The sex hormone oestrogen plays a vital role in the development of the female skeleton. Testosterone (male hormone) also assists with the development of the female skeleton.

Adolescence

During puberty the increased levels of the sex hormones lead to an increase in size and bone mass of the skeleton.³⁰ Ongoing production of oestrogen is vital in adolescent females and young women so as to maintain bone mass. Reduced exposure to oestrogen during life as can occur when there are absent or infrequent menstrual cycles, delay in the onset of the first period or early menopause will affect the attainment of peak bone mass and maintenance of bone mass.

Preceding menopause

Even in the years immediately proceeding menopause there can be a drop in oestrogen levels that leads to a fall in bone mineral density.⁵

Menopause

Menopause is associated with a dramatic fall in oestrogen levels that results in significant loss of bone mass, which can last from 4 to 8 years after the onset of menopause. This bone loss initially mainly affects the spinal column (vertebrae). Usually, however, most bone is lost in the first 3 years after menopause and then the rate of bone loss slows. During the first 3 years after menopause, women may lose up to approximately 2% of bone mass per year especially in the spinal bones (vertebral
bones). ^5,31,32 The extent of bone loss in hips and wrist may be similar or slightly less.^5,31,32 Once women have passed through this rapid rate of bone loss, the rate of bone loss significantly slows and women generally can expect to lose approximately less than 1% of bone density at the hip per year, with the rate of change in the spine being even slower.^5,31,32

Content updated February 20, 2006