Air pollution exposure linked to bone damage in postmenopausal women

Higher levels of air pollutants were associated with reduced bone mineral density (BMD) among postmenopausal women, in a recent investigation. Nitrogen oxides exposure was identified as a leading contributor to bone loss.¹

Air pollution has been linked to a range of adverse health effects, including respiratory problems, cardiovascular disease, and now, according to a recent study, bone damage. Investigators noted the results of the study were striking.

All 4 pollutants assessed were negatively associated with whole-body, total hip, femoral neck, and lumbar spine bone mineral density. According to data, lumbar spine bone mineral density decreased 0.026 (95% CI: 0.016, 0.036) g/cm2/year per a 10% increase in 3-year mean NO2 concentration.

The findings suggested that exposure to air pollutants could have a significant impact on bone health, particularly among postmenopausal women.

The Implications of Air Pollution

Data demonstrated that NO2 and NO had the highest correlations across all averaging periods assessed, with correlation coefficients of 0.83, 0.85, and 0.86 for 1-, 3-, and 5-year means. Conversely, the lowest correlations were found between SO2 and PM10, with coefficients of -0.06, -0.06, and -0.1 for 1-, 3-, and 5-year means, as well as between SO2 and NO, with coefficients of -0.12, -0.09, and -0.07 for 1-, 3-, and 5-year means.

Included in the evaluation was a total of 9041 participants with 32,663 visits in the Women's Health Initiative (WHI). The participants' characteristics at enrollment showed that the average age was 63.3 years and most were White with a college or vocational education level.

In general, participants had a modest income, consumed less than seven servings of alcoholic drinks per week, were never smokers, and had low physical activity. There was a reduction in bone mineral density (BMD) with age.

Diddier Prada, MD, PhD, Department of Environmental Health Science, Mailman School of Public Health, Columbia University, and investigators, stated that the study's results have important implications for public health, given that osteoporosis is a significant health issue for postmenopausal women.

Evaluating Pollution, Bone Health Postmenopause

The cross-sectional, obsersvational investigation used data from the Women's Health Initiative Study, which enrolled postmenopausal women between September 1994-December 1998. Investigators estimated daily mean concentrations of 4 criteria air pollutants (PM10, NO, NO2, and SO2) at participants' geocoded addresses using log-normal, ordinary kriging.

The team then measured bone mineral density at enrollment and follow-up (Y1, Y3, Y6) using dual-energy X-ray absorptiometry.

The study also used Bayesian kernel machine regression (BKMR) models to investigate mixture effects of the four pollutants. The models indicated that nitrogen oxides exposure was inversely associated with whole-body and lumbar spine BMD, highlighting it as a leading contributor to bone loss.

Osteoporosis affects around 200 million women worldwide, and the associated fractures can have a significant impact on quality of life and mortality rates.

Investigators acknowledged that further research is needed to investigate the mechanisms underlying the association between air pollution and bone damage. However, they suggested that inflammation and oxidative stress could play a role, given that exposure to air pollutants has been linked to these processes in other studies.

In conclusion, the results provided compelling evidence that exposure to air pollutants is associated with reduced bone mineral density among this population. These data added to the growing body of research illuminating the wide-ranging health impacts of air pollution and underscores the urgent need for action to address this global health crisis.

This article was originally published by our sister publication HCP Live.

References:

1. Prada, D., Crandall, C. J., Kupsco, A., Kioumourtzoglou, M. A., Stewart, J. D., Liao, D., Yanosky, J. D., Ramirez, A., Wactawski-Wende, J., Shen, Y., Miller, G., Ionita-Laza, I., Whitsel, E. A., & Baccarelli, A. A. (2023). Air pollution and decreased bone mineral density among Women's Health Initiative participants. EClinicalMedicine, 42, 101864. doi: 10.1016/j.eclinm.2023.101864.