Characterization of per- and polyfluoroalkyl substances (PFAS) concentrations in a community-based sample of infants from Samoa

Per- and polyfluoroalkyl substances (PFAS) are persistent contaminants with documented harmful health effects. Despite increasing research, little attention has been given to studying PFAS contamination in low- and middle-income countries, including Samoa. Using data and biosamples collected through the Foafoaga o le Ola ("Beginning of Life") Study, which recruited a sample of mothers and infants from Samoa, we conducted an exploratory study to describe concentrations of 40 PFAS analytes in infant cord blood collected at birth (n = 66) and infant dried blood spots (DBS) collected at 4 months post-birth (n = 50). Of the 40 PFAS analytes tested, 19 were detected in cord blood, with 10 detected in >50% of samples (PFBA, PFPeA, PFOA, PFNA, PFDA, PFUnA, PFTrDA, PFHxS, PFOS, and 9Cl-PF3ONS); and 12 analytes were detected in DBS, with 3 detected in >50% of samples (PFBA, PFHxS, and PFOS). PFAS concentrations were generally lower than those reported in existing literature, with the exception of PFHxS, which was detected at higher concentrations. In cord blood, we noted suggestive (p < 0.05) or significant (p < 0.006) associations between higher PFHxS and male sex; higher PFPeA and residence in Northwest 'Upolu (NWU) compared to the Apia Urban Area (AUA); lower PFUnA and 9Cl-PF3ONS and greater socioeconomic resources; lower PFOA and higher parity; higher PFDA and higher maternal age; and lower PFUnA, PFTrDA, and 9Cl-PF3ONS and higher maternal BMI. In DBS, we found suggestive (p < 0.05) or significant (p < 0.025) associations between lower PFBA and residence in NWU versus AUA; lower PFBA and PFHxS and higher maternal age; and higher PFBA and higher maternal BMI. Finally, we observed associations between nutrition source at 4 months and DBS PFBA and PFHxS, with formula- or mixed-fed infants having higher concentrations compared to exclusively breastfed infants. This study represents the first characterization of PFAS contamination in Samoa. Additional work in larger samples is needed to identify potentially modifiable determinants of PFAS concentrations, information that is critical for informing environmental and health policy measures.

Characterization of Per- and Polyfluoroalkyl Substance (PFAS) concentrations in a community-based sample of infants from Samoa

Per- and polyfluoroalkyl substances (PFAS) are persistent contaminants with documented harmful health effects. Despite increasing research, little attention has been given to studying PFAS contamination in low- and middle-income countries, including Samoa, where there is more recent modernization and potential window to examine earlier stages of PFAS exposure and consequences. Using data and biosamples collected through the Foafoaga o le Ola ("Beginning of Life") Study, which recruited a sample of mothers and infants from Samoa, we conducted an exploratory study to describe concentrations of 40 PFAS analytes in infant cord blood collected at birth (n=66) and dried blood spots (DBS) collected at 4 months post-birth (n=50). Of the 40 PFAS analytes tested, 19 were detected in cord blood, with 11 detected in >10% of samples (PFBA, PFPeA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFTrDA, PFHxS, PFOS, and 9Cl-PF3ONS); 12 analytes were detected in DBS, with 3 detected in >10% of samples (PFBA, PFHxS, and PFOS). PFAS concentrations were generally lower than those reported in existing literature, with the exception of PFHxS, which was detected at higher concentrations. In cord blood, we noted associations between higher PFHxS and male sex, higher PFPeA and residence in Northwest 'Upolu (NWU) compared to the Apia Urban Area (AUA), and lower PFUnA and 9Cl-PF3ONS with greater socioeconomic resources. In DBS, we found associations between higher PFBA and greater socioeconomic resources, and between lower PFBA and PFHxS and residence in NWU versus AUA. However, the latter association did not hold when controlling for socioeconomic resources. Finally, we observed associations between nutrition source at 4 months and DBS PFBA and PFHxS, with formula- or mixed-fed infants having higher concentrations compared to exclusively breastfed infants. This study presents the first evidence of PFAS contamination in Samoa. Additional work in larger samples is needed to identify potentially modifiable determinants of PFAS concentrations, information that is critical for informing environmental and health policy measures.

Preterm birth among Pacific Islanders in the United States and the US-affiliated Pacific Islands: A systematic review and meta-analysis

OBJECTIVE

To better understand the epidemiology of preterm birth among Pacific Islanders in the United States and the US-Affiliated Pacific Islands.

METHODS

Systematic searches of MEDLINE, Embase, CINAHL, PsycINFO, two nonindexed regional journals, and gray literature were conducted and finalized in September 2021. Observational studies published since January 2010 that documented preterm birth outcomes among Pacific Islanders in the United States and the US-Affiliated Pacific Islands were eligible for inclusion. Outcomes of interest included preterm birth prevalence, risk compared with white women, and risk factors for preterm birth among Pacific Islanders.

RESULTS

Fourteen of the 3183 screened articles were included in meta-analyses. Random-effects models were used for pooled estimates with 95% confidence intervals. The pooled prevalence of preterm birth among Pacific Islanders was 11.2%, 95% CI: 9.3%-13.6%. Marshallese women had the highest pooled prevalence (20.7%, 95% CI 18.6%-23.0%) among Pacific Islander subgroups. Compared with white women, Pacific Islander women had higher odds of experiencing preterm birth (OR = 1.40, 95% CI: 1.28-1.53). Four risk factors for preterm birth could be explored with the data available: hypertension, diabetes, smoking, and pre-pregnancy body mass index; hypertension and diabetes significantly increased the odds of preterm birth.

CONCLUSIONS

Existing literature suggests that United States Pacific Islanders were more likely to experience preterm birth than white women, although the pooled prevalence varied by Pacific Islander subgroup. Data support the need for disaggregation of Pacific Islanders in future research and argue for examination of subgroup-specific outcomes to address perinatal health disparities.

Cross-sectional and prospective associations between household socioeconomic resources, appetite traits, and body size among Samoan infants

In high-income countries, household socioeconomic resources (as measured by education, occupation, income, and/or household assets) and childhood obesity risk tend to be negatively associated. This association may arise in part because children from households with fewer resources are exposed to obesogenic environments that shape appetite trait development. In contrast, many low- and middle-income countries (LMICs) exhibit a positive association between socioeconomic resources and child body size. There is less evidence from LMIC settings about when during development this association emerges and whether appetite traits play a mediatory role. To explore these questions, we examined cross-sectional and longitudinal associations between socioeconomic resources, appetite traits, and body size among infants in Samoa, an LMIC in Oceania. Data were from the Foafoaga O le Ola prospective birth cohort of 160 mother-infant dyads. Appetite traits were characterized using the Baby and Child Eating Behavior Questionnaires and household socioeconomic resources were quantified using an asset-based measure. While infant body size and household socioeconomic resources were positively associated in both cross-sectional and prospective analyses, we found no evidence that appetite traits mediate this relationship. These results suggest that other aspects of the food environment, such as food security and feeding style, may explain the positive association between socioeconomic resources and body size observed in many LMICs.

How much does it cost to implement the Baby-Friendly Hospital Initiative training step in the United States and Mexico?

The Baby-Friendly Hospital Initiative (BFHI) has been shown to increase breastfeeding rates, improving maternal and child health and driving down healthcare costs via the benefits of breastfeeding. Despite its clear public health and economic benefits, one key challenge of implementing the BFHI is procuring funding to sustain the program. To address this need and help healthcare stakeholders advocate for funds, we developed a structured method to estimate the first-year cost of implementing BFHI staff training, using the United States (US) and Mexico as case studies. The method used a hospital system-wide costing approach, rather than costing an individual hospital, to estimate the average per birth BFHI staff training costs in US and Mexican hospitals with greater than 500 annual births. It was designed to utilize publicly available data. Therefore, we used the 2014 American Hospital Association dataset (n = 1401 hospitals) and the 2018 Mexican Social Security Institute dataset (n = 154 hospitals). Based on our review of the literature, we identified three key training costs and modelled scenarios via an econometric approach to assess the sensitivity of the estimates based on hospital size, level of obstetric care, and training duration and intensity. Our results indicated that BFHI staff training costs ranged from USD 7.27–125.39 per birth in the US and from PPP 2.68–6.14 per birth in Mexico, depending on hospital size and technological capacity. Estimates differed between countries because the US had more hospital staff per birth and higher staff salaries than Mexico. Future studies should examine whether similar, publicly available data exists in other countries to test if our method can be replicated or adapted for use in additional settings. Healthcare stakeholders can better advocate for the funding to implement the entire BFHI program if they are able to generate informed cost estimates for training as we did here.

Pregnancy health and perinatal outcomes among Pacific Islander women in the United States and US Affiliated Pacific Islands: Protocol for a scoping review

This scoping review examines the literature on pregnancy and perinatal outcomes among Pacific Islander women in the United States (U.S.) and U.S.-affiliated Pacific Islands. Our aim was to identify research that disaggregated Pacific Islanders from other population groups. We conducted a systematic search of MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCO), and PsycINFO (Ovid) databases and a hand-search of grey literature. Forty-eight articles published between January 2010 and June 2020 were included. The majority of studies were conducted in Hawaii and utilized clinical record data. Infant outcomes were more commonly reported than maternal outcomes. We highlighted several limitations of the existing literature that included aggregation of Pacific Islanders with Asian American and other ethnic groups; limited comparison between Pacific Islander sub-groups; inadequate definitions of the nationality and ethnic composition of Pacific Islander groups; a lack of hypothesis-driven primary data collection and clinical trials; and underrepresentation of Pacific Islanders in population-based studies. Researchers should address these limitations to improve pregnancy and perinatal outcomes among Pacific Islanders, who comprise the second fastest growing ethnic minority in the U.S.

Feasibility of using infrared thermal imaging to examine brown adipose tissue in infants aged 18 to 25 months

BACKGROUND

Recent studies in adults indicate that cold-induced temperature change of supraclavicular skin corresponds with brown adipose tissue (BAT) thermogenesis.

AIM

This study examined the feasibility of using thermography to assess temperature changes in infants aged 18-25 months after mild cooling. Further, this study sought to evaluate whether cold exposure induces a thermal response suggestive of BAT activity underlying the supraclavicular region.

SUBJECTS AND METHODS

Changes in maximum skin temperature at the supraclavicular and interscapular regions were determined using thermal imaging following a mild 5-minute cooling condition (by removal of clothes in a climate-controlled room) in 67 Samoan infants. Temperature changes of the forehead and hand, known BAT-free regions, served as indicators of cooling efficacy.

RESULTS

Infants with increased hand and forehead temperatures after cold exposure were excluded from analysis, reducing the effective sample size to 19 infants. On average, forehead (p < 0.001), hand (p < 0.001) and back (0.029) temperatures dropped significantly while supraclavicular temperatures remained constant. Participants with greater decreases in forehead temperature tended to exhibit greater supraclavicular thermogenesis (p = 0.084), suggesting potential BAT activity in this region.

CONCLUSIONS

While further work is necessary to develop a reliable cooling condition, this study provides proof-of-concept for non-invasive assessment of BAT activity in infants.

Preterm birth among Pacific Islander women and related perinatal outcomes: a scoping review protocol

INTRODUCTION

Infants born alive <37 weeks are classified as premature. The global estimate of preterm birth in 2014 was 10.6%, and it is the leading cause of death of children under the age of 5 years. Preterm birth disproportionately affects women of minority populations, yet knowledge about the incidence and associated outcomes among Pacific Islanders is limited. The objectives of this scoping review are to identify studies that describe risk factors, maternal-child health outcomes and existing interventions to prevent preterm birth among Pacific Islanders, and to summarise the barriers and facilitators to decrease the burden.

METHODS AND ANALYSIS

We will follow the Joanna Briggs Institute Manual for Evidence Synthesis for scoping reviews and the Preferred Reporting Items for Scoping Reviews (PRISMA-ScR) to conduct this scoping review. The Covidence web application will be used for data management and consensus review. We will search on MEDLINE ALL (Ovid), EMBASE (Ovid), Web of Science Core Collection (as licensed at Yale), the Cochrane Library, CINAHL (EBSCOhost) and two non-indexed regional journals (Pacific Journal of Reproductive Health and Pacific Health Dialog). Title-abstract and full-text screening of eligible studies will be performed by two authors, and data will be extracted by the first author. Outcomes extracted will be presented using evidence mapping.

ETHICS AND DISSEMINATION

Findings will drive suggestions for new data collection needed to fill knowledge gaps and improve future study designs to decrease the burden of preterm birth among Pacific Islanders. There are no ethical concerns. This protocol will be disseminated in related peer-reviewed journals.

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.

Body size and composition of Samoan toddlers aged 18-25 months in 2019

BACKGROUND

The "Foafoaga O le Ola (Beginning of Life)" study is a prospective birth cohort of n = 160 Samoan mother-infant dyads established in 2017-2018. A primary study aim is to explore how a missense variant at CREBRF rs373863828 impacts growth in early life, given its association with increased body size but lower risk of diabetes in adult Samoans. Here, we examine body size and composition by genotype among toddlers aged 18.7-24.5 months.

METHODS

Height, weight, head circumference, mid-upper-arm circumference, and abdominal circumference, as well as subscapular, triceps, iliac crest and thigh skinfold thickness were measured among 107 toddlers with known rs373863828 genotype; 42 of these toddlers completed dual-energy X-ray absorptiometry (DXA) scans from which body composition (total body less head fat mass, lean mass, bone mass, % fat mass and % fat-free mass) was estimated.

RESULTS

After controlling for sex and age, toddlers with at least one copy of the CREBRF minor allele (AA/AG) were 1.31 cm taller (SE = 0.64, p = 0.045) than toddlers with the GG genotype.

CONCLUSION

Whether greater linear growth in early childhood could contribute to the metabolically protective effects associated with the CREBRF variant in adulthood should be explored in future studies.

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.

Effect of maternal nutrient intake during 31-37 weeks gestation on offspring body composition in Samoa

BACKGROUND

Pregnancy dietary intake may be associated with newborn body composition, a predictor of future obesity. In Samoa, an energy-dense diet contributes to an alarming prevalence of adult obesity. Identifying associations between pregnancy nutrition and infant body composition in this setting may guide strategies to mitigate intergenerational transmission of obesity risk.

AIM

To examine dietary macro- and micronutrient intake of Samoan women during the third trimester of pregnancy and associations with infant body composition.

SUBJECTS AND METHODS

At 34-41 weeks of gestation, we measured dietary intake from the prior month using a Food Frequency Questionnaire (FFQ). Dual-energy X-ray absorptiometry (DXA) measured infant body composition at 1-14 days. We used multivariable linear regression models accounting for confounders to identify independent effects of nutrient intake on infant body composition.

RESULTS

After adjusting for maternal body mass index, age, gravidity, infant age, and sex, a respective 0.2 g increase and 0.2 g decrease in infant bone mass was associated with fibre and saturated fat intake. Increased protein intake was associated with 0.02 g decrease in bone mass.

CONCLUSIONS

While maternal dietary intake was not associated with infant adiposity or lean mass, we observed an effect on bone mass whose role in regulating metabolic health is overlooked.

Oral contraceptives cause evolutionarily novel increases in hormone exposure: A risk factor for breast cancer

Background and objectives: In the evolutionary past, women spent most of their reproductive lives either pregnant or in lactational amenorrhea, and rarely menstruated. The current pattern of frequent menses, and the associated increase in endogenous hormonal exposure, has been implicated in the current breast cancer epidemic. It is not known, however, whether oral contraceptives further increase, or actually decrease, hormonal exposure over one menstrual cycle. Here, we examined variation in hormonal exposure across seven oral contraceptive (OC) formulations, and produced the first quantitative comparison of exogenous versus endogenous hormone exposure. Methodology: Data from 12 studies of serum estradiol (E2) and progesterone (P4) were aggregated to create a composite graph of endogenous hormone levels over one menstrual cycle in European or American women (age 19-40 years). Pharmacokinetic package insert data, also from Western women, were used to calculate exposures for hormones in seven different OC formulations. Endogenous and exogenous hormone levels were compared after adjusting for the relative binding affinity (RBA) of progestin to the progesterone receptor and ethinyl estradiol (EE) to the estrogen receptor. Results: After adjusting for RBA, median ethinyl estradiol exposure across 28 days in the OCs was 11.4 nmol/l, similar to median E2 exposure. One formulation, however, was 40% higher in ethinyl estradiol exposure relative to median endogenous estradiol. Median exposure from progestins in OCs (1496 nmol/l) was 4-fold higher than the median endogenous exposure from P4 (364 nmol/l). Exposure from OC progestins ranged from one sixtieth to 8-fold median endogenous P4 over 28 days. Conclusions and implications: Given that breast cancer risk increases with hormonal exposure, our finding that four widely prescribed formulations more than quadruple progestin exposure relative to endogenous progesterone exposure is cause for concern. As not all formulations produce the same exposures, these findings are pertinent to contraceptive choice. We also identify critical gaps in the provision of relevant data on pharmacokinetics and carcinogenicity by drug manufacturers.