The sex hormone oestrogen plays a vital role in the development of the female skeleton. Testosterone (male hormone) also assists 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 skeleton³⁰. Ongoing production of oestrogen is vital in adolescent females and young women so as to maintain bone mass. Testosterone plays an important but lesser role in bone formation. Reduced exposure to oestrogen during life as can occur in the setting of absent or infrequent menstrual cycles, delayed onset of the first period or early menopause will affect the attainment of peak bone mass and maintenance of bone density.

Levels of growth hormone and sex hormones increase rapidly during puberty. Adequate levels of growth hormone during the pubertal period contribute to bone growth¹.

Preceding menopause

In the years immediately before menopause there can be a drop in oestrogen levels, and this can lead to a reduction in bone mineral density⁵. It is during this time that the balance between bone loss and bone formation favours increased loss of bone.

Menopause

Menopause is associated with a dramatic fall in oestrogen levels, and the loss of bone is accelerated and even greater than during the peri-menopause. This period of significant bone loss can last from 4 to 8 years after the onset of menopause. The degree of bone loss is typically most severe at the spinal column (vertebrae). Bone loss is most severe during the first 3 years after menopause and women may lose approximately 2 per cent of bone mass per year in the spinal bones^5,31,32. The extent of bone loss at the hip and wrist may be similar or slightly less^5,31,32. After this period of rapid bone decline has passed, the rate of bone loss significantly slows: Women can generally expect to lose less than 1 per cent of bone density at the hip per year, with the rate of change in the spine being even slower^5,31,32.

Content updated July 27, 2011