Intergenerational influences on the growth of Maya children: The effect of living conditions experienced by mothers and maternal grandmothers during their childhood

Maternal Height-standardized Prevalence of Stunting in 67 Low- and Middle-income Countries

BACKGROUND

Prevalence of stunting is frequently used as a marker of population-level child undernutrition. Parental height varies widely in low- and middle-income countries (LMIC) and is also a major determinant of stunting. While stunting is a useful measure of child health, with multiple causal components, removing the component attributable to parental height may in some cases be helpful to identify shortcoming in current environments.

METHODS

We estimated maternal height-standardized prevalence of stunting (SPS) in 67 LMICs and parental height-SPS in 20 LMICs and compared with crude prevalence of stunting (CPS) using data on 575,767 children under-five from 67 Demographic and Health Surveys (DHS). We supplemented the DHS with population-level measures of other child health outcomes from the World Health Organization's (WHO) Global Health Observatory and the United Nations' Inter-Agency Group for Child Mortality Estimation. Prevalence of stunting was defined as percentage of children with height-for-age falling below -2 z-scores from the median of the 2006 WHO growth standard.

RESULTS

The average CPS across countries was 27.8% (95% confidence interval [CI], 27.5-28.1%) and the average SPS was 23.3% (95% CI, 23.0-23.6%). The rank of countries according to SPS differed substantially from the rank according to CPS. Guatemala, Bangladesh, and Nepal had the biggest improvement in ranking according to SPS compared to CPS, while Gambia, Mali, and Senegal had the biggest decline in ranking. Guatemala had the largest difference between CPS and SPS with a CPS of 45.2 (95% CI, 43.7-46.9%) and SPS of 14.1 (95% CI, 12.6-15.8%). Senegal had the largest increase in the prevalence after standardizing maternal height, with a CPS of 28.0% (95% CI, 25.8-30.2%) and SPS of 31.6% (95% CI, 29.5-33.8%). SPS correlated better than CPS with other population-level measures of child health.

CONCLUSION

Our study suggests that CPS is sensitive to adjustment for maternal height. Maternal height, while a strong predictor of child stunting, is not amenable to policy interventions. We showed the plausibility of SPS in capturing current exposures to undernutrition and infections in children.

Birth weight, birth order, and age at first solid food introduction influence child growth and body composition in 6- to 8-year-old Maya children: The importance of the first 1000 days of life

OBJECTIVES

To analyze the relationship of birth weight, birth order, breastfeeding duration, and age of introduction of solid foods with height, fat mass, and fat-free mass in a sample of Maya children when aged 6 to 8 years old.

METHODS

We collected data on anthropometry, body composition, children's birth weight, birth order, early feeding practices, and household socioeconomic characteristics in a sample of 260 Maya children aged 6 to 8 years living in Merida and Motul, two cities in Yucatan, Mexico. Multiple regression models were performed to identify variables associated with height-for-age (HAZ), fat mass index (FMI), and fat-free mass index (FFMI). The predictors included in the models were birth weight (kg), birth order, duration of breastfeeding (months), age at introduction of solid foods (months), maternal age (years), and height (cm). Models were adjusted for the influence of children's age and sex, maternal educational level, and household overcrowding.

RESULTS

HAZ was positively associated with child birthweight and maternal height and age, but inversely associated with birth order and age of introduction of solid foods. FMI was positively associated with birth weight, maternal age, and height, and negatively associated with birth order. FFMI was positively associated with maternal age and birth weight.

CONCLUSIONS

These results are evidence of the importance of the first 1000 days of life for the growth and body composition of Maya children and contributed to understand the development of nutritional dual burden in this population.

Body proportions of 6–18-year-old children in Merida, Mexico

The purpose of this study was to find out the differences in body physique and its proportions between children from Creole, Maya and Mestizo ethnic groups living in Merida, Mexico. The study was conducted between 1996–1999 and comprised of 4636 children and youth aged 6–18 years from three ethnic groups: Maya, Mestizo, and Creole. There were 1362 boys and 1314 girls from Creole group and 803 boys and 857 girls from the pooled Maya/Mestizo group. Anthropometric measurements included body height, arm and leg length, shoulder and hip width. The following indexes were calculated: leg length-to-body height, upper-to-lower limb, shoulder-to-body height, hip-to-body height, and hip-to-shoulder. Two-way analysis of variance (two-way ANOVA) was used to test the main effect and the interaction effects of age and ethnicity on height, leg length and body proportions, separately for boys and girls. All statistical analyses were performed using Statistica software version 13.1. All p-values lower than 0.05 were considered significant. Results of this study revealed that average values of body height, leg length and upper-to-lower limb and shoulder width proportions were statistically significantly different between ethnic groups. Creole children were taller and longer-legged than their Maya/Mestizo peers, and the greatest difference was noted after puberty. Maya/Mestizo children had relatively longer arm as compared to Creoles. Results of two-way ANOVA revealed that age and ethnicity were combined (interaction effect) factors for variation in body height both in boys and girls, and upper-to-lower limb proportion in boys, shoulder-to-body height proportion in girls. Ethnicity was the main effect factor for leg length both in boys and girls, and for the body proportions: upper-to-lower limb in girls and shoulder-to-body height in boys. Age was the main effect factor for upper-to-lower limb proportion in girls, shoulder-to-body height in boys, hip-to-body height in boys and girls, and hip-to-shoulder, both in boys and girls. In conclusion it may be stated that variation in body physique and body proportions during the postnatal growth in different ethnic groups is under the influence of complex interaction between genetic and environmental factors to which the individual is exposed.

Caesarean birth and adiposity parameters in 6- to 8-year-old urban Maya children from two cities of Yucatan, Mexico

OBJECTIVES

The purpose of this study was to analyze the association between birth mode and fat mass index (FMI = fat mass [kg]/height [m]² ), and z-score values of waist circumference (WCZ) and sum of triceps and subscapular skinfolds (SumSkfZ) in a sample of 256 6- to 8-year-old urban Maya children from the cities of Merida and Motul in Yucatan, Mexico.

METHODS

From September 2011 to January 2014, we measured height, weight, waist circumference and skinfolds in children, and height and weight in their mothers. Body composition was estimated in both generations through bioelectrical impedance analysis. Data on children's birth mode and birth weight were obtained from birth certificates. A pre-validated questionnaire for mothers was used regarding household living conditions. Multiple regression models were used to analyze the association between birth mode and adiposity parameters, adjusting for the effect of place of residence, household crowding index, children's birth weight, and maternal fat mass. Separate regression models were run for boys and girls.

RESULTS

Caesarean-born children comprised 43% of the entire sample. Caesarean section (CS) was found to be associated with higher values of body adiposity in girls, but not in boys. Specifically, our models predicted that girls born by CS had an increased value of 0.817 kg/m² in FMI and showed higher SDs values for WCZ and SumskfZ (0.29 and 0.32 SD, respectively) than girls who were delivered vaginally.

DISCUSSION

Our results support the hypothesis that CS is associated with increased levels of adiposity in childhood, but only in girls.

Geographic variation in the growth status of indigenous school children and youth in Mexico

OBJECTIVE

To analyze variation in the growth status of indigenous children and youth attending bilingual schools, escuelas albergues, for the indigenous population in México.

MATERIALS AND METHODS

The children and youth attended escuelas albergues in 1,009 localities in 21 Mexican states in 2012. Heights and weights of 31,448 boys and 27,306 girls 6-18 years of age were measured by trained staff at each school; the BMI was calculated. The students were divided into five geographic regions for analysis: North, Central, South-Gulf, South-Pacific, and South-Southeast. Growth status was compared to United States reference percentiles (P).

RESULTS

Mean heights of children and youth from the five regions varied between P10 and P5 of the reference until about 13 years (girls) and 14 years (boys); subsequently, heights were ≤P5. Mean weights in both sexes were at P25 of the reference between 6 and 12 years, and then varied between P25 and P10 in boys and were ≥P25 in girls. Given the elevated weights relative to heights compared to the reference, mean BMIs of indigenous boys and girls were at or above the reference medians. Children and youth in the North and Central regions were, on average, taller than those in the South-Pacific and South-Southeast regions, while heights of those in the South-Gulf region were generally intermediate. In contrast, mean weights and BMIs differed negligibly among the regions.

CONCLUSIONS

The geographic gradient in heights of indigenous children and youth was consistent with a north-to-south pattern noted among indigenous adults in studies spanning 1898 through 2013. Variation in height among children and youth likely reflected ethnic-specific and geographic variation interacting with economic and nutritional factors.

Adolescent mothers' anthropometrics and grandmothers' schooling predict infant anthropometrics in Ethiopia, India, Peru, and Vietnam

We investigated intergenerational associations of adolescent mothers' and grandmothers' anthropometrics and schooling with adolescent mothers' offspring's anthropometrics in Ethiopia, India, Peru, and Vietnam. We examined birthweight (n = 283), birthweight Z-score (BWZ), conditional growth in weight-for-age Z-score (cWAZ, residuals from a regression of WAZ at last survey round on BWZ, sex, and age), and height-for-age Z-score (HAZ) of children born to older cohort adolescent girls in the Young Lives study. Our key independent variables were adolescent mothers' body size: HAZ and body-mass-index-for-age Z-score (BMIZ) at age 8, conditional HAZ (cHAZ, residuals from a regression of HAZ at the end of a growth period on prior HAZ, age, and sex), conditional BMIZ growth (cBMIZ, calculated analogously), and grandmaternal BMIZ, HAZ, and schooling. We adjusted for child, maternal, and household characteristics. Adolescent mothers' cHAZ (ages 8-15) predicted birthweight (β = 130 g, 95% confidence interval (CI) 31-228), BWZ (β = 0.31, CI 0.09-0.53), and cWAZ (β = 0.28, CI 0.04-0.51). Adolescent mothers' BMIZ at age 8 predicted birthweight (β = 79 g, CI 16-43) and BWZ (β = 0.22, CI 0.08-0.36). Adolescent mothers' cBMIZ (ages 12-15) predicted child cWAZ and HAZ. Grandmothers' schooling predicted grandchild birthweight (β = 22 g, CI 1-44) and BWZ (β = 0.05, CI 0.01-0.10).

Maternal height and its relationship to offspring birth weight and adiposity in 6- to 10-year-old Maya children from poor neighborhoods in Merida, Yucatan

OBJECTIVE

To analyze the relationship between maternal height, offspring birth weight, and adiposity at 6-10 years of age in a sample of 197 mother-child dyads from Merida, Mexico.

MATERIALS AND METHODS

During 2008-2009 and 2011-2013, measurements were taken of maternal height and weight; and height, waist circumference (WC), and skinfolds (triceps, subscapular, and suprailiac) of their children. Participant body composition was estimated using a bioelectrical impedance analyzer. A questionnaire was applied to document household socioeconomic conditions. Multiple linear regression models were used to study the association between maternal height, offspring birth weight and fat mass index (FMI), WC, and sum of skinfolds (SumSkfZ) in boys and girls, separately.

RESULTS

After adjusting for child age and household socioeconomic conditions, maternal height was identified to be significantly associated (p < .05) with FMI, WC, and SumSkf only in boys. In all models, child adiposity was inversely related to maternal height. Offspring birth weight was not associated with any adiposity parameter.

DISCUSSION

The results suggest that maternal nutritional history as reflected in short maternal stature is associated with higher body fat in children, and that male offspring are more vulnerable to intergenerational influences.