Osteopenia is a loss of bone capital: a degradation of bone density or quality. It is necessary to prevent this loss of bone mass, primarily to prevent it from progressing to osteoporosis, a stage of bone demineralization more advanced than osteopenia. More present in women, especially after menopause, osteopenia can also be a secondary consequence of many diseases, whether metabolic, endocrine, inflammatory or even cardiac … Its prevention mainly involves regular physical activity, as well as a diet rich in vitamin D or even supplementation, and a sufficient supply of calcium.

Definition of osteopenia

Osteopenia is not really a disease as such: it indicates a fragility of the bone, caused by a decrease in bone mineral density. By demineralizing and decalcifying, the bone weakens and loses density. Osteopenia can develop into a more advanced stage of bone loss called osteoporosis.

Osteponia is a normal stage in the life of an aging person. However, it is possible to delay its development. Resulting in a decrease in bone mass, this osteopenia can also affect the quality of the bone. Up to 11% decrease in bone density, it is osteopenia, beyond that, it is osteoporosis. Osteopenia is therefore an intermediate state between normal bone and osteoporosis.

Causes of osteopenia

Bone is a very dynamic tissue, which is continuously destroyed and rebuilt. This dynamism, or balance, is provided by good coordination between the cells that destroy old bone, called osteoclasts, and those that rebuild it, known as osteoblasts.

But certain pathologies cause an imbalance between these two activities: “The destruction of bone by osteoclasts then takes precedence over bone formation by osteoblasts”, indicates a CNRS-INSERM research team, led by Anne Blangy.

It is this disruption of the balance between bone resorption, or its degradation, and its formation, which is involved in osteopenia, and can even cause a higher stage of bone loss such as osteoporosis.

The degradation of bone quality can also be caused by changes in the structures of the cell, for example related to changes in the microscopic cell architecture.

Diagnosis of osteopenia

The diagnosis of osteopenia is carried out via bone osteodensitometry, an examination carried out by a radiologist. It measures bone density in the lumbar spine as well as the femoral neck, the upper end of the femur. This bone densitometry, also called X-ray absorptiometry (or DXA) is the key examination, because it is precise, reproducible and harmless (without injection of product and without sampling).

The T-score is assessed in relation to a subject with the maximum bone mass: if it is greater than -1 SD (standard deviation) it corresponds to a normal density, if the T-score is between -1 and -2,5, 2,5, it corresponds to osteopenia, finally if it is less than XNUMX, the patient is at the stage of osteoporosis.

Other explorations are possible, in case of clinical doubt:

• Scintigraphy
• the scanner
• l’IRM
• Finally, a blood test can help look for a physiological cause, such as an inflammatory syndrome or hypercalcemia (elevation of extra-cellular calcium).

The people concerned

Osteopenia affects women more particularly, from the menopause, especially when this menopause is early (before 40 years), and this because of the significant drop in estrogen levels in the blood. Children born prematurely are also frequently affected. People who drink a lot of alcohol are also particularly affected. Osteopenia is present in humans, especially in cases of hypogonadism (loss of function of the testes). In addition, this osteopenia can be caused by taking corticosteroids.

In addition, many pathologies have osteopenia or osteoporosis as a secondary consequence:

• inflammatory diseases, such as celiac disease, a chronic and autoimmune disease of the intestine after ingestion of gluten;
• phenylketuronia, a rare genetic disease caused by a disorder in the metabolism of an amino acid (building block of proteins), phenylalaline;
• People with Crohn’s disease are also at risk for osteopenia (36% develop osteopenia, and 15% develop osteoporosis);
• People affected by ulcerative colitis are also concerned (32% osteopenia, 7% osteoporosis); 
• Rheumatoid arthritis;
• autoimmune diseases, especially lupus erythematosus; 
• endocrine disease such as hyperthyroidism;
• type 1 diabetes (or juvenile diabetes) and type 2 diabetes, due among other things to hyperglycemia which itself has a toxic effect on osteoblasts;
• Other pathologies: protoporphyria, hyponatremia, chronic obstructive pulmonary disease, cardiovascular diseases such as heart failure, liver cirrhosis and hepatitis, renal failure, frailty syndrome (i.e. the clinical consequences of the decline in physiological functions during aging), beta-thalassemia, sickle cell disease …

Risk factors

• Sedentary lifestyle is a major risk factor in the development of osteopenia. 
• Prolonged immobilization, for example during a fracture, an accident or a complicated pregnancy, can also increase osteopenia, which is natural in adults.
• Excessive alcohol intake also greatly increases the risk of developing osteopenia: recent findings show that alcohol has a dose-dependent toxic effect, and leads to an imbalance in bone remodeling.
• Other risk factors: age, low BMI (body mass index), vitamin D and calcium deficiency, family history.

Osteopenia is not a disease in itself. It is often a secondary consequence of conditions such as, for example, parathyroid pathologies, hypercalcemia. Osteopenia is most often asymptomatic.

Several of its symptoms can result in:

• a spontaneous fracture.
• compression of the vertebrae.
• a fracture of the neck of the femur.

Calcium and vitamin D supplementation are ways of fighting osteopenia, if their deficiency has been determined by their dosage. However, this supplementation alone is often of little benefit: it can be combined with treatments, such as bisphosphonates, a category of drugs that limit bone resorption.

Among the bisphosphonates, there are:

• the Actonel (Risidronate);
• the Fosamax (Alendronate);
• l’Ibandronate (Bonviva) ;
• Zoledronate (Aclasta).

In addition, other anti-absorption drugs are available for osteoporosis, such as denosumab or raloxifene, or the administration of teriparatide. Specific procedures are recommended for certain diseases, such as celiac disease or phenylketonuria. 

Medical research

Most of the existing treatments for pathological bone loss suppress osteoclasts. The problem ? These bone-destroying cells also stimulate bone formation by their presence. New therapeutic approaches are therefore aimed at preventing the activity of these osteoclasts without affecting their viability.

This is notably the case with an innovative treatment, successfully tested in 2015 in mice: C21 blocks the bone degradation activity of osteoclasts while maintaining them present; thus, bone formation during treatment is ensured. But it is probably more the stage of osteoporosis than that of osteoponia itself that will be targeted by this type of very promising strategies.

Alternative treatments

An alternative treatment against osteopenia could, according to some sources, be offered in homeopathy: the systematic intake of one dose per week of Silicea 9 CH.

Finally, a balanced diet, with lots of dairy products, rich in calcium and vitamin D, is recommended.

The main prevention of osteopenia is regular physical activity. Indeed, physical exercise stimulates bone formation and increases bone mineral density: thus, leptin, secreted during physical or sports activity by human osteoblasts, promotes bone mineralization.

Other preventive factors: a healthy lifestyle with a limited intake of alcohol and the absence of tobacco, as well as sufficient calcium and vitamin D intake through food, especially dairy products.

The main goal of prevention is to prevent osteopenia from reaching the stage of osteoporosis.