Factor analysis of climacteric symptoms in Japan

Abstract

Objectives To identify menopausal and climacteric symptoms among midlife Japanese women by factor analysis of symptom frequency and severity data. Methods Demographic information, anthropometric data, 2-week recalls of 82 symptoms, and assessment of epidemiological menopausal and self-defined kōnenki (climacteric) status were collected from 140 Japanese women living in Kyoto and Fukushima prefectures. Factor analysis was performed using symptom frequency scores and frequency-severity scores. To identify the symptoms constituting menopausal and climacteric syndromes in Japan, regression scores for individual factors were compared by menopausal and kōnenki status groups using non-parametric tests. Results Among 140 women aged 49.5 ± 3.0 years (mean ± S.D.), the three most prevalent symptoms were shoulder stiffness, memory loss, and stress. Analysis of frequency data resulted in an eight-factor solution, and frequency-severity data in a seven-factor solution. Anxiety and depression factors and a sexual-vasomotor factor were observed in almost all factor solutions, with additional factors comprised of psychosomatic and somatic symptoms. Anxiety scores differed by menopausal status, depression scores by kōnenki status, and sexual-vasomotor scores by both. Chilliness was highly correlated with sexual-vasomotor symptoms and frequency scores differed significantly between menopausal but not kōnenki groups. Conclusions Sexual-vasomotor symptoms constitute a robust menopausal and kōnenki symptom grouping among Japanese women, but do not include night sweats or the foreign word hotto furasshu, yet do include chilliness, which may reflect thermoregulatory instability. Overlap of factors displaying significant differences between menopausal and kōnenki groups indicate a transition to a more medicalized concept of kōnenki in use by Japanese women.