The study included 4,041 patients with hip fractures who received N-BPs and 11,802 who did not. Over a median follow-up time of 2.7 years, N-BPs were associated with a 24% lower risk of pneumonia compared with no treatment (69 versus 90 cases per 1,000 people per year).

A similar association was observed with pneumonia mortality, with a 35% lower risk associated with N-BPs (23 versus 35 per 1,000 patients per year for the N-BP and non-N-BP groups, respectively).

Results from previous animal studies indicate that N-BP treatment leads to a high concentration of N-BPs in the respiratory tract. "Together with its anti-inflammatory and immune-modulatory properties, this may explain why N-BPs were associated with reduced risk of pneumonia, as revealed in our study," said senior author Ching-Lung Cheung, PhD, of The University of Hong Kong. He added that studying the potential of N-BPs for treating symptoms of COVID-19 may be warranted.