Impact of treatment with inhaled corticosteroids on bone mineral density of patients with asthma: related with age.

Abstract

The effect of inhaled corticosteroid on bone mineral density (BMD) was investigated in 44 asthmatic patients after median treatment duration of 6.5 years. Compared with controls, BMD decreased only in patients aged <50 years in both the spine (11.3 %, p = 0.013) and hip (8.8 %, p = 0.044), whereas in patients ≥50 years BMD did not decrease significantly. The results of studies which addressed the impact of inhaled corticosteroid (ICS) therapy on BMD of patients with asthma are conflicting. This case-control study aimed to compare BMD status in ICS user with asthma with healthy controls according to age. BMD at the lumbar spine (LS), femoral neck (FN) was measured by dual energy X-ray absorptiometry (DEXA). Patients and controls were compared according to BMD gr/cm(2), BMD T-score, BMD Z-score, frequency of osteoporosis (defined as BMD T-score ≤-2.5), and frequency of patients with BMD Z-score <-1 at LS and FN with regard to age <50 and ≥50 years old. Forty-four ICS user patients (females 63.6 %) with median treatment duration of 6.5 years and 50 controls (females, 69.4 %) with respective mean age of 49.2 ± 9.5 and 47.4 ± 10.5 years (p = 0.38 and p = 0.35) entered the study. Overall LS-BMD and FN-BMD gr/cm2 in total patients were lower than in controls by 6 % (p = 0.065) and 5.9 % (p = 0.09), respectively. In patients <50 years, mean LS-BMD gr/cm(2) was lower than controls by 11.3 % (p = 0.013) and FN-BMD by 8.8 % (p = 0.044). Mean BMD T-score and BMD Z-score in both measurement sites were also lower than controls (p = 0.013 and 0.01, respectively. Frequency of osteoporosis did not differ but frequency of patients with BMD Z-score <-1 was significantly higher in patients (odds ratio (OR) = 6.57 95 % CI, 1.8-23.9, p = 0.004). In age group ≥50 years old, reduction of BMD in both measurement sites did not reach to a significant level. This study indicates that BMD reduction in ICS user with asthma is dependent on age and appears that younger patients are at greater risk of BMD loss. These findings suggest preventive measures particularly in patients <50 years.