London Dec 16: A study of over a million women has shown that women who had their first menstrual cycle at age 10 or younger or age 17 or older may be at higher risk of developing heart disease stroke and complications of high blood pressure. Having the first menstrual cycle at the age of 13 appears to be the safest according to the study. 'The size of our study the wide range of ages considered and the vascular diseases being examined made it unique and informative' said study lead author Dexter Canoy from University of Oxford. For the study