What blood tests are used to diagnose possible osteoporosis?

From the Guidelines

Blood tests for osteoporosis should include a comprehensive metabolic panel, complete blood count, thyroid function tests, vitamin D levels, calcium levels, and possibly hormone levels like estrogen or testosterone, as recommended by the most recent study 1. When evaluating for osteoporosis, it's essential to consider the patient's overall health and potential underlying conditions that may contribute to bone loss. The following blood tests can help identify these conditions:

• Comprehensive metabolic panel to evaluate kidney and liver function
• Complete blood count to rule out underlying blood disorders
• Thyroid function tests to detect hyperthyroidism or hypothyroidism
• Vitamin D levels to assess for deficiency
• Calcium levels to evaluate for hyperparathyroidism or other conditions
• Hormone levels like estrogen or testosterone to assess for hormonal imbalances These tests can help guide treatment and management of osteoporosis, but it's crucial to note that the definitive test for osteoporosis is a bone mineral density (BMD) test, typically a dual-energy X-ray absorptiometry (DXA) scan, as stated in the 2022 update of the ACR Appropriateness Criteria1. The DXA scan measures bone density at the hip and spine, providing a T-score that determines if the patient has normal bone density, low bone mass (osteopenia), or osteoporosis. According to the study published in the Journal of the American College of Radiology 1, DXA is the primary imaging modality used to screen for osteoporosis in women over 65 years of age and men over 70 years of age, and may be used in patients under 65 years of age with additional risk factors. In certain situations, vertebral fracture assessment and trabecular bone score may further predict fracture risk, particularly in patients who are not yet osteoporotic but are in the range of osteopenia, as noted in the study 1. It's essential to consult with a healthcare provider to determine the appropriate testing and treatment for osteoporosis, especially if the patient is over 65, has risk factors like family history, or has experienced fractures, as the study 1 emphasizes the importance of early detection and treatment to reduce osteoporosis-associated morbidity and mortality. The study published in Clinical Infectious Diseases 2 also highlights the importance of evaluating for secondary causes of osteoporosis, including history and physical examination, complete blood count, routine blood chemistry tests, and determination of creatinine, blood urea nitrogen, total calcium, phosphate, albumin, and alkaline phosphatase levels. However, the most recent and highest quality study 1 provides the most up-to-date recommendations for osteoporosis testing and management.

From the Research

Blood Tests for Osteoporosis

• There is no direct evidence of blood tests being used to diagnose osteoporosis, as the condition is typically diagnosed using a T-score of -2.5 or less or the presence of a fragility fracture 3, 4, 5.
• However, blood tests may be used to evaluate the underlying causes of low bone density and to monitor the effectiveness of treatment 3, 4.
• Some studies suggest that blood tests can be used to measure bone turnover markers, but this is typically only done in bone specialist centers for treatment monitoring purposes 4.

Diagnostic Criteria

• Osteoporosis can be diagnosed based on a T-score of -2.5 or less or the presence of a fragility fracture 3, 5.
• The T-score is a measure of bone mineral density (BMD) compared to the average BMD of a healthy young adult 3, 5.
• Fragility fractures, such as hip fractures, can also be used to diagnose osteoporosis 3, 6.

Screening Recommendations

• The Bone Health and Osteoporosis Foundation recommends screening men 70 years and older and men with clinical risk factors for osteoporosis 3.
• The U.S. Preventive Services Task Force did not find sufficient evidence to support routine screening in men, but recommends screening women 65 years and older or women who are postmenopausal with clinical risk factors 3.
• Other studies recommend screening all women 65 and older, as well as younger postmenopausal women with elevated risk factors 5.