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Prenatal exposure to phthalate and decreased body mass index of children: a systematic review and meta-analysis.
Lee, DW, Lim, HM, Lee, JY, Min, KB, Shin, CH, Lee, YA, Hong, YC
Scientific reports. 2022;12(1):8961
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Phthalates are widely used chemicals to improve the utility of plastics and personal care products. Phthalates can be classified as high-molecular-weight phthalates and low-molecular-weight phthalates. The aim of this study was to clarify whether prenatal and postnatal exposures to phthalates are associated with physical growth as measured by body composition indices in children. This study is a systematic literature review and meta-analysis of 39 studies about the association of phthalates with body composition indices among children. Results showed that prenatal exposure to phthalates is significantly associated with low body mass index in children, but not with body fat mass. In addition, prenatal phthalate exposure may affect the disturbance of normal growth of children rather than act as an obesogen. Authors conclude that it is necessary to administer stricter and broader regulations on phthalates in living environments.
Abstract
Phthalates are well-known endocrine-disrupting chemicals. Many detrimental health effects of phthalates were investigated, but studies on the association of phthalates with obesity in children showed inconsistent results. Thus, this systematic review and meta-analysis were performed to clarify whether prenatal and postnatal exposures to phthalates are associated with physical growth disturbances in children. We performed the systematic review and meta-analysis following the PRISMA 2020 statement guidelines, and found 39 studies that met our inclusion criteria, including 22 longitudinal and 17 cross-sectional studies. We observed a significant negative association between the prenatal exposure to DEHP and the body mass index (BMI) z-score of the offspring (β = - 0.05; 95% CI: - 0.10, - 0.001) in the meta-analysis, while no significant association between the prenatal exposure to DEHP and the body fat percentage of the offspring was observed (β = 0.01; 95% CI: - 0.41, 0.44). In the systematic review, studies on the association between phthalates exposure in childhood and obesity were inconsistent. Prenatal exposure to phthalates was found to be associated with decreased BMI z-score in children, but not associated with body fat percentage. Our findings suggest that phthalates disturb the normal muscle growth of children, rather than induce obesity, as previous studies have hypothesized.
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A systematic review and meta-analysis of school-based interventions with health education to reduce body mass index in adolescents aged 10 to 19 years.
Jacob, CM, Hardy-Johnson, PL, Inskip, HM, Morris, T, Parsons, CM, Barrett, M, Hanson, M, Woods-Townsend, K, Baird, J
The international journal of behavioral nutrition and physical activity. 2021;18(1):1
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Obesity in childhood and adolescence is associated with an increased risk of non-communicable diseases such as Type 2 diabetes, cardiovascular disease, chronic obstructive lung disease and some forms of cancer. The aim of this study was to investigate the effectiveness of health education interventions delivered in school settings to prevent overweight and obesity and/ or reduce BMI in adolescents, and to explore the key features of effectiveness. This study is a systematic review and meta-analysis of 39 publications based on 33 studies. Six studies recruited adolescent girls only, one adolescent boys only and one study included parent-student dyad. Results show that: - Most of the effective interventions were delivered by teachers who were trained prior to the intervention. - School-based interventions are often delivered through school-staff, however, appropriate training/ CPD prior to the intervention could be a crucial component to support the provision and uptake of the intervention. - Many of the effective interventions included parental involvement and modifications to the school environment. - Interventions should target the biological, psychosocial, environmental, and behavioural influences on diet and physical activity. Authors conclude that school-based health education interventions could potentially help in improving BMI outcomes in the adolescent age group.
Abstract
BACKGROUND Adolescents are increasingly susceptible to obesity, and thus at risk of later non-communicable diseases, due to changes in food choices, physical activity levels and exposure to an obesogenic environment. This review aimed to synthesize the literature investigating the effectiveness of health education interventions delivered in school settings to prevent overweight and obesity and/ or reduce BMI in adolescents, and to explore the key features of effectiveness. METHODS A systematic search of electronic databases including MEDLINE, CINAHL, PsychINFO and ERIC for papers published from Jan 2006 was carried out in 2020, following PRISMA guidelines. Studies that evaluated health education interventions in 10-19-year-olds delivered in schools in high-income countries, with a control group and reported BMI/BMI z-score were selected. Three researchers screened titles and abstracts, conducted data extraction and assessed quality of the full text publications. A third of the papers from each set were cross-checked by another reviewer. A meta-analysis of a sub-set of studies was conducted for BMI z-score. RESULTS Thirty-three interventions based on 39 publications were included in the review. Most studies evaluated multi-component interventions using health education to improve behaviours related to diet, physical activity and body composition measures. Fourteen interventions were associated with reduced BMI/BMI z-score. Most interventions (n = 22) were delivered by teachers in classroom settings, 19 of which trained teachers before the intervention. The multi-component interventions (n = 26) included strategies such as environment modifications (n = 10), digital interventions (n = 15) and parent involvement (n = 16). Fourteen studies had a low risk of bias, followed by 10 with medium and nine with a high risk of bias. Fourteen studies were included in a random-effects meta-analysis for BMI z-score. The pooled estimate of this meta-analysis showed a small difference between intervention and control in change in BMI z-score (- 0.06 [95% CI -0.10, - 0.03]). A funnel plot indicated that some degree of publication bias was operating, and hence the effect size might be inflated. CONCLUSIONS Findings from our review suggest that school-based health education interventions have the public health potential to lower BMI towards a healthier range in adolescents. Multi-component interventions involving key stakeholders such as teachers and parents and digital components are a promising strategy.