Major Osteoporotic Fracture in Older Women Not Linked to Long-Term ICS Use

In older women, the risk for major osteoporotic fracture is not associated with long-term inhaled corticosteroid (ICS) use and consequent respiratory diseases, according to findings published in Osteoporosis International. 

This retrospective cohort study included 6880 older women (mean age, 64.6 years), of whom 62.1% had chronic obstructive pulmonary disease (COPD) and 37.9% had asthma. Researchers compiled data from Manitoba’s health administrative databases and  the bone mineral density (BMD) registry.

The primary outcome was time to incident major osteoporotic fracture. ICS use was stratified by exposure tertiles, measured as total use within 1 year of the index BMD test, with the primary exposure characterized by total days and quantity dispensed. ICS use was measured through the end of follow-up; however, exposure was measured using a medication possession ratio and average annual dose. Cox proportional hazards models were used to assess the correlation between ICS use and long-term major osteoporotic fracture rates.

During a mean 7.7±3.9 years of follow-up, 11.8% (n=810) of participants experienced a major osteoporotic fracture. Of these, 4.4% were forearm, 3.5% hip, 3.3% were vertebral, and 2.3% humeral fractures. None of the tertiles of ICS use were associated with significantly different risk for major osteoporotic fractures compared with no ICS use, by either dispensed days (P =.90) or dispensed quantity (P =.67). ICS use was also not associated with fracture during follow-up either by medication possession ratio (P =.62) or quantities (P =.58).

Study limitations included the use of administrative health data to derive prescription records, which may not provide actual intake data; inability to measure indicators of disease severity outside of medical claims and hospitalizations; the potential overrepresentation of osteoporosis because of the inclusion criteria of referral for BMD testing, which is more likely to occur in older populations; the 95% confidence interval’s upper bounds correlating with a slightly higher fracture risk; and a lack of information on supplements and over-the-counter medication use.

The researchers concluded that their findings “…do not support an association between long-term ICS use across a range of intensities, in terms of both days of use and dispensed quantity, and an increase in major osteoporotic fracture risk in older women with asthma and/or COPD.” These results add to “…the few previous studies evaluating the impact of ICS use on fracture risk in older women, particularly in asthma.”

Reference

Ng BC, Leslie WD, Johnson KM, FitzGerald JM, Sadatsafavi M, Chen W. Effects of long-term inhaled corticosteroid treatment on fragility fractures in older women: the Manitoba BMD registry study [published online March 2, 2020]. Osteoporos Int. doi:10.1007/s00198-020-05361-9