Patients with cirrhosis and ascites have false values of bone density: implications for the diagnosis of osteoporosis.

UNLABELLED

The effect of ascites on bone densitometry has been assessed in 25 patients with advanced cirrhosis, and it was concluded that ascites over 4 l causes inaccuracy of BMD measurements, particularly at the lumbar spine. This fact must be considered when assessing bone mass in patients with decompensated cirrhosis.

INTRODUCTION

Bone mineral density (BMD) measured by dual-energy x-ray absorptiometry (DXA) is the best procedure for assessment of osteoporosis and fracture risk, but BMD values at the central skeleton may be influenced by changes in soft tissues. Therefore, we have studied the effect of ascites on BMD.

METHODS

BMD was measured by DXA at the lumbar spine, femoral neck and total hip, just before and shortly after therapeutic paracentesis in 25 patients with advanced liver cirrhosis. Changes in BMD, lean and fat mass, abdominal diameter and weight, as well as the amount of removed ascites were measured.

RESULTS

The amount of drained ascites was 6.6 ± 0.5 l (range: 3.0 to 12.7 l). After paracentesis, BMD increased at the lumbar spine (from 0.944 ± 0.035 to 0.997 ± 0.038 g/cm(2), p < 0.001) and at the total hip (from 0.913 ± 0.036 to 0.926 ± 0.036 g/cm(2), p < 0.01). Patients with a volume of drained ascites higher than 4 l showed a significant increase in lumbar BMD (7.0%), compared with patients with a lower amount (1.5%) (p < 0.03). The decrease in total soft tissue mass correlated with the amount of removed ascites (r = 0.951, p < 0.001). Diagnosis of osteoporosis or osteopenia changed after paracentesis in 12% of patients.

CONCLUSION

Ascites over 4 l causes inaccuracy of BMD measurements, particularly at the lumbar spine. This fact must be considered when assessing bone mass in patients with advanced cirrhosis.