Laboratory Evaluation for Loss of Height
For patients presenting with height loss, obtain a comprehensive metabolic panel including serum calcium, phosphate, alkaline phosphatase, parathyroid hormone (PTH), 25-hydroxyvitamin D, thyroid-stimulating hormone (TSH), complete blood count, and consider iron studies to evaluate for osteoporosis, vertebral fractures, and metabolic bone disease. 1
Core Laboratory Tests
The following labs should be drawn based on the strongest guideline evidence:
Essential Initial Panel
- Complete blood count (CBC) - to assess for anemia and general hematologic status 1
- Serum electrolytes including calcium and magnesium - critical for detecting hypocalcemia and parathyroid disorders 1
- Serum creatinine and blood urea nitrogen - to evaluate renal function which affects bone metabolism 1
- Thyroid-stimulating hormone (TSH) - hypothyroidism is a well-established cause of growth impairment and can affect bone health 1, 2
- 25-hydroxyvitamin D level - vitamin D deficiency is strongly associated with height loss and vertebral fractures 1, 3
Bone-Specific Markers
- Alkaline phosphatase - elevated levels suggest active bone disease or metabolic bone disorders 1
- Parathyroid hormone (PTH) - to detect hyperparathyroidism or secondary hyperparathyroidism from vitamin D deficiency 1
- Serum phosphate - low levels may indicate phosphate wasting disorders or vitamin D deficiency 1
Additional Recommended Tests
- Liver function tests - to assess for hepatic causes of metabolic bone disease 1
- Fasting blood glucose or glycohemoglobin - diabetes affects bone health and fracture risk 1
- Iron studies (serum iron, ferritin, transferrin saturation) - iron deficiency can coexist with other metabolic abnormalities 1, 4
Clinical Context Matters
When Height Loss is Documented
Height loss of ≥2 cm has a positive likelihood ratio of 2.35 for detecting vertebral fractures, increasing to 2.89 at ≥3 cm and 2.89 at ≥4 cm of height loss 3. Historical height loss >4 cm is a specific indication for vertebral fracture assessment according to bone health guidelines 1.
Age-Specific Considerations
- Adults ≥40 years: The above comprehensive panel is essential, with particular attention to bone metabolism markers 1
- Postmenopausal women and men ≥50 years: All listed tests are indicated as part of osteoporosis evaluation 1
- Younger adults with risk factors: Focus on secondary causes including thyroid disease, vitamin D deficiency, and malabsorption 1
Common Pitfalls to Avoid
Do not skip vitamin D testing - vitamin D deficiency is extremely common and directly contributes to height loss through vertebral fractures and osteomalacia 1, 3. Severe deficiency (25[OH]D <15 ng/mL) can cause osteomalacia with bone pain and muscle weakness 1.
Do not overlook thyroid function - subclinical hypothyroidism can impair growth and bone health, and treatment with levothyroxine significantly improves height velocity 2. TSH should be checked even in the absence of obvious thyroid symptoms 1.
Do not forget calcium and PTH together - checking only one can miss primary hyperparathyroidism or secondary hyperparathyroidism from vitamin D deficiency, both of which cause bone loss 1.
Measure height accurately - document current height without shoes and compare to documented peak height to quantify actual height loss 1, 3. This measurement itself is critical for determining the need for further workup.
Secondary Causes Requiring Specific Testing
If initial labs are abnormal or clinical suspicion exists for specific conditions:
- Hypogonadism: Consider testosterone (men) or estradiol (women) if clinically indicated 1
- Malabsorption: Celiac serology if vitamin D deficiency is severe or refractory 1
- Glucocorticoid use: No additional labs needed beyond the core panel, but document cumulative steroid exposure 1
The 2022 AHA/ACC/HFSA guidelines emphasize that this laboratory panel should be obtained to "optimize management" and identify treatable causes 1. The 2017 ACR guidelines specifically recommend measuring height at each visit for patients on chronic glucocorticoids to detect early vertebral compression fractures 1.