Faculty Bibliography

[This corrects the article DOI: 10.1371/journal.pone.0215571.].

BACKGROUND:Because of the strong link between childhood obesity and adulthood obesity comorbidities, and the difficulty in decreasing body mass index (BMI) later in life, effective strategies are needed to address this condition in early childhood. The ability to predict obesity before age five could be a useful tool, allowing prevention strategies to focus on high risk children. The few existing prediction models for obesity in childhood have primarily employed data from longitudinal cohort studies, relying on difficult to collect data that are not readily available to all practitioners. Instead, we utilized real-world unaugmented electronic health record (EHR) data from the first two years of life to predict obesity status at age five, an approach not yet taken in pediatric obesity research. METHODS AND FINDINGS/RESULTS:We trained a variety of machine learning algorithms to perform both binary classification and regression. Following previous studies demonstrating different obesity determinants for boys and girls, we similarly developed separate models for both groups. In each of the separate models for boys and girls we found that weight for length z-score, BMI between 19 and 24 months, and the last BMI measure recorded before age two were the most important features for prediction. The best performing models were able to predict obesity with an Area Under the Receiver Operator Characteristic Curve (AUC) of 81.7% for girls and 76.1% for boys. CONCLUSIONS:We were able to predict obesity at age five using EHR data with an AUC comparable to cohort-based studies, reducing the need for investment in additional data collection. Our results suggest that machine learning approaches for predicting future childhood obesity using EHR data could improve the ability of clinicians and researchers to drive future policy, intervention design, and the decision-making process in a clinical setting.

BACKGROUND:Melamine and cyanuric acid, which are currently used in a variety of common consumer products and present in foods, have been implicated in the development of urolithiasis and acute kidney injury in Chinese children. To determine whether US children have measurable concentrations of these chemicals in their bodies and whether they are at greater risk of acute kidney injury, we measured melamine and cyanuric acid exposure in a cohort of US children and determined their relationship with markers of kidney injury. METHODS:We measured urinary melamine and cyanuric acid in a convenience sample of 109 children (4 months - 8 years) from Seattle, WA and New York City, NY using liquid chromatography with tandem mass spectrometry. We measured several urinary markers of kidney injury: fatty acid binding protein 3 (FABP3), kidney injury molecule 1 (KIM1), neutrophil gelatinase-associated lipocalin (NGAL) using Luminex xMAP methods, and urine urea was measured using standard laboratory methods. We described urinary melamine and cyanuric acid concentrations and assessed predictors of the exposures. We used multivariable linear regression to assess relationships between melamine/cyanuric acid and kidney injury markers in unadjusted and adjusted (creatinine, age, sex) analyses. RESULTS:Melamine and cyanuric acid were above the limit of detection (LOD) in 78% and 95% of all samples, respectively. The mean concentrations (SD) for melamine and cyanuric acid were 27.4 ng/ml (141.9 ng/ml) and 35.3 ng/ml (42.4 ng/ml). In unadjusted analyses, we observed statistically significant increases in the percentages of FABP3 and KIM1 in relation to a one log unit change in melamine and cyanuric acid, respectively. In adjusted analyses, we observed a 55% (95% CI 0, 141) increase in KIM1 in relation to a one log unit increase in cyanuric acid. CONCLUSIONS:US children have detectable concentrations of melamine and cyanuric acid in urine, and these concentrations are higher than those reported in children from other countries. This is a novel finding that improves upon previous exposure estimates using questionnaires only and suggests widespread exposure in the population. Cyanuric acid is associated with increased KIM 1 concentrations, suggesting kidney injury. Given the potential widespread exposure, future analyses should examine melamine and cyanuric acid in relation to chronic kidney disease and markers of kidney injury in a larger cohort that is representative of the general population.

Food insecurity, or the limited access to food, has been associated with maternal child feeding styles and practices. While studies in other parenting domains suggest differential and additive impacts of poverty-associated stressors during pregnancy and infancy, few studies have assessed relations between food insecurity during these sensitive times and maternal infant feeding styles and practices. This study sought to analyze these relations in low-income Hispanic mother-infant pairs enrolled in a randomized controlled trial of an early obesity prevention program (Starting Early). Food insecurity was measured prenatally and during infancy at 10 months. Food insecurity timing was categorized as never, prenatal only, infancy only, or both. Regression analyses were used to determine relations between food insecurity timing and styles and practices at 10 months, using never experiencing food insecurity as the reference, adjusting for family characteristics and material hardships. 412 mother-infant pairs completed 10-month assessments. Prolonged food insecurity during both periods was associated with greater pressuring, indulgent and laissez-faire styles compared to never experiencing food insecurity. Prenatal food insecurity was associated with less vegetable and more juice intake. If food insecurity is identified during pregnancy, interventions to prevent food insecurity from persisting into infancy may mitigate the development of obesity-promoting feeding styles and practices.

OBJECTIVE:Prenatal maternal stresses have been associated with infant temperament patterns linked to later behavioral difficulties. Material hardships, defined as inability to meet basic needs, are important prenatal stressors. Our objective was to determine the associations between prenatal material hardships and infant temperament at 10 months. METHODS:This was a longitudinal study of mother-infant pairs in a randomized controlled trial of a primary care-based early obesity prevention program (Starting Early). Independent variables representing material hardship were: housing disrepair, food insecurity, difficulty paying bills and neighborhood stress (neighborhood safety). Dependent variables representing infant temperament were assessed using questions from three subscales of the Infant Behavior Questionnaire: orienting/regulatory capacity, negative affect, and surgency/extraversion. We used linear regression to investigate associations between individual and cumulative hardships and each temperament domain, adjusting for confounders, and testing for depression as a moderator. RESULTS:412 mother-infant pairs completed 10 month assessments. 32% reported food insecurity, 26% difficulty paying bills, 35% housing disrepair and 9% neighborhood stress. In adjusted analyses, food insecurity was associated with lower orienting/regulatory capacity scores (B=-0.25, 95% CI -0.47, -0.04), as were neighborhood stress (B=-0.50, 95% CI -0.83, -0.16) and experiencing 3-4 hardships (compared with none) (B=-0.54, 95% CI -0.83, -0.21). For neighborhood stress, the association was stronger among infants of mothers with prenatal depressive symptoms (interaction term p=0.06). CONCLUSION/CONCLUSIONS:Prenatal material hardships were associated with lower orienting/regulatory capacity. These findings support the need for further research exploring how temperament relates to child behavior, and for policies to reduce prenatal material hardships.

OBJECTIVE: To describe infant activity at 3 months old and to test the efficacy of a primary care-based child obesity prevention intervention on promoting infant activity in low-income Hispanic families. METHODS: This study was a randomized controlled trial (n = 533) comparing a control group of mother-infant dyads receiving standard prenatal and pediatric primary care with an intervention group receiving "Starting Early," with individual nutrition counseling and nutrition and parenting support groups coordinated with prenatal and pediatric visits. Outcomes included infant activity (tummy time, unrestrained floor time, time in movement-restricting devices). Health literacy was assessed using the Newest Vital Sign. RESULTS: Four hundred fifty-six mothers completed 3-month assessments. Infant activity results were: 82.6% ever practiced tummy time; 32.0% practiced tummy time on the floor; 34.4% reported unrestrained floor time; 56.4% reported >/=1 h/d in movement-restricting devices. Inadequate health literacy was associated with reduced tummy time and unrestrained floor time. The intervention group reported more floor tummy time (OR 2.16, 95% CI 1.44-3.23) and unrestrained floor time (OR 1.69, 95% CI 1.14-2.49) compared to controls. No difference in the time spent in movement-restricting devices was found. CONCLUSIONS: Tummy time and unrestrained floor time were low. Primary care-based obesity prevention programs have potential to promote these activities.