Secular Trends and Socioeconomic Differentials in Menarcheal Age for South Korean Women

Background: In this study, we assessed the secular trends and socioeconomic differentials in menarcheal age among women aged 25-64 year. Methods: Using the 5th Korea National Health and Nutrition Examination Survey (KNHANES, 2010-2012), bivariate analysis and one-way analysis of variance were used to test the statistical differences between age groups. Results: The mean age at menarche was 14.3 yr with a steep decrease in the younger cohort: from 15.9 yr in 1951-1955 to 13.1 yr in 1986-1990. Height as a proxy marker for early nutrition showed an inverse relationship with menarcheal age. The earlier menarcheal age patterns in women of higher socioeconomic position were ob-served according to one's education, monthly family income, occupation, region (urban vs. rural), and parental education. Conclusion: This result suggests a fast and ongoing trend in age at menarche and the socioeconomic discrepan-cy among Korean women in the last four decades.