Relation between body mass index and bone mineral density among haemodialysis patients with chronic kidney disease

Renal osteodystrophy is a serious problem for patients with chronic kidney disease. Measurements of bone mineral density, T-score and Z-score were taken in the lumbar region and femur of 73 patients who were being treated on the haemodialysis programme. These measurements were compared with the anthropometric values of weight, height and body mass index (BMI) obtaining a positive correlation between them.

Alterations in the bone mineral metabolism are an important cause of morbidity and mortality among haemodialysis patients with chronic renal failure. Bone mass diminution, together with fracture risk, is a frequent finding in these patients; this fact is explained by different factors, amongst which are those related to their anthropometric values.

Bone mineral density (BMD) was studied, T-score and Z-score measurements were taken in the neck of the femur, trochanter, intertrochanter, 1/3 of proximal femur, Ward's triangle and L2, L3 and L4 vertebrae; body composition was also studied. With this aim, DXA densitometry was used on 73 haemodialysis patients (40 men and 33 women). The mean of the total haemodialysis time in these patients was 9.7 years. The group showed a very significant positive correlation between BMD, weight, height, BMI, fractures, dialysis time and intact PTH.

CKD patients undergoing the haemodialysis programme show a significant BMD reduction, which affects both lumbar spine and femur. Weight and height affect BMD and bone change, being thus important factors of prediction for fracture risk. Furthermore, BMI is the main determinant of BMD, a finding that is confirmed in the units in this study and with the evidence described by other authors (Negri et al. (2005).