Age at menarche was investigated using data collected from demographic surveys (WFS, DHS) conducted in Nigeria between 1982 and 2018, all of which were based on large representative samples of the female population. Linear-logistic regressions were used to estimate mean age at menarche, its trends and its risk factors. Mean age at menarche had underwent a marked secular decline from 15.02 years for girls born in 1933 to 13.78 years for girls born in 2003. In multivariate analysis, height (stature), body mass index (BMI), level of education and household wealth had independent effects on age at menarche, whereas urban residence had no effect. Socioeconomic gradients were large: +9 years of schooling was associated with a –0.52 year decrease in age at menarche, and +2 standard deviations in household wealth with a –0.33 year decrease. The impact of anthropometry was even greater: +2 standard deviations in height was associated with a –0.99 year decrease in age at menarche, and +2 standard deviations in BMI with a –1.42 year decrease. Northern provinces had a higher mean age at menarche than southern provinces. Compared with independent sources, long-term trends in age at menarche, as well as their fluctuations, appeared to be correlated with trends and fluctuations in income per capita and in under-five mortality, but not with divergent trends in adult height.

中文翻译：

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尼日利亚人口调查中的初潮年龄

使用从 1982 年至 2018 年间在尼日利亚进行的人口调查（WFS、DHS）收集的数据对初潮年龄进行了调查，所有这些数据均基于女性人口的大量代表性样本。线性逻辑回归用于估计初潮平均年龄、趋势和风险因素。初潮的平均年龄从 1933 年出生的女孩的 15.02 岁显着下降到 2003 年出生的女孩的 13.78 岁。在多变量分析中，身高（身高）、体重指数（BMI）、教育水平和家庭财富对初潮年龄的独立影响，而城市居住没有影响。社会经济梯度很大：受教育超过 9 年与初潮年龄下降 –0.52 年相关，家庭财富标准差 +2 与下降 –0.33 年相关。人体测量学的影响甚至更大：身高+2 标准差与初潮年龄下降–0.99 岁相关，BMI 标准差+2 与–1.42 岁下降相关。北方省份的初潮平均年龄高于南方省份。与独立来源相比，初潮年龄的长期趋势及其波动似乎与收入的趋势和波动相关人均和 5 岁以下儿童死亡率，但与成人身高的不同趋势无关。