Correlation of bone mineral density with the histological findings of renal osteodystrophy in patients on hemodialysis

Aims. To examine the distribution of bone mineral density (BMD) in differen t histological groups of renal osteodystrophy. Patients. We prospectively studied 62 patients, 41 men and 21 women, aged 5 7+/-11.5 years, who had been on hemodialysis for 60+/-55 months. The women had been amenorrheic for 13+/-4 years and 7 patients (11%) had a positive f racture history. Methods. A bone biopsy was taken after tetracycline labelling and BMD of th e lumbar spine and proximal femur was measured by dual-energy X-ray absorpt iometry (DEXA); serum intact parathyroid hormone (iPTH), bone Gla protein ( BGP), phosphorus, calcium and alkaline phosphatase (ALP)were also determine d. Results. Histologically, 40 patients showed secondary hyperparathyroidism ( sHPT), 6 mixed bone disease, 14 adynamic bone disease (A) and 2 osteomalaci a. BMD of the lumbar spine was decreased in 43 patients (69%) and in 9 (14. 5%) it was lower than -2 Z score units. BMD of the femoral neck was low in 55 patients (89%) and in 22 (35.5%) it was lower than -2 Z scores. BMD was lower in patients with sHPT than in those with adynamic bone disease (p<0.0 5) in which it was close to normal. BMD in both these sites correlated inve rsely with the biochemical markers (serum iPTH, BGP and ALP) and the histom orphometric indices of bone turnover. Conclusions. Osteopenia is frequent in patients on hemodialysis, especially those with biochemical and histological finding of sHfT.