Long-term exposure to air pollution increases hip fracture incidence rate and related mortality: analysis of National Hip Fracture Database

Abstract

Until now, the influence of air pollution on bone mineral density and associated fractures has drawn little attention, and the consequences are controversial. To investigate the association between air pollution and hip fracture incidence and related short-term mortality. We constructed a cohort of all the National Hip Fracture Database beneficiaries (513,540 patients) in the UK from 2013 to 2018. Per year averages of PM2.5, PM10, O3, NO2, and SO2 were estimated according to the person's residence. The incidence rate ratio with 95% confidence interval and all-cause mortality within 30-day post-fracture (ACM30D) rate ratios were estimated using generalized additive models. The average levels of PM2.5, PM10, and NO2 exhibited a positive association with the incidence rate of hip fracture (IHF) and ACM30D. Whereas, this association was negative for O3 levels. Each increase of 5 μg per cubic meter in PM2.5, PM10, and NO2 leads to 9.5%, 9.2%, and 4.1% higher hip fracture rate, respectively, and also 9.3%, 8.3%, and 2.9% higher ACM30D, respectively. When we restricted the analysis to low-level exposure of air pollutants, similar results were obtained. Our study found a moderate, positive association between IHF, ACM30D, and the levels of specific air pollutants in the entire National Hip Fracture Database population. A reduction in the levels of PM2.5, PM10, and NO2 may decrease the hip fracture incidence rate and associated short-term mortality in older adults. Our study highlights the influence of air pollution on hip fracture.