Biochemical and imaging alterations of renal bone disease in newly detected predialysis and on maintenance dialysis patients.

Skeletal involvement in chronic kidney disease manifests long before the initiation of dialysis. This study aimed at identifying the extent of renal bone disease among predialysis and on maintenance dialysis patients. Thirty-two patients (Group 1) on maintenance hemodialysis (MHD) for a variable period of time were compared with 20 newly detected irregularly treated advanced renal failure (immediately predialysis), patients (Group 2) for their clinical, biochemical and imaging features. The mean age of Group 1 and Group 2 patients was 45+/-14 vs. 34+/-15 years (p<0.05). Comparison of blood biochemistries between Groups 1 and 2 showed serum creatinine 9.9+/-2.9 vs. 13.4+/-4.4 mg/dL (p<0.01); calcium 10.1+/-1.8 vs. 7.8+/-1.2 mg/dL (p<0.001); phosphate 4.4+/-1.2 vs. 7.9+/-2.1 mg/dL (p<0.001); alkaline phosphatase 116.4+/-31.7 vs. 85.7+/-30.6 IU/L (p<0.05); and parathormone 71.7+/-48.2 vs. 146.9+/-92.1 pg/mL (p<0.05). Radiological changes present in the 2 groups were as follows: osteopenia 63% vs. 65% (ns); trabecular resorption 53% vs. 20% (p<0.05); soft tissue calcification 31% vs. 10% (p<0.05); bone cysts 16% vs. 26% (ns); and subperiosteal bone resorption 16% vs. 20% (ns). Technetium 99 methylene diphosphonate (Tc-99 MDP) bone scans in both groups of patients showed similar increased uptake in wrist joint, tibia-fibula, costochondral junction, vertebral column, sternum, radius-ulna and mandible. X-ray findings were positive for bone involvement in 59% of cases, and Tc-99 scan was positive in 80% (p<0.05). It is concluded that newly detected, irregularly treated patients with advanced renal failure who are predialysis may present with deranged calcium homeostasis and a high prevalence of bone involvement similar to MHD patients.