ETHNICITY AND INCOME IMPACT ON BMI AND STATURE OF SCHOOL CHILDREN LIVING IN URBAN SOUTHERN MEXICO

Secular trends in the anthropometric characteristics of children in a rural community in Yucatan, Mexico

OBJECTIVE

To analyze changes in height, weight, and body mass index (BMI = kg/m2 ) from 1986 to 2022 in 3-11 year old children from Dzeal, a rural Maya community in Yucatan, Mexico.

MATERIALS AND METHODS

From October-2022 to February-2023 (third-wave survey), we obtained anthropometric measurements of children (n = 80) and family socioeconomic data and compared them with data obtained in 1986 (n = 38) and 2000 (n = 76). Comparisons of anthropometric parameters by sex between years of measurement were performed graphically and through one-way ANOVA, splitting children into two age groups: 3-7 and 8-11. Bonferroni adjustments for multiple comparisons were used when ANOVAs were statistically significant (p < .05).

RESULTS

In girls, significant increases in height and weight between surveys were found in 3-7 and 8-11 age groups; in boys, significant increases were only found in the 8-11 age group. Regarding BMI, there were increases in 2022 compared with 1986/2000 in both sexes from 8 years onwards. Differences indicate increases of 3.9 and 4.4 cm per decade in girls aged 3-7 and 8-11, respectively, and increases in weight of 1.1 and 3.3 kg per decade, respectively. Increases in boys 8-11 years were 2.3 cm and 2.4 kg per decade.

CONCLUSION

Significant increases in growth parameters were observed in specific-age children in the community studied in the context of changes in livelihoods and improvements in household material conditions.

Differential fetal growth rates mediated by sociodemographic factors in Yucatan, Mexico: an epidemiological study

BACKGROUND

Fetal growth restriction (FGR) may be related to ethnicity. Additionally, ethnic groups experience adverse socioeconomic circumstances that increase FGR risk. However, the dearth of evidence of the interaction between socioeconomic factors and FGR highlights the need for additional research.

OBJECTIVE

To analyze the association between socioeconomic factors and FGR in Maya and non-Maya populations in Yucatan, Mexico.

METHODS

A total of 21,320 singleton births in 2017 in Yucatan were analyzed. The student's t-test and the chi-square test were used to compare the means and proportions of maternal and perinatal variables between the FGR group and the birthweight appropriate for gestational age (AGA) group. Path analysis was performed to identify the direct and indirect effects of socioeconomic factors on FGR and mediators between predictors and FGR.

RESULTS

The prevalence of FGR at birth was 9.06%; this rate was higher in the Maya population (12.4, 95% CI 11.3-13.5), without differences between socioeconomic levels. Path analysis revealed sociostructural variables (ethnicity and poverty) are reliable predictors of FGR at birth mediated by maternal education (β = -.152, p < .001) and teenage pregnancy (β = .065, p = .037). The proposal path model had a good fit index CFI = .968, TLI = .920, RMSEA = .046.

CONCLUSION

The prevalence of FGR was higher among Maya women than non-Maya women The socioeconomic conditions associated with FGR at birth were ethnicity, poverty, maternal education, and teenage pregnancy. Maternal education and teenage pregnancy act as mediators between sociostructural variables and FGR at birth.

Development of birthweight and length for gestational age and sex references in Yucatan, Mexico

OBJECTIVE

To develop sex- and gestational age specific reference percentiles and curves for birth weight and length for Yucatec neonates using data from birth registers of infants born during 2015-2019.

MATERIAL AND METHODS

Observational, descriptive, epidemiologic study in a 5-year period including every registered birth in the state of Yucatan, Mexico using birth registries. A total of 158 432 live, physically healthy singletons (76 442 females and 81 990 males) between 25 and 42 weeks of gestation were included in the analysis. We used the LMS method to construct smoothed reference centiles (3rd, 10th, 25th, 50th, 75th, 95th, and 97th) and curves for males and females separately.

RESULTS

Mean maternal age was 26 (SD = 6.22) years. Fifty-two percent of births occurred by vaginal delivery, 37% were firstborn and similar proportions were second (33%) and third or more (30%) born. 5.5% of newborns included in the references corresponds to neonates born before 37 weeks of gestation (5.9% boys and 5.1% girls). In both sexes, the percentage of infants with a birthweight less than 2500 g was 6.7%. The birthweight at the 50th percentile for males and females at 40 weeks of gestation in this cohort was 3256 and 3167 g, respectively, and the corresponding values for birth length were 50.23 and 49.84 cm (mean differences between sexes: 89 g and 0.40 cm, respectively).

CONCLUSION

The reference percentile and curves developed in this study are useful for research purposes and can help health practitioners to assess the biological status of infants born in Yucatán.

The Associations Between Maternal Socioeconomic Factors and Adequacy of Energy and Macronutrient Intakes in Pregnant Women From Yucatan, Mexico

BACKGROUND

Socioeconomic factors influence diet quality during pregnancy. However, dearth of evidence about the influence on energy and macronutrients adequacy calls for research.

OBJECTIVE

To analyze the association between socioeconomic factors and adequacy rates of energy and macronutrients intakes in pregnant women from Merida, Yucatan, Mexico.

METHODS

During September to December 2019, we applied a socioeconomic questionnaire and three 24-hour dietary recalls to 83 pregnant females resident in Merida, Yucatan. Energy and macronutrient intakes were compared with the estimated trimester-specific energy and macronutrient requirements to calculate adequacies (%). Outcome variables were average adequacy of energy, carbohydrates, total fat, and protein intakes and the main predictors were maternal education, monthly family income, working status, and marital status. Descriptive statistics of adequacy were calculated for each category of predictors. The association between socioeconomic factors and outcome variables was analyzed through simple and multiple linear regression models.

RESULTS

Adequacy rates of energy and macronutrients decreased as education and familial income levels increased, as well as among unemployed women. Consistently with these results, simple linear regressions showed that years of education, family income, and working status (i.e., women working to earn money), were negatively associated with adequacy rates of energy and macronutrients intakes. When all predictors and covariates were included in a multiple linear regression model, only having a job was significantly associated with adequacy rates. Marital status was not associated with outcomes.

CONCLUSIONS

Women in disadvantaged socioeconomic conditions (unemployed and low levels of education and familial income) show greater energy and macronutrient intakes.

Analysis of risk factors and construction of a prediction model for short stature in children

BACKGROUND

Short stature in children is an important global health issue. This study aimed to analyze the risk factors associated with short stature and to construct a clinical prediction model and risk classification system for short stature.

METHODS

This cross-sectional study included 12,504 children aged 6-14 years of age from 13 primary and secondary schools in Pingshan District, Shenzhen. A physical examination was performed to measure the height and weight of the children. Questionnaires were used to obtain information about children and their parents, including sex, age, family environment, social environment, maternal conditions during pregnancy, birth and feeding, and lifestyle. The age confounding variable was adjusted through a 1 : 1 propensity score matching (PSM) analysis and 1,076 children were selected for risk factor analysis.

RESULTS

The prevalence of short stature in children aged 6-14 years was 4.3% in the Pingshan District, Shenzhen. The multivariate logistic regression model showed that the influencing factors for short stature were father's height, mother's height, annual family income, father's level of education and parents' concern for their children's height in the future (P < 0.05). Based on the short stature multivariate logistic regression model, a short stature nomogram prediction model was constructed. The area under the ROC curve (AUC) was 0.748, indicating a good degree of discrimination of the nomogram. According to the calibration curve, the Hosmer-Lemesio test value was 0.917, and the model was considered to be accurate. Based on a risk classification system derived from the nomogram prediction model, the total score of the nomogram was 127.5, which is considered the cutoff point to divides all children into low-risk and high-risk groups.

CONCLUSION

This study analyzed the risk factors for short stature in children and constructed a nomogram prediction model and a risk classification system based on these risk factors, as well as providing short stature screening and assessment individually.

Changes in blood pressure according to stature in Mexican adults

OBJECTIVE:

To determine the possible existence of differences in blood pressure change over time according to stature in Mexican adults.

METHODS:

We analyzed the National Household Living Standards Survey databases following household members between 2005 and 2009. We selected participants who were between 20 and 40 years old (n = 7,130). We estimated multilevel models with random intercept to analyze differences in blood pressure changes according to stature. We adjusted the models for age, locality size, geographic region, per capita family income, waist-to-height ratio, physical activity, alcohol consumption, smoking, and use of antihypertensive drugs.

RESULTS:

In both sexes, baseline blood pressure tended to be lower as stature decreased. The differences were maintained in both the crude and adjusted models. In men, the increases in systolic pressure over time tended to be higher as stature increased.

CONCLUSIONS:

Contrary to what studies observed in high-income countries, in Mexico blood pressure was positively associated with stature.

Mala nutrición en población escolar mexicana: factores geográficos y escolares asociados

OBJETIVOS

Determinar prevalencias de mala nutrición [sobrepeso u obesidad (Sp+O) y talla baja (TB)] en población mexicana de 6 a 12 años de edad de nivel básico de primaria, y su asociación con características geográficas (ámbito, marginación y región del país), y de la escuela (tipo, turno y grado).

MÉTODOS

Con información de 10 528 676 escolares, se estimaron prevalencias (e I.C. 95%), a nivel nacional y por características de interés, y su asociación mediante modelos de regresión logística.

RESULTADOS

La prevalencia nacional de Sp+O fue 34.4%, 36.5% en ámbito urbano y 40.2% en escuelas privadas. La prevalencia nacional de TB fue 8.7%; en área rural, 13.7% y 28.8% en escuelas tipo indígenas. El Sp+O y la TB se asociaron significativamente con características geográficas y de escuelas.

CONCLUSIONES

Existe una polarización nutricional en el contexto escolar del país. Es importante continuar con sistemas de monitoreo y vigilancia nutricional.

Identification and characterization of factors associated with short stature and pre-shortness in Chinese preschool-aged children

OBJECTIVES

We aimed to identify and characterize potential factors, both individually and jointly as a nomogram, associated with short stature and pre-shortness in Chinese preschool-aged children.

METHODS

Total of 9501 children aged 3-6 years were recruited from 30 kindergartens in Beijing and Tangshan from September to December 2020 using a stratified random sampling method. Effect-size estimates are expressed as odds ratio (OR) and 95% CI.

RESULTS

The prevalence of short stature and pre-shortness in preschool-aged children was 3.9% (n = 375) and 13.1% (n = 1616), respectively. Factors simultaneously associated with the significant risk for short stature, pre-shortness and both included BMI, paternal height, maternal height, birth weight, birth height, latter birth order (≥2) and less parental patience to children. Besides, breastfeeding duration (≥12 months) was exclusively associated with pre-shortness (OR, 95% CI, P: 1.16, 1.01 to 1.33, 0.037), and childhood obesity with both short stature (3.45, 2.62 to 4.54, <0.001) and short stature/pre-shortness (1.37, 1.15 to 1.64, <0.001). Modeling of significant factors in nomograms had descent prediction accuracies, with the C-index being 77.0, 70.1 and 71.2% for short stature, pre-shortness and both, respectively (all P < 0.001).

CONCLUSIONS

Our findings indicate the joint contribution of inherited characteristics, nutrition status from the uterus to childhood, and family psychological environment to short stature and pre-shortness in Chinese preschool-aged children. Further validation in other independent groups is warranted.

Identification of contributing predictors for short stature and pre-shortness among 7310 Chinese preschool-aged children

PURPOSES

We aimed to identify the contributing predictors for short stature and pre-shortness in Chinese preschool-aged children, and further to construct nomogram prediction models.

METHODS

A large cross-sectional, kindergarten-based study was conducted during September-November, 2019 in Beijing. Utilizing a stratified random sampling method, total 20 kindergartens with 7310 children with complete data were eligible for analysis.

RESULTS

The prevalence of short stature and pre-shortness was 3.0% (n = 222) and 11.6% (n = 848), respectively. Six contributing predictors were significantly associated with short stature, including parental height (odds ratio, 95% confidence interval, P: 0.773, 0.69-0.86, <0.001), maternal height (0.723, 0.64-0.82, <0.001), birthweight (0.826, 0.74-0.92, 0.001), birth height (0.831, 0.69-1.00, 0.046), children body mass index (1.204, 1.43-1.82, <0.001), and maternal age at menarche (1.614, 1.43-1.82, <0.001). Seven significant contributing predictors were found for pre-shortness, including parental height (0.805, 0.76-0.85, <0.001), maternal height (0.821, 0.77-0.87, <0.001), birthweight (0.881, 0.83-0.93, <0.001), birth height (0.86, 0.78-0.95, 0.003), gestational weight gain (0.851, 0.77-0.94, 0.002), children body mass index (1.142, 1.05-1.24, 0.002), and chronic disease (4.016, 1.66-9.70, 0.002). The nomogram models for short stature and pre-shortness had descent prediction accuracies.

CONCLUSIONS

Our findings indicate that short stature is predominantly determined by inherited and natal factors, and pre-shortness is additionally by modifiable factors.

Nutritional status and masticatory function of the indigenous compared with non-indigenous people of Nayarit, Mexico

OBJECTIVE

The objective of this study was to compare the nutritional statuses and masticatory function of the non-indigenous and indigenous adult people of the state of Nayarit, Mexico.

DESIGN

Forty-two indigenous (Cora or Huichol ethnic group) and 100 non-indigenous people, all adults with natural dentition, participated in this cross-sectional study. They performed a free-style masticatory test consisting five trials of chewing silicon pieces for 20 cycles. Masticatory performance was determined by sieving the silicon particles, masticatory laterality was determined by calculating the asymmetry index, and the cycle duration was also recorded. Weight and body fat mass were measured using a portable digital weighing machine and height and body circumferences were recorded to calculate the body mass index (BMI), body fat percentage, and the waist-hip ratio. Each aspect of masticatory function and each nutritional variable were compared using T-test, analysis of variance, and Kruskal-Wallis or Mann-Whitney tests, as appropriate.

RESULTS

Body fat percentage, BMI, and waist-hip ratio were higher (P < 0.0005) in the indigenous group compared to the non-indigenous. The indigenous group had a significantly shorter stature than the non-indigenous group. Cora group had a higher BMI and higher percentage of body fat than the Huichol group (P < 0.05). No significant differences were detected between the groups for any aspect of masticatory function.

CONCLUSIONS

Indigenous people from the Nayarit, especially the Cora ethnic group, are more obese, have more total body fat, and more abdominal fat than non-indigenous people. Indigenous people show similar masticatory function.

The association of sex of co-twin and birth size in twins born in Yucatan, Mexico between 2008 and 2017

Background: Birth measures of twins are potentially influenced by sex of co-twin.Aim: To analyse the association between sex of co-twin and birth weight, length and ponderal index in twin infants from Yucatan, Mexico.Subjects and methods: A total of 2057 twin pairs born during 2008-2017 were analysed. Female-female (F-F), male-male (M-M) and male-female (M-F) twin pair types were defined. Multiple linear regression models were used to analyse the association of (1) being female from M-F pairs and birth measures among overall female infants (M-F and F-F), and (2) being male from M-F pairs and birth measures among overall male infants (M-F and M-M). The length of gestation and mothers' age and level of education were used as covariates.Results: Models showed that being male from M-F pairs was associated with increases of 81 g in birth weight and 0.61 cm in length, compared to males from M-M pairs, and being female from opposite-sex pairs was associated with increases of 0.36 cm in length, compared to females from same-sex pairs.Conclusions: Males from M-F pairs show greater birth size than males from same-sex pairs, which supports the hypothesis that birth measures of twins are influenced by sex of the co-twin.

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 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.

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.

Genetic variation of FTO: rs1421085 T>C, rs8057044 G>A, rs9939609 T>A, and copy number (CNV) in Mexican Mayan school-aged children with obesity/overweight and with normal weight

OBJECTIVES

Genetic variation of the fat mass and obesity associated gene (FTO) has been identified as a risk factor for obesity and obesity traits. Distribution of FTO single nutleotide polymorphisms (SNPs) rs1421085T>C, rs9939609T>A, rs8057044G>A and copy number variation (CNV) was evaluated in association with childhood obesity or overweight status in children with Mayan ethnicity.

METHODS

We included 318 school-aged children with obesity or overweight status (body mass index [BMI]: >85th percentile) and 303 children with normal weight (BMI: 15th-85th percentile). Genotyping was performed using real-time polymerase chain reaction (RT-PCR) with TaqMan probes. The cross-sectional study was carried out using univariate and multivariate logistic regression models adjusted for gender.

RESULTS

FTO-SNP rs1421085 showed significant differences between children with obesity and children with normal weight for the heterozygous genotype (P = 0.003) and for allele frequencies (P = 0.023). Adjusting by gender, significant differences were found in frequencies of the hetezygous genotype of SNPs rs9939609 (P = 0.023) and rs1421085 (P = 0.003) as well as in allele frequencies (P = 0.042 and P = 0.013, respectively) between girls with obesity and girls without obesity. In contrast, SNP rs8057044 was significantly different only between heterozygous overweight versus normal weight boys (P = 0.035) and for the allele frequency of rs8057044 (P = 0.021). The mean relative CNV was significantly higher in male overweight children than in boys with normal weight (P = 0.000).

CONCLUSIONS

The FTO SNP rs1421085 is a genetic factor associated with obesity in Mayan school-aged children. FTO SNPs rs1421085 and rs9939609 affect genetic susceptibility for obesity only in girls, whereas, SNP rs8057044 and CNV are associated with overweight status only in boys.

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.