Maternal responsiveness and toddler body mass index z-score: Prospective analysis of maternal and child mealtime interactions.

Responsive feeding, where parents are guided by children's hunger and satiation cues and provide appropriate structure and support for eating, is believed to promote healthier weight status. However, few studies have assessed prospective associations between observed parental feeding and toddler growth. We characterized toddler growth from 18 to 36 months and, in a subset of families, examined whether observed maternal responsiveness to toddler satiation cues and encouraging prompts to eat at 18 and 24 months were associated with toddler body mass index z-score (BMIz) from 18 to 36 months. Participants included 163 toddlers and their mothers with overweight/obesity who had participated in a lifestyle intervention during pregnancy. Anthropometrics were measured at 18, 24, and 36 months. In a subsample, mealtime interactions were recorded in families' homes at 18 (n = 77) and 24 (n = 75) months. On average, toddler BMIz remained stable from 18 to 36 months with 31.3% (n = 51) categorized with a healthy weight, 56.4% (n = 92) with at risk for overweight and 12.3% (n = 20) with overweight. Fewer maternal prompts to eat at 18 months was associated with both higher probability of having at risk for overweight/overweight (p < .05), and higher child 36-month BMIz (p = .002). Higher child weight status at 12 months was also associated with both higher probability of having at risk for overweight/overweight (p < .05), and higher child 36-month BMIz (p < .001). Neither 24-month maternal prompts nor 18 or 24 month responsiveness to satiation cues were associated with toddler BMIz. In this diverse sample, weight status was relatively stable from 18 to 36 months. Maternal prompts to eat measured earlier in toddlerhood and prior child weight status were associated with toddler BMIz.

Factorial validation analysis of the Baby and Children's Eating Behavior Questionnaires in Samoa.

Survey instruments for assessing eating behaviors in infancy and early childhood have yet to be validated among Pacific Islanders, among whom the prevalence of pediatric obesity is steadily increasing. This study aimed to evaluate Baby Eating Behavior Questionnaire (BEBQ) and Children's Eating Behavior Questionnaire (CEBQ) factor structures against data collected from mother-infant dyads in Samoa. The BEBQ was administered across two time points: approximately 2 months (mean = 2.37 [SD = 0.34]; N = 105) and 4 months postpartum (mean = 4.22 [SD = 0.44]; N = 117). The CEBQ was administered at approximately 21 months postpartum (mean = 21.45 [SD = 1.72]; N = 113). Both the original four-factor BEBQ and seven-factor CEBQ models failed to replicate in confirmatory factor analyses. BEBQ data from 2 and 4 months demonstrated acceptable fit to a nine-item, two factor model, generated by elimination of factors with low internal reliability. A series of exploratory factor analyses on CEBQ data from 21 months postpartum ultimately revealed 16-item, three-factor structure. There was little correlation between BEBQ and CEBQ scores, suggesting either that infant feeding behaviors before and after weaning are not strongly associated, or that the BEBQ and CEBQ function better in cross-sectional, rather than longitudinal analyses. Newly derived CEBQ factors raise concerns regarding whether original CEBQ items and factors were sufficiently theoretically distinct. Study results suggest that demographic and cultural differences may impact both BEBQ and CEBQ factor structure. Further qualitative research is necessary to address these issues.

A missense variant in CREBRF, rs373863828, is associated with fat-free mass, not fat mass in Samoan infants.

BACKGROUND/OBJECTIVES: In Samoa, where 80% of the adult population is living with obesity, understanding the determinants of adiposity and growth during infancy may inform prevention efforts. We examined the association of a missense variant, rs373863828, in the CREBRF gene with body composition in Samoan infants. Adults with one or more copies of the rs373863828 minor allele (A) have higher odds of obesity, based on body-mass index (BMI), but paradoxically decreased odds of diabetes compared to those without the allele. Our study may offer novel insight into the natural history and pathogenesis of this unexpected relationship. SUBJECTS/METHODS: In a prospective study, we measured body composition in early infancy, and at 2- and 4-months of age using anthropometry and dual-energy x-ray absorptiometry (DXA). We genotyped subjects at the CREBRF rs373863828 locus and compared infants with (AA/AG) and without (GG) the variant. In longitudinal analyses, we calculated the absolute change in each outcome from the early infant to the 4-month assessment, adjusting for baseline and other covariates. RESULTS: In cross-sectional analyses, there was no significant difference in infant BMI or fat mass by genotype. After adjusting for covariates, infants with the variant had 4.0 ± 1.8 g more bone mass (p = 0.026) and 210.9 ± 79.6 g more lean mass (p = 0.009) at 4-months and accumulated 176.9 ± 73.0 g more lean mass between the early infant and 4-month assessment (p = 0.017). CONCLUSIONS: The CREBRF rs373863828 minor allele (A) was not associated with increased BMI or adiposity in Samoan infants, but instead with increased lean and bone mass. Our findings suggest that lean (i.e., muscle) and bone mass accretion should be explored as pathways to explain the "protective" effect of the CREBRF variant against diabetes.

Reproductive health, obesity, and cardiometabolic risk factors among Samoan women.

OBJECTIVES: Obesity leads to deleterious effects on not only cardiovascular health but also on the reproductive health of women. We estimate the prevalence of menstrual irregularity and of polycystic ovarian syndrome (PCOS) in Samoan women, among whom obesity prevalence is extremely high. We explore the association of these reproductive health conditions with adiposity, cardiometabolic risk factors, and androgen levels. METHODS: A cross-sectional sample of Samoan women 25-39 years of age (n = 470) from a larger population-based genome-wide association study of adiposity and cardiometabolic disease was assessed for the prevalence of oligomenorrhea/amenorrhea (OM/AM) using a self-reported questionnaire. Serum androgens and anti-Müllerian hormone levels were assayed to determine hyperandrogenemia and presence of polycystic ovaries (PCO), respectively, using criterion values. PCOS was classified using NIH guidelines of having at least two of the three conditions: menstrual irregularity, hyperandrogenism, and PCO. We contrasted socio-demographic, reproductive health, and cardiometabolic risk factors between those with and without OM/AM and similarly for PCOS. RESULTS: The prevalence of OM/AM was 7.4% (95% CI: 5.1, 9.8), and women with OM/AM had significantly higher central adiposity. PCOS was estimated at 6.8% (95% CI: 4.5, 9.1), and those with PCOS were younger but had higher overall and central adiposity measures, higher triglycerides, and higher prevalence of insulin resistance than women without PCOS. CONCLUSIONS: The prevalence of menstrual irregularity and PCOS are less than hypothesized given the high levels of adiposity in this population. Nevertheless, Samoan women with menstrual irregularity and other features of PCOS have significantly poorer metabolic health.

Effect of experimental change in children's sleep duration on television viewing and physical activity.

BACKGROUND: Paediatric observational studies demonstrate associations between sleep, television viewing and potential changes in daytime activity levels. OBJECTIVE(S): To determine whether experimental changes in sleep lead to changes in children's sedentary and physical activities. METHODS: Using a within-subject counterbalanced design, 37 children 8-11 years old completed a 3-week study. Children slept their typical amount during a baseline week and were then randomized to increase or decrease mean time in bed by 1.5 h/night for 1 week; the alternate schedule was completed the final week. Children wore actigraphs on their non-dominant wrist and completed 3-d physical activity recalls each week. RESULTS: Children reported watching more television (p < 0.001) and demonstrated lower daytime actigraph-measured activity counts per epoch (p = 0.03) when sleep was decreased (compared with increased). However, total actigraph-measured activity counts accrued throughout the entire waking period were higher when sleep was decreased (and children were awake for longer) than when it was increased (p < 0.001). CONCLUSION(S): Short sleep during childhood may lead to increased television viewing and decreased mean activity levels. Although additional time awake may help to counteract negative effects of short sleep, increases in reported sedentary activities could contribute to weight gain over time.

The contribution of feeding mode to obesogenic growth trajectories in American Samoan infants.

UNLABELLED: What is already known about this subject Samoan adults are recognized for their particularly high body mass index and prevalent obesity. While Polynesians are understudied, in other populations infancy is a critical period in the development of obesity. Breastfeeding has been shown to attenuate obesity risk. What this study adds Samoan infants show remarkably rapid gain in weight but not length in early infancy resulting in a prevalence of overweight and obesity far higher than has been previously reported elsewhere. Breastfeeding is associated with slower weight gain in infancy suggesting that its protective benefits for obesity risk are generalizable outside of European-derived populations. BACKGROUND: Samoans are recognized for their particularly high body mass index and prevalent adult obesity but infants are understudied. OBJECTIVE: To examine the prevalence of overweight and obesity and determine the contribution of feeding mode to obesogenic growth trajectories in American Samoan infants. METHODS: Data were extracted from the well baby records of 795 (n = 417 male) Samoan infants aged 0-15 months. Mixed-effects growth models were used to produce individual weight and length curves. Further mixed-effects models were fitted with feeding mode (breastfed, formula- or mixed-fed) as a single observation at age 4 (±2) months. Weight and length values were converted to z-scores according to the Centers for Disease Control 2000 reference. RESULTS: At 15 months, 23.3% of boys and 16.7% of girls were obese (weight-for-length > 95th percentile). Feeding mode had a significant effect on weight and length trajectories. Formula-fed infants gained weight and length faster than breastfed infants. Formula-fed boys were significantly more likely to be obese at 15 months (38.6%) than breastfed boys (23.4%), χ(2) = 8.4, P < 0.01, odds ratio = 2.05, 95% confidence interval (1.04, 4.05). CONCLUSION: Obesity in American Samoans is not confined to adults. Obesity prevention efforts should be targeted at early life and promotion of breastfeeding may be a suitable intervention target.

Bonded stationary phases for reversed phase liquid chromatography with a water mobile phase: application to subcritical water extraction.

Reversed phase high-performance liquid chromatography (RP-HPLC) is demonstrated for hydrophobic analytes such as aromatic hydrocarbons on a chemically bonded stationary phase and a mobile phase consisting of only water. Reversed phase liquid chromatography separations using a water-only mobile phase has been termed WRP-LC for water-only reversed phase LC. Reasonable capacity factors are achieved through the use of a non-porous silica substrate resulting in a chromatographic phase volume ratio much lower than usually found in RP-HPLC. Two types of bonded WRP-LC columns have been developed and applied. A brush phase was synthesized from an organochlorosilane. The other phase, synthesized from an organodichlorosilane, is termed a branch phase and results in a polymeric structure of greater thickness than the brush phase. A baseline separation of a mixture containing benzaldehyde, benzene, toluene, and ethyl benzene in less than 5 min is demonstrated using a water mobile phase with 12 000 plates generated for the unretained benzaldehyde peak. The theoretically predicted minimum reduced plate height is also shown to be approached for the unretained analyte using the brush phase. As an application, subcritical water extraction (SWE) at 200 degrees C is combined with WRP-LC. This combination allows for the extraction of organic compounds from solid matrices immediately followed by liquid chromatographic separation of those extracted compounds all using a solvent of 100% water. We demonstrate SWE/WRP-LC by spiking benzene, ethyl benzene, and naphthalene onto sand then extracting the analytes with SWE followed by chromatographic separation on a WRP column. A sand sample contaminated with gasoline was also analyzed using SWE/WRP-LC. This extraction process also provides kinetic information about the rate of analyte extraction from the sand matrix. Under the conditions employed, analytes were extracted at different rates, providing additional selectivity in addition to the WRP-LC separation.