Surname‐Inferred andean ancestry is associated with child stature and limb lengths at high altitude in Peru, but not at sea level

Abstract

ObjectivesNative Andean ancestry gives partial protection from reduced birthweight at high altitude in the Andes compared with European ancestry. Whether Andean ancestry is also associated with body proportions and greater postnatal body size at altitude is unknown. Therefore, we tested whether a greater proportion of Andean ancestry is associated with stature and body proportions among Peruvian children at high and low altitude.MethodsHeight, head circumference, head‐trunk height, upper and lower limb lengths, and tibia, ulna, hand and foot lengths, were measured in 133 highland and 169 lowland children aged 6 months to 8.5 years. For highland and lowland groups separately, age‐sex‐adjusted anthropometry z scores were regressed on the number of indigenous parental surnames as a proxy for Andean ancestry, adjusting for potential confounders (maternal age and education, parity, altitude [highlands only]).ResultsAmong highland children, greater Andean ancestry was negatively associated with stature and tibia, ulna, and lower limb lengths, independent of negative associations with greater altitude for these measurements. Relationships were strongest for tibia length: each additional Andean surname or 1,000 m increase at altitude among highland children was associated with 0.18 and 0.65 z score decreases in tibia length, respectively. Anthropometry was not significantly associated with ancestry among lowland children.ConclusionsGreater Andean ancestry is associated with shorter stature and limb measurements at high but not low altitude. Gene‐environment interactions between high altitude and Andean ancestry may exacerbate the trade‐off between chest dimensions and stature that was proposed previously, though we could not test this directly. Am. J. Hum. Biol. 27:798–806, 2015. © 2015 The Authors American Journal of Human Biology Published by Wiley Periodicals, Inc.

Regional variation in weight‐for‐height z‐scores and surface area/body mass ratio of Chilean children from birth to 3 years of age

“…Altitude is another ecogeographic factor that could affect the variation of weight‐for‐height or SA/mass in the present study. However, the effect is generally observed in altitudes above ∼2,500 m above sea level (Pomeroy et al, ), while in the present study the counties with the highest altitude do not exceed 520 m above sea level and most of the counties are coastal (Easter Island, Coquimbo, Talcahuano, Tirúa, Puerto Montt, and Punta Arenas, Figure ).…”

Human Genetic Adaptation to High Altitude: Evidence from the Andes

“…However, there appears to be an interaction between Andean ancestry and high-altitude residence that acts to increase the altitude-associated expansion of chest dimensions and lung volumes [ 19 ] and reduction in stature and limb measurements [ 21 ]. While more studies are needed with controls for confounding factors, the improved efficiency of O 2 transfer is likely important for maintaining arterial O 2 saturation and thus, blood O 2 content during exercise [ 16 , 22 ].…”

A decade of rapid change: Biocultural influences on child growth in highland Peru

“…Conventional physiological explanations of developmental delay during childhood include malnutrition (Leonard, ; Obert et al, ), infectious disease (Martorell, ), and genetics (Greksa, ; Pomeroy et al, ). Research in the Andes has perforce needed to also focus on the altitude at which a child lives because of the physiological effects of high altitude hypoxia such as slowed fetal growth (Carter, ) and shorter stature (Frisancho, ; Román et al, ; Stinson, ).…”