The application of soy isoflavones for subjective symptoms and objective signs of vaginal atrophy in menopause: A systematic review of randomised controlled trials.

Vaginal atrophy is a common complaint among many women in their menopause, presenting with a cluster of symptoms including dryness, itching, burning/soreness, discharge, irritation and painful intercourse. We searched for existing pertinent data in three chief registries. Specified time brackets included 1996-2013 for Medline, 1990-2013 for Scopus and 2013 for Cochrane Central Register of Controlled Trials (issue 1). Of 110 potentially relevant publications, 17 and 9 trials (7 on maturation value and 2 on vaginal dryness) were selected for qualitative and quantitative analysis, respectively. In general, soy isoflavones seem to improve vaginal symptoms as opposed to control arms. Soy isoflavones were also shown to be more efficacious in quantitative analysis, though this was statistically non-significant. Standardised difference in means of maturation value change was 0.072 (95% confidence interval [CI]: - 0.42 to 0.57), p = 0.777; heterogeneity P = 0.00; I(2) = 85.15%. Difference in means of vaginal dryness was - 0.204 (95% CI: - 0.28 to - 0.126), p < 0.001; heterogeneity P = 0.423; I(2) = 0.00. Soy isoflavones may relieve vaginal symptoms during menopause; nevertheless beneficial effects still remain uncertain due to possible publication bias or vast heterogeneity of the selected studies. Further studies with consistency in design as well as statistics are warranted.