DIAGNOSTIC ACCURACY OF LUMBOSACRAL SPINE X-RAY IN ASSESSING RISK OF SENILE OSTEOPOROSIS AMONG MALE PATIENTS USING SERUM VITAMIN D3 LEVELS AS REFERENCE

Abstract

Background:
Senile osteoporosis in men is often underdiagnosed despite its growing public health impact. Serum Vitamin D₃ deficiency is strongly correlated with reduced bone mineral density (BMD) and serves as a biochemical marker of osteoporosis risk. Although dual-energy X-ray absorptiometry (DEXA) remains the gold standard for BMD measurement, its limited availability and cost restrict its use in routine screening. Conventional radiography may offer a practical alternative.

Objective:
To evaluate the diagnostic accuracy of lumbosacral spine radiography in detecting senile osteoporosis in male patients, using serum Vitamin D₃ levels as the reference standard with low serum Vitamin D₃ levels being indicative of increased risk of osteoporosis.

Methods:
This cross-sectional study was conducted in the Radiology Department of Capital Hospital, CDA, Islamabad, from 15 June to 15 September 2025. A total of 121 men aged 60–90 years with suspected osteoporosis underwent X-ray of the lumbosacral spine. Radiographs were interpreted by an experienced radiologist for characteristic osteoporotic changes. Serum Vitamin D₃ levels were measured for all participants. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall diagnostic accuracy of X-ray findings were calculated against Vitamin D₃ status.

Results:
Among 121 participants, 75 had radiographic evidence of osteoporosis; of these, 65 had low Vitamin D₃ levels (true positives) and 15 had normal Vitamin D₃ levels (false positives). Of 41 patients without radiographic features, 10 had low Vitamin D₃ levels (false negatives) and 31 had normal levels (true negatives). Lumbosacral spine X-ray showed a sensitivity of 86.7%, specificity of 67.4%, PPV of 81.3%, NPV of 75.6%, and an overall diagnostic accuracy of 79.3% (95% CI calculated for all parameters).

Conclusion:
Lumbosacral spine radiography demonstrates good sensitivity and moderate specificity in detecting senile osteoporosis in male patients when compared with serum Vitamin D₃ levels. Given its affordability and accessibility, it may serve as a useful initial screening tool where DEXA is unavailable, though confirmatory testing remains advisable.