Being a skinny teenager increases woman's risk of early menopause - study
Being a skinny teenager increases a woman's risk of having an early menopause, new research suggests.
The same association was found for women who are underweight in their mid-30s.
In addition, underweight women who lost 20 pounds or more on at least three occasions between the ages of 18 and 30 doubled their chances of ending reproductive life prematurely, the study found.
Early menopause is defined as naturally ceasing to have periods before the age of 45.
Researchers analysed data from 78,759 pre-menopausal women aged 25 to 42 who joined the US Nurses' Health Study II in 1989. The study was one of a series of major investigations into the causes of chronic disease in women.
Lead scientist Dr Kathleen Szegda, from the University of Massachusetts, said: "Our findings suggest that women who are underweight in early or mid-adulthood may be at increased risk for early menopause.
"Up to 10% of women experience early menopause and it is associated with a higher risk of cardiovascular disease, and other health conditions such as cognitive decline, osteoporosis and premature death, so these findings have important implications for women and their doctors.
"Underweight women may want to consider discussing the potential implications of these findings with their doctors."
Women taking part in the study provided information about medical history and health-related behaviour such as smoking and exercise.
Their progress was followed until 2011, by which time 2,804 participants had reported experiencing an early menopause.
Being underweight was defined as having a Body Mass Index (BMI) of less than 18.5. BMI is a standard measurement that relates weight and height.
Women who fell into this category at any age had a 30% increased risk of early menopause compared with lean or normal-weight women with BMIs of between 18.5 and 22.4.
For those who were underweight at age 18 with a BMI of less than 17.5, the risk was increased by 50%. Women who were classified as underweight at the age of 35 had a 59% greater likelihood of early menopause.
Underweight women who lost 20 pounds or more at least three times between the ages of 18 and 20 more than doubled their premature menopause chances.
However, the scientists said this finding should be treated with caution since it only applied to seven women.
Dr Szegda said: "Causes of early menopause are not clearly understood. Our findings suggest that being underweight may have an impact on the timing of menopause. More research is needed to understand how it increases the risk of early menopause."
The findings appear in the latest issue of the journal Human Reproduction.
Kathy Abernethy, who chairs the British Menopause Society, said: "The findings of this study highlight the need for women to maintain a healthy weight, for health reasons, not just after menopause, but across all ages.
"The risks of being overweight are generally better understood, but women often don't realise the potential hormonal complications of being very underweight, even in younger years.
"Sustained low weight described in this study of BMI of 18.5 or less (healthy BMI is usually 20-25) would have many health implications for a woman and earlier menopause is one risk."