Menopause, Bone Density, and the role of HRT

Feb 17, 2025 | Living with Osteoporosis, Awareness, General

One of the most critical concerns associated with menopause is the decline in bone density, which significantly increases the risk of osteoporosis and fractures. This phenomenon is primarily driven by hormonal shifts, particularly the decline in estrogen levels.

Bone is a dynamic tissue that undergoes a continuous process of renewing old or damaged bone with healthy bone – and estrogen plays a crucial role in maintaining this balance. However, as menopause approaches and estrogen levels decline, this equilibrium is disrupted, leading to accelerated bone loss.

The role of hormones

  • In addition to estrogen, there are other hormones that play a role in bone metabolism. These hormones are: progesterone, testosterone, parathyroid hormone, and calcitonin. Progesterone and testosterone contribute to bone formation, while parathyroid hormone and calcitonin regulate calcium homeostasis. The hormonal fluctuations experienced during menopause alter these regulatory mechanisms, exacerbating bone loss and increasing susceptibility to fractures.
  • The onset of menopause is associated with a rapid decline in bone mineral density – and studies indicate that women can lose up to 20% of their bone mass within the first five to seven years post-menopause.
  • Loss of estrogen leads to increased porosity of bones, making them fragile and more prone to fractures. Additionally, low estrogen levels are associated with decreased calcium absorption in the intestines and increased calcium excretion, further compromising bone integrity.
  • While estrogen is the primary hormone involved in bone preservation, the decline of progesterone and testosterone also plays a role. Progesterone helps stimulate bone formation. Testosterone, although present in smaller amounts in women, supports bone density by increasing bone building and muscle mass, which in turn helps protect bones from fractures. As the levels of these hormones decrease with menopause, the protective effects on bone health diminish.

Risk factors during menopause

  • From genetics to nutrition, body size, lifestyle and medications, we are surrounded by risks to bone health. A family history of osteoporosis increases susceptibility to bone loss; insufficient calcium and Vitamin D intake can impair bone mineralisation.
  • Smoking, excessive alcohol consumption, and a sedentary lifestyle negatively affect bone density. Women in particular with smaller bone structures tend to have less bone mass and a higher risk of fractures. In addition, long-term use of corticosteroids and certain other drugs can accelerate bone loss.
  • Hormonal decline during menopause can lead to an increased risk of osteoporosis, a condition characterised by weak and brittle bones, leading to an increased risk of fractures – the spine, hips, and wrists being particularly vulnerable. These fractures can severely impact mobility and quality of life, often leading to long-term disability.
  • As vertebral bones weaken, compression fractures can occur, leading to a gradual loss of height and a stooped posture known as kyphosis. This can result in chronic back pain and reduced mobility.
  • Hip fractures, a common consequence of severe bone loss, are associated with high mortality rates in older women. Many individuals who suffer from hip fractures experience long-term complications, including reduced independence and increased dependency on caregivers.

HRT and alternatives

Assistance can come in the form of a calcium-rich diet, Vitamin D supplements, and fortified protein intake. Exercises in the form of weight-bearing, resistance training, and flexibility training, and balancing exercise, are is important, along with sensible lifestyle changes. A key factor is medical intervention – particularly in the form of Hormone Replacement Therapy (HRT). However, while estrogen therapy can slow bone loss and reduce fracture risk, it is not suitable for everyone, should not be initiated after the age of 60, and should be considered carefully due to potential side effects.

Side effects of HRT:

As with any medication, there can be side effects – and these can differ between individuals. Depending on severity and duration, you may need to see your doctor, but generally common side effects usually clear up within a few weeks.

  • headaches
  • breast pain or tenderness
  • unexpected vaginal bleeding or spotting
  • feeling sick (nausea)
  • mood changes, including low mood or depression
  • leg cramps
  • mild rash or itching
  • diarrhoea
  • hair loss

Alternatives to HRT for those who cannot or don’t want to use HRT include:
Bisphosphonates – these medications help slow bone resorption and are commonly prescribed for osteoporosis.
Selective Estrogen Receptor Modulators (SERMs) – these drugs mimic estrogen’s protective effects on bones without some of the risks associated with HRT.
Denosumab, a human monoclonal antibody reduces bone resorption by blocking osteoclast maturation.
Parathyroid Hormone Therapy – for severe osteoporosis, PTH analogs like Teriparatide can stimulate new bone formation.

Understanding the relationship between menopause, hormonal changes, and bone health is essential for developing strategies to maintain skeletal strength and prevent osteoporosis in the post-menopausal timeframe. By taking proactive measures, women can mitigate the effects of menopause on their bones and enjoy a healthier, more active life well into their later years.

NOFSA (National Osteoporosis Foundation South Africa)

NOFSA is the only non-profit, voluntary health organisation dedicated to promoting lifelong bone health. We focus on reducing the widespread prevalence of osteoporosis while working to find a cure for the disease, and by supporting research and developing programmes of education and advocacy.

Find out more about our work at: www.osteoporosis.org.za

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