Fujii Katsunori, Demura Shinichi
Health Science, General Education, Aichi Institute of Technology, Yakusa-cho, Toyota-city, Japan.
J Physiol Anthropol Appl Human Sci. 2003 Mar;22(2):97-104. doi: 10.2114/jpa.22.97.
Body mass index (BMI) is widely used as an index of obesity in people from the school age children to adults. However, the relationship between the change in BMI with age and the coming of menarche has not been discussed as there are few reports on the changes in BMI with age. In this study, the change in BMI with age was examined by applying the wavelet interpolation method (WIM), and a critical period for body fat in terms of the coming of menarche was estimated from the growth velocity. We investigated delayed menarche according to the influence of stress in athletes by comparing delayed menarche between athletes and non-athletes in relation to the critical period. Data were obtained from 144 female athletes in their first year at university in the Tokai area, all of whom had competed in a national sports competition in high school (athlete group). Health examination records showing these subjects' heights and weights from the first grade of elementary school to the final year of high school (1984-1995) were collected and BMI was calculated for each grade. Ages at menarche were ascertained from questionnaires. A control group of 73 non-athletes was similarly examined. The age at maximum peak velocity (MPV) derived from the growth (aging) distance curve of BMI was determined in the control group to be 11.96+/-0.97 years old. This age at MPV of BMI was almost the same as the age at menarche (12.11+/-0.93 years old). Therefore, this age at MPV of BMI is estimated to be the critical period of body fat for the coming of menarche. The interval between the age at MPV of BMI and age at menarche was 0.74+/-1.30 years in the athlete group and 0.15+/-0.81 years in the control group, so there was a significant difference (P<0.01) between the two groups. It is suggested that the delayed menarche in athletes is influenced by the stress of regular sports training.
身体质量指数（BMI）被广泛用作衡量从学龄儿童到成年人肥胖程度的指标。然而，由于关于BMI随年龄变化的报道较少，BMI随年龄的变化与初潮到来之间的关系尚未得到讨论。在本研究中，应用小波插值法（WIM）研究了BMI随年龄的变化，并根据生长速度估计了初潮到来时身体脂肪的关键时期。我们通过比较运动员和非运动员在关键时期的初潮延迟情况，研究了运动员压力对初潮延迟的影响。数据来自东海地区144名大学一年级的女运动员，她们都曾在高中参加过全国体育比赛（运动员组）。收集了这些受试者从小学一年级到高中最后一年（1984 - 1995年）的身高和体重健康检查记录，并计算了各年级的BMI。通过问卷调查确定初潮年龄。对73名非运动员组成的对照组进行了类似检查。在对照组中，从BMI的生长（年龄增长）距离曲线得出的最大峰值速度（MPV）年龄为11.96±0.97岁。这个BMI的MPV年龄与初潮年龄（12.11±0.93岁）几乎相同。因此，估计这个BMI的MPV年龄是初潮到来时身体脂肪的关键时期。运动员组中BMI的MPV年龄与初潮年龄之间的间隔为0.74±1.30岁，对照组为0.15±0.81岁，两组之间存在显著差异（P<0.01）。提示运动员的初潮延迟受常规体育训练压力的影响。
