Quantitative ultrasound at the calcaneus in corticosteroid-treated male patients with bronchial asthma

Abstract

The aim of the study was to assess skeletal status in bronchial asthma male patients after long-term corticosteroid (CSt) therapy. A total of 25 men patients (mean age 53.8 ± 11.6 years) were compared with 343 men: 256 control men without fractures (mean age 54.4 ± 13.1 years) and 87 men with previous osteoporotic fractures (mean age 54.7 ± 11.6 years). The mean age and body size did not differ among groups studied. The duration of CSt therapy expressed as median was 6 years (range 1 to 30 years), and a mean dose equivalent to prednisone was 9.3 ± 4.5 mg. Skeletal status was evaluated by quantitative ultrasound (QUS) measurements at the heel using the Achilles system (Lunar), which measures speed of sound (SOS) in m/s and broadband ultrasound (US) attenuation (BUA) in dB/MHz. The Achilles software calculates also a stiffness index (SI) in %. The CV% values were: 2.48% for BUA, 0.33% for SOS and 2.56% for SI. Values of BUA, SOS, SI, T-score and Z-score in patients were significantly lower than in controls and did not differ between patients and men with fractures. The duration of CSt therapy and childhood and current calcium daily intake did not influence skeletal variables measured. ROC analysis was performed to assess the discriminatory capability of calcaneal QUS for fractured and CSt-treated patients by calculating the area under the ROC curve (AUC). AUCs were: 0.74 ± 0.027 and 0.72 ± 0.05 for SOS, 0.71 ± 0.03 and 0.66 ± 0.05 for BUA and 0.74 ± 0.03 and 0.71 ± 0.05 for SI, respectively. Concluding, in male patients with bronchial asthma on prolonged CSt therapy, skeletal status was affected, and calcaneal QUS measurements can be a useful tool in the assessment of skeletal side effects after long-term CSt treatment. (E-mail: bognadr@poczta.onet.pl)