Association between air pollutants with calcaneus ultrasound T-score change in a large Taiwanese population follow-up study

Abstract

Exposure to ambient air pollution has been associated with increased rates of mortality and morbidity and a shorter life expectancy. Few studies have evaluated the associations between air pollution and change in calcaneus ultrasound T-score (∆T-score). Therefore, in this longitudinal study, we explored these associations in a large group of Taiwanese participants. We used data from the Taiwan Biobank database and Taiwan Air Quality Monitoring Database, which contains detailed daily data on air pollution. We identified 27,033 participants in the Taiwan Biobank database who had both baseline and follow-up data. The median follow-up period was 4 years. The studied ambient air pollutants included particulates of 2.5 μm or less (PM_2.5), particulates of 10 μm or less (PM₁₀), ozone (O₃), carbon monoxide (CO), sulfur dioxide (SO₂), nitric oxide (NO), nitrogen dioxide (NO₂), and nitrogen oxide (NO_x). Multivariable analysis showed that PM_2.5 (β, -0.003; 95% confidence interval (CI), -0.004 to -0.001; p < 0.001), PM₁₀ (β, -0.005; 95% CI, -0.006 to -0.004, p < 0.001), O₃ (β, -0.008; 95% CI, -0.011 to -0.004; p < 0.001), and SO₂ (β, -0.036; 95% CI, -0.052 to -0.020; p < 0.001) were negatively associated with ∆T-score, and that CO (β, 0.344; 95% CI, 0.254, 0.433; p < 0.001), NO (β, 0.011; 95% CI, 0.008 to 0.015; p < 0.001), NO₂ (β, 0.011; 95% CI, 0.008 to 0.014; p < 0.001), and NO_x (β, 0.007; 95% CI, 0.005 to 0.009; p < 0.001) were positively significantly associated with ∆T-score. Furthermore, PM_2.5 and SO₂ (β, -0.014; 95% CI, -0.016 to -0.013; p < 0.001) and PM₁₀ and SO₂ (β, -0.008; 95% CI, -0.009 to -0.007; p < 0.001) had synergistic negative effects on ∆T-score. In conclusion, we found that high PM_2.5, PM₁₀, O₃, and SO₂ were associated with a rapid decline in T-score, whereas high CO, NO, NO₂, and NO_x were associated with a slow decline in T-score. Furthermore, PM_2.5 and SO₂ and PM₁₀ and SO₂ had synergistic negative effects on ∆T-score, causing an acceleration in T-score decline. These findings may be helpful when developing policies on air pollution regulation.

Keywords: Air pollutants; Follow-up; Osteoporosis; T-score; Taiwan Biobank.