Data from: Thrifty phenotype vs cold adaptation: trade-offs in upper limb proportions of Himalayan populations of Nepal

The multi-stress environment of high altitude has been associated with growth deficits in humans, particularly in zeugopod elements (forearm, lower leg). This is consistent with the thrifty phenotype hypothesis, which has been observed in Andeans, but has yet to be tested in other high altitude populations. In Himalayan populations, other factors, such as cold stress, may shape limb proportions. The current study investigated whether relative upper limb proportions of Himalayan adults (n=254) differ between highland and lowland populations, and whether cold adaptation or a thrifty phenotype mechanism may be acting here. Height, weight, humerus length, ulna length, hand length, and hand width were measured using standard methods. Relative to height, total upper limb and ulna lengths were significantly shorter in highlanders compared to lowlanders in both sexes, whilst hand and humerus length were not. Hand width did not significantly differ between populations. These results support the thrifty phenotype hypothesis, as hand and humerus proportions are conserved at the expense of the ulna. The reduction in relative ulna length could be attributed to cold adaptation, but the lack of difference between populations in both hand length and width indicate that cold adaptation is not shaping hands proportions in this case.

高海拔多应激环境已被证实与人类生长发育缺陷存在关联，尤以肢节（zeugopod elements，即前臂、小腿）最为显著。这与节俭表型假说（thrifty phenotype hypothesis）相符，该假说已在安第斯人群中得到验证，但尚未在其他高海拔人群中得到检验。在喜马拉雅人群中，寒冷应激等其他因素或可影响肢体比例。本研究针对254名喜马拉雅成年人展开，旨在探究其上肢相对比例在高海拔与低海拔人群间是否存在差异，以及寒冷适应或节俭表型机制是否在此发挥作用。研究采用标准测量方法获取了受试者的身高、体重、肱骨（humerus）长度、尺骨（ulna）长度、手长及手宽。以身高为参照时，两性高海拔人群的上肢总长度与尺骨长度均显著短于低海拔人群，而手长与肱骨长度则无显著组间差异。不同人群的手宽则无显著差异。本研究结果支持节俭表型假说：手与肱骨的比例得以保留，而尺骨长度为此做出了牺牲。相对尺骨长度的缩短或可归因于寒冷适应，但手长与手宽在人群间均无显著差异，说明寒冷适应并未在此研究中影响手部比例。