[Determinants of chilliness among young women and their application to psychopharmacological trials]

Chilliness is a common complaint among menopausal women. Increasing evidence indicates that young women also suffer from chilliness, resulting in decreased learning, motivation, and concentration. Neither diagnostic criteria nor drug therapies exist for chilliness, and thus, young women suffer from insomnia, fatigue, and mood disturbance. Because chilliness is correlated with hormonal changes observed during premenstrual, postpartum, and menopausal periods, reproductive hormones are likely involved. Recently, we elucidated methodological issues related to identifying young women with chilliness. We used a new questionnaire to determine complaint severity with regard to chills and assessed physical parameters (BMI, body fat ratio, basal metabolism, blood pressure), peripheral circulation, and recovery of skin surface temperature after mild cold-water finger immersion. Using a discriminant analysis (hit ratio, 84.5%), we demonstrated that four parameters (blood flow, difference between underarm and surface temperature, recovery rate after mild cold exposure, and score for chilliness-related complaints) were important determinants of chilliness. Among traditional candidate substances for alleviating chilliness, Piper longum and royal jelly showed significant effects. Additionally, we investigated seasonal change in the experience of chilliness and found that young women suffer from chilliness during the summer. These findings have important implications for understanding chilliness in women.