Computed tomography-measured trabecular attenuation at first lumbar vertebra as a surrogate marker of bone mineral density and osteoporosis in patients undergoing hemodialysis.

The risk of fractures and osteoporosis is higher in patients on hemodialysis than in the general population. We examined the association between computed tomography (CT)-measured trabecular attenuation at the first lumbar vertebra (L1 CT-attenuation), bone mineral density (BMD), and osteoporosis in patients on hemodialysis. We retrospectively included Japanese patients on hemodialysis who underwent non-enhanced abdominal CT and dual-energy X-ray absorptiometry (DEXA) analyses as part of a medical checkup between April 2019 and March 2021. L1 CT-attenuation (Hounsfield units, HU) and BMD of the femoral neck and lumbar spine were measured. We analyzed associations between L1 CT-attenuation and BMD and examined its diagnostic accuracy and odds ratio for detecting osteoporosis, defined as a DEXA T-score of < -2.5 at either site. A total of 119 patients (mean age: 67.2 years; men; 63.0%; body mass index [BMI]: 22.4 ± 3.9 kg/m²) were included, of whom 49 had osteoporosis. L1 CT-attenuation was independently linked to BMD at the femoral neck and lumbar spine. The optimal cutoff derived from receiver operating characteristic curve analysis was 109.3 HU. Thresholds of ≤71.3 HU and ≥151.1 HU provided 90% specificity and 90% sensitivity for distinguishing patients with and without osteoporosis. The age-, sex-, and BMI-adjusted odds ratio of L1 CT-attenuation (per 10 HU) for diagnosing osteoporosis was 0.73. L1 CT-attenuation was independently associated with BMD and may be utilized for osteoporosis screening in Japanese patients on hemodialysis. Opportunistic abdominal CT may aid early detection and intervention for osteoporosis in these patients.