BMD: the test to diagnose osteoporosis

BMD (Bone Mineral Density) is the equipment used for bone densitometry, a test used to diagnose osteoporosis and, in general, to measure the mineral density of bones in individuals at risk, allowing for the assessment of the risk of spontaneous fractures over a period of 10 years.

What is Bone Mineral Density Testing (BMD)

BMD allows for the diagnosis of osteoporosis but, more importantly, it precisely detects bone mineral density, especially in individuals at higher risk of fracture. It is recommended for all women going through the post-menopausal period (thus above 65 years old), all women who have experienced a height loss of more than 6 cm, women who exhibit estrogen deficiency – which can occur due to various factors, such as prolonged secondary amenorrhea (absence of menstruation), pre-menopausal amenorrhea lasting more than 6 months – or women who have experienced early menopause, which starts before the age of 45.

For women with a positive maternal family history of osteoporosis, it is also indicated to undergo this examination, particularly in cases of familial history of femoral, hip, or vertebral fractures. Regarding men, the recommendation is to undergo BMD testing starting at the age of 70. Regardless of whether the patient is a man or a woman, it is advised to perform bone densitometry for all individuals undergoing pharmacological therapies based on cortisone and other osteopenic medications, those who are excessively thin, those who have suffered fractures due to bone fragility, or those with a family history of osteoporosis.

Another category of individuals recommended to undergo bone densitometry are those for whom previous radiological exams have shown vertebral collapses. There are also several other risk factors that make BMD testing appropriate for certain individuals, but we will analyze them further later on.

BMD: how it’s done

Although BMD testing can be considered invasive, all scans are done at very low doses, with radiation much lower than that emitted, for example, during a traditional X-ray examination, so much so that the technician performing the exam can remain in the room without any shielding. It is an examination that does not cause any discomfort to the patient.

To perform a lumbar scan, the patient lies supine with their legs supported on a special platform, while for a femoral scan, the patient is asked to spread their legs and place a cushion between their feet. Before the examination, the patient must remove their pants to prevent any metallic elements from affecting the analysis result, remaining still until the operator communicates the end of the scan.

Several bones can provide values for mineral density: the main thoracic bones, the femur, hip joints, the calcaneus, ulna, and radius, vertebrae, and phalanges of the hands and feet. Since the most clinically (and statistically) relevant fractures affect the femur and vertebrae, the most frequently analyzed bone sites are the lumbar spine and the femur.

In addition to bone mineral density of the femur and spine, the diagnostic area of MiniHospital “Sandro Pertini” is equipped to perform total body bone densitometry. In this way, precise measurements of bone density and body composition, including the division between fat mass and lean mass, are provided in a single scan.

When to get BMD testing

We know that bones undergo changes over time, so it is very important to repeat the examination periodically, especially for patients with osteoporosis, particularly those who are losing bone mass at an excessive rate.

Regardless of age, when osteoporosis is diagnosed or when risk factors exist (such as poor mobilization), the doctor will advise when to repeat the next examination. Generally, it is good practice to repeat the examination every 18-24 months. The situation is different for patients diagnosed with a strongly osteopenic condition, who on the advice of the attending physician or specialist may be asked to repeat the examination before 18 months.

In any case, regardless of fractures suffered, confirmed osteoporosis, or the patient’s lifestyle, it is recommended to repeat BMD testing every two years for all women over 65 and all men over 70.

Additional risk factors considered to indicate bone densitometry for the patient include low calcium intake in their diet, vitamin D deficiency, a lifestyle characterized by excessive smoking or alcohol consumption.

MOC and Osteoporosis

As we’ve seen, BMD analysis is the main tool for diagnosing osteoporosis, a systemic skeletal disorder characterized by low bone mineral density and deterioration of bone tissue microarchitecture, leading to increased bone fragility.

Osteoporosis is divided into two types: primary and secondary. Primary osteoporosis can be due to aging (senile osteoporosis) or estrogen loss (postmenopausal osteoporosis). Secondary osteoporosis is caused by certain medications (proton pump inhibitors, antiepileptic drugs, or systemic corticosteroids) or is a consequence of other diseases (hematological, endocrine, gastrointestinal, renal, rheumatological, and neurological).

Osteoporosis leads to weakness and fragility of bone tissue and therefore a greater predisposition of the skeleton to fractures in the future. This disease affects both men and women, with women being considered at higher risk due to longer life expectancy, lower calcium content in bones, and menopause. Menopause results in a reduction in estrogen production, which, among its many functions, also has a protective effect on bones.

Statistics indicate that approximately one in four women suffers from this condition; among men, osteoporosis affects one in ten individuals, as the decline in the production of sex hormones is much lower than in women. However, men at higher risk are those with low testosterone levels or who suffer from hypogonadism, the reduced ability of the testes to produce sex hormones.

Among the main risk factors associated with the onset of osteoporosis are:

Low or no sun exposure
Vitamin D deficiency
Excessive sodium intake in the diet
Low calcium intake in the diet
Excessive alcohol consumption
Excessive smoking habit
Lack of physical activity
Prolonged immobilization
Low body mass index
Organ transplants

BMD Testing at MiniHospital “Sandro Pertini”

The equipment used at MiniHospital “Sandro Pertini” for computerized bone mineralometry (BMD)

is an OsteoSys PRIMUS that utilizes dual-energy X-ray absorptiometry (DEXA) technique and is used to study bone density, body composition (fat mass, lean mass, BMC, visceral fat). The machine employs an algorithm (FRAX®) to calculate the probability of future bone fractures over 10 years in both women and men.

BMD testing does not require any special preparation other than ensuring the removal of any metallic accessories before the exam, such as jewelry.

ABSOLUTE CONTRAINDICATIONS TO THE EXAM: