Increased bone strontium levels in hemodialysis patients with osteomalacia

Background. In this study, we report on the association between increased b one strontium levels and the presence of osteomalacia in end-stage renal fa ilure patients treated by hemodialysis. Method's. We performed a histologic examination and determined the strontiu m content and strontium/calcium ratios in bone biopsies of 100 hemodialysis patients recruited from various centers all over the world. Aside from the bone strontium concentration, the bone aluminum content was assessed. The bone zinc concentration, a nonrelevant element for bone toxicity, was also measured. Results. Bone strontium levels and bone strontium/calcium ratios were incre ased in subjects with osteomalacia when compared with those with the other types of renal osteodystrophy. Bone strontium and bone calcium levels corre lated with each other. The slope of the linear regression curve correlating these parameters was much steeper in the osteomalacic group (Y = 2.22X - 1 20) as compared with the other types of renal osteodystrophy (Y = 0.52X - 5 .7). Within the group of patients with osteomalacia, bone strontium levels also significantly correlated with the bone aluminum content (r = 0.72, P = 0.018). No such correlation was found for the other types of renal osteody strophy. The bone zinc concentration of subjects with normal renal function did not differ significantly from the values noted for the various types o f renal osteodystrophy taken as separate groups, nor could increased bone z inc concentrations be associated with a particular bone lesion. Conclusions. Our data demonstrate an association between osteomalacia and i ncreased bone strontium concentrations in dialysis patients. Further studie s are warranted to establish whether strontium plays either a primary, seco ndary, or contributive role in the development of the latter type of renal osteodystrophy.