Early menstruation increases the likelihood of hot flushes and nights sweats decades later at menopause, according to a study. The research led by University of Queensland researchers is published in BJOG: an International Journal of Obstetrics and Gynaecology. School of Public Health researchers analysed data from more than 18,000 middle-aged women across the UK, USA and Australia, as part of the Life-course Approach to reproductive health and Chronic disease Events (InterLACE) international collaboration. UQ's Dr Hsin-Fang Chung said the study showed women who started menstruating aged 11 or younger had a 50 per cent higher risk of experiencing frequent hot flushes and night sweats - known as vasomotor symptoms - at menopause. The group was compared with women who had their first period at 14 or older. "The risk of the women who menstruated early experiencing both symptoms was greater than having either hot flushes or night sweats alone," Dr Chung said. She said early menstruation previously had been linked to adverse health conditions later in life, including type 2 diabetes and cardiovascular diseases. InterLACE project leader Professor Gita Mishra said obesity played a significant role in the findings.