Household income and maternal education in early childhood and risk of overweight and obesity in late childhood: Findings from seven birth cohort studies in six high-income countries

Abstract

Background/objectives This study analysed the relationship between early childhood socioeconomic status (SES) measured by maternal education and household income and the subsequent development of childhood overweight and obesity. Subjects/methods Data from seven population-representative prospective child cohorts in six high-income countries: United Kingdom, Australia, the Netherlands, Canada (one national cohort and one from the province of Quebec), USA, Sweden. Children were included at birth or within the first 2 years of life. Pooled estimates relate to a total of N = 26,565 included children. Overweight and obesity were defined using International Obesity Task Force (IOTF) cut-offs and measured in late childhood (8–11 years). Risk ratios (RRs) and pooled risk estimates were adjusted for potential confounders (maternal age, ethnicity, child sex). Slope Indexes of Inequality (SII) were estimated to quantify absolute inequality for maternal education and household income. Results Prevalence ranged from 15.0% overweight and 2.4% obese in the Swedish cohort to 37.6% overweight and 15.8% obese in the US cohort. Overall, across cohorts, social gradients were observed for risk of obesity for both low maternal education (pooled RR: 2.99, 95% CI: 2.07, 4.31) and low household income (pooled RR: 2.69, 95% CI: 1.68, 4.30); between-cohort heterogeneity ranged from negligible to moderate (p: 0.300 to < 0.001). The association between RRs of obesity by income was lowest in Sweden than in other cohorts. Conclusions There was a social gradient by maternal education on the risk of childhood obesity in all included cohorts. The SES associations measured by income were more heterogeneous and differed between Sweden versus the other national cohorts; these findings may be attributable to policy differences, including preschool policies, maternity leave, a ban on advertising to children, and universal free school meals.

Small for gestational age preterm infants and later adiposity and height: A systematic review and meta‐analysis

“…We defined appropriate control for confounding as adjusting for any SDOH [14][15][16] and maternal weight status. 17 Studies that did not adjust for both the SDOH and maternal weight were considered to have residual confounding.…”

“…Infants born SGA, particularly those born preterm, are of particular concern, given the potential for increased risk of adverse outcomes consequent to suboptimal fetal growth. To gain an understanding of the causal relationships between size at birth and excess adiposity in later life, analyses should adjust for baseline confounders/common causes, including the social determinants of health (SDOH) [13][14][15][16] and maternal pre-pregnancy weight status 17 and should not adjust for later weight or other intermediate factors including growth that fall on the causal pathway between prenatal exposures and later metabolic and adiposity outcomes. 4,5 Our objective was to conduct a systematic review and metaanalyses of the available published literature on differences in anthropometric measures (adiposity and height) in later childhood or adulthood among preterm SGA infants compared with those born preterm but non-SGA, with a focus on the statistical methods and adjustments used in the analysis of individual studies.…”

“…It should be noted that only two 32,41 of the included 39 studies adjusted crude estimates for relevant confounding variables, such as SDOH and maternal weight status, which limited our ability to examine the effect of unmeasured confounding. Maternal weight status 17 and SDOH [13][14][15][16] are associated with both SGA births and higher offspring adiposity, so the failure to adjust for these important confounders in many studies likely resulted in bias in some of our pooled estimates. The lack of adjustment for these potential confounders likely biased the results towards higher adiposity in SGA infants, which increases our confidence that SGA preterm infants do not have excess adiposity compared to their preterm non-SGA peers.…”

Low maternal education increases the risk of Type 1 Diabetes, but not other autoimmune diseases: a mediating role of childhood BMI and exposure to serious life events

“…Other potential factors could be the increasing hygiene 40 , changes of microbiome of the body such as skin, respiratory tract or gut microbiome 41 . We have found in repeated studies that in the Swedish ABIS cohort, in contrast to other birth cohorts conducted in high-income countries, the association between health outcomes and income is weaker than the association with maternal education [42][43][44] . Income differences between families with children in early childhood is reduced in Sweden due to policies including the parental leave insurance that have an upper level of compensation and by the fact that high educated fathers take longer parental leave 43,45 .…”

Household income and maternal education in early childhood and activity-limiting chronic health conditions in late childhood: findings from birth cohort studies from six countries

“…The Elucidating Pathways Of Child Health inequalities (EPOCH) study draws on data from birth cohort studies across high-income countries to explore the pathways from early SES exposure to child health outcomes during later childhood. Outcomes investigated include Attention Deficit Hyperactivity Disorder (ADHD),19 oral health20 and obesity,21 among others. This current project within the larger EPOCH study explores pathways to ALCHCs in six prospective cohort studies based in six countries.…”