Fracture and bone mineral density in hemodialysis patients

The aim of this cross-sectional study was to determine in hemodialysis patients the pattern of low trauma fracture, the ability of dual X-ray absorptiometry (DXA) to discriminate between patients with and without fracture, and the magnitude, distribution and mechanism of bone loss.

Eighty-eight patients were studied. Bone mineral density (BMD) was measured by DXA at lumbar spine (LS), femoral neck (FN) and 3 radius sites (UD, MID and 1/3R). In 11 patients (12.5%), 16 fractures occurred and were predominant at the distal forearm and ribs.

Patients with fracture had a significatively lower BMD Z-score at LS (-1.34 +/- 1.66 vs -0.42 +/- 1.23), at FN (-1.58 +/- 1.25 vs -0.60 +/- 1.01), at MID radius (-2.59 +/- 1.34 vs -0.93 +/- 1.76) and 1/3 radius (-1.62 +/- 1.60 vs -0.39 +/- 1.32). They also had a longer history of dialysis (113 +/- 64 vs 53 +/- 65 months). Prevalence of osteoporosis varied from 23% at LS to 50% at MID radius.

Multiple regression analysis showed that there was no influence of gender, age, parathormone status and primary renal disease on BMD. However, at FN, UD, MID and 1/3 radius, a significantly negative correlation was found between length of dialysis and BMD Z-score. By contrast at LS, there was a positive correlation between age at onset of dialysis and BMD Z-score. Despite occurrence of fracture at the fistula forearm, BMD levels were similar in both arms.