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

Follow-up of a randomized trial optimizing neonatal nutrition in preterm very low birthweight infants: growth, serum adipokines, renal function and blood pressure

OBJECTIVE

The primary objectives were to compare body mass index (BMI) Z-score (Z), systolic blood pressure (SBP), serum leptin:adiponectin (L:A) ratio and estimated glomerular filtration rate (eGFR) at ~3 years adjusted age between two arms of a randomized controlled trial (RCT) comparing two modes of human milk fortification for very low-birthweight infants in the neonatal intensive care unit.

STUDY DESIGN

Follow-up of RCT at 33-48 months.

RESULTS

Follow-up data are available in 82/120 infants. Infants in the experimental arm have anthropometric data consistent with central obesity and higher serum L:A ratio (sensitivity analysis adjusting for sex and using all available data), but have similar eGFR and SBP at follow-up compared with controls. Serum L:A ratio is strongly correlated with anthropometric measurements suggesting central obesity.

CONCLUSIONS

Infants in the experimental arm have central obesity and higher serum L:A ratio compared with controls. Notably, serum L:A ratio is strongly correlated with weight gain.

TRIAL REGISTRATION

This randomized controlled trial was registered at ClinicalTrials.gov NCT02372136.

Development of a Family-Centered Communication Tool for Kidney Health in Premature Infants: Qualitative Focus Group Study Using Human-Centered Design Methodology

BACKGROUND

Premature infants are at increased risk of kidney-related complications, including acute kidney injury (AKI) and chronic kidney disease (CKD). The risk of CKD in prematurely born infants is underrecognized by health care teams and caregivers. Understanding how to communicate the risk of CKD to caregivers is essential for longitudinal clinical follow-up and adherence.

OBJECTIVE

This study aimed to determine family caregiver attitudes toward kidney health and risk communication during a neonatal intensive care admission. We also sought to understand caregiver preferences for the communication of information surrounding the risk of CKD in premature infants.

METHODS

We augmented standard qualitative group sessions with human-centered design methods to assess parent preferences and clinician perspectives. Caregivers recruited had a prematurely born child who spent time in the neonatal intensive care unit at Riley Hospital for Children in Indianapolis, Indiana, and experienced AKI or another kidney complication, which put them at risk for future CKD. We used a variety of specific design methods in these sessions, including card sorting, projective methods, experience mapping, and constructive methods.

RESULTS

A total of 7 clinicians and 8 caregivers participated in 3 group sessions. Caregivers and clinicians readily acknowledged barriers to and drivers of long-term kidney monitoring as well as opportunities for communication of the risk of long-term kidney disease. Caregivers' primary concerns were for both the type and depth of information conveyed as well as the time at which it was communicated. Participants emphasized the importance of collaboration between the hospital care team and the primary care provider. Participant input was synthesized into several prototype concepts and, ultimately, into a rough prototype of a website and an informational flyer.

CONCLUSIONS

Caregivers of premature infants are open to communication about kidney health during their neonatal admission. The next phase of this work will translate caregivers' preferences into family-centered communication tools and test their efficacy in the neonatal intensive care unit.

Persistent high blood pressure and renal dysfunction in preterm infants during childhood

BACKGROUND

Infants born very preterm (≤32 weeks gestational age, GA) and very-low birth weight (≤1500 g; PT-VLBW) demonstrate high systolic blood pressure (SBP), renal dysfunction, and obesity at 6 months-3 years and in early adulthood. Their parallel measurement and progression during childhood is unclear.

METHODS

We reenrolled 62/120 patients originally seen at 1-3 years at 10-13 years and remeasured anthropometric indices, SBP, and serum creatinine (Cr) and cystatin C (cysC) to determine estimated glomerular filtration rate (eGFR). We selected Term-matched Controls at 10-13 years from the 2015-2016 NHANES database at a ratio of 2 Controls:1 Case (124:62).

RESULTS

Reenrolled patients were predominantly Hispanic, birth weight 1073 ± 251 g, and GA at birth 28 ± 2 weeks. At 10-13 years, 45% were classified overweight/obese, 48% had SBP ≥ 90th centile (77% considered hypertensive), and 34% had low eGFR (<90 mL min^-1 [1.73 m²]^-1). Notably, 57% of reenrolled PT-VLBW Cases had low eGFR_cysC at both 1-3 and 10-13 years, P < 0.03. Compared to Controls, Cases had four times the adjusted odds for having an elevated SBP and low eGFR_Cr despite similar proportions with overweight/obesity among Cases and Controls.

CONCLUSIONS

PT-VLBW infants seen at 1-3 years exhibit obesity, elevated SBP, and low eGFR in infancy and 10-13 years. Although the small sample size may limit conclusions, pediatricians should consider serial evaluations of PT-VLBW throughout childhood.

IMPACT

The association between preterm birth and elevated blood pressure, renal dysfunction, and obesity in young adults begins as early as 1 year and persists at 10-13 years of age. This is the first study reporting serial measurements of blood pressure, renal function, and obesity from infancy to preadolescence in children born very preterm. Fifty-seven percent of preterm 1-3 year olds have persistent low estimated glomerular filtration rate associated with hypertension at 10-13 years. Clinicians should consider serial evaluations of blood pressure, renal function, and obesity throughout infancy and childhood in all preterm births.

Quality improvement project designed to reduce disproportionate growth in extremely low gestational age neonates: cognitive neurodevelopmental outcome at 18-41 months

OBJECTIVE

To assess if the adjusted odds of low composite cognitive Bayley-III scores changed after implementing a single-institution quality improvement (QI) project designed to decrease discharge Z-scores for weight, body mass index (BMI), and weight-for-length, but not length or fronto-occipital circumference (FOC) in infants 23-28 weeks gestational age (GA).

METHODS

Compare Bayley-III outcomes at ≥18 months corrected age (postnatal age adjusted for prematurity) in infants tested before (Epoch-1) and after (Epoch-2) QI implementation.

RESULTS

Bayley testing was available in 134/156 infants (86%) in Epoch-1 and 139/175 (79%) in Epoch-2. There was no change in frequency of low (<85) cognitive score (p = 0.5) or in median cognitive scores (80 in Epoch-1 vs. 85 Epoch-2, p = 0.35). The adjusted odds of low cognitive scores was not different between Epochs.

CONCLUSION

No change in cognitive outcome at ≥18 months corrected age was observed after implementing a QI project designed to reduce discharge weight-for-length disproportion in very preterm infants.

Association of age of initiation and type of complementary foods with body mass index and weight-for-length at 12 months of age in preterm infants

OBJECTIVE

To assess whether in very preterm infants (1) body mass index (BMI) Z-score and weight-for-length (WtFL) Z-score at 1 year of age and (2) head growth from discharge to 1 year are associated with breastfeeding at discharge and the age of onset and type of complementary foods.

STUDY DESIGN

Observational cohort study.

RESULTS

Infants started on only ready-made complementary (RMC) feedings at ≤26 weeks adjusted age had the highest adjusted BMI Z-score and WtFL Z-score at 1 year of age. Adjusted change in fronto-occipital circumference was highest in infants either discharged on breastmilk or receiving home-made complementary food with/without RMC (HMM) at ≤26 weeks adjusted age.

CONCLUSIONS

Infants started on RMC ≤26 weeks adjusted age had the highest BMI Z-score and WtFL Z-score at 1 year. Head growth from discharge to 1 year was highest in infants either discharged on breastmilk or receiving HMM at ≤26 weeks adjusted age.

Optimizing individual nutrition in preterm very low birth weight infants: double-blinded randomized controlled trial

OBJECTIVE

In preterm neonates fed human milk, fortification may be adjusted by (1) optimization, based on growth rate and serum nutrient analyses, or (2) individualization, based on serial milk nutrient analyses. The primary aim was to determine whether individualized plus optimized nutrition (experimental) improves velocity of weight gain and linear growth from birth to endpoint (36 weeks postmenstrual age or discharge) when compared with optimized nutrition alone (controls).

STUDY DESIGN

Double-blinded parallel group randomized trial in 120 neonates <29 weeks gestational age (GA) or <35 weeks and small for GA (birth weight < 10th centile).

RESULT

Weight-gain velocity (13.1 ± 2.1, n = 57 controls, vs. 13.0 ± 2.6 g kg^-1 day^-1, n = 59 experimental, P = 0.87), linear growth (0.9 ± 0.2, n = 55, vs. 0.9 ± 0.2 cm week^-1, n = 52, P = 0.90) and frequency of weight/length disproportion (2% vs. 2%, P = 0.98) were similar in both groups.

CONCLUSIONS

Individualized plus optimized nutrition does not improve weight gain, linear growth, or weight/length disproportion at endpoint versus optimized nutrition alone.

Prevalence of hyperfiltration among US youth/young adults with overweight and obesity: A population-based association study

OBJECTIVE

Determine prevalence of hyperfiltration (high estimated glomerular filtration rate "eGFR" >95th percentile for age/sex) among youth and association with BMI classification.

METHODS

With the use of 1999 to 2016 National Health and Nutrition Examination Survey data from 12- to 29-year-olds, data for serum creatinine and thresholds for high eGFR were normed using a metabolically healthy subsample (no albuminuria, healthy weights, normal blood pressures, blood glucoses, lipids, and liver enzymes). Logistic regression examined the association of BMI classification (healthy weight, overweight, and obesity classes 1-3) with hyperfiltration (eGFR > 95th percentile for age/sex), adjusted for diabetes and other covariates.

RESULTS

Of 12- to 29-year-olds (N = 18 698), 27.4% (n = 5493) met criteria for entry into the "healthy subsample" and contributed data to derive normative values for serum creatinine/hyperfiltration thresholds. In the full sample, hyperfiltration prevalence in 12- to 29-year-olds classified as healthy-weight, overweight, and obesity classes 1 to 3 was 4.9%, 4.7%, 6.5%, 8.7%, and 11.8%, respectively (P < .001). In multivariable analysis, obesity classes 2 and 3 were associated with greater likelihood of hyperfiltration (adjusted ORs for class 2: 1.5, 95% CI, 1.1-2.1; and for class 3, 2.1, 95% CI, 1.5-2.9). Diabetes also was associated with hyperfiltration (AOR, 4.0; 95% CI, 2.2-7.4).

CONCLUSION

Obesity classes 2 to 3 are associated with hyperfiltration in youth. Age/sex-specific norms for creatinine and hyperfiltration thresholds may aid recognition of kidney dysfunction early.

Extremely Low Birth Weight Predisposes to Impaired Renal Health: A Pooled Analysis

BACKGROUND

A number of studies examined the association between preterm delivery and kidney size and function later in life. However, the number of cases in published cohort studies is low. This study was aimed at performing a multicenter collaboration to pool data to obtain more accurate results to quantify the extent of renal impairment in former extremely low birth weight (ELBW; <1,000 g) children.

METHODOLOGY

We performed a subject-level meta-analysis to pool data from Cracow (64 cases/34 controls) and Leuven (93 cases/87 controls). We assessed and analyzed cystatin C, estimated glomerular filtration rate (eGFR), ultrasound kidney length, and blood pressure (BP) in 11-year-old ELBW children compared with controls born at term. The prevalence of hypertension (HT) and prehypertension (preHT) in both groups was also analyzed.

RESULTS

The study group comprised 157 former ELBW children (gestational age 23-33 weeks and birth weight 430-1,000 g) and 123 children born at term. Former ELBW children had lower mean eGFR (100.62 ± 16.53 vs. 111.89 ± 15.26 mL/min/1.73 m2; p < 0.001), smaller absolute kidney length (8.56 ± 0.78 vs. 9.008 ± 0.73 cm; <0.001), and higher systolic (111.8 ± 9.8 vs. 107.2 ± 9.07 mm Hg; p = 0.01) and diastolic (68.6 ± 6.8 vs. 66.3 ± 7.7 mm Hg; p = 0.03) BP. Smaller renal size in former ELBW children was positively associated with lower birth weight, shorter gestational age, and severity of perinatal complications (intraventricular hemorrhage, length of stay, mechanical ventilation, and oxygen therapy).

CONCLUSION

ELBW is associated with lower eGFR and a high frequency of preHT and HT.

Adjustable feedings plus accurate serial length measurements decrease discharge weight-length disproportion in very preterm infants: quality improvement project

BACKGROUND

Preterm very-low-birth-weight (≤1500 g) infants exhibit disproportionate weight-for-length growth in the Neonatal Intensive Care Unit.

LOCAL PROBLEM

High frequency of body mass index (BMI) > 90th centile at discharge and 1-year postnatal age associated with elevated blood pressure and serum leptin in infancy and adolescence.

METHODS

Single-institution quality improvement project in appropriately grown infants born at 23^0/7-28^6/7 weeks gestational age and discharged home.

INTERVENTION

Adjustable feeding protocol based on valid serial length measurements (board or caliper).

RESULTS

The average monthly percentage of weight-for-length disproportion at discharge decreased from 13% in Epoch 1 to 0% in Epoch 2 (P < 0.05). Although the average Z-score for BMI at discharge was lower in Epoch 2 versus Epoch 1 (P < 0.01), this was absent by 1 year follow-up (P = 0.91).

CONCLUSIONS

Adjustable feedings plus use of accurate serial length measurements decreases weight-for-length disproportion at hospital discharge but not at 1 year.

Effects of Prenatal Growth Status on Subsequent Childhood Renal Function Related to High Blood Pressure

BACKGROUND

Hypertension is one of the major causes of chronic diseases. The effect on high blood pressure (BP) with fetal growth restriction is now well-established. Recent studies suggest that a reduced number of nephrons programmed during the intrauterine period contribute to a subsequently elevated BP, due to a permanent nephron deficit. However, few studies have examined this in children. We investigated the effects of low birth weight (LBW) and preterm birth on the renal function markers related to a high BP in childhood.

METHODS

We used data from 304 children aged 7-12 years who participated in the 2014 Ewha Birth and Growth Cohort survey in Korea. We assessed the serum uric acid, cystatin C, blood urea nitrogen (BUN), creatinine levels, and the estimated glomerular filtration rate (eGFR) in childhood. Anthropometric characteristics, BP in childhood, birth weight and gestational age were collected.

RESULTS

The serum uric acid was significantly higher in LBW children (4.0 mg/dL) than in normal birth weight children (3.7 mg/dL). The cystatin C levels were highest among children who were very preterm (0.89 mg/dL) compared with those who were not (preterm, 0.84 mg/dL; normal, 0.81 mg/dL), although the result was only borderline significant (P for trend = 0.06). Decreased birth weight was found to be significantly associated with an increased serum BUN level in childhood. In the analysis of the effects of renal function on BP, subjects with an eGFR lower than the median value had a significantly higher diastolic BP in childhood (difference = 2.4 mmHg; P < 0.05).

CONCLUSION

These findings suggest that LBW and preterm birth are risk factors for increased serum levels of renal function markers in childhood. Reduced eGFR levels were significantly associated with elevated diastolic BP in childhood. It is necessary to identify vulnerable individuals during their life and intervene appropriately to reduce the risk of an increased BP in the future.

Kidney Size, Renal Function, Ang (Angiotensin) Peptides, and Blood Pressure in Young Adults Born Preterm

Preterm birth incurs a higher risk for adult cardiovascular diseases, including hypertension. Because preterm birth may impact nephrogenesis, study objectives were to assess renal size and function of adults born preterm versus full term and to examine their relationship with blood pressure (BP; 24-hour ambulatory BP monitoring) and circulating renin-Ang (angiotensin) system peptides. The study included 92 young adults born (1987-1997) preterm (≤29 weeks of gestation) and term (n=92) matched for age, sex, and race. Young adults born preterm had smaller kidneys (80±17 versus 90±18 cm³/m²; P<0.001), higher urine albumin-to-creatinine ratio (0.70; interquartile range, 0.47-1.14 versus 0.58, interquartile range 0.42 to 0.78 mg/mmol, P=0.007), higher 24-hour systolic (121±9 versus 116±8 mm Hg; P=0.001) and diastolic (69±5 versus 66±6 mm Hg; P=0.004) BP, but similar estimated glomerular filtration rate. BP was inversely correlated with kidney size in preterm participants. Plasma Ang I was higher in preterm versus term participants (36.3; interquartile range, 13.2-62.3 versus 19.4; interquartile range, 9.9-28.1 pg/mL; P<0.001). There was no group difference in renin, Ang II, Ang (1-7), and alamandine. In the preterm, but not in the term group, higher BP was significantly associated with higher renin and alamandine and lower birth weight and gestational age with smaller adult kidney size. Young adults born preterm have smaller kidneys, higher urine albumin-to-creatinine ratio, higher BP, and higher circulating Ang I levels compared with term controls. Preterm young adults with smaller kidneys have higher BP. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT03261609.

Blood Pressure Trajectories from Childhood to Adolescence in Pediatric Hypertension

It has been known for a long time that elevated blood pressure (BP) in the young may persist and progress into adult hypertension (HTN). Multiple studies have revealed the predicted BP trajectory lines starting from childhood and related them to later cardiovascular (CV) risks in adulthood. As a small baby grows into a tall adult, BP will also naturally increase. Among early-life predictors of adult HTN, birth history, such as prematurity, and low birth weight have been popular subjects in research on pediatric HTN, because body size at birth has been reported to be inversely related to the risk of adulthood HTN. The hypothesis of HTN in prematurely born adolescents has been postulated as a physiological predisposition to postnatal excessive weight gain. Current body weight is a well-known independent predictor of HTN in children, and some studies showed that children demonstrating upward crossing of their weight percentiles while growing into adolescents have significantly increased risk for elevated BP later in life. Recently, reports focused on the adverse effect of excessive catch-up growth in this population are gradually drawing attention. Accordingly, children born prematurely or with intrauterine growth restriction who show rapid changes in their weight percentile should be under surveillance with BP monitoring. Prevention of childhood obesity, along with special care for premature infants or infants small for their gestational age, by providing healthy nutritional guidelines should be cardinal strategies for the prevention of adult HTN and CV risks later in life.

The Joint Association of Small for Gestational Age and Nighttime Sleep with Blood Pressure in Childhood

Children born small for gestational age (SGA) are more likely to develop high blood pressure. In prior studies, longer sleep duration is associated with lower BP, and SGA is associated with shorter sleep duration in childhood. We investigated whether sleep duration in early childhood modifies the association between SGA and higher childhood SBP in 1178 children recruited at birth and followed up to age 9 years. We ascertained birthweight and gestational age from medical records. We derived child sleep duration from maternal questionnaire interview. We calculated child SBP percentile according to U.S. reference data. We defined elevated SBP as SBP ≥75^th percentile. In this sample, 154 (13.1%) children were born SGA. Children born SGA had higher SBP percentiles and higher risk of elevated SBP. Among children born SGA, those in the highest compared to the lowest tertile for sleep had a 12.28 lower (−22.00, −2.57) SBP percentile and 0.44 (0.25 to 0.79) times lower risk of developing elevated SBP. Our data are consistent with an interaction between SGA and sleep duration on childhood elevated SBP (P_interaction = 0.0056). In conclusion, in this prospective birth cohort, longer sleep duration in early childhood may mitigate the blood pressure-raising effect of being born small.

Prematurity and future kidney health: the growing risk of chronic kidney disease

PURPOSE OF REVIEW

The purpose of this review is to describe the role prematurity plays in the development of chronic kidney disease (CKD) and to discuss potential reasons for this association including decreased nephron mass, as well as postnatal insults such as neonatal acute kidney injury (nAKI).

RECENT FINDINGS

New observational studies in humans and experimental studies in animal models have strengthened the association between prematurity, low birth weight and CKD. Growing evidence suggests increased susceptibility to CKD is caused by decreased nephron mass at birth. Beginning with a low nephron count may cause only subtle abnormalities during childhood, however may result in CKD, hypertension and albuminuria in adolescence or adulthood. Recent studies in premature infants reveal a high incidence of nAKI, which may also contribute to ongoing CKD risk.

SUMMARY

Children born at low birth weights (both due to prematurity and/or intrauterine growth restriction) show increased risk of kidney dysfunction during adulthood. A better understanding of the modulators of nephron mass in premature infants as well as the effects of the extrauterine environment is essential. Additionally, improved awareness of at-risk infants is important as is early evaluation and detection of kidney dysfunction, allowing interventions to slow the progression to CKD.

Ibuprofen exposure in early neonatal life does not affect renal function in young adolescence

INTRODUCTION

Ibuprofen exposure results in acute transient renal dysfunction in preterm neonates, but we are unaware of data on long-term renal safety.

METHODS

In a previously studied cohort of extreme low birth weight (ELBW, <1000 g) cases, the PREMATurity as predictor of children's Cardiovascular-renal Health study generated data on renal function (renal length, estimated glomerular filtration rate based on cystatin C (eGFR_cysC) at the age of 11 years. This data set in 93 ELBW cases may also generate data on long-term drug safety on ibuprofen. In this post hoc analysis, we linked markers of renal function in young adolescence in ELBW cases with their perinatal (prenatal maternal, setting at birth, treatment modalities including drug prescription during neonatal stay, neonatal creatinine values, postdischarge growth) characteristics, including but not limited to ibuprofen exposure during neonatal stay.

RESULTS

Ibuprofen exposure was not associated with significant differences in renal length or eGFR_cysC. Moreover, we were unable to identify any other risk factor (perinatal characteristics, postnatal creatinine trends, postdischarge growth) on renal outcome in this cohort.

CONCLUSIONS

Neonatal exposure to ibuprofen did not affect renal function. Larger studies are needed to explore the confounders of variability in renal function in former ELBW cases. This matters since ELBW relates to risk for hypertension, cardiovascular events and renal disease in later life and identification of risk factors holds the promise of secondary prevention.

TRIAL REGISTRATION NUMBER

NCT02147457.

Risk factors associated with a decreased estimated glomerular filtration rate based on cystatin C levels in school-age children with extremely low birthweight

AIM

A single centre retrospective cohort study was designed to investigate the estimated glomerular filtration rate (eGFR) in school-age children born with extremely low birthweight (ELBW) and to determine risk factors predictive of decreased eGFR.

METHODS

We compared eGFR based on cystatin C (CysC-eGFR) between school-age children born with ELBW (ELBW group, n = 48; median gestational age: 26.9 weeks; median birthweight: 792 g) and children born at term (control group, n = 48). The ELBW group was then further divided into a decreased CysC-eGFR subgroup (eGFR <90 mL/min per 1.73 m² , n = 20) and a normal CysC-eGFR subgroup (n = 28), and perinatal background factors were compared.

RESULTS

The ELBW group showed a significantly lower CysC-eGFR compared with the control group (P < 0.001). Comparison between the decreased and normal CysC-eGFR subgroups in the ELBW group showed that children with lower birthweight, shorter gestational age, lower 5-min Apgar score, longer length of mechanical ventilation, lower weight gain in the first 11 weeks, chronic lung disease, and postnatal corticosteroid administration had significantly decreased CysC-eGFR. Multivariate logistic regression showed that a lower 5-min Apgar score was the only independent risk factor for decreased CysC-eGFR.

CONCLUSIONS

CysC-eGFR might already be decreased at school age in children born with ELBW. Renal assessment in regular follow-up examinations is recommended.

Preterm birth and ventilation decrease surface density of glomerular capillaries in lambs, regardless of postnatal respiratory support mode

BACKGROUND

Prematurity is often complicated by respiratory support, including invasive mechanical ventilation (IMV) and noninvasive support (NIS). Compared with IMV, NIS reduces injury to the lung and brain. Prematurity may also disrupt glomerular architecture. Whether NIS differentially affects glomerular architecture is incompletely understood. We hypothesized that IMV would lead to greater disruption of glomerular architecture than NIS.

METHODS

This is a secondary analysis of kidneys from moderately preterm lambs delivered at ~131 d gestation (term ~150 d) that had antenatal steroid exposure and surfactant treatment before resuscitation by IMV. At ~3 h of age, half of the lambs were switched to NIS. Support was for 3 d or 21 d. Structural indices of glomerular architecture were quantified.

RESULTS

The number of glomerular generations was unaffected by moderate preterm birth and respiratory support, either IMV or NIS. At 3 d and 21 d of IMV or NIS, glomerular capillary surface density was not different. Glomerular capillary surface density was significantly lower in the inner and outer cortex compared with unventilated gestation age-matched or postnatal age-matched reference lambs.

CONCLUSION

Moderate preterm birth and invasive or noninvasive respiratory support decreases glomerular capillarization in the lamb kidney. This adverse effect on glomerular development may contribute to increased risk for adult-onset hypertension and renal dysfunction.

Biomarkers of adiposity are elevated in preterm very-low-birth-weight infants at 1, 2, and 3 y of age

BACKGROUND

Preterm, very-low-birth-weight (PT-VLBW) neonates are at-risk for metabolic syndrome later in life. At 1-3 y, they exhibit excessive weight-for-length z-scores (Wt-L_Z) and elevated systolic blood pressures (SBP). Serum adipokines are biomarkers of adiposity, but expression in PT-VLBW infants is unclear. We examined the correlation between serum adipokine levels, anthropometric measures and SBP in PT-VLBW neonates at follow-up.

METHODS

This was a cross-sectional cohort study of PT-VLBW infants at 1, 2, and 3 y of age (40/cohort). We measured SBP, abdominal circumference (AC) and anthropometrics; calculated age/gender-specific z-scores for Wt, L, Wt-L and subscapular skin fold (SS_Z), and measured serum adipokines.

RESULTS

Serum leptin was unaffected by chronologic age and gender, but was positively correlated with weight, Wt-L_Z, AC, and SS_Z at 1 and 3 y (P < 0.01). Female infants at 1 and 3 y had a more significant relationship than males between serum leptin and SS_Z (P < 0.001, R = 0.75 and P < 0.001, R = 0.70, respectively). Adiponectin levels were 16-20% lower at 3 vs. 1-2 y (P = 0.02, ANOVA) and negatively correlated with SBP.

CONCLUSION

Although serum leptin was unrelated to advancing age, gender, and SBP in PT-VLBW infants, levels correlated with measures of adiposity at 1 and 3 y, females > males, suggesting leptin resistance may occur in early infancy.

The Impact of Kidney Development on the Life Course: A Consensus Document for Action

Hypertension and chronic kidney disease (CKD) have a significant impact on global morbidity and mortality. The Low Birth Weight and Nephron Number Working Group has prepared a consensus document aimed to address the relatively neglected issue for the developmental programming of hypertension and CKD. It emerged from a workshop held on April 2, 2016, including eminent internationally recognized experts in the field of obstetrics, neonatology, and nephrology. Through multidisciplinary engagement, the goal of the workshop was to highlight the association between fetal and childhood development and an increased risk of adult diseases, focusing on hypertension and CKD, and to suggest possible practical solutions for the future. The recommendations for action of the consensus workshop are the results of combined clinical experience, shared research expertise, and a review of the literature. They highlight the need to act early to prevent CKD and other related noncommunicable diseases later in life by reducing low birth weight, small for gestational age, prematurity, and low nephron numbers at birth through coordinated interventions. Meeting the current unmet needs would help to define the most cost-effective strategies and to optimize interventions to limit or interrupt the developmental programming cycle of CKD later in life, especially in the poorest part of the world.

Complications during pregnancy and fetal development: implications for the occurrence of chronic kidney disease

INTRODUCTION

Numerous epidemiological studies indicate an inverse association between birth weight and the risk for chronic kidney disease. Areas covered: Historically, the first studies to address the developmental origins of chronic disease focused on the inverse relationship between birth weight and blood pressure. A reduction in nephron number was a consistent finding in low birth weight individuals and experimental models of developmental insult. Recent studies indicate that a congenital reduction in renal reserve in conjunction with an increase in blood pressure that has its origins in fetal life increases vulnerability to renal injury and disease. Expert commentary: Limited experimental studies have investigated the mechanisms that contribute to the developmental origins of kidney disease. Several studies suggest that enhanced susceptibility to renal injury following a developmental insult is altered by sex and age. More in-depth studies are needed to clarify how low birth weight contributes to enhanced renal risk, and how sex and age influence this adverse relationship.

Making a diagnosis of hypertension and defining treatment threshold in very low birth weight infants’ need revision?

Introduction: Recent evidence suggests that preterm birth is a possible risk factor for high blood pressure (BP) in later life. The most widely quoted blood pressure centiles for very low birth weight (VLBW, ≤1500 g birth weight) infants at corrected term gestation is based on a cohort with mostly late preterm or term infants (Zubrow curves).

Objectives: The objective of this study was to determine the clinical utility of the Zubrow curves in diagnosis of hypertension in VLBW infants at their term corrected gestational age (CGA).

Patients and Methods: In a case-control study, we compared BP in 75 VLBW infants at 40 weeks CGA (cases) to 69 full term infants admitted to neonatal intensive care unit (NICU) (controls).

Results: In spite of having lower weights, VLBW infants compared to term infants (2612.8 ± 546 vs. 3308.2 ± 373 g, P ≤ 0.001) had higher average systolic (88.8 ± 7.6 vs. 82.33 ± 8.5 mm Hg; P ≤ 0.001) and mean BP (61.2 ± 6.6 vs. 57.61 ± 6.9, P = 0.01). Although 41% (31/75) VLBW infants would have met the criteria for hypertension according to Zubrow curves only 4% (3/75) were diagnosed with hypertension.

Conclusion: Since Zubrow BP centiles were based on a heterogeneous population of infants including preterm and term infants, new BP centiles based on chronological data from VLBW infants would allow a better definition of hypertension in these infants and identify the threshold BP for initiating treatment.

The association of birth weight with cardiovascular risk factors and mental problems among Iranian school-aged children: the CASPIAN-III study

OBJECTIVE

Both high and low birth weights (HBW and LBW) are risk factors for adulthood diseases. The aim of this study was to investigate the association of birth weight with cardiovascular disease (CVD) risk factors and mental problems among Iranian school-aged children.

METHODS

This national multicenter study of school-aged children entitled CASPIAN III was conducted among 5528 students in ranging from ages 10 to 18 y. Biochemical indices and anthropometric measurements were collected. Mental health was assessed by questionnaire. To investigate the association between birth weight categories and CVD risk factors and mental problems, multivariate logistic regression was used.

RESULTS

HBW adolescents were at higher risk for elevated diastolic blood pressure (DBP) (Ptrend < 0.05), low levels of high-density lipoprotein cholesterol (HDL-C) (Ptrend < 0.05), and lower risk for general obesity (Ptrend < 0.05) compared with the LBW category. HBW had no significant association with mental problems (Ptrend > 0.05) compared with LBW adolescents. The results of regression analysis, which considered normal birth weight as the reference group, showed that LBW students had lower risk for overweight and obesity (P < 0.01), as well as higher DBP (P < 0.05) but they were at higher risk for lower levels of HDL-C (P < 0.01). Furthermore, birth-weight categories had a U-shaped relationship with mental problems and sleep disorders (P < 0.05). Risk for confusion was higher among the LBW group (P < 0.05).

CONCLUSION

Findings from this population-based study revealed a positive relation between birth weight categories and CVD risk factors. Compared with students born with normal weight, those born with HBW and LBW were at higher risk for mental problems, sleep disorders, and confusion.

Investigating the relationship between prenatal growth and postnatal outcomes: a systematic review of the literature

Theories regarding the relationship between pre- and postnatal growth and programming of health have been based on characteristics at birth, with little or no reference to the patterns of growth occurring in utero. Review of the literature to identify studies using ultrasonographically obtained fetal dimensions to track prenatal growth and relate these patterns of growth to postnatal anthropometry and cardiovascular and metabolic risk factors. Review of Medline, Scopus and Proquest for studies reporting on ultrasonographically derived estimates of fetal growth and their association with postnatal anthropometry, body composition or cardiovascular and metabolic risk factors. Quality of papers were assessed using the method developed by Downs and Black. Twenty-nine studies met the inclusion criteria, with a mean score of high quality. Twenty of the studies had follow-up in infancy, five in childhood, three in adolescence and one in adulthood. The associations observed suggest that centile tracking may occur early in pregnancy though whether this is as early as the first trimester is uncertain. The second trimester may be a critical period for the programming of blood pressure and abdominal circumference may be the most sensitive fetal dimension to indicate any programming.