Growth in height and its association with overweight and obesity in Mexican children: an evaluation based on a nationally representative sample (ENSANUT 2018)

The present study aimed to estimate the height growth curve for Mexican boys and girls based on their body mass index (BMI) status (normal and overweight/obese) and to develop a height Lambda, Mu, and Sigma (LMS) growth reference for Mexican children aged 2 to 18 years.

Methods

Chronological age and height records (7,097 boys and 6,167 girls) were obtained from the Mexican National Survey of Health and Nutrition database. Height growth curves were fitted using the Preece-Baines 1 (PB1) model and the LMS method.

Results

Age at peak height velocity (APHV) was 12.4 and 12.7 years for overweight-obese and normal-weight boys, respectively, and was 9.6 and 10.4 years for overweight-obese and normal-weight girls, respectively. Growth velocity was higher at the age of take-off (TO) in overweight-obese children than in normal-weight children (5.2 cm/year vs. 5 cm/year in boys and 6.1 cm/year vs. 5.6 cm/year in girls); nevertheless, the growth velocity at APHV was higher for normal-weight children than for overweight-obese children (7.4 cm/year vs. 6.6 cm/year in boys and 6.8 cm/year vs. 6.6 cm/year in girls, respectively). Distance curves developed in the present study and by the World Health Organization (WHO) using LMS showed similar values for L and S parameters and a higher M value compared with the WHO reference values.

Conclusion

This study concluded that overweight-obese children had earlier APHV and lower PHV than normal-weight children. Furthermore, Mexican children and adolescents were shorter than the WHO growth reference by age and sex.

Age at menarche, environmental stress, and social inequality: Evidence from Poland in the 1930s-1950s

OBJECTIVE

To address the relationship between socioeconomic factors and age of menarche among Polish women born and reared in periods that varied considerably in environmental stresses: the Great Depression of the 1930s, the interval of World War II, and the interval of communist rule following World War II through the 1950s.

METHODS

The data set included information on age at menarche and socioeconomic status (SES) of 718 women born during the Great Depression (n = 182), WWII (n = 189), and post-WWII through the 1950s (n = 347). A structured semi-parametric statistical model (generalized additive model [GAM] class) was used for analysis. An ANOVA-like linear model was used to test for marginal effects of SES-related factors and their interactions together with nonparametric seasonal effect.

RESULTS

The influence of period of birth, month of birth, region of early childhood, and father's education, and the interaction between period of birth and father's education on age at menarche were statistically significant. During the economic crisis and the interval of WWII, differences in ages at menarche between the extreme categories of father's education were marked. The differences in ages at menarche between women from the lowest and highest social groups were markedly reduced among women born during the post-war interval. In addition, women born in February-March attained menarche earlier than women born in September-October.

CONCLUSIONS

Unpredictable conditions associated with the economic crisis and war conditions had a stronger impact on age at menarche among women from families of lower SES compared to women from better economic circumstances. Individuals born and reared in low SES conditions likely suffered more severe deterioration across the spectrum of the standard of living and quality of life compared to those with a higher SES.

Association of early menarche with elevated BMI, lower body height and relative leg length among 14- to 16-year-old post-menarcheal girls from a Maya community in Yucatan, Mexico

Human body segments have different timing and tempo of growth. Early menarche (EM) as an indicator of early reproductive maturity results in a shortened height and leg length. Relatively larger trunk may increase risk for more body fat deposit and higher body mass index (BMI) due to the allometry of total body fat with body proportions. The objective of the study was to assess the association of EM with BMI, absolute body size [height, sitting height (SH), subischial leg length (SLL)] and relative body dimensions [sitting height to subischial leg length ratio (SHSLLR), relative subischial leg length (RSLL)] among 14- to 16-year-old post-menarcheal girls from a rural Maya community in Quintana Roo, Yucatan, Mexico. In a cross-sectional study, post-menarcheal girls (n=51) aged 14 to 16 years had EM (n=22) (<12 years of age) and not early menarche (NEM, n=29). Anthropometric measurements of height, weight, and SH were recorded. Derived variables were BMI, height and BMI-for-age z-scores, SLL, SHSLLR, and RSLL. Mean value of age at menarche (AM) was 13 years (EM 11 years, NEM 14 years). Mean values of height (EM 159 cm, NEM 164 cm), BMI (EM 20 kg/m2, NEM 19 kg/m2), sitting height (EM 81 cm, NEM 78 cm), SLL (EM 79 cm, NEM 85 cm), SHSLLR (EM 102.93%, NEM 92.03%), and RSLL (EM 49%, NEM 52%) were different (p<0.05) in the two groups. BMI showed significant negative correlation with AM (Pearson’s r=-0.29, p<0.04). Linear regression models adjusted for age showed that EM had different interrelationships (p<0.05) with body dimensions: positive with BMI, SH, SHSLLR, and negative with height, SLL, and RSLL. Earlier AM was associated with higher BMI, SH, SHSLLR and lower SLL, RSLL, explaining lower body height and leg length among the participant EM girls. In the light of life history theory, EM results in a growth trade-off, short stature and larger trunk relative to leg length that might enhance risk for body fat gain.

Family environmental antecedents of pubertal timing in girls and boys: A review and open questions

Across nonhuman species, pubertal timing is affected by the social environment, with consequences for reproductive success and behavior. In human beings, variations in pubertal timing have not been systematically examined in relation to social environmental antecedents, although their psychological consequences are well documented. This paper focuses on links in human beings between pubertal timing and the childhood social environment, with several sections: A review of studies relating pubertal timing to the family context, a key aspect of the social environment; challenges in studying the issue; and opportunities for future work that takes advantage of and creates links with evidence in other species. The review shows that pubertal timing in girls is accelerated by adversity in aspects of the early family social context, with effects small in size; data in boys are not sufficient to enable conclusions. Inferences from existing studies are limited by variations in conceptualizations and measurement of relevant aspects of puberty and of the family social environment, and by methodological issues (e.g., reliance on existing data, use of retrospective reports, nonrandom missing data). Open questions remain about the nature, mechanisms, and specificity of the links between early family social environment and pubertal timing (e.g., form of associations, consideration of absence of positive experiences, role of timing of exposure). Animal studies provide a useful guide for addressing these questions, by delineating potential hormonal mechanisms that underlie links among social context, pubertal timing, and behavior, and encouraging attention to aspects of the social environment outside the family, especially peers.

Maternal Grandmothers' Household Residency, Children's Growth, and Body Composition Are Not Related in Urban Maya Families from Yucatan

This study analyzes the influence of grandmothers' household residency on the presence of low height-for-age and excessive fat (FMI = fat mass [kg]/height [m²]), waist circumference, and sum of triceps and subscapular skinfolds in a sample of 247 6- to 8-year-old urban Maya children from Yucatan, Mexico. Between September 2011 and January 2014, we obtained anthropometric and body composition data from children and mothers, as well as socioeconomic characteristics of participants and households. Grandmothers' place of residence was categorized as either in the same household as their grandchildren (n = 71) or in separate households (n = 176). Multiple logistic regression models were used to analyze the association between grandmothers' residency and outcome variables. Models were adjusted for maternal anthropometric characteristics and the following socioeconomic variables: family size, location, maternal education, monthly family income, and household crowding. Models showed that the presence of grandmothers in their grandchildren's households was not associated with any of the outcome variables. In contrast, larger family size, overcrowding in the household, and lower family income predicted low height-for-age in children. Larger family size decreased the risk for being overweight based on the three parameters of body composition. Overcrowding in the household increased the risk for greater skinfolds thickness, while low family income increased the risk for higher fat mass index. The residency of grandmothers in their adult daughters' households is not significantly associated with the outcome variables in this sample of urban Maya families. Instead, maternal anthropometric characteristics and socioeconomic conditions of the family have a greater influence on the overall growth of children.

Secular trends in age at menarche in 20th century Mexico: Differences by ethnicity, area of residency, and socioeconomic status

OBJECTIVES

This study aims to assess the secular trend in age at menarche (AAM) in Mexico over the 20th century, and compare the patterns according to area of residence (rural/urban), socioeconomic status (SES), and ethnicity (indigenous/nonindigenous).

METHODS

Data on AAM from 24 380 women aged ≥20 years born between 1906 and 1986 were obtained from the Mexican National Health and Nutrition Survey 2006. Birth cohorts were compared to test for a secular trend and differences in mean AAM by area of residence, SES, and ethnicity were evaluated using the Welch test for heterogeneous variances followed by Tamhane T² for post hoc comparisons.

RESULTS

Mean AAM declined from 13.3 years among Mexican women born before the 1940s to 12.56 years among those born in the 1980s. Across birth cohorts, urban women had significantly earlier AAM than their rural counterparts. Nonindigenous urban women reached menarche the earliest and rural indigenous women the latest of all groups. Nonindigenous urban residents experienced a comparatively earlier decline, while that for the indigenous rural women occurred last. High SES women reached menarche the earliest and low SES women the latest. The historical decline in AAM for high and medium SES groups occurred relatively early, whereas that for the low SES occurred last.

CONCLUSIONS

Mean AAM was associated with area of residence, ethnicity, and SES. Our findings indirectly suggest that advances in living conditions experienced in Mexico during the 20th century appear to have been insufficient to overcome the social and biological inequalities accumulated over centuries in some groups.

Body Mass Index in Mother and Child Dyads and its Association With Household Size and Parents' Education in 2 Urban Settings of Yucatan, Mexico

BACKGROUND

Overweight/obesity (OW/OB) coexists in mother-child dyads. However, a dearth of evidence on the factors associated with this phenomenon calls for research.

OBJECTIVE

To analyze the association of sociodemographic factors with OW/OB in a sample of 260 Maya mother-child dyads from Yucatan, Mexico.

METHODS

During 2011 to 2014, we measured height and weight in children and their mothers and calculated their body mass index (BMI). The OW/OB cutoff points were defined, for mothers, as having a BMI >25 kg/m² and, for children, as having a BMI-for-age >2 standard deviation of the World Health Organization references. Mother-child dyads were grouped according to their BMI status: (1) normal weight mother and child, (2) normal weight mother and OW/OB child, (3) OW/OB mother and normal weight child, and (4) OW/OB mother and child. A multinomial logistic regression model was used to analyze the interrelationships among BMI status in mother-child dyads, household size, and parental education.

RESULTS

Overweight/obesity coexisted in 40% of dyads. Compared to normal weight dyads (1), each unit increase in household size and in years of maternal education decreased the risks of the coexistence of OW/OB in mother-child dyads (odds ratio [OR] = 0.72, 95% confidence interval [CI] 0.55-0.94, P = .015; OR = 0.70, 95% CI 0.52-0.94, P = .019, respectively). Conversely, each year increase in paternal education increased the risk for OW/OB in dyads (OR = 1.47, 95% CI 1.08-1.99, P = .015).

CONCLUSIONS

Results suggest that household size and parental education contribute to shape BMI-based nutritional status in this sample of mother-child dyads.