Zamudio S, Droma T, Norkyel K Y, Acharya G, Zamudio J A, Niermeyer S N, Moore L G
Cardiovascular Pulmonary Research Laboratory, University of Colorado Health Sciences Center, Denver 80262.
Am J Phys Anthropol. 1993 Jun;91(2):215-24. doi: 10.1002/ajpa.1330910207.
Intrauterine growth retardation has long been recognized at high altitude. Since growth-retarded babies have a decreased chance of survival, intrauterine growth retardation would be expected to have been selected against in populations long resident at high altitude. We have previously reported that Tibetan babies born at 3,658 m weighed more than their North or South American altitude counterparts. This study sought to determine whether Tibetans were protected from altitude-associated intrauterine growth retardation. We compared birth weights in Tibetans living at low altitude in Kathmandu, Nepal (elevation 1,200 m), or at high altitude in Lhasa, Tibet Autonomous Region, China (elevation 3,658 m). Birth weights were similar in 45 low-altitude and 34 high-altitude Tibetan births regardless of whether all infants or only full-term births were considered, or whether birth weight was adjusted for variation in maternal parity, gestational age, and infant sex. In comparison with literature observations, the altitude-associated difference in birth weight was smallest in Tibetans, intermediate in South America, and greatest in North America. These data support the hypothesis that Tibetans are protected from altitude-associated intrauterine growth retardation and suggest that selection for optimization of birth weight at high altitude has occurred in Tibetans.
宫内生长迟缓在高海拔地区早已为人所知。由于生长迟缓的婴儿存活几率降低，因此预计长期居住在高海拔地区的人群中，宫内生长迟缓会被自然选择淘汰。我们之前曾报道，在海拔3658米出生的藏族婴儿比他们在北美洲或南美洲相同海拔出生的婴儿体重更重。本研究旨在确定藏族人是否能免受与海拔相关的宫内生长迟缓影响。我们比较了居住在尼泊尔加德满都低海拔地区（海拔1200米）或中国西藏自治区拉萨高海拔地区（海拔3658米）的藏族人的出生体重。无论考虑所有婴儿还是仅考虑足月儿，或者是否根据产妇产次、孕周和婴儿性别差异对出生体重进行调整，45例低海拔藏族婴儿和34例高海拔藏族婴儿的出生体重相似。与文献观察结果相比，藏族人中与海拔相关的出生体重差异最小，南美洲居中，北美洲最大。这些数据支持了藏族人能免受与海拔相关的宫内生长迟缓影响这一假设，并表明藏族人在高海拔地区已发生了为优化出生体重的自然选择。
