Abstract: Objective To observe bone mineral density (BMD) at different sites and its correlation with clinical and laboratory indices in maintenance hemodialysis (MHD) patients. Methods In this observational study, BMD at lumbar spine (L1-L4), femoral neck and radius were measured by dual energy X-ray absorptiometry
(DEXA) in MHD patients. Clinical and laboratory indices including age, body mass index (BMI), dialysis duration, albumin, corrected calcium (corrected Ca), serum phosphorus (P), calcium phosphorus product (Ca×P), C reactive protein (CRP), intact parathyroid hormone (iPTH), and alkaline phosphatase (ALP) were
investigated. Stepwise multiple linear regression analysis was used to identify risk factors for BMD. Results A total of 62 patients on MHD for 27.7+29.78 months (30 males and 32 females) were included in this study. The mean T-scores of lumbar spine, femoral neck and radius were -0.80 ±1.65, -1.12 ± 1.15, and -1.80 ± 2.06, respectively. T-score of radius was significantly lower than that of lumbar spine (P=0.011). The prevalence of osteoporosis was 14.5%, 16.1% and 38.7% and the prevalence of osteopenia was 35.5%, 35.5% and 19.4%, in lumbar spine, femoral neck and radius, respectively. Stepwise multiple linear regression analysis demonstrated that sex and BMI were the independent factors for lumbar spine T-score; sex, age and BMI were the independent factors for femoral neck T-score; and ALP was the independent factor for radius T-score. In patients with aortic calcification, lumber spine T-score had no correlation with radius T-score. Conclusion The incidence of osteoporosis is high in MHD patients. Lumbar spine and femoral neck BMD are correlated with patient’s sex, age and BMI, but radius BMD is predominantly correlated with the specific factors for CKD such as ALP. Aortic calcification may influence the measurement of lumbar BMD by DEXA.

Key words: Bone mineral density, Dual energy X-ray absorptiometry, Hemodialysis, Vascular calcification