Trade-Offs in Relative Limb Length among Peruvian Children

Extending the Thrifty Phenotype Hypothesis to Limb Proportions

Dados Bibliográficos

ID23355643
AutoresE Pomeroy (0000-0001-6251-2165, University of Cambridge, autor correspondente), Jay T Stock (0000-0003-0147-8631, University of Cambridge), Sanja Stanojevic (0000-0001-7931-8051, Hospital for Sick Children), J Jaime Miranda (0000-0002-4738-5468, Universidad Peruana Cayetano Heredia), Tim J Cole (0000-0001-5711-8200, University College London), J Wells (0000-0003-0411-8025, University College London), Jonathan C K Wells
EditoresCarol V Ward (0000-0001-6255-9668)
Ano2012
Volume7
Fascículo12
Páginase51795
Data de publicação2012-12-13
Peer ReviewedSim
Open AccessSim
TipoARTICLE
PeriódicoPLoS ONE (JOURNAL)
Identificadores do periódicoISSN: 1932-6203 • E-ISSN: 1932-6203
EditoraPublic Library of Science (PLoS) (PUBLISHER)
DOI10.1371/journal.pone.0051795
PMID23272169
PMCIDPMC3521697
OpenAlexW2056771921
IdiomaEN
Citações recebidas63
Referências citadas80

BACKGROUND AND METHODS: Both the concept of 'brain-sparing' growth and associations between relative lower limb length, childhood environment and adult disease risk are well established. Furthermore, tibia length is suggested to be particularly plastic under conditions of environmental stress. The mechanisms responsible are uncertain, but three hypotheses may be relevant. The 'thrifty phenotype' assumes that some components of growth are selectively sacrificed to preserve more critical outcomes, like the brain. The 'distal blood flow' hypothesis assumes that blood nutrients decline with distance from the heart, and hence may affect limbs in relation to basic body geometry. Temperature adaptation predicts a gradient of decreased size along the limbs reflecting decreasing tissue temperature/blood flow. We examined these questions by comparing the size of body segments among Peruvian children born and raised in differentially stressful environments. In a cross-sectional sample of children aged 6 months to 14 years (n = 447) we measured head circumference, head-trunk height, total upper and lower limb lengths, and zeugopod (ulna and tibia) and autopod (hand and foot) lengths. RESULTS: Highland children (exposed to greater stress) had significantly shorter limbs and zeugopod and autopod elements than lowland children, while differences in head-trunk height were smaller. Zeugopod elements appeared most sensitive to environmental conditions, as they were relatively shorter among highland children than their respective autopod elements. DISCUSSION: The results suggest that functional traits (hand, foot, and head) may be partially protected at the expense of the tibia and ulna. The results do not fit the predictions of the distal blood flow and temperature adaptation models as explanations for relative limb segment growth under stress conditions. Rather, our data support the extension of the thrifty phenotype hypothesis to limb growth, and suggest that certain elements of limb growth may be sacrificed under tough conditions to buffer more functional traits.

Biology · Gene · Phenotype · Birth, Development, and Health · Body Composition Measurement Techniques · Bone fractures and treatments · Demography · Genetics · Medicine