Gillett-Netting Rhonda, Meloy Melissa, Campbell Benjamin C
Department of Anthropology University of Arizona, Tucson, Arizona 85721-0030, USA.
Am J Hum Biol. 2004 Nov-Dec;16(6):658-69. doi: 10.1002/ajhb.20081.
To compare the timing of reproductive maturation among urban and rural Tonga girls in Zambia, anthropometric measures and Tanner stages of breast development were obtained. Subjects were 774 (282 rural, 492 urban) girls ages 6-18. Results indicate that rural girls are shorter and have smaller triceps and subscapular skinfolds than their urban counterparts. Median age at menarche for the entire sample, as estimated by probit analysis, was 14.8 years (95% CL = 14.34-15.40). Onset of breast development among urban girls was significantly younger than for the rural girls: 11.47 (95% CL 11.22-11.71) years vs. 13.15 (95% CL 12.40-14.15) years. In contrast, the two groups did not differ in timing of pubertal completion as assessed by median age for Tanner Breast Stage 5: 17.01 (95% CL 16.30-18.33) vs. 16.96 (95% CL 16.37-17.56) years. Predictors of pubertal onset, based on multivariate logistic regression, included dental maturation, height, and triceps skinfold. Triceps skinfold was the only significant predictor of pubertal completion. These results suggest that rural girls progress through puberty more rapidly than the urban girls despite their later start. This finding of maturational catch-up contrasts with earlier urban/rural comparisons of girls as well as previous results among Gwembe boys, for which later pubertal onset is associated with longer duration of pubertal maturation. While the mechanism remains unclear, biocultural explanations suggest preferential feeding during adolescence as a source for rural girl's maturational catch-up.
为比较赞比亚城市和农村的汤加女孩生殖成熟的时间，研究人员获取了她们的人体测量数据以及乳房发育的坦纳分期。研究对象为774名6至18岁的女孩（282名农村女孩，492名城市女孩）。结果表明，农村女孩比城市女孩更矮，肱三头肌和肩胛下皮褶厚度更小。通过概率分析估计，整个样本月经初潮的中位年龄为14.8岁（95%可信区间=14.34 - 15.40）。城市女孩乳房发育开始的时间明显早于农村女孩：分别为11.47岁（95%可信区间11.22 - 11.71）和13.15岁（95%可信区间12.40 - 14.15）。相比之下，根据坦纳乳房分期5期的中位年龄评估，两组在青春期结束时间上没有差异：分别为17.01岁（95%可信区间16.30 - 18.33）和16.96岁（95%可信区间16.37 - 17.56）。基于多因素逻辑回归分析，青春期开始的预测因素包括牙齿成熟度、身高和肱三头肌皮褶厚度。肱三头肌皮褶厚度是青春期结束的唯一显著预测因素。这些结果表明，尽管农村女孩青春期开始较晚，但她们度过青春期的速度比城市女孩更快。这一成熟追赶的发现与早期女孩城乡比较以及之前格温贝男孩的研究结果形成对比，在那些研究中，青春期开始较晚与青春期成熟持续时间较长相关。虽然其机制尚不清楚，但生物文化学解释认为青春期的优先喂养是农村女孩成熟追赶的一个原因。
