Category Archives: American Journal of Human Biology
Mother’s education and infant survival in Ethiopia
Abstract
Objective
Few studies in Ethiopia have explored the impact of the mothers' education on infant survival. Therefore, this study aimed to identify and analyze the proximate factors in the relationship between maternal education and infant survival in Ethiopia.
Methods
This study used the nationally representative 2016 Ethiopian Demographic and Health Survey dataset. It analyzed a sample of 3831 newborn children using Cox regression models.
Results
The findings revealed that infants born to educated mothers had lower odds of infant mortality than those born to mothers without formal education. Specifically, infants whose mothers had completed secondary school and had a better antenatal care attendance rate had 49.9% lower odds of infant mortality than those born to mothers with no formal education and a poor antenatal care attendance rate. Furthermore, infants whose mothers had at least some postsecondary education and who used delivery by health-care professionals, clean drinking water, and improved toilet facilities had 65.3%, 56.3%, and 68.6% lower odds of infant mortality, respectively, than those born to mothers with no formal education and who did not use those facilities.
Conclusions
This study concluded that the mothers' educational disparity is intimately tied to infant mortality, and that access to formal education, mainly for women, increases infant survival in Ethiopia. Future research should focus on mothers without formal education who do not have access to antenatal care visits for safe pregnancy, delivery by health-care professionals, clean drinking water, and improved toilet facilities in Ethiopia and elsewhere in Sub-Saharan Africa.
Period: The real story of menstruation. By Clancy KBH, Princeton, New Jersey: Princeton Press. 2023. pp. 264. $27.95
Issue Information
Sleep duration in middle childhood and age at menarche
Abstract
Objective
Puberty affects sleep phasing. However, it is unclear if sleep duration earlier in childhood could influence the timing of pubertal events. We aimed to assess the association between middle childhood nighttime sleep duration and age at menarche (AAM).
Methods
In a cohort of 819 premenarcheal Colombian girls who were followed annually for the occurrence of menarche, we estimated adjusted hazard ratios (HR) with 95% confidence intervals (CI) for menarche by categories of recommended sleep duration in middle childhood using Cox models. Analyses were stratified by age at sleep assessment.
Results
Among girls aged 9 to <11 years, compared with girls who slept within recommendations, sleeping above recommendations was related to an adjusted 76% (95% CI: 4%, 198%; p = .04) higher probability of experiencing menarche during follow up. In girls aged ≥11 years, compared with girls who slept within recommendations, sleeping under recommendations was related to an adjusted 42% (95% CI: 5%, 93%; p = .03) higher probability of experiencing menarche during follow-up. Sleep duration was not associated with AAM in girls aged <9 years at the time of sleep assessment.
Conclusions
Sleeping above recommendations in girls 9 to <11 years-old and sleeping under recommendations in girls ≥11 years-old is associated with earlier menarche.
Thermoregulation of Tuvan pastoralists and Western Europeans during cold exposure
Abstract
Objectives
This study compared the metabolic and vascular responses, to whole-body and finger cold exposure, of a traditional population lifelong exposed to extreme cold winters with Western Europeans.
Methods
Thirteen cold acclimatized Tuvan pastoralist adults (45 ± 9 years; 24.1 ± 3.2 kg/m2) and 13 matched Western European controls (43 ± 15 years; 22.6 ± 1.4 kg/m2) completed a whole-body cold (10°C) air exposure test and a cold-induced vasodilation (CIVD) test, which involved the immersion of the middle finger into ice-water for 30 min.
Results
During the whole-body cold exposure, the durations until the onset of shivering for three monitored skeletal muscles were similar for both groups. Cold exposure increased the Tuvans' energy expenditure by (mean ± SD) 0.9 ± 0.7 kJ min−1 and the Europeans' by 1.3 ± 1.54 kJ min−1; these changes were not significantly different. The forearm-fingertip skin temperature gradient of the Tuvans was lower, indicating less vasoconstriction, than the Europeans during the cold exposure (0 ± 4.5°C vs. 8.8 ± 2.7°C). A CIVD response occurred in 92% of the Tuvans and 36% of the Europeans. In line, finger temperature during the CIVD test was higher in the Tuvans than the Europeans (13.4 ± 3.4°C vs. 3.9 ± 2.3°C).
Conclusion
Cold-induced thermogenesis and the onset of shivering were similar in both populations. However, vasoconstriction at the extremities was reduced in the Tuvans compared to the Europeans. The enhanced blood flow to the extremities could be beneficial for living in an extreme cold environment by improving dexterity, comfort, and reducing the risk of cold-injuries.
Dried blood spot based biomarkers in the Health and Retirement Study: 2006 to 2016
Abstract
Introduction
The Health and Retirement Study (HRS) has collected biomarker data over multiple waves. Such data can help improve our understanding of health changes in individuals and the causal pathways related to health. There are, however, technical challenges to using the HRS dried blood spots (DBS) biomarker data due to changes over time in assay protocols, platforms, and laboratories. We provide technical and summary information on biological indicators collected as part of the HRS from 2006 to 2016 that should be helpful to users of the data.
Methods
We describe the opportunities and challenges provided by the HRS DBS data as well as insights provided by the data. The HRS collected DBS from its nationally representative sample of respondents 51 years of age or older from 2006 to 2016. DBS-based biomarkers were collected from half the sample in 2006, 2010, and 2014, and from the other half of the sample in 2008, 2012, and 2016. These DBS specimens were used to assay total and HDL cholesterol, glycosylated hemoglobin, C-reactive protein, and cystatin C from 2006 to 2016, and Interleukin 6 was added in 2014/2016. Samples included approximately 6000 individuals at each wave, and completion rates ranged from 81% to 90%. HRS transformed DBS values into venous blood equivalents to make them more comparable to those of the whole blood-based assays collected in most other studies and to facilitate longitudinal analysis.
Results
Distribution of changes over time by age shows that total cholesterol levels decreased for each age, while HbA1c levels increased. Cystatin C shows a clear age gradient, but a number of other markers do not. Non-Hispanic Black persons and Hispanic respondents have a higher incidence of risk levels of each biomarker except for CRP among non-Hispanic Black older persons.
Conclusion
These public-use DBS data provide analysis opportunities that can be used to improve our understanding of health change with age in both populations and among individuals.
Small bites: Biocultural dimensions of children’s food and nutrition. By Tina Moffat, Vancouver, BC: University of British Columbia Press. 2022. pp. 244. $65 (cloth)
Effects of household composition on infant feeding and mother–infant health in northern Kenya
Abstract
Background
Households with alloparents, individuals other than the mother who care for an infant, can shift members' roles and affect mother–infant health.
Aims
To investigate how household composition relates to infant feeding and infectious disease risk in mother–infant dyads, the team utilized data from breastfeeding dyads (n 208) surveyed during a prolonged drought and food scarcity in northern Kenya.
Methods
Households were classified by the presence/absence of potential alloparents, distinguishing non-siblings and siblings of the infant. Regression models for breastfeeding frequency, complementary feeding status, and recent infections (n 83) evaluated these outcomes' associations with household type while accounting for food insecurity, adjusted for infant age, infant sex, and maternal age.
Results
Household type was unassociated with breastfeeding frequency, but the presence of non-sibling alloparents interacted with food insecurity, predicting increasing breastfeeding frequency as food insecurity intensified among dyads living with non-sibling alloparents. Households with non-sibling alloparents were also inversely associated with complementary feeding but had no association with infection. Households with siblings were inversely associated with (protective against) infant and maternal infection.
Conclusion
Further research is needed to understand the interactive influence of household social and food ecologies on mother–infant diet and health under diverse cultural rules and norms for alloparenting.
Composite indexes of anthropometric failure in children under 5 years of age in Argentina: Comparative analysis among regions: 2019–2020
Abstract
Objectives
Composite Index of Anthropometric Failure (CIAF) and Extended CIAF (ECIAF) allow for the identification of simultaneous presence of two or more types of malnutrition. The objective of this study was to analyze anthropometric failure in Argentinean children under 5 years old, taking into consideration regional and socioeconomic perspectives.
Materials and Methods
Data from the National Survey of Children and Adolescents MICS 2019–2020 were used, which included 5473 children under 5 years old of both sexes residing in the six regions of Argentina. CIAF and ECIAF excludes children not in anthropometric failure (group A) and was calculated from a percentage of children included in malnutrition categories B: wasting only; C: wasting and underweight; D: wasting, stunting, and underweight; E: stunting and underweight; F: stunting only; Y: underweight only; G: only weight excess; and H: stunting and weight excess. The data were analyzed according to region and wealth quintile.
Results
In children aged 0–2.99 years, CIAF was 12.5% and ECIAF was 27.7%, with boys being more affected. In children aged 3–4.99 years, the rates were 9.7% and 22.3%, respectively, with girls showing a higher prevalence. The highest ECIAF was recorded in the Patagonia region (31.3%), while the highest ECIAF was observed in the poorest quintile.
Discussion
The presence of double burden of malnutrition has been observed across all regions and household income levels. Additionally, overweight has shown a higher intensity in economically prosperous regions and households, while stunting has been more prevalent in economically disadvantaged areas.