Abstract
The sudden drop in estrogen levels during menopause causes a variety of generalized complaints such as hot flashes, sweating, and fatigue in addition to skin symptoms such as irritation, pruritus and dryness. However, few studies have focused on these symptoms, especially skin symptoms, and much is still unknown about their causes. In this study, we first investigated the correlation between the severity of menopausal symptoms (Simplified Menopausal Index: SMI) and variety of skin problems by a questionnaire survey conducted on 176 women aged 45 to 55 who were aware of menopausal symptoms. In addition to hot flashes and sweating, many skin problems related with dry skin and barrier dysfunctions including pruritus were correlated with SMI scores. Moreover, subjects with high SMI showed increased levels of transepidermal water loss compared with those with low SMI. Thus, we examined the usefulness of hyaluronic acid fragments (molecular weight in the range of 50000-110000) as a novel mean to relieve menopausal skin symptoms, mainly targeting dysfunction of the epidermis. Hyaluronic acid fragments accelerated both proliferation and differentiation of cultured human epidermal keratinocytes, although hyaluronic acid with smaller molecular weight (under 10000) enhanced the proliferation but not the differentiation and hyaluronic acid with high molecular weight (over 1000000) supported the differentiation but not the proliferation. Finally, topical application of hyaluronic acid fragments restored impaired permeability barrier function and increased hydration of the stratum corneum in subjects with high SMI scores, accompanying with an increase of satisfaction with their skin condition. These results that hyaluronic acid fragments could be useful for alleviating skin symptoms during menopause.
