Epidemiological characteristics of elderly osteoporosis fractures and their association with air pollutants: a multi-center study in Hebei Province

To investigate the population distribution characteristics of elderly osteoporosis fracture patients in Hebei Province and analyze the effects of air pollutants on elderly osteoporosis fractures, We retrospectively collected 18,933 cases of elderly osteoporosis fractures from January 1, 2019, to December 31, 2022, from four hospitals in Hebei Province. The average age was 76.44 ± 7.58 years, predominantly female (13,189 patients, 69.66%). The number of hospitalized patients increased progressively from 2019 to 2022. The Distribution Lag Nonlinear Model (DLNM) showed that the cumulative lagged effects of PM2.5 and PM10 on the number of hospitalized elderly osteoporosis fracture patients exhibited a bimodal distribution, with the Relative Risk (RR) reaching its peak at a 1-day lag (PM2.5: RR = 1.032, 95% CI: 1.019, 1.045; PM10: RR = 1.022, 95% CI: 1.014, 1.029). Similarly, the cumulative lagged effect of NO₂ displayed a bimodal pattern, with the RR peaking at a 12-day lag (RR = 1.138, 95% CI: 1.101, 1.187). The single-day lag effect of SO₂ was statistically significant from day 9 to day 12, reaching its maximum at day 11 (RR = 1.054, 95% CI: 1.032, 1.71). PM2.5, PM10, NO₂, and SO₂ increase the risk of osteoporosis fractures in the elderly, including single-day and cumulative lag effects. Further studies are needed to explore the molecular mechanisms behind this relationship.