Earlier menarche is associated with an increased risk of type 2 diabetes, whereas later menarche is associated with lower risk, researchers have said.
Early menarche (the first time a woman experiences menstruation) has previously been associated with a greater risk of gestational diabetes – which can precede type 2 diabetes – later in life.
In this latest study, a team from the North American Menopause Society (NAMS) analysed more than 15,000 postmenopausal women in China and the time in which they started menstruating. This analysis was then used to estimate the relationship between age of menarche and type 2 diabetes risk.
Earlier onset of menarche was associated with type 2 diabetes later in life, however this association was likely driven by adult BMI according to the researchers, which was calculated to account for around a quarter of the associated risk.
However, for every year that menstruation was delayed, the risk of developing type 2 diabetes later in life was 6% lower.
The menstrual cycle normally begins between the ages of 12-14, but it can also start in children as young as eight. A period is the regular natural change that occurs in the female reproductive system that makes pregnancy possible.
The association does not mean that early menarche causes a greater risk of type 2 diabetes. It is possible that certain factors increase the risk of both early menarche and type 2 diabetes, leading to the association seen on the study.
In addition to BMI, nutrition is another factor that could explain the association between early menarche and type 2 diabetes risk, according to lead author Dr Stephanie Faubion, the NAMS medical director.
Dr Faubion said: “This study of rural Chinese women indicates that the average age of menarche is delayed relative to western countries at 16.1 years and is linked with lower risk of type 2 diabetes.
“Earlier onset of menses was associated with diabetes in later life, likely driven by adult BMI. Other factors such as nutrition and BMI in childhood may also play a role in this association.”
The findings of this study have been published in the Menopause journal.