Purpose: The objective of this study was to determine the relationship between muscular strength and bone mineral density (BMD) in patients undergoing regular haemodialysis.
Methods: The BMD was measured in the lumbar spine (L2-L4) and in the proximal femur (femoral neck and trochanter) with dual-energy X-ray absorptiometry DEXA (Lunar DPX). Muscular strength of the extensors, flexors and abductors muscles of the femur (proximal muscles) and the extensors muscles of the back was measured with an isometric dynamometer. Thirty patients, 15 women with a mean age of 33.7 years (18-43) and 15 men with a mean age of 45.5 years (18-65) were included in the study.
Results: There was a positive and significant correlation between the BMD of the femoral neck and muscular strength of the flexors (r = 0.490, P < 0.005), the extensors (r = 0.658, P < 0.01) and the abductors muscles of the femur (r = 0.671, P < 0.0008), as well as between the muscular strength of the flexors (r = 0.413, P < 0.02) and extensors muscles of the femur (r = 0.433, P < 0.01) with BMD of the trochanter. There was no correlation between the muscular strength of the back extensor muscles and the BMD of the lumbar spine (r = -0.119, P NS). There was no correlation between the BMD and the number of years of haemodialysis therapy (r = -0.032, P NS), the patient's age (r = -159, P NS), or the value of serum PTH (r = 0.369, P NS) respectively. However, there was a significant correlation between the BMD of the femoral neck with muscular strength (r = 0.602, P < 0.05).
Conclusion: This study reveals the close relationship that exists between muscular strength of the proximal muscles and the BMD of proximal femur in patients undergoing haemodialysis.