Growth references for Tsimane forager‐horticulturalists of the Bolivian Amazon

Abstract

Objectives Growth standards and references currently used to assess population and individual health are derived primarily from urban populations, including few individuals from indigenous or subsistence groups. Given environmental and genetic differences, growth may vary in these populations. Thus, there is a need to assess whether international standards are appropriate for all populations, and to produce population specific references if growth differs. Here we present and assess growth references for the Tsimane, an indigenous population of Bolivian forager-horticulturalists. Methods Mixed cross-sectional/longitudinal anthropometrics (9,614 individuals; 30,118 observations; ages 0–29 years) were used to generate centile curves and Lambda-Mu-Sigma (LMS) tables for height-for-age, weight-for-age, body mass index (BMI)-for-age, and weight-for-height (WFH) using Generalized Additive Models for Location Shape and Scale (GAMLSS). Velocity curves were generated using SuperImposition by Translation and Rotation (SITAR). Tsimane ≤5 years were compared World Health Organization (WHO) standards while those >5 years were compared to WHO school age references. All ages were compared to published references for Shuar forager-horticulturalists of the Ecuadorian Amazon. Results Tsimane growth differs from WHO values in height and weight, but is similar for BMI and WFH. Tsimane growth is characterized by slow height velocity in childhood and early adolescent peak height velocity at 11.3 and 13.2 years for girls and boys. Tsimane growth patterns are similar to Shuar, suggesting shared features of growth among indigenous South Americans. Conclusions International references for BMI-for-age and WFH are likely appropriate for Tsimane, but differences in height-for-age and weight-for-age suggest Tsimane specific references may be useful for these measures.

Growth curves and the international standard: How children's growth reflects challenging conditions in rural Timor‐Leste

“…Growth velocity was modeled for height and weight using the SuperImposition by Translation And Rotation (SITAR) method (Cole, Donaldson, & Ben‐Shlomo, ), following the R code provided by Blackwell et al (). This method fits a random effects model to individual growth curves.…”

Relationship of sanitation, water boiling, and mosquito nets to health biomarkers in a rural subsistence population

“…Most water collection is done by women and children, and thus male respondents may be over estimating the proportion of time that water is being boiled (Rosinger, ). Children facing trade‐offs between growth and immune function may be at particular risk (Blackwell et al, ; Urlacher et al, ), especially because children are usually bare‐foot, and therefore have more direct exposure to soil‐transmitted parasites. Future studies will focus on how these behaviors impact child growth and well‐being.…”

“…While many studies examine how water, bed nets, and sanitation interact with health in rural settings, we expand on the current literature by testing whether these behaviors are additive or interactive; for example is latrine use more effective if water is also boiled? Exposure to pathogens such as those found in contaminated water can influence fecundity, growth, and productivity (Blackwell et al, ; Blackwell et al, ; Blackwell et al, ). Since sewage, clean water, and mosquito nets are all commonly utilized by public health interventions, understanding the objective health contributions of water source, sanitation, and mosquito net use can help public health institutions prioritize scarce resources.…”

Anthropometric heritability and child growth in a Caribbean village: A quantitative genetic analysis of longitudinal height, weight, and body mass index in Bwa Mawego, Dominica

“…Secular trends among U.S. children and adolescents show similar increases in weight (+5–7 kg) and relatively smaller gains in height (+1.5–2.0 cm) from 1960–2002 (Ogden, Fryar, Carroll, & Flegal, ). Longitudinal data from Tsimane forager‐horticulturalists show that adolescents gained 0.6 cm in height, 0.5–1.4 kg in weight, and 0.16–0.56 units in BMI per decade from 2002 to 2015 (Blackwell et al, ). Few individuals in Bwa Mawego fall into clinically defined overweight or obese categories at any time point in these longitudinal data (Table ; Figure ), and we do not find clear evidence of a population‐wide increase in BMI in these younger generations (Table ; Figure ).…”