic kidney disease patients with hyperuricemia

Background

Febuxostat is tolerable in chronic kidney disease (CKD) patients with hyperuricemia. However, the long-term effect of lowering uric acid with febuxostat on renal function and blood pressure has not been elucidated.

Methods

This was a 2 years retrospective observational study. 86 CKD patients with hyperuricemia who continued with allopurinol (allopurinol group, n?=?30), switched from allopurinol to febuxostat (switched group, n?=?25), or were newly prescribed febuxostat (febuxostat group, n?=?31) were included in this study. Serum uric acid, estimated glomerular filtration rate (eGFR), blood pressure, and urinary protein were analyzed. Moreover, the impact of serum uric acid reduction on renal function and blood pressure was assessed.

Results

Serum uric acid in the switched and febuxostat groups was significantly reduced at 6 months (switched group; 8.49?±?1.32–7.19?±?1.14 mg/dL, p?<?0.0001, febuxostat group; 9.43?±?1.63–6.31?±?0.90 mg/dL, p?<?0.0001). In the allopurinol group, serum uric acid was increased (6.86?±?0.87–7.10?±?0.85 mg/dL, p?=?0.0213). eGFR was significantly increased (35.2?±?12.8–37.3?±?13.9 mL/min/1.73 m², p?=?0.0232), while mean arterial pressure (93.1?±?10.8–88.2?±?9.5 mmHg, p?=?0.0039) was significantly decreased at 6 months in the febuxostat group, resulting in the retention of eGFR for 2 years.

Conclusions

The impact of serum uric acid reduction might have beneficial effects on CKD progression and blood pressure. However, a large prospective study is needed to determine the long-term efficacy of febuxostat therapy in CKD patients with hyperuricemia.

     

The Effect of Biliopancreatic Diversion Surgery on Renal Function—a Retrospective Study

Background

The prevalences of obesity and chronic kidney disease (CKD) have increased simultaneously. Should a pathophysiological relationship exist between the two conditions, bariatric surgery and associated weight loss could be an important intervention in extremely obese individuals to slow the progression of CKD.

Methods

We conducted a retrospective analysis of 25 patients who had undergone biliopancreatic diversion (BPD) surgery for extreme obesity (body mass index >40 kg/m²), with mean follow-up of 4 years. We assessed pre- and post-surgery renal function, body weight and blood pressure (BP) obtained from electronic hospital and primary care records.

Results

There was a significant reduction in mean body weight at 4 years by 50.3 kg (SD?=?20.65). The creatinine and estimated glomerular filtration rate (eGFR) also improved significantly: serum creatinine reduced by 16.2 μmol/l (SD?=?19.57) while the eGFR improved by 10.6 ml/min/m² (SD?=?15.45). The greatest improvement in eGFR was in the group (n?=?7) with eGFR ≤60 ml/min/m². A subset of patients (n?=?11) had evaluable BP readings and had a reduction in BP of 17/10 mmHg (SD?=?33/12).

Conclusions

This retrospective study demonstrates a clinically significant improvement in renal function following BPD. Several mechanisms including weight loss could account for the positive impact on renal function. The physiology underlying this improvement requires further study.     

Circulating endothelial cells in pediatric renal transplant recipients

Background

An increase in the number of circulating endothelial cells (CEC) indicates endothelial damage and the risk of cardiovascular disease. The aim of our study was to investigate the association of CEC with various clinical parameters in pediatric renal transplant recipients.

Methods

CEC, defined as CD45^?CD146⁺, were enumerated by flow cytometry from the peripheral blood of 50 pediatric renal transplant recipients and 20 healthy controls. Clinical parameters, including renal function tests, fasting blood glucose, serum cholesterol and triglyceride, cyclosporine A (CsA) (trough and 2nd-hour) and tacrolimus (tac) trough blood levels and their association with CEC numbers were analyzed.

Results

CEC numbers of patients were higher than those of controls (respectively, 128?±?89 cells/ml (42–468 cells/ml), 82?±?33 cells/ml (32–137 cells/ml), p?=?0.024). There was a statistically significant negative correlation between CEC numbers and glomerular filtration rate (GFR) (r?=??0.300, p?=?0.012). There was also a statistically positive association between CEC numbers and transplant duration as well as cyclosporine trough level (respectively, r?=?0.397, p?=?0.004, r?=?0.714, p?=?0.004). CEC numbers in patients on tac and CsA were similar (p?=?0.716).

Conclusions

Our results demonstrate that renal transplant recipients with high CsA trough blood level, longer transplant duration, and lower GFR, are at greater risk of developing endothelial damage.     

Increased urinary angiotensinogen is an effective marker of chronic renal impairment in very low birth weight children

Background

Recent advancements in perinatal and neonatal care have increased the survival of preterm infants with lower birth weight and very low birth weight (VLBW; < 1,500 g) infants. Such infants are exposed to a higher risk of renal insufficiency in later life due to congenitally fewer nephrons; however, urinalysis in order to detect renal insufficiency in those infants at school age has not yet been established. The aim of the study was to assess chronic renal impairment in VLBW infants during their childhood after discharge from the neonatal intensive care unit (NICU) until adolescence using urinary angiotensinogen (uAGT).

Methods

We compared serum levels of angiotensinogen (sAGT), creatinine, β₂-microglobulin (sβ2MG) and cystatin C (sCysC), and urinary levels of uAGT, creatinine (uCre),β₂-microglobulin (uβ2MG) and albumin between two infant groups—the VLBW group (50 children who were admitted to our NICU as infants), and a control group of 25 children who were born as full-term infants with birth weight ≥2,500 g. The median age of the VLBW group and control group infants was 60 months (range 7–135) and 57 months (range 5–144), respectively, at the time of evaluation.

Results

In the VLBW group, sCysC levels were high (p < 0.05) and estimated glomerular filtration rate (eGFR) was low (p < 0.05). There were no significant differences in the ratios of uβ2MG to creatinine and urinary albumin to creatinine between the two groups. Although there were no differences in concentration of sAGT between the two groups (p = 0.062), the ratio of uAGT to creatinine was significantly higher in the VLBW group (p < 0.01). The examination of 19 VLBW infants (19/50) with eGFR ≤90 ml/min/1.73 m² showed a positive correlation between uAGT/creatinine and urinary albumin/creatinine (r = 0.531, p?VLBW infants (19/50) with eGFR ≤90 ml/min/1.73 m², 18 of whom had stage II chronic kidney disease and one who had stage III disease (r = ?0.512, p ≤ 0.05).

Conclusions

uAGT is an effective marker for predicting the progression of chronic renal impairment in preterm VLBW infants after their growth. uAGT measurement is easier to conduct, less invasive and more sensitive than conventional uβ2MG or urinary albumin measurement.