The stepwise assembly of the neonatal virome is modulated by breastfeeding.

The gut of healthy human neonates is usually devoid of viruses at birth, but quickly becomes colonized, which-in some cases-leads to gastrointestinal disorders1-4. Here we show that the assembly of the viral community in neonates takes place in distinct steps. Fluorescent staining of virus-like particles purified from infant meconium or early stool samples shows few or no particles, but by one month of life particle numbers increase to 109 per gram, and these numbers seem to persist throughout life5-7. We investigated the origin of these viral populations using shotgun metagenomic sequencing of virus-enriched preparations and whole microbial communities, followed by targeted microbiological analyses. Results indicate that, early after birth, pioneer bacteria colonize the infant gut and by one month prophages induced from these bacteria provide the predominant population of virus-like particles. By four months of life, identifiable viruses that replicate in human cells become more prominent. Multiple human viruses were more abundant in stool samples from babies who were exclusively fed on formula milk compared with those fed partially or fully on breast milk, paralleling reports that breast milk can be protective against viral infections8-10. Bacteriophage populations also differed depending on whether or not the infant was breastfed. We show that the colonization of the infant gut is stepwise, first mainly by temperate bacteriophages induced from pioneer bacteria, and later by viruses that replicate in human cells; this second phase is modulated by breastfeeding.

Cardiometabolic risk in young adults with Down syndrome.

Studies regarding cardiometabolic risk (CMR) for individuals with Down syndrome (DS) conflict. Our previous research in youth with DS, aged 10-20 years, found increased prevalence of dyslipidemia and prediabetes compared to matched peers without DS. Herein, we compare CMR in young adults with DS, aged 18-35 years, to a similar population-based sample from the 2001-2018 National Health and Nutrition Examination Survey (NHANES). The group with DS had higher NonHDL-C (mean DS 131.9 mg/dL; NHANES 126.1 p < 0.001), lower HDL-C (DS 47.5 mg/dL; NHANES 52.2 p < 0.001), higher LDL-C (DS 109.3 mg/dL; NHANES 105.4 p < 0.001), higher triglycerides (DS 102.9 mg/dL; NHANES 86.9 p < 0.001), but lower fasting glucose (DS 85.8 mg/dL; NHANES 95.2 p < 0.0001), lower HOMA-IR (DS 2.17; NHANES 2.24 p = 0.0006), lower systolic (DS 109.7 mmHg; NHANES 114.6 p < 0.0001) and lower diastolic (DS 60.9 mmHg; NHANES 67.8 p < 0.0001) blood pressures. There was relationship of higher HDL-C, triglycerides, glucose, systolic, and diastolic blood pressure with increasing BMI in the NHANES cohort which was dampened in the group with DS. These results indicate that more information is needed to guide clinicians in screening for CMR in individuals with DS.

African American mothers' perceptions of infant body size are prospectively associated with infant growth and BMI.

OBJECTIVES: The effect of mothers' perceptions of infant body size on infant growth and later BMI is poorly understood. We aimed to assess whether maternal perceptions were associated with infant BMI and weight gain and to identify factors that may influence maternal perceptions. METHODS: We analyzed data from a prospective, longitudinal study of pregnant African American women living with healthy weight (BMI < 25 kg/m2 ) or obesity (BMI ≥ 30 kg/m2 ). We collected sociodemographic, feeding mode, perceived stress, depression, and food insecurity information. The African American Infant Body Habitus Scale assessed maternal perceptions of infant body size at age 6 months. A "maternal satisfaction with infant body size" score was derived. Infant BMI z-scores (BMIZ) were calculated at 6 and 24 months. RESULTS: Maternal perception and satisfaction scores did not differ between obese (n = 148) and healthy weight (n = 132) groups. Perception of infant size at 6 months was positively associated with infant BMIZ at 6 and 24 months. A positive association of maternal satisfaction scores with change in infant BMIZ from 6 to 24 months indicated that BMIZ changed less for infants whose mothers preferred them to be smaller at 6 months. Perception and satisfaction scores were not associated with feeding variables, maternal stress, depression, socioeconomic status, or food security status. CONCLUSION: Mothers' perceptions of and satisfaction with infant size correlated with current and later infant BMI. However, mother's perceptions were not associated with maternal weight status or other factors explored for their potential to impact maternal perceptions. Further work is needed to elucidate factors linking maternal perception/satisfaction and infant growth.

Clinical Effectiveness of Elexacaftor/Tezacaftor/Ivacaftor in People with Cystic Fibrosis: A Clinical Trial.

Rationale: The cystic fibrosis (CF) modulator drug, elexacaftor/tezacaftor/ivacaftor (ETI), proved highly effective in controlled clinical trials for individuals with at least one F508del allele, which occurs in at least 85% of people with CF. Objectives: PROMISE is a postapproval study to understand the broad effects of ETI through 30 months' clinical use in a more diverse U.S. patient population with planned analyses after 6 months. Methods: Prospective, observational study in 487 people with CF age 12 years or older with at least one F508del allele starting ETI for the first time. Assessments occurred before and 1, 3, and 6 months into ETI therapy. Outcomes included change in percent predicted FEV1 (ppFEV1), sweat chloride concentration, body mass index (BMI), and self-reported respiratory symptoms. Measurements and Main Results: Average age was 25.1 years, and 44.1% entered the study using tezacaftor/ivacaftor or lumacaftor/ivacaftor, whereas 6.7% were using ivacaftor, consistent with F508del homozygosity and G551D allele, respectively. At 6 months into ETI therapy, ppFEV1 improved 9.76 percentage points (95% confidence interval [CI], 8.76 to 10.76) from baseline, cystic fibrosis questionnaire-revised respiratory domain score improved 20.4 points (95% CI, 18.3 to 22.5), and sweat chloride decreased -41.7 mmol/L (95% CI, -43.8 to -39.6). BMI also significantly increased. Changes were larger in those naive to modulators but substantial in all groups, including those treated with ivacaftor at baseline. Conclusions: ETI by clinical prescription provided large improvements in lung function, respiratory symptoms, and BMI in a diverse population naive to modulator drug therapy, using existing two-drug combinations, or using ivacaftor alone. Each group also experienced significant reductions in sweat chloride concentration, which correlated with improved ppFEV1 in the overall study population. Clinical trial registered with www.clinicaltrials.gov (NCT NCT04038047).

Infant Body Mass Index or Weight-for-Length and Risk of Undernutrition in Childhood Among Children with Cystic Fibrosis.

OBJECTIVES: To compare performance of weight-for-length and body mass index as estimators of undernutrition in children with cystic fibrosis (CF). STUDY DESIGN: We analyzed pediatric anthropometric data from the Cystic Fibrosis Foundation Patient Registry. Undernutrition was defined by weight-for-length z score (WFLZ) or body mass index z score (BMIZ) ≤-1 (15th-percentile). Group 1, reference group, consisted of subjects with both BMIZ and WFLZ >-1; group 2: BMIZ ≤-1 and WFLZ >-1; group 3: BMIZ >-1 and WFLZ ≤-1; and group 4: BMIZ and WFLZ ≤-1. Group differences in length-for-age-Z across ages 2-24 months were tested using generalized estimating equations. The association of group at age 2 months with BMIZ <-1 at age 6 years was tested using logistic regression adjusted for demographic and disease characteristics. RESULTS: Overall, 163 482 anthropometric measurements were available from 12 640 individuals, of whom 16.8% were discordant for undernutrition status at age 2 months. Discordance (1.5%-10%) was less common with increasing age. Length-for-age-Z was lower in group 2 than group 1 and group 3 between birth and 24 months (P < .05). Odds of WFLZ-defined undernourished at 2 months were lower for shorter individuals (OR 1.5, CI 1.4-1.6, P < .001). Undernutrition risk at age 6 years was greater for group 2 vs group 3 (OR 1.9 vs 1.0, P < .001). CONCLUSIONS: Infants with cystic fibrosis classified as undernourished by BMIZ, but not WFLZ, had greater risk of undernourished status later in childhood. Infants with low BMIZ but normal WFLZ tended to be shorter, suggesting BMIZ may better capture undernourished status than WFLZ in shorter infants.

Endocrine-sensitive physical endpoints in newborns: ranges and predictors.

BACKGROUND: In neonates, endocrine-sensitive physical endpoints, including breast and reproductive tissues, may reflect effects of fetal environmental exposure. Studies using standardized measurement techniques that describe demographic and clinical variability in these endpoints are lacking. METHODS: Three hundred and eighty-eight healthy term newborns <3 days old were evaluated, 69% African American and 25% White. Measures included breast bud diameter, anogenital distance (AGD), stretched penile length (SPL), and testicular volume (TV). RESULTS: Breast buds were larger in females than males bilaterally (right: 13.0 ± 4.0 vs. 12.0 ± 4.0 mm, p = 0.008; left: 13.0 ± 4.0 vs. 11.0 ± 3.0 mm, p < 0.001). Breast bud size correlated positively with gestational age (regression coefficient = 0.46 ± 0.12 mm, p < 0.001) and weight Z-score (0.59 ± 0.24 mm, p = 0.02), and negatively with White race (-1.00 ± 0.30 mm, p = 0.001). AGD was longer in males (scrotum-to-anus) than females (fourchette-to-anus) (21.0 ± 4.0 vs. 13.0 ± 2.0 mm, p < 0.001) and did not differ by race. SPL was shorter in White infants (35.0 ± 5.0 vs. 36.0 ± 5.0 mm, p = 0.04). Median TV was 0.5 cm3, and larger in White males (odds ratio 1.71, 95% confidence interval: 1.02-2.88) CONCLUSIONS: This study provides a range of physical measurements of endocrine-sensitive tissues in healthy infants from the United States, and the associations with demographic and clinical characteristics. IMPACT: This study reports physical measurements for endocrine-sensitive endpoints in healthy US newborns, including breast buds, AGD, SPL, and TV. Associations of measurements to demographic and clinical factors (including race, gestational age, and newborn length and weight) are presented. Contemporary ranges and identification of predictive factors will support further study on effects of pre- and postnatal exposures to endocrine-sensitive tissues in the infant.

Genetic potential and height velocity during childhood and adolescence do not fully account for shorter stature in cystic fibrosis.

BACKGROUND: Despite improved health, shorter stature is common in cystic fibrosis (CF). We aimed to describe height velocity (HV) and contribution of height-related genetic variants to height (HT) in CF. METHODS: HV cohort: standard deviation scores (-Z) for HT, mid-parental height-adjusted HT (MPAH), and HV were generated using our Pediatric Center's CF Foundation registry data. HV-Z was compared with population means at each age (5-17 y), the relationship of HV-Z with HT-Z assessed, and HT-Z compared with MPAH-Z. GRS cohort: HT genetic risk-Z (HT-GRS-Z) were determined for pancreatic exocrine sufficient (PS) and insufficient (PI) youth and adults from our CF center and their relationships with HT-Z assessed. RESULTS: HV cohort: average HV-Z was normal across ages in our cohort but was 1.5× lower (p < 0.01) for each SD decrease in HT-Z. MPAH-Z was lower than HT-Z (p < 0.001). GRS cohort: HT-GRS-Z more strongly correlated with HT-Z and better explained height variance in PS (rho = 0.42; R2= 0.25) vs. PI (rho = 0.27; R2 = 0.11). CONCLUSIONS: Despite shorter stature compared with peers and mid-parental height, youth with CF generally have normal linear growth in mid- and late childhood. PI tempered the heritability of height. These results suggest that, in CF, final height is determined early in life in CF and genetic potential is attenuated by other factors. IMPACT: Children with CF remain shorter than their healthy peers despite advances in care. Our study demonstrates that children with CF have persistent shorter stature from an early age and fail to reach their genetic potential despite height velocities comparable to those of average maturing healthy peers and similar enrichment in known height increasing single-nucleotide polymorphisms (SNPs). Genetic risk scores better explained variability in pancreatic sufficient than in pancreatic insufficient individuals, suggesting that other modifying factors are in play for pancreatic insufficient individuals with CF. Given the CF Foundation's recommendation to target not only normal body mass index, but normal height percentiles as well, this study adds valuable insight to this discussion.

Real-world treatment escalation from metformin monotherapy in youth-onset Type 2 diabetes mellitus: A retrospective cohort study.

BACKGROUND: Due to high rates of comorbidities and rapid progression, youth with Type 2 diabetes may benefit from early and aggressive treatment. However, until 2019, the only approved medications for this population were metformin and insulin. OBJECTIVE: To investigate patterns and predictors of treatment escalation within 5 years of metformin monotherapy initiation for youth with Type 2 diabetes in clinical practice. SUBJECTS: Commercially-insured patients with incident youth-onset (10-18 years) Type 2 diabetes initially treated with metformin only. METHODS: Retrospective cohort study using a patient-level medical claims database with data from 2000 to 2020. Frequency and order of treatment escalation to insulin and non-insulin antihyperglycemics were determined and categorized by age at diagnosis. Cox proportional hazards regression was used to evaluate potential predictors of treatment escalation, including age, sex, race/ethnicity, comorbidities, complications, and metformin adherence (medication possession ratio ≥ 0.8). RESULTS: The cohort included 829 (66% female; median age at diagnosis 15 years; 19% Hispanic, 17% Black) patients, with median 2.9 year follow-up after metformin initiation. One-quarter underwent treatment escalation (n = 207; 88 to insulin, 164 to non-insulin antihyperglycemic). Younger patients were more likely to have insulin prescribed prior to other antihyperglycemics. Age at diagnosis (HR 1.14, 95% CI 1.07-1.21), medication adherence (HR 4.10, 95% CI 2.96-5.67), Hispanic ethnicity (HR 1.83, 95% CI 1.28-2.61), and diabetes-related complications (HR 1.78, 95% CI 1.15-2.74) were positively associated with treatment escalation. CONCLUSIONS: In clinical practice, treatment escalation for pediatric Type 2 diabetes differs with age. Off-label use of non-insulin antihyperglycemics occurs, most commonly among older adolescents.

Association between prediabetes diagnosis and body mass index trajectory of overweight and obese adolescents.

BACKGROUND: Prediabetes awareness in adults has been associated with improved weight management. Whether youth with prediabetes diagnosis experience similar improvements is unknown. OBJECTIVE: To investigate the association between prediabetes identification and body mass index (BMI) trajectory in overweight and obese adolescents. SUBJECTS: Youth who were followed longitudinally in a large academic-affiliated primary care network and who were overweight/obese while 10 to 18 years old. METHODS: Retrospective cohort study. Subjects were categorized as "screened" if at least 1 hemoglobin A1c (HbA1c) result was available. Time series analysis was used to determine the difference in difference (DID) in BMI Z-score (BMI-Z) slope before and after HbA1c between: (a) screened youth found to have prediabetes-range HbA1c (5.7%-6.4%, 39-46 mmol/mol) versus normal HbA1c and (b) screened versus age-matched unscreened obese youth. RESULTS: A total of 4184 (55.6% female) screened subjects (median follow-up 9.7 years) were included. In which, 637 (15.2%) had prediabetes-range HbA1c. Prediabetes was associated with a greater decrease in BMI-Z slope than normal HbA1c (DID: -0.023/year [95% CI: -0.042 to -0.004]). When compared to age-matched unscreened subjects (n = 2087), screened subjects (n = 2815) experienced a greater decrease in BMI-Z slope after HbA1c than unscreened subjects at a matched age (DID: -0.031/y [95% CI -0.042 to -0.021]). CONCLUSIONS: BMI-Z trajectory improved more among youth with prediabetes-range HbA1c but also stabilized in screened youth overall. Prospective studies are needed to identify provider- and patient-level drivers of this observation.

Islet Hormone and Incretin Secretion in Cystic Fibrosis after Four Months of Ivacaftor Therapy.

RATIONALE: Diabetes is associated with worse cystic fibrosis (CF) outcomes. The CFTR potentiator ivacaftor is suggested to improve glucose homeostasis in individuals with CF. OBJECTIVES: To test the hypothesis that clinically indicated ivacaftor would be associated with improvements in glucose tolerance and insulin and incretin secretion. METHODS: Oral glucose tolerance tests, mixed-meal tolerance tests, and glucose-potentiated arginine tests were compared preivacaftor initiation and 16 weeks postivacaftor initiation in CF participants with at least one CFTR gating or conductance mutation. Meal-related 30-minute (early phase) and 180-minute incremental area under the curves were calculated as responses for glucose, insulin, C-peptide, and incretin hormones; glucagon-like peptide-1; and glucose-dependent insulinotropic polypeptide. First-phase insulin secretion, glucose potentiation of arginine-induced insulin secretion, and disposition index were characterized by glucose-potentiated arginine stimulation tests. MEASUREMENTS AND MAIN RESULTS: Twelve subjects completed the study: six male/six female; seven normal/five abnormal glucose tolerance (oral glucose tolerance test 1-h glucose ≥155 and 2-h glucose <200 mg/dl); of median (minimum-maximum) age (13.8 yr [6.0-42.0]), body mass index-Z of 0.66 (-2.4 to 1.9), and FEV1% predicted of 102 (39-122). Glucose tolerance normalized in one abnormal glucose tolerance subject. Ivacaftor treatment did not alter meal responses except for an increase in early phase C-peptide (P = 0.04). First-phase (P = 0.001) and glucose potentiation of arginine-induced (P = 0.027) insulin secretion assessed by acute C-peptide responses improved after ivacaftor treatment. Consistent with an effect on ß-cell function, the disposition index relating the amount of insulin secreted for insulin sensitivity also improved (P = 0.04). CONCLUSIONS: Insulin secretion improved following 4 months of clinically indicated ivacaftor therapy in this relatively young group of patients with CF with normal to mildly impaired glucose tolerance, whereas incretin secretion remained unchanged.

A Multidisciplinary Approach to Pretransplant and Posttransplant Management of Cystic Fibrosis-Associated Liver Disease.

Approximately 5%-10% of patients with cystic fibrosis (CF) will develop advanced liver disease with portal hypertension, representing the third leading cause of death among patients with CF. Cystic fibrosis with advanced liver disease and portal hypertension (CFLD) represents the most significant risk to patient mortality, second only to pulmonary or lung transplant complications in patients with CF. Currently, there is no medical therapy to treat or reverse CFLD. Liver transplantation (LT) in patients with CFLD with portal hypertension confers a significant survival advantage over those who do not receive LT, although the timing in which to optimize this benefit is unclear. Despite the value and efficacy of LT in selected patients with CFLD, established clinical criteria outlining indications and timing for LT as well as disease-specific transplant considerations are notably absent. The goal of this comprehensive and multidisciplinary report is to present recommendations on the unique CF-specific pre- and post-LT management issues clinicians should consider and will face.

Cross-Sectional Study of Arterial Stiffness in Adolescents with Down Syndrome.

OBJECTIVES: To test whether youth with Down syndrome have aortic stiffness indices, as measured by pulse wave velocity (PWV), that differ from youth without Down syndrome and to compare reference-based age-adjusted (age-PWV-Z) and height-adjusted (Ht-PWV-Z) in youth with and without Down syndrome. STUDY DESIGN: Cross-sectional study of PWV in 129 adolescents with Down syndrome and 97 youth of comparable age, sex, race/ethnicity, and body mass index (BMI). PWV, age-PWV-Z, and Ht-PWV-Z were compared. Regression models were developed to test for associations with PWV. RESULTS: Youth with Down syndrome and controls were comparable in BMI-Z (1.4 [-1.5 to 2.8] vs 1.2 [-2.0 to 2.8], P = .57) but not Ht-Z (-2.3 [-4.7 to 0.8] vs 0.4 [-2.0 to 2.6], P < .0001). PWV (m/s, 5.0 [3.1-7.9] vs 5.0 [3.6-8.0], P = .5) and mean arterial pressure (MAP, mm Hg) (78 [61-102] vs 74 [64-97], P = .09) were not different between groups. In adjusted analyses confined to Down syndrome, PWV was associated only with BMI, but not age, black race, or MAP (R2 = 0.11). In contrast, BMI, age, black race, and MAP were all positively associated with and better explained PWV in controls (R2 = 0.50). PWV was not associated with height in youth with or without Down syndrome. Although age-PWV-Z was not different in Down syndrome (-0.36 [-2.93 to 3.49]) vs -0.15 [-2.32 to 3.22]), Ht-PWV-Z was greater in Down syndrome (0.32 [-2.28 to 4.07] vs -0.08 [-2.64 to 2.64], P = .002), and Ht-PWV-Z was greater than age-PWV-Z in Down syndrome (P < .0001). CONCLUSIONS: The lack of relationship of PWV, an independent predictor of adult cardiovascular events, with its traditional determinants including MAP suggests Down syndrome-specific phenomena may alter such relationships in this population. In youth with Down syndrome, Ht-adjusted PWV may overestimate aortic stiffness. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01821300.

Body Mass Index Is a Better Indicator of Body Composition than Weight-for-Length at Age 1 Month.

OBJECTIVE: To assess whether body mass index (BMI) provides a better assessment of measured adiposity at age 1 month compared with weight-for-length (WFL). STUDY DESIGN: Participants were healthy term-born infants in the Infant Growth and Microbiome (n = 146) and the Baby Peas (n = 147) studies. Length, weight, and body composition by air displacement plethysmography were measured at 1 month. World Health Organization-based WFL and BMI z-scores were calculated. Within-cohort z-scores of percent fat-Z, fat mass-Z, fat mass/length2-Z, fat mass/length3-Z, fat-free mass-Z, and fat-free mass/length2-Z were calculated. Correlation and multiple linear regression (adjusted for birth weight) analyses tested the associations between body composition outcomes and BMI-Z vs WFL-Z. Quantile regression was used to test the stability of these associations across the distribution of body compositions. RESULTS: The sample was 52% female and 56% African American. Accounting for birth weight, both BMI-Z and WFL-Z were strongly associated with fat mass-Z (coefficients 0.56 and 0.35, respectively), FM/L2-Z (0.73 and 0.51), and FM/L3-Z (0.79 and 0.58), with stronger associations for BMI-Z compared with WFL-Z (P < .05). Even after accounting statistically for birth weight, BMI-Z was persistently more strongly associated than WFL-Z with body composition outcomes across the distribution of body composition outcomes. CONCLUSIONS: We demonstrate in 2 distinct cohorts that BMI is a better indicator of adiposity in early infancy compared with WFL. Our findings support the preferred use of BMI for growth and nutritional status assessment in infancy.

Prevalence of unsuspected abnormal echocardiograms in adolescents with down syndrome.

The purpose of this article is to describe the prevalence of cardiac disease previously undiagnosed in healthy asymptomatic children and adolescents with Down syndrome (DS). Subjects with DS ages 10-20 years were recruited from two sites, the Children's Hospital of Philadelphia (Philadelphia, PA) and Children's National Health System (Washington, DC) for a cross-sectional study of body composition and cardiometabolic risk. Echocardiographic and clinical data were collected from patients enrolled in the parent study of cardiometabolic risk. Nine (6%) new cardiac diagnoses were identified out of 149 eligible patients. All new findings resulted in outpatient referrals to pediatric cardiology. Current guidelines recommend screening all newborns with DS for congenital heart disease. Older patients with DS may benefit from rescreening.

Relationships of Body Composition to Cardiac Structure and Function in Adolescents With Down Syndrome are Different than in Adolescents Without Down Syndrome.

Median survival in Down syndrome (DS) is 60 years, but cardiovascular disease risk and its markers such as left ventricular mass (LVM) have received limited attention. In youth, LVM is typically scaled to height2.7 as a surrogate for lean body mass (LBM), the strongest predictor of LVM, but whether this algorithm applies to DS, a condition which features short stature, is unknown. To examine the relationships of LVM and function with height, LBM, and moderate-to-vigorous physical activity(MVPA) in DS, DS youth aged 10-20 years, and age-, sex-, BMI-, race-matched nonDS controls underwent echocardiography for LVM, ejection fraction (EF), and left ventricular diastolic function (measured as E/E'); dual-energy X-ray absorptiometry (DXA)-measured LBM; accelerometry for MVPA. (DS vs. nonDS median [min-max]): DS had lower height (cm) (144.5 [116.7-170.3] vs. 163.3 [134.8-186.7]; p < 0.0001); LBM (kg) (33.48 [14.5-62.3] vs 41.8 [18.07-72.46], p < 0.0001); and LVM (g) (68.3 [32.1-135] vs 94.0 [43.9-164.6], p < 0.0001); similar EF (%) (65 [54-77] vs 64 [53-77], p = 0.59); and higher E/E' (8.41 [5.54-21.4] vs 5.81 [3.44-9.56], p < 0.0001). In height2.7-adjusted models, LVM was lower in DS (ß = - 7.7, p = 0.02). With adjustment for LBM, LVM was even lower in DS (ß = - 15.1, p < 0.0001), a finding not explained by MVPA. E/E' remained higher in DS after adjustment for age, height, HR, SBP, and BMI (ß = 2.6, p < 0.0001). DS was associated with stiffer left ventricles and lower LVM, the latter magnified with LBM adjustment. Scaling to height2.7, the traditional approach for assessing LVM in youth, may underestimate LVM differences in DS. Whether lower LVM and diastolic function are intrinsic to DS, pathologic, or protective remains unknown.Clinical Trial Registration: NCT01821300.

Assessment of the efferent auditory system in children with suspected auditory processing disorder: the Middle ear muscle reflex and contralateral inhibition of OAEs.

OBJECTIVE: To determine whether children aged 7 to 12 years with listening difficulties show objective evidence for efferent auditory function based on measurements of medial olivo-cochlear and middle ear muscle reflexes. DESIGN: Click-evoked otoacoustic emissions recorded with and without contralateral broadband noise and ipsilateral and contralateral tonal (1000, 2000 Hz) middle ear muscle reflex thresholds were examined. STUDY SAMPLE: 29 children diagnosed with suspected auditory processing disorder (APD) and a control group of 34 typically developing children participated in this study. RESULTS: Children with suspected APD had poorer performance on auditory processing tests than the control group. Middle ear muscle reflex thresholds were significantly higher at 2000 Hz in the suspected APD group for contralateral stimulation. MOC inhibition effects did not differ between APD and control groups. CONCLUSIONS: This research supports earlier studies showing altered acoustic reflexes in children with APD. No group differences were found for the MOC reflex measures, consistent with some earlier studies in children with APD.

Long-Term Parathyroid Hormone 1-34 Replacement Therapy in Children with Hypoparathyroidism.

OBJECTIVE: To determine whether multiple daily injections of parathyroid hormone (PTH) 1-34 are safe and effective as long-term therapy for children with hypoparathyroidism. STUDY DESIGN: Linear growth, bone accrual, renal function, and mineral homeostasis were studied in a long-term observational study of PTH 1-34 injection therapy in 14 children. METHODS: Subjects were 14 children with hypoparathyroidism attributable to autoimmune polyglandular syndrome type 1 (N = 5, ages 7-12 years) or calcium receptor mutation (N = 9, ages 7-16 years). Mean daily PTH 1-34 dose was 0.75 ± 0.15 µg/kg/day. Treatment duration was 6.9 ± 3.1 years (range 1.5-10 years). Patients were evaluated semiannually at the National Institutes of Health Clinical Center. RESULTS: Mean height velocity and lumbar spine, whole body, and femoral neck bone accretion velocities were normal throughout the study. In the first 2 years, distal one-third radius bone accrual velocity was reduced compared with normal children (P < .003). Serum alkaline phosphatase correlated with PTH 1-34 dose (P < .006) and remained normal (235.3 ± 104.8 [SD] U/L, N: 51-332 U/L). Mean serum and 24-hour urine calcium levels were 2.05 ± 0.11 mmol/L (N: 2.05-2.5 mmol/L) and 6.93 ± 1.3 mmol/24 hour (N: 1.25-7.5 mmol/24 hour), respectively-with fewer high urine calcium levels vs baseline during calcitriol and calcium treatment (P < .001). Nephrocalcinosis progressed in 5 of 12 subjects who had repeated renal imaging although renal function remained normal. CONCLUSIONS: Twice-daily or thrice-daily subcutaneous PTH 1-34 injections provided safe and effective replacement therapy for up to 10 years in children with hypoparathyroidism because of autoimmune polyglandular syndrome type 1 or calcium receptor mutation.

ß-Cell secretory defects are present in pancreatic insufficient cystic fibrosis with 1-hour oral glucose tolerance test glucose ≥155 mg/dL.

BACKGROUND: Patients with pancreatic insufficient cystic fibrosis (PI-CF) meeting standard criteria for normal glucose tolerance display impaired ß-cell secretory capacity and early-phase insulin secretion defects. We sought evidence of impaired ß-cell secretory capacity, a measure of functional ß-cell mass, among those with early glucose intolerance (EGI), defined as 1-hour oral glucose tolerance test (OGTT) glucose ≥155 mg/dL (8.6 mmol/L). METHODS: A cross-sectional study was conducted in the Penn and CHOP Clinical & Translational Research Centers. PI-CF categorized by OGTT as normal (PI-NGT: 1-hour glucose <155 mg/dL and 2-hour <140 mg/dL [7.8 mmol/L]; n = 13), PI-EGI (1-hour ≥155 mg/dL and 2-hour <140 mg/dL; n = 13), impaired (PI-IGT: 2-hour ≥140 and <200 mg/dL [11.1 mmol/L]; n = 8), and diabetic (cystic fibrosis-related diabetes, CFRD: 2-hour ≥200 mg/dL; n = 8) participated. Post-prandial glucose tolerance and insulin secretion, and ß-cell secretory capacity and demand were derived from mixed-meal tolerance tests (MMTTs), and glucose-potentiated arginine (GPA) tests, respectively. RESULTS: PI-EGI had elevated post-prandial glucose with reduced early-phase insulin secretion during MMTT compared to PI-NGT (P < .05). PI-EGI also exhibited impaired acute insulin and C-peptide responses to GPA (P < .01 vs PI-NGT), measures of ß-cell secretory capacity. Proinsulin secretory ratios were higher under hyperglycemic clamp conditions in PI-IGT and CFRD (P < .05 vs PI-NGT), and correlated with 1-hour glucose in PI-CF (P < .01). CONCLUSIONS: PI-CF patients with 1-hour OGTT glucose ≥155 mg/dL already manifest impaired ß-cell secretory capacity with associated early-phase insulin secretion defects. Avoiding hyperglycemia in patients with EGI may be important for preventing excessive insulin demand indicated by disproportionately increased proinsulin secretion.

A trans-ethnic genome-wide association study identifies gender-specific loci influencing pediatric aBMD and BMC at the distal radius.

Childhood fractures are common, with the forearm being the most common site. Genome-wide association studies (GWAS) have identified more than 60 loci associated with bone mineral density (BMD) in adults but less is known about genetic influences specific to bone in childhood. To identify novel genetic factors that influence pediatric bone strength at a common site for childhood fractures, we performed a sex-stratified trans-ethnic genome-wide association study of areal BMD (aBMD) and bone mineral content (BMC) Z-scores measured by dual energy X-ray absorptiometry at the one-third distal radius, in a cohort of 1399 children without clinical abnormalities in bone health. We tested signals with P < 5 × 10(-6) for replication in an independent, same-age cohort of 486 Caucasian children. Two loci yielded a genome-wide significant combined P-value: rs7797976 within CPED1 in females [P = 2.4 × 10(-11), ß =- 0.30 standard deviations (SD) per T allele; aBMD-Z] and rs7035284 at 9p21.3 in males (P = 1.2 × 10(-8), ß = 0.28 SD per G allele; BMC-Z). Signals at the CPED1-WNT16-FAM3C locus have been previously associated with BMD at other skeletal sites in adults and children. Our result at the distal radius underscores the importance of this locus at multiple skeletal sites. The 9p21.3 locus is within a gene desert, with the nearest gene flanking each side being MIR31HG and MTAP, neither of which has been implicated in BMD or BMC previously. These findings suggest that genetic determinants of childhood bone accretion at the radius, a skeletal site that is primarily cortical bone, exist and also differ by sex.

Caregiver-Reported Quality of Life in Youth with Down Syndrome.

OBJECTIVES: To describe caregiver-reported quality of life (QOL) in youth with Down syndrome (DS) and to examine the role of obesity on QOL. STUDY DESIGN: Caregivers of youth with and without DS aged 10 through 20 years completed questionnaires examining QOL (Pediatric Quality of Life Questionnaire) and weight-related QOL (Impact of Weight on Quality of Life - Kids). Age- and sex-specific z scores were generated for body mass index. Obesity was defined as a body mass index ≥95th percentile for age and sex. RESULTS: Caregiver-reported Total QOL, Physical Health, and Psychosocial Health summary scores were all lower in the DS group compared with the non-DS controls (P < .001). Social and School Functioning were also lower (P < .001), but Emotional Functioning did not differ between DS and non-DS groups (P = .31). Physical Functioning (P = .003) and Total scores (P = .03) differed between youth without DS with and without obesity, but no differences were reported between youth with DS with and without obesity. On the Impact of Weight on Quality of Life - Kids, caregivers of youth with DS reported greater Body Esteem (P = .020) and Social Life scores (P = .03) than caregivers of non-DS youth. Caregivers of youth with obesity, regardless of DS status, reported significantly lower weight-specific QOL scores than caregivers of youth without obesity. CONCLUSION: Caregivers reported lower QOL in youth with DS compared with youth without DS with the exception of emotional functioning. Obesity influences most domains of weight-related QOL in youth with and without DS; therefore, providers should address weight concerns in youth with obesity even in the presence of DS. CLINICAL TRIAL REGISTRATION: NCT01821300.