Associations between Long-Term Air Pollution Exposure and Risk of Osteoporosis-Related Fracture in a Nationwide Cohort Study in South Korea

Abstract

Bone health is a major concern for aging populations globally. Osteoporosis and bone mineral density are associated with air pollution, but less is known about the impacts of air pollution on osteoporotic fracture. We aimed to assess the associations between long-term air pollution exposure and risk of osteoporotic fracture in seven large Korean cities. We used Cox proportional hazard models to estimate hazard rations (HRs) of time-varying moving window of past exposures of particulate matter (PM10), sulfur dioxide (SO2), carbon monoxide (CO), nitrogen dioxide (NO2), and ozone (O3) for osteoporotic fracture in Korean adults (age ≥50 y) in the National Health Insurance Service-National Sample Cohort data, followed 2002 to 2015. HRs were calculated for an interquartile range (IQR) increase. Comorbidity and prescription associated with osteoporosis, age, sex, body mass index, health behaviors, and income were adjusted in the models. Effect modification by age, sex, exercise, and income was examined. We assessed 56,467 participants over 535,481 person-years of follow up. Linear and positive exposure-response associations were found for SO2, while PM10 and NO2 showed nonlinear associations. SO2 was associated with osteoporosis-related fracture with marginal significance (HR for an IQR [2 ppb] increase = 1.04, 95% CI: 1.00, 1.09). The SO2 HR estimates were robust in analyses applying various moving windows of exposure (from one to three years of past exposure) and two-pollutant models. The central HR estimate of O3 implied positive associations but was not significant (HR for 0.007 ppm increase = 1.01, 95% CI: 0.97, 1.06). PM10, CO, and NO2 did not show associations. Vulnerable groups by sex, age, exercise, and income varied across air pollutants and there was no evidence of effect modifications. Long-term exposure to SO2, but not PM10, CO, NO2 and O3, was associated with increased osteoporotic fracture risks in Korean adults.

Associations between long-term exposure to fine particulate matter and osteoporotic fracture risks in South Korea

“…2010-2016) for the residential districts and assigned the averages to each participant (Oh and Song 2020). In our previous research where we examined exposure windows using the 3 yr moving average PM 10 concentration, the exposure-response relationship curves for osteoporotic fracture indicated an inverted U-shaped curve and the estimated HRs of PM 10 were not significant (Heo et al 2022).…”

“…A previous Korean study of women aged ⩾50 years in three metropolitan cities found significant osteoporotic fracture risks for PM 2.5 but not for PM 10 (Sung et al 2020). Our previous study of men and women in seven metropolitan cities in South Korea examined the impacts of PM on osteoporotic fractures using PM 10 monitoring data, but PM 2.5 monitoring data were not available for our study period (Heo et al 2022). Given that PM 2.5 can be more harmful than PM 10 due to the smaller size and deeper penetrations into the lungs and organs, examining varying sizes of PM in relation to osteoporotic fracture risks is important in establishing the regulation standards for PM.…”

“…Only a few studies have examined potential effect modifications by socioeconomic status (e.g. income), exercise, and diet for the associations between PM and osteoporotic fracture (Prada et al 2020, Heo et al 2022. A previous US study found that the highest income group had significantly lower associations between PM 2.5 and osteoporotic fracture than lower income groups (Prada et al 2020).…”

“…The 10 yr moving average PM 2.5 concentration for the risk in 2012 is the PM 2.5 exposure levels in 2002-2011. Similar approaches for time-variant exposure levels were applied in previous studies (Heo et al 2022). We used the 6 yr exposure window for the main results and sub-group analysis as positive exposure-response relationships were found for exposure in the past 6 years or more (i.e.…”

Osteoporosis in Patients With Respiratory Diseases

“…Disturbance of calcium absorption without the assistance of vitamin D was not conducive to bone remodeling. The contents of automobile exhaust leading to the occurrence of osteoporosis were mainly SO 2 and NO 2 ( Liu et al, 2021 ; Heo et al, 2022 ). Long-term exposure to SO 2 and NO 2 increased the risk of osteoporotic fractures ( Mazzucchelli et al, 2018 ).…”