Osteoporosis is a medical condition marked by significant losses in bone density that makes the bones susceptible to fractures. The risk of osteoporosis has a relation with age and gender, with premenopausal women and people belonging to the older age group included in the high-risk group. Osteoporosis is referred to as silent disease because there are hardly any noticeable symptoms that make you unaware of the condition until you fracture a bone.
The disease is of two types differentiated by the possible causes. Primary osteoporosis develops without any apparent cause and is associated with age, with the condition more common in women than in men. Secondary osteoporosis refers to bone loss due to other diseases and the condition is equally common in both men and women. The condition might be caused by several disorders like rheumatoid arthritis, Cushing disease, multiple myeloma, chronic kidney disease etc.
Several diagnostic tests can be done to detect osteoporosis and below given are some of the tests for osteoporosis diagnosis.
Bone Mineral Density (BMD) Test
The most preferred diagnostic test for osteoporosis is BMD test that identifies the loss in bone density. Dexa-scan is an accurate way to measure BMD and the technique evaluates bone density at hip and spine using low energy X rays. Peak bone mass in young adults is taken as the benchmark value to measure BMD. BMD values that are less than 1 standard deviation from the mean BMD in young adults is considered normal. BMD values that are -1 to -2.5 standard deviations below the young adult mean is characteristic of osteopenia, while the BMD values that are less than -2.5 standard deviation below the mean are indicative of osteoporosis.
Body Composition Analysis
It is a general screening test that is used to determine the percentages of the person’s body weight due to bone, muscle, fat and water. A few different ways are available to analyze the body composition and specialized instruments are often used for the analysis. Tracking the results of body composition analysis from year to year may help detect bone losses.
The diagnostic imaging test, bone scan is different from BMD test because the former is invasive while the latter is not. Bone scan is a nuclear medicine test used to detect serious conditions of bones, if any. The screening test is performed by injecting a radioactive tracer into the vein of the arm, and the traces then travel through the blood and are absorbed by the bones. The radioactivity level detected in the bones is evaluated and the results can point to medical conditions like infection, metastatic cancer, reasons for bone pain etc.
Blood Calcium Level Test
Blood calcium level tests are usually suggested for diagnosing osteoporosis although it can be used to detect other bone conditions too. The test can help in the diagnosis of several medical conditions that affect kidneys, thyroid, nerves etc, and is usually suggested when people show symptoms of increased or decreased calcium levels.
The blood sample is collected from the vein in the arm. If urine sample is required, a timed collection of a short duration or a 24-hour sample is usually taken. The current test practices do not require fasting but you might probably be instructed to discontinue medications like lithium, diuretics, antacids as well as vitamin D supplements to ensure the accuracy of the results.
Vitamin D Test
Abnormal levels of calcium, parathyroid hormone as well as phosphorous are indicative of bone diseases and you might want to undergo tests for vitamin D. The test is usually done prior to starting the treatment for osteoporosis and the blood sample is drawn from the vein in the arm.
As per the definitions of the Endocrine Society, the levels of 25-hydroxy vitamin D below 20 ng/mL is indicative of vitamin D deficiency while the 21-29ng/mL range corresponds to vitamin D insufficiency. Vitamin D plays a crucial role in regulating the levels of calcium in the body, which in turns contributes to bone health, and deficiency of vitamin D compromises bone health.
Women are more prone to osteoporosis once they enter menopause and an FSH (Follicle Stimulating Hormone) test can help determine if a women is entering menopause. FSH test has multiple applications like evaluating fertility issues in men and women, as well as the functioning of the pituitary glands, but the prediction of menopause is the application in osteoporosis.
For FSH test, blood sample is drawn by needle from a vein. As a woman enters menopause, the ovaries stop working and as a result, the levels of FSH rise. High FSH levels indicate the entry to menopause that increases the risk of osteoporosis.
Early diagnosis of osteoporosis helps avoid the chances of bone fractures, and if the diagnostic methods confirm the presence of the condition, better begin the treatment at the earliest.