Menopause is a natural part of aging. Women's oestrogen levels decline resulting in a permenant stop in periods. As a woman ages, the number of her egg cells are reducing, and eventually the amount falls below a ‘critical level’. The Menopause transition is broken down into two parts: Early and Late, defined by the time intervals without menstruation.
The transition starts with the early phase as a woman has a variation or skip in her usual cycle as ovulation reduces. The shift into the late stage occurs when there are more than 60 days with no period. The late stage is categorised by more infrequent periods until there has been no period for a year.
Throughout the early phase there is a fluctuation of hormone levels with a subsequent decrease in certain types of oestrogen. Oestrogen activates signaling pathways in nearly every tissue of the body, so it is not surprising that women experience symptoms in many areas of the body during these hormonal changes.
The most well known skeletal condition associated with menopause is osteoporosis. Osteoporosis is a health condition that weakens bones, making them fragile and more likely to break.
There are 3 main cells involved in maintaining bone; Osteoclasts (which are responsible for bone reabsorption), osteoblasts (which are bone forming cells) and osteocytes (which help with bone formation). Oestrogen helps to stimulate the activity of the bone forming cells. As oestrogen levels decrease, there is increased osteoclast activity and therefore a shift towards more bone reabsorption rather than maintenance.
This decrease in bone density is a natural process, however there are other factors that are associated with bone loss that can be controlled to help minimise the reduction;
Exercises, including resistance training, have been shown to help reduce vertebral fracture risk. Aerobic exercise can help to improve bone density in the hip. Half of your bone density is accrued in the teenage years, so physical activity as a child helps give you a strong starting point.
Calcium consumption and adequate Vitamin D levels are also really important in maintaining bone density. Sun light should provide natural Vitamin D, however some lifestyles do not permit enough exposure to the sun so supplementation can be helpful.
Smoking is an important modifiable risk factor. Nicotine leads to reduced bone formation and stimulates bone reabsorption.
Alcohol consumption reduces bone density through many ways including decreasing oestrogen levels, associated with poor nutrient absorption.
Obesity causes a release of various chemical messengers in the body that reduce the stimulation and activity of the bone-forming osteoblasts cells.