Height-income association in developing countries: Evidence from 14 countries

Dynamic influence of maternal education on height among Chinese children aged 0-18 years

Background

Maternal education is one of key factors affecting nurturing environment which significantly impacts children's height levels throughout their developmental stages. However, the influence of maternal education on children's height is less studied. This study aims to investigate the dynamic influence of maternal education on children's height among Chinese children aged 0-18 years.

Methods

Children undergoing health examinations from January 2021 to September 2023 were included in this study. Clinical information including height, weight, maternal pregnancy history, blood specimens for bone metabolism-related indicators and maternal education level was collected. Children's height was categorized into 14 groups based on age and gender percentiles, following WHO 2006 growth standards. One-way analysis of variance (ANOVA), linear regression, chi-square test and Fisher's exact test were applied for data analysis.

Results

A total of 6269 samples were collected, including 3654 males and 2615 females, with an average age of 8.38 (3.97) for males and 7.89 (3.55) for females. Significant correlations between maternal education level, birth weight, birth order, weight percentile, vitamin D, serum phosphorus, alkaline phosphatase levels, and children's height were identified. Birth weight's influence on height varied across age groups. Compared with normal birth weight children, low birth weight children exhibited catch-up growth within the first 6 years and a subsequent gradual widening of the height gap from 6 to 18 years old. Remarkably, the impact of maternal education on height became more pronounced among children above 3-6 years old, which can mitigate the effect of low birth weight on height.

Conclusion

We found that weight percentile, birth weight, birth order, bone marker levels, and maternal education level have significant effect on height. Maternal education attenuates the impact of low birth weight on height. The findings indicated that maternal education plays a consistent and critical role in promoting robust and healthy growth.

Trends in women's height and the effect of early childbearing on height retardation: An analysis of the height of Bangladeshi women born between 1974 and 1998

Background

Depending on race, ethnicity, and region, genetic variants determine human height by 65% to 80%, while the remaining variance of 20% to 35% is influenced by nutrition and other individual or environmental exposures in the early years of life. An improvement in nutrition and health in the early years in a population underprivileged in health and nutrition will likely increase the group's average height. Due to outstanding improvements in these areas in recent decades, we hypothesised that the average height of Bangladeshi women has increased. Moreover, because pregnancy at an early age affects women's health and nutrition, we hypothesised that women who began childbearing early would experience growth retardation compared to women who had pregnancies at a later age.

Methods

We used data from five national surveys conducted between 2004 and 2018 that collected height data from ever-married women aged 15-49 years. We analysed the height of women aged 20-29 years (born between 1974 and 1998) and examined the mean height by birth years, age at first birth (AFB), economic status, religion and region. We conducted multiple linear regression models, controlling for the differential effects of the socio-demographic characteristics on women's height over time and by AFB.

Results

The average height of women born between 1974 and 1998 significantly increased by 0.03 cm annually, with fluctuations between 150.3 and 151.6 cm. We also found an association between age at childbearing and height in adulthood - women who began childbearing before age 17 were approximately one centimetre shorter in adulthood than those who began childbearing at a later age.

Conclusions

We found evidence of an increasing trend in women's height in Bangladesh and an inhibiting effect of early teenage childbearing on attaining the potential growth of women. The findings call for further studies to investigate early childbearing and its consequences on women's and their children's growth in diverse settings, considering socio-cultural customs influencing early marriage and childbearing.

The height premium: A systematic review and meta-analysis

The taller people are, the more money they tend to earn. This phenomenon is widely known as the height premium. However, it is not yet known whether the height premium is universal, or whether it varies by context. To that end, a systematic review of the literature was performed. Five databases were searched until August 2020. Ultimately, a list of 42 studies were included in a narrative synthesis, and 17 studies were included in a meta-analysis. Based on the meta-analysis, we found evidence that the height premium varied by context: the height premium was smaller in the U.S. and Australia, and larger in Latin America and Asia. Within geographies, there appeared to be a larger height premium for men than for women. Cultural factors, labor market structures and biology may play a role in determining the strength of the height premium.

Assessment of Undernutrition Among Children in 55 Low- and Middle-Income Countries Using Dietary and Anthropometric Measures

IMPORTANCE

Evidence on the suitability of anthropometric failure (ie, stunting, underweight, and wasting) as a stand-alone measure of child undernutrition can inform global and national nutrition and health agendas.

OBJECTIVE

To provide a comprehensive estimate of the prevalence of child undernutrition by evaluating both dietary and anthropometric measures simultaneously across 55 low- and middle-income countries.

DESIGN, SETTING, AND PARTICIPANTS

This was a cross-sectional study that used Demographic and Health Surveys program data from July 2009 to January 2019, to allocate children into dietary and anthropometric failure categories. Nationally representative household surveys were conducted in 55 low- and middle-income countries. Participants included children aged 6 to 23 months who were born singleton and had valid anthropometric measures as well as available 24-hour food intake recollection. Data analysis was conducted from August 23 to October 22, 2020.

EXPOSURES

Two factors were considered to allocate children into the respective categories. Dietary failure was based on the World Health Organization standards for minimum dietary diversity. Anthropometric failure was constructed using the World Health Organization child growth reference standard z score for stunted growth, muscle wasting, and less than average weight for age.

MAIN OUTCOMES AND MEASURES

Dietary and anthropometric failures were cross-tabulated, which yielded 4 potential outcomes: dietary failure only, anthropometric failure only, both failures, and neither failure. Total child populations for each category were extrapolated from United Nations population estimates.

RESULTS

Of the 162 589 children (median age [range], 14 months [6-23 months]; 83 467 boys [51.3%]; 78 894 Asian children [48.5%]) in our sample, 42.9% of children had dietary failure according to the standard World Health Organization definition without being identified as having anthropometric failures. In all, 34.7% had both failures, 42.9% had dietary failure only, 8.3% had anthropometric failure only, and 14.1% had neither failure. Dietary and anthropometric measures were discordant for 51.2% of children; these children had nutritional needs identified by only 1 of the 2 measures. Dietary failure doubled the proportion of children in need of dietary interventions compared with anthropometry alone (43%). A total of 45.3 million additional children who experienced undernutrition in these 55 countries were not captured through the evaluation of anthropometric failures only. These results were consistent across geographic regions.

CONCLUSIONS AND RELEVANCE

The results of this cross-sectional study suggest that the current standard of measuring child undernutrition by estimating the prevalence of anthropometric failure should be complemented with dietary and food-based measures. Anthropometry alone may fail to identify many children who have insufficient dietary intake.

Height and quality of life among older adults (50+) in India: a cross-sectional study

Adult height is a summary measure of health and net nutrition in early childhood. This study examines the association between height and quality-of-life outcomes in older adults (50+) in India. Cross-sectional data from Wave 1 of the World Health Organization (WHO) Study on global AGEing and adult health (SAGE) conducted in 2007 were analysed. The association between height and quality of life was assessed using bivariate and multivariate logistic and linear regression models. The mean WHO quality-of-life score (WHO-QoL) increased from 45.2 among the older adults in the lowest height quintile to 53.2 for those in the highest height quintile. However, the prevalence of self-rated poor quality of life declined from 16.4% in the lowest height quintile to 6.1% in the highest height quintile. In the fully adjusted regression model, height was found to be positively associated with quality-of-life outcomes among both men and women, independent of socioeconomic and physical health confounders. The association was particularly strong for women. Women in the highest height quintile had a 2.65 point higher WHO-QoL score than those in the lowest height quintile. Similarly, the likelihood of reporting a poor quality of life was lower among women in the highest height quintile. Furthermore, measures of economic status, handgrip strength, cognitive ability and poor self-rated health were significantly associated with WHO-QoL and self-rated poor quality of life. Overall, this study revealed a significant association between height and quality of life among older adults in India, suggesting a significant role of childhood circumstances in quality of life in later life.