Osteoporosis and bone metabolism

Bone metabolism:

Bone metabolism plays a crucial role in the health of our bones and joints. Bones are primarily made up of various minerals, water and collagen fibers.

The following substances play a central role in bone metabolism:

• Calcium: In combination with phosphate, calcium is the main component of our bones and ensures their stability. Our entire skeleton contains around one kilogram of calcium. It must be supplied daily through food, with the recommended amount being 1000 mg per day. The calcium balance is influenced and controlled by vitamin D and parathyroid hormone, which is produced by the parathyroid gland.
• Vitamin D: Vitamin D helps the body to absorb calcium from food and store it in the bones. Sunlight plays a key role in the production of vitamin D, as its precursor is broken down by UV rays in the skin and then converted into vitamin D itself in the liver and kidneys.
• Parathyroid hormone: Parathyroid hormone is produced by the parathyroid gland and leads to a breakdown of bone substance and thus simultaneously to an increase in the calcium level in the blood.

Normally, there is a balance between cells that build bone (osteoblasts) and break it down (osteoclasts). Various factors, such as an inadequate calcium supply, various diseases or overloading of the bone, can lead to an imbalance and thus to increased bone resorption and/or reduced bone formation.

Osteoporosis:

Osteoporosis describes a bone disease characterized by reduced bone density andan increased risk of fractures. Postmenopausal (after the menopause) women are particularly affected: almost a quarter of women over the age of 65.

Signs of osteoporosis can be

• Bone fractures (especially vertebral body and femoral neck fractures)
• Pain (especially back pain)
• Permanent changes to the spine (decrease in height of the vertebral bodies, hunchback)

Osteoporosis is a disease that progresses gradually and therefore remains undetected for a long time. Accordingly, the majority of those affected are symptom-free at the onset of the disease.

In the later stages, osteoporosis can manifest itself in bone fractures that occur without adequate trauma, for example when lifting heavy objects or making abrupt movements.

Typical localizations of bone fractures (fractures) are:

• Vertebral body fractures
• Fractures of the neck of the femur
• Fractures of the humerus close to the body (subcapital humerus fracture)
• Radius fractures distal to the body (distal radius fracture)

Pain may also occur at the respective location of the fractures. In the vast majority of cases, back pain is caused by vertebral body fractures. These fractures also lead to permanent changes in the spine, more specifically to a reduction in the height of the vertebral bodies and a hunched back. This leads to an overall decrease in height and, as a result, to a so-called fir tree phenomenon (folds of skin on the back that descend from the middle and resemble a fir tree).

The overriding cause of osteoporosis is an imbalance between bone formation and bone resorption. Depending on the specific cause, it is divided into primary and secondary osteoporosis.

Causes of osteoporosis include

• Primary osteoporosis:
  • Postmenopausal hormonal changes
  • Age-related
• Secondary osteoporosis:
  • Long-term use of medication
  • Malnutrition
  • Various diseases (including diseases of the thyroid and parathyroid glands, type I diabetes mellitus)

In the majority of cases, this is primary osteoporosis, which can occur as a result of reduced oestrogen levels during and after the menopause. Oestrogen plays a decisive role in bone metabolism, as it reduces the breakdown of bone substance. A lack of oestrogen therefore leads to faster bone resorption. Primary osteoporosis can also occur as a result of reduced bone formation in old age.

In the context of secondary osteoporosis, specific factors can be named as the cause of osteoporosis. These include the long-term use of certain medications, in particular cortisone, but also drugs from the group of proton pump inhibitors, antiepileptic drugs and individual antidepressants. Furthermore, people who are underweight and/or suffer from eating disorders are predestined for osteoporosis, as the nutrients that are crucial for bone metabolism are not sufficiently absorbed. In addition, various diseases, such as an overactive parathyroid gland, hyperthyroidism or type 1 diabetes mellitus, lead to increased bone resorption.

Risk factors that favor the development of osteoporosis are:

• Alcohol and nicotine consumption
• Low physical activity
• Vitamin D deficiency
• Calcium deficiency

In a detailed consultation with our osteoporosis specialist Priv.-Doz. Dr. Pestka, questions regarding your medical history and possible causes of osteoporosis (medication, previous illnesses, hormone status) will be clarified. This is followed by a thorough physical examination in which typical locations of osteoporotic bone fractures, such as the spine, are palpated and tapped. Any pain that occurs can be interpreted as an indication of existing fractures.

If osteoporosis is suspected, bone density measurement (DXA osteodensitometry) is the gold standard for diagnosis. Even if there are risk factors, a bone density measurement should be carried out as a precautionary measure. This involves measuring the bone density of the lumbar spine and femur and determining the so-called T-score. This indicates how much the patient's bone density deviates from the bone density of healthy people. Depending on this value, the patient's age and individual risk factors, a diagnosis can then be made and a decision taken on possible treatment options. Whenever possible, these decisions are made in accordance with the guidelines of the German Osteology Association (DVO).

We offer bone density measurement at the Orthozentrum Freiburg . Make an appointment directly with Priv.-Doz. Dr. Pestka in the osteoporosis consultation:

or call us at 0761 7077300

With the help of an X-ray examination, old and fresh fractures can be detected and other diseases ruled out.

As part of the investigation into the cause, a blood test is usually also carried out, in which typical markers of bone metabolism (calcium, phosphate, vitamin D) and the thyroid and parathyroid glands (TSH) are determined.

Osteoporosis should be treated if there is evidence of osteoporosis with a significantly increased risk of bone fractures or if bone fractures have already occurred. The aim of treatment is to stabilize bone metabolism and thus prevent bone fractures.

Basic measures:

The following basic measures are possible:

• Movement
• Abstaining from alcohol and nicotine
• Vitamin D intake, calcium intake if necessary
• Reducing the risk of falling

Regular physical activity and strength training adapted to individual fitness levels are crucial in the treatment of osteoporosis and the prevention of bone fractures, as the use of our muscles stimulates bone growth.

Alcohol and nicotine should also be avoided. The intake of vitamin D, coupled with sufficient sunlight, is a standard part of any osteoporosis therapy. Calcium should only be used if the daily requirement (1000 mg) is not covered by the diet. Calcium is mainly found in green vegetables (e.g. spinach, broccoli) and in dairy products or calcium-enriched milk substitutes.

Fall prevention is essential, especially for patients who are unsteady on their feet, in order to reduce the risk of falls and therefore bone fractures. Depending on the patient's general condition, rollators, walking sticks or hip protectors can be used, for example. Fall training can also be helpful.

Drug therapy:

In addition to the measures mentioned above, the administration of various osteoporosis medications can be considered on an individual basis. These include anti-resorptives such as bisphosphonates, denosumab and selective oestrogen receptor modulators, which can stabilize bone density and prevent fractures very effectively. In severe cases of osteoporosis, it is possible to use drugs that build up bone density, such as romosozumab or teriparatide.