Elevated levels of air pollution increases bone loss from osteoporosis in postmenopausal women, with effects most evident in the lumbar spine
According to new research led by scientists at Columbia University Mailman School of Public Health, air pollution can actually speed up the rate of bone loss in those suffering from osteoporosis.
The effects were most evident on the lumbar spine, with nitrous oxides twice as damaging to the area than seen with normal ageing.
The research findings appear in the peer-reviewed journal eClinicalMedicine, part of The Lancet Discovery Science suite of open-access journals.
Previous studies have pointed to the adverse effects of air pollution
This is by no means the firsts study to suggest that air pollution can have a terrible impact on bone density. For example, previous studies on individual air pollutants have shown that they can adversely affect:
- Bone mineral density
- Osteoporosis risk
- Fractures in older individuals
The new study is the first to explore the connection between air pollution and bone mineral density, specifically in postmenopausal women and the first to explore the effects of air pollution mixtures on bone outcomes.
161,808 postmenopausal women participated
In this study, researchers analyzed data collected through the Women’s Health Initiative study. This contains an ethnically diverse cohort of 161,808 postmenopausal women.
The team estimated air pollution (PM10, NO, NO2, and SO2) exposures based on participants’ home addresses. They measured bone mineral density (BMD; whole-body, total hip, femoral neck, and lumbar spine) at enrollment at follow-up at year one, year three, and year six using dual-energy X-ray absorptiometry.
The magnitude of the effects of nitrogen oxides on lumbar spine BMD would amount to 1.22% annual reductions—nearly double the annual effects of age on any of the anatomical sites evaluated. These effects are believed to happen through bone cell death by way of oxidative damage and other mechanisms.
Do socioeconomic and demographic factors impact results?
First study author Diddier Prada, MD, PhD, associate research scientist in the Department of Environmental Health Sciences at Columbia Mailman School of Public Health explained, “Our findings confirm that poor air quality may be a risk factor for bone loss, independent of socioeconomic or demographic factors. For the first time, we have evidence that nitrogen oxides, in particular, are a major contributor to bone damage and that the lumbar spine is one of the most susceptible sites of this damage.”.
‘Improvements in air pollution exposure… will reduce bone damage in postmenopausal women’
“Improvements in air pollution exposure, particularly nitrogen oxides, will reduce bone damage in postmenopausal women, prevent bone fractures, and reduce the health cost burden associated with osteoporosis among postmenopausal women. Further efforts should focus on detecting those at higher risk of air pollution-related bone damage,” adds lead author Andrea Baccarelli, MD, PhD, chair of the Department of Environmental Health Sciences at Columbia Mailman School of Public Health.
Car and truck exhausts, along with the emissions from electrical power generation plants, are a major source of nitrous oxides.
2.1 million osteoporosis-related bone fractures happen every year
In fact, approximately 2.1 million osteoporosis-related bone fractures occur annually. The resulting annual direct health costs amount to $20.3 billion.
Women are affected by osteoporosis more than men, with 80% of the estimated 10 million Americans with osteoporosis being women. Furthermore, postmenopausal women are at higher risk, with one in two women over 50 experiencing a bone fracture because of osteoporosis.
Previously, Columbia researchers showed that long-term air pollution exposure reduces BMD and increases bone fracture risk in later life. Subsequently, these findings have been confirmed in multiple human studies.
