The effect of inhaled corticosteroids on bone mineral density measured by quantitative ultrasonography in an older population

Introduction: Prolonged use of systemic corticosteroids leads to reduced bone mineral density and osteoporosis, in turn increasing the risk of minimal trauma fractures with their associated morbidity and mortality in elderly populations. However, the effect of inhaled corticosteroids on bone mineral density has been debated in the medical literature. Objectives: We aimed to determine the effect of inhaled corticosteroids on bone mineral density measured using calcaneal quantitative ultrasonography in a cohort of older Australians. Methods: Data was collected from the Hunter Community Study, a longitudinal cohort of Australians aged 55-85. Simple and multiple linear regression methods were used to test the cross-sectional association between inhaled corticosteroids and calcaneal bone mineral density measured with quantitative ultrasound at baseline. A causal diagram was used to determine the minimally sufficient number of co-variates necessary to determine the unconfounded effect of inhaled corticosteroids on bone mineral density; these included gender, body mass index, smoking, asthma, alcohol use, age, physical activity, and diet. Results: There were 152 (6.8%) patients on inhaled corticos teroids and 2098 (93%) controls. Simple and multiple linear regression methods showed a non-significant effect of inhaled steroids on BMD with slight decrease of BMD -0.010 g/cm² (95% CI -0.042 to 0.022, P =.55) and -0.013 g/cm² (95% CI -0.062 to 0.036, P =.61) respectively. Age, gender, body mass index, and smoking were stronger predictors of BMD. Conclusions: No statistically significant relationship was detected between the use of inhaled corticosteroids and reduced bone mineral density in this observational study of a cohort of older Australians.