Air pollution appears to contribute independently to bone damage in postmenopausal women, new data suggest.
The findings come from a new analysis of data from the Women’s Health Initiative (WHI) and location-specific air particulate information from the US Environmental Protection Agency.
“Our findings confirm that poor air quality may be a risk factor for bone loss, independent of socioeconomic or demographic factors, and expands previous findings to postmenopausal women. Indeed, to our knowledge, this is the first study of the impact of criteria air pollutants on bone health in postmenopausal women,” write Diddier Prada, MD, PhD, Mailman School of Public Health, Columbia University, New York City, and colleagues.
The results are also the first to show that “nitrogen oxides contribute the most to bone damage and that the lumbar spine is one of the most susceptible sites,” they add.
Public health policies should aim to reduce air pollution in general, they continue, and reducing nitrogen oxides, in particular, will reduce bone damage in postmenopausal women, prevent bone fractures, and reduce the health cost burden associated with osteoporosis in this population.
The findings were recently published in eClinicalMedicine, a Lancet journal.
Asked to comment, Giovanni Adami, MD, PhD, told Medscape Medical News that the study “adds to the body of literature on air pollution and bone health. The study confirms and provides further evidence linking air pollution exposure and osteoporosis.”
Adami, of the University of Verona, Italy, who also studies this topic, said that these new findings align with those from his group and others.
“The scientific literature in the field is clearly pointing toward a negative effect of chronic pollution exposure on bone health.”
He pointed to one study from his group that found chronic exposure to ultrafine particulate matter is associated with low BMD, and consequently, bone fragility, and another study that showed acute exposure to high levels of pollutants could actually cause fractures.
As for what might be done clinically, Adami said: “It is difficult to extrapolate direct and immediate recommendations for patients.”
“However, it might be acceptable to say that patients at risk of osteoporosis, such as older women or those with prior bone fractures, should avoid chronic exposure to air pollution, perhaps using masks when walking in traffic or using air filters for indoor ventilation.”
Adami also said that this evidence so far might spur the future inclusion of chronic exposure to air pollution in fracture risk assessment tools, although this isn’t likely to come about in the near future.
Particulates Linked to Whole-Body, Hip, Lumbar, and Femoral Neck BMD
The prospective observational study included 9041 WHI participants seen over 32,663 visits who were an average of 63 years old at baseline. More than 70% were White, and just under half were college graduates.
With geocoded address data used to estimate particulate matter concentrations, mean levels of particulate matter of 10 µm or less (PM10), nitrogen oxide (NO), nitrogen dioxide (NO2), and sulfur dioxide (SO2) over 1, 3, and 5 years were all negatively associated with whole-body, total hip, femoral neck, and lumbar spine BMD.
In the multivariate analysis, the highest correlations were found between NO and NO2. For example, lumbar spine BMD decreased by 0.026 g/cm2 per year per 10% increase in 3-year mean NO2 concentration.
“Our findings show that both particulate matter and gases may adversely impact BMD and that nitrogen oxides may play a critical role in bone damage and osteoporosis risk,” Prada and colleagues write.
Adami added: “We need more data to understand the precise magnitude of effect of air pollution on fractures, which might depend on levels of exposure but also on genetics and lifestyle.”
The study was funded by the National Institutes of Health. The authors have reported no relevant financial relationships. Adami has reported receiving fees from Amgen, Eli Lilly, UCB, Fresenius Kabi, Galapagos, and Theramex.
eClinicalMedicine. Published online February 14, 2023. Full text
Miriam E. Tucker is a freelance journalist based in the Washington, DC, area. She is a regular contributor to Medscape, with other work appearing in The Washington Post, NPR’s Shots blog, and Diabetes Forecast magazine. She is on Twitter: @MiriamETucker.
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