Menarche and Sleep among Japanese Schoolgirls: An Epidemiological Approach to Onset of Menarche

Abstract

Menarche occurs in the pubertal period of normal girls without endocrine disorders; nevertheless, the mechanism of its onset remains unclear. A cross-sectional study was conducted in 254 schoolgirls aged 9 to 15 years to clarify the effects of age, body weight, height, hours of sleep, and sleep conditions on the onset of menarche. Among six schoolyear groups comprising about 42 girls for each, the menarcheal percent, body weight, and height significantly increased according to the school year; by contrast, hours of sleep shortened significantly. The maximal increase in the menarcheal percent followed the abrupt decrease in hours of sleep. The result of multiple logistic regression analysis indicated that body weight, height, and hours of sleep were significantly related to the presence/absence of manarche while controlling for the effects of age and sleep conditions. These data suggest that the onset of menarche is affected by hours of sleep, as well as body weight and height reported in the previous studies. © 1993, Tohoku University Medical Press. All rights reserved.