Outdoor air pollution, bone density and self-reported forearm fracture: the Oslo Health Study

Air Pollution and Osteoporosis

PURPOSE OF REVIEW

The purpose of this review is to provide a background of osteoporosis and air pollution, discussing increasing incidence of the disease with exposure to pollutants and the role that inflammation may play in this process.

RECENT FINDINGS

Osteoporosis-related fractures are one of the most pressing challenges for the ageing global population, with significant increases in mortality known to occur after major osteoporotic fractures in the elderly population. Recent studies have established a firm correlative link between areas of high air pollution and increased risk of osteoporosis, particularly alarming given the increasingly urban global population. While the culprit pollutants and molecular mechanisms underlying this phenomenon have not yet been elucidated, initial studies suggest a role for inflammatory cascades in this phenomenon. While much more research is required to identify the most damaging air pollutants and to delineate the specific inflammatory molecular mechanisms, it is clear from the literature that shedding light on these pathways would unveil potential therapeutic targets to treat bone diseases, including osteoporosis. Major deficiencies of current animal models highlight the need for complex human in vitro models such as organ-on-a-chip technology to better understand the impact of air pollution.

Association between Personal Abiotic Airborne Exposures and Body Composition Changes among Healthy Adults (60-69 Years Old): A Combined Exposome-Wide and Lipidome Mediation Approach from the China BAPE Study

BACKGROUND

Evidence suggested that abiotic airborne exposures may be associated with changes in body composition. However, more evidence is needed to identify key pollutants linked to adverse health effects and their underlying biomolecular mechanisms, particularly in sensitive older adults.

OBJECTIVES

Our research aimed to systematically assess the relationship between abiotic airborne exposures and changes in body composition among healthy older adults, as well as the potential mediating mechanisms through the serum lipidome.

METHODS

From September 2018 to January 2019, we conducted a monthly survey among 76 healthy adults (60-69 years old) in the China Biomarkers of Air Pollutant Exposure (BAPE) study, measuring their personal exposures to 632 abiotic airborne pollutions using MicroPEM and the Fresh Air wristband, 18 body composition indicators from the InBody 770 device, and lipidomics from venous blood samples. We used an exposome-wide association study (ExWAS) and deletion/substitution/addition (DSA) model to unravel complex associations between exposure to contaminant mixtures and body composition, a Bayesian kernel machine regression (BKMR) model to assess the overall effect of key exposures on body composition, and mediation analysis to identify lipid intermediators.

RESULTS

The ExWAS and DSA model identified that 2,4,5-T methyl ester (2,4,5-TME), 9,10-Anthracenedione (ATQ), 4b,8-dimethyl-2-isopropylphenanthrene, and 4b,5,6,7,8,8a,9,10-octahydro-(DMIP) were associated with increased body fat mass (BFM), fat mass indicators (FMI), percent body fat (PBF), and visceral fat area (VFA) in healthy older adults [Bonferroni-Hochberg false discovery rate ( FD R BH ) < 0.05 ]. The BKMR model demonstrated a positive correlation between contaminants (anthracene, ATQ, copaene, di-epi-α -cedrene, and DMIP) with VFA. Mediation analysis revealed that phosphatidylcholine [PC, PC(16:1e/18:1), PC(16:2e/18:0)] and sphingolipid [SM, SM(d18:2/24:1)] mediated a significant portion, ranging from 12.27% to 26.03% (p-value < 0.05 ), of the observed increase in VFA.

DISCUSSION

Based on the evidence from multiple model results, ATQ and DMIP were statistically significantly associated with the increased VFA levels of healthy older adults, potentially regulated through lipid intermediators. These findings may have important implications for identifying potentially harmful environmental chemicals and developing targeted strategies for the control and prevention of chronic diseases in the future, particularly as the global population is rapidly aging. https://doi.org/10.1289/EHP13865.

Association Between Long‑Term Exposure to Air Pollution and the Rate of Mortality After Hip Fracture Surgery in Patients Older Than 60 Years: Nationwide Cohort Study in Taiwan

BACKGROUND

To enhance postoperative patient survival, particularly in older adults, understanding the predictors of mortality following hip fracture becomes paramount. Air pollution, a prominent global environmental issue, has been linked to heightened morbidity and mortality across a spectrum of diseases. Nevertheless, the precise impact of air pollution on hip fracture outcomes remains elusive.

OBJECTIVE

This retrospective study aims to comprehensively investigate the profound influence of a decade-long exposure to 12 diverse air pollutants on the risk of post-hip fracture mortality among older Taiwanese patients (older than 60 years). We hypothesized that enduring long-term exposure to air pollution would significantly elevate the 1-year mortality rate following hip fracture surgery.

METHODS

From Taiwan's National Health Insurance Research Database, we obtained the data of patients who underwent hip fracture surgery between July 1, 2003, and December 31, 2013. Using patients' insurance registration data, we estimated their cumulative exposure levels to sulfur dioxide (SO2), carbon dioxide (CO2), carbon monoxide (CO), ozone (O3), particulate matter having a size of <10 μm (PM10), particulate matter having a size of <2.5 μm (PM2.5), nitrogen oxides (NOX), nitrogen monoxide (NO), nitrogen dioxide (NO2), total hydrocarbons (THC), nonmethane hydrocarbons (NMHC), and methane (CH4). We quantified the dose-response relationship between these air pollutants and the risk of mortality by calculating hazard ratios associated with a 1 SD increase in exposure levels over a decade.

RESULTS

Long-term exposure to SO2, CO, PM10, PM2.5, NOX, NO, NO2, THC, NMHC, and CH4 demonstrated significant associations with heightened all-cause mortality risk within 1 year post hip fracture surgery among older adults. For older adults, each 1 SD increment in the average exposure levels of SO2, CO, PM10, PM2.5, NOX, NO, NO2, THC, NMHC, and CH4 corresponded to a substantial escalation in mortality risk, with increments of 14%, 49%, 18%, 12%, 41%, 33%, 38%, 20%, 9%, and 26%, respectively. We further noted a 35% reduction in the hazard ratio for O3 exposure suggesting a potential protective effect, along with a trend of potentially protective effects of CO2.

CONCLUSIONS

This comprehensive nationwide retrospective study, grounded in a population-based approach, demonstrated that long-term exposure to specific air pollutants significantly increased the risk of all-cause mortality within 1 year after hip fracture surgery in older Taiwanese adults. A reduction in the levels of SO2, CO, PM10, PM2.5, NOX, NO, NO2, THC, NMHC, and CH4 may reduce the risk of mortality after hip fracture surgery. This study provides robust evidence and highlights the substantial impact of air pollution on the outcomes of hip fractures.

Potential causal associations of PM2.5 and osteoporosis: a two-sample mendelian randomization study

Background: Observational studies suggest a potential association between atmospheric particulate matter 2.5 (PM2.5) and osteoporosis, but a causal association is unclear due to the presence of confounding factors. Methods: We utilized bone mineral density indices at four specific sites to represent osteoporosis: femoral neck (FN-BMD), lumbar spine (LS-BMD), forearm (FA-BMD), and heel (HE-BMD). The PM2.5 data was obtained from the UK Biobank database, while the datasets for FN-BMD, LS-BMD, and FA-BMD were obtained from the GEFOS database, and the dataset for HE-BMD was obtained from the EBI database. A two-sample Mendelian randomization analysis was conducted using mainly the inverse variance weighted method, horizontal pleiotropy and heterogeneity were also assessed. Results: The results indicated that PM2.5 was not correlated with a decrease in FN-BMD (β: -0.305, 95%CI: -0.762, 0.153), LS-BMD (β: 0.134, 95%CI: -0.396, 0.666), FA-BMD (β: -0.056, 95%CI: -1.172,1.060), and HE-BMD (β: -0.084, 95%CI: -0.261,0.093). Additionally, acceptable levels of horizontal pleiotropy and heterogeneity were observed. Conclusion: In contrast to most observational studies, our research did not discover a potential causal relationship between PM2.5 and the development of osteoporosis.

Tumor necrosis factor mediates the impact of PM2.5 on bone mineral density: Inflammatory proteome Mendelian randomization and colocalization analyses

To assess the causal effect of particulate matter 2.5 (PM2.5) on human bone mineral density (BMD) and to explore the possible mechanism and proportion mediated by inflammation-related protein. The genetic correlation between PM2.5 and BMD was assessed using the Linkage Disequilibrium Score (LDSC), and the causal effect between PM2.5 and BMD was assessed by two-sample Mendelian randomization (TSMR). A 2-step Mendelian randomization (MR) approach was employed to evaluate the potential role of inflammation-associated protein as the mediator in the causal association between PM2.5 and BMD. The multivariate Mendelian randomization (MVMR) study was designed to perform mediation analyses, exclude possible confounders and calculate the proportion of mediation. Subsequently, we used Bayesian colocalization analysis to consolidate the MR results. Finally, using drug-target MR design, we evaluated the potential repurposing of tumor necrosis factor (TNF) inhibitors for the treatment of osteoporosis (OP). The results of the analyses show that BMD is negatively influenced by PM2.5 (Inverse variance weighted [IVW] beta [β] = -0.288, 95% confidence interval [CI]: -0.534 - -0.042, P < 0.05). PM2.5 has a positive causal association with TNF (IVW β = 1.564, 95% CI: 0.155 - 2.973, P < 0.05) and a negative causal association with protachykinin-1 (TAC-1) (IVW β = -1.654, 95% CI: -3.063 - -0.244, P < 0.05). TNF has a negative causal association with BMD (Wald ratio β = -0.082, 95% CI: -0.165 - 0.000, P < 0.05) and TAC-1 has a positive causal association with BMD (IVW β = 0.042, 95% CI: 0.007 - 0.077, P < 0.05). After adjusting TNF and TAC-1, PM2.5 has no causal association with BMD (IVW β = -0.200, 95% CI: -0.579 - 0.179, P > 0.05). After adjusting PM2.5 and TAC-1, there was still a negative causal association between TNF and BMD (IVW β = -0.089, 95% CI: -0.166 - -0.012, P < 0.05). In the final drug-target MR study, the protective effect of TNF/TNF receptor 1 (TNFR1) inhibition on BMD was observed. For every 10% decrease of circulating C-reactive protein (CRP) achieved by TNF/TNF receptor 1 (TNFR1) blockade, β was 0.540 (95% CI: 0.040-1.040) for BMD. We found a negative causal association between PM2.5 and BMD and that causal association was mediated by TNF. The results of drug-target MR do support TNFR1 as a promising target for OP prevention among the general population.

Short-term exposure to gaseous pollutants is neglected factors for knee osteoarthritis: evidence from a humid subtropical region of China

Few studies were performed on the impact of exposure to gaseous pollutants on the risk of knee osteoarthritis (KOA). We conducted this study to analyze the association between short-term exposure to gaseous pollutants and the risk of hospitalizations for KOA. A total of 2952 KOA hospitalizations derived from two hospitals in Hefei, and the relationship between gaseous pollutants and KOA hospitalizations was analyzed by a distributed lag non-linear model combined with a generalized linear model. We found that the decreased risk of hospitalizations for KOA were both related to exposure to NO2 (RR = 0.993, lag19 day) and O3 (RR = 0.984, lag0 day), while exposure to CO could increase the risk of hospitalizations for KOA (RR = 1.076, lag2 day). Stratified analyses suggested that the KOA patients < 65 years were more susceptible to O3 exposure, and the female, male, patients ≥ 65 years, and patients < 65 years were both more sensitive to CO exposure. Our findings demonstrated that exposure to NO2, O3 resulted in a decreased risk for KOA hospitalizations, and CO exposure might increase the risk of KOA hospitalizations.

Ambient PM2.5 Components Are Associated With Bone Strength: Evidence From a China Multi-Ethnic Study

CONTEXT

The relationship between the components of particulate matter with an aerodynamic diameter of 2.5 or less (PM2.5) and bone strength remains unclear.

OBJECTIVE

Based on a large-scale epidemiologic survey, we investigated the individual and combined associations of PM2.5 and its components with bone strength.

METHODS

A total of 65 906 individuals aged 30 to 79 years were derived from the China Multi-Ethnic Cohort Annual average concentrations of PM2.5 and its components were estimated using satellite remote sensing and chemical transport models. Bone strength was expressed by the calcaneus quantitative ultrasound index (QUI) measured by quantitative ultrasound. The logistic regression model and weighted quantile sum method were used to estimate the associations of single and joint exposure to PM2.5 and its components with QUI, respectively.

RESULTS

Our analysis shows that per-SD increase (μg/m3) in 3-year average concentrations of PM2.5 (mean difference [MD] -7.38; 95% CI, -8.35 to -6.41), black carbon (-7.91; -8.90 to -6.92), ammonium (-8.35; -9.37 to -7.34), nitrate (-8.73; -9.80 to -7.66), organic matter (-4.70; -5.77 to -3.64), and soil particles (-5.12; -6.10 to -4.15) were negatively associated with QUI. In addition, these associations were more pronounced in men, and people older than 65 years with a history of smoking and chronic alcohol consumption.

CONCLUSION

We found that long-term exposure to PM2.5 and its components may lead to reduced bone strength, suggesting that PM2.5 and its components may potentially increase the risk of osteoporosis and even fracture. Nitrate may be responsible for increasing its risk to a greater extent.

A comprehensive review on environmental pollutants and osteoporosis: Insights into molecular pathways

A significant problem that has an impact on community wellbeing is environmental pollution. Environmental pollution due to air, water, or soil pollutants might pose a severe risk to global health, necessitating intense scientific effort. Osteoporosis is a common chronic condition with substantial clinical implications on mortality, morbidity, and quality of life. It is closely linked to bone fractures. Worldwide, osteoporosis affects around 200 million people, and every year, there are almost 9 million fractures. There is evidence that certain environmental factors may increase the risk of osteoporosis in addition to traditional risk factors. It is crucial to understand the molecular mechanisms at play because there is a connection between osteoporosis and exposure to environmental pollutants such as heavy metals, air pollutants, endocrine disruptors, metal ions and trace elements. Hence, in this scoping review, we explore potential explanations for the link between pollutants and bone deterioration through deep insights into molecular pathways. Understanding and recognizing these pollutants as modifiable risk factors for osteoporosis would possibly help to enhance environmental policy thereby aiding in the improvement of bone health and improving patient quality of life.

Exposure to Multiple Air Pollutants and the Risk of Fractures: A Large Prospective Population-Based Study

Atmospheric chemistry studies suggest air pollution impedes ultraviolet B photons and thus reduces cutaneous vitamin D3 synthesis. Biological evidence shows that inhaled pollutants disrupt circulating 25-hydroxyvitamin D (25[OH]D) metabolism and ultimately impact bone health. The hypothesis is that higher air pollution concentrations are associated with a higher risk of fractures, mediated by lower circulating 25(OH)D. The study included participants of the UK Biobank who were free of fracture history at enrollment (2006 to 2010) and analyzed their environmental exposure data (2007 to 2010). Air pollution measurements included the annual averages of air particulate matter (PM2.5 , PM2.5-10 , and PM10 ), nitrogen oxides (NO2 and NOx ), and a composite air pollution score. Multivariable Cox proportional hazard models were used to assess the associations of the individual pollutants and the score with fracture risks. Mediation analyses were conducted to assess the underlying role of serum 25(OH)D in such associations. Among 446,395 participants with a median of 8-year follow-up, 12,288 incident fractures were documented. Participants living in places with the highest quintile of air pollution score had a 15.3% increased risk of fractures (hazard ratio [95%CI]: 1.15[1.09,1.22]) compared to those in the lowest, and 5.49% of this association was mediated through serum 25(OH)D (pmediation  < 0.05). Pollutant-specific hazard of top-to-bottom quintiles was 16% for PM2.5 , 4% for PM2.5-10 , 5% for PM10 , 20% for NO2 , and 17% for NOx , with a 4% to 6% mediation effect of serum 25(OH)D concentrations. The associations of the air pollution score with fracture risks were weaker among female participants, those who drank less alcohol, and consumed more fresh fruit than their counterparts (pinteraction  < 0.05). © 2023 American Society for Bone and Mineral Research (ASBMR).

Association between traffic-related air pollution and osteoporotic fracture hospitalizations in inland and coastal areas: evidences from the central areas of two cities in Shandong Province, China

Our result showed that short-term exposure to traffic-related air pollutants (TRAPs) might increase the risk of hospitalizations for osteoporotic fractures. It was suggested that government should formulate emission reduction policies to protect the health of citizens.

INTRODUCTION

As the main source of urban air pollution in China, exhaust emissions of motor vehicles have been linked to adverse health outcomes, but evidence of the relationship between short-term exposure to TRAPs and osteoporotic fractures is still relatively rare.

METHODS

In this study, a total of 5044 inpatients from an inland city (Jinan) and a coastal city (Qingdao), two cities with developed transportation in Shandong Province, were included. A generalized additive model (GAM) was used to investigate the association between TRAPs and hospitalizations for osteoporotic fractures. The stratified analyses were performed by gender and age.

RESULTS

Positive associations between TRAPs and osteoporotic fracture hospitalizations were observed. We found that short-term exposure to TRAPs was associated with increased numbers of hospitalizations for osteoporotic fractures. PM2.5 and PM10 were statistically significant associated with hospitalizations for osteoporotic fractures at both single-day and multiday lag structures only in Qingdao, with the strongest associations at lag06 and lag07 [RR=1.0446(95%CI: 1.0018,1.0891) for PM2.5, RR=1.0328(95%CI: 1.0084,1.0578) for PM10]. For NO2 and CO, we found significant associations at lag4 in the single lag structure in Jinan [RR=1.0354 (95%CI: 1.0071, 1.0646) for NO2, RR=1.0014 (95%CI: 1.0002, 1.0025) for CO], while only CO at lag4 was significantly associated with hospitalizations for osteoporotic fractures in Qingdao [1.0038 (1.0012, 1.0063)]. Stratified analyses indicated that the associations were stronger in females and older individuals (65 + years).

CONCLUSION

This study implied that short-term exposure to TRAPs pollution was associated with an increased risk of hospitalizations for osteoporotic fractures. Female patients and patients aged 65 + years appeared to be more vulnerable to TRAPs, suggesting that poor air quality is a modifiable risk factor for osteoporotic fractures.

Endocrine Disruptor-Induced Bone Damage Due to Hormone Dysregulation: A Review

Hormones are indispensable for bone development, growth, and maintenance. While many of the genes associated with osteogenesis are well established, it is the recent findings in endocrinology that are advancing the fields of bone biology and toxicology. Endocrine-disrupting chemicals (EDCs) are defined as chemicals that interfere with the function of the endocrine system. Here, we report recent discoveries describing key hormone pathways involved in osteogenesis and the EDCs that alter these pathways. EDCs can lead to bone morphological changes via altering hormone receptors, signaling pathways, and gene expression. The objective of this review is to highlight the recent discoveries of the harmful effects of environmental toxicants on bone formation and the pathways impacted. Understanding the mechanisms of how EDCs interfere with bone formation contributes to providing a comprehensive toxicological profile of a chemical.

Outdoor air pollution exposure, bone mineral density, osteoporosis, and osteoporotic fractures: A systematic review and meta-analysis

BACKGROUND

The prevalence of osteoporosis and osteoporotic fractures is expected to increase with the aging of the population in the coming decades. In this study, we systematically reviewed the evidence on the association between exposure to air pollution and osteoporosis-related outcomes.

METHODS

We systematically searched evidence according to the PRISMA on PubMed, Scopus, and Web of Science (until August 2022). The risk of bias (RoB) was assessed using the Risk of Bias in the Non-randomized Studies of Exposures (ROBINS-E) tool. Random effects meta-analysis was applied to calculate combined estimates. We evaluated the heterogeneity using Cochran's Q test and quantified it by I² and tau² statistics. The overall body of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation system (GRADE) tool.

RESULTS

Out of 5254 retrieved articles, 19 studies (11 cross-sectional, seven cohorts, and one case-control) met our inclusion criteria. Most of the studies had a high probability of RoB (n = 17), and only two had a moderate RoB. Different outcomes including bone mineral density, bone mineral content, osteoporotic fracture, osteoporosis, and osteopenia were reported across the studies. The associations were reported for different air pollutants including PM2.5, PM10, nitrogen oxides, nitrogen dioxide, ozone, black carbon, carbon monoxide, sulfur dioxide, nitrogen oxide, and coarse particulate matter. Evidence was suggestive of the negative role of PM10, PM2.5, and nitrogen dioxide (e.g. bone mineral density pooled estimate: -0.02, 95%CI: -0.03: -0.01). The overall body of evidence for most of the exposure-outcome pairs was low and very low.

CONCLUSIONS

The evidence on the association between air pollution exposure and osteoporosis-related outcomes is heterogenic. However, the evidence suggests an increased risk of osteoporotic fracture and osteoporosis in outdoor air pollutants. Due to the small number of studies in each group, also observed heterogeneity, and publication bias, the results should be interpreted with caution.

Air pollution, genetic factors and the risk of osteoporosis: A prospective study in the UK biobank

Purpose

To reveal relationship between air pollution exposure and osteoporosis (OP) risk.

Methods

Based on large-scale data from the UK Biobank, we evaluated the relationship between OP risk and several air pollutants. Then air pollution scores (APS) were constructed to assess the combined effects of multiple air pollutants on OP risk. Finally, we constructed a genetic risk score (GRS) based on a large genome-wide association study of femoral neck bone mineral density and assessed whether single or combined exposure to air pollutants modifies the effect of genetic risk on OP and fracture risk.

Results

PM_2.5, NO₂, NO_x, and APS were significantly associated with an increased risk of OP/fracture. OP and fracture risk raised with increasing concentrations of air pollutants: compared to the lowest APS quintile group, subjects in the highest quintile group had a hazard ratio (HR) (95% CI) estimated at 1.140 (1.072-1.213) for OP and 1.080 (1.026-1.136) for fracture. Moreover, participants with low GRS and the highest air pollutant concentration had the highest risk of OP, the HRs (95% CI) of OP were 1.706 (1.483-1.964), 1.658 (1.434-1.916), 1.696 (1.478-1.947), 1.740 (1.506-2.001) and 1.659 (1.442-1.908), respectively, for PM_2.5, PM₁₀, PM_2.5-10, NO₂, and NO_x. Similar results were also observed for fractures. Finally, we assessed the joint effect of APS and GRS on the risk of OP. Participants with higher APS and lower GRS had a higher risk of developing OP. Similar results were observed in the joint effect of GRS and APS on fracture.

Conclusions

We found that exposure to air pollution, individually or jointly, could improve the risk of developing OP and fractures, and increased the risk by interacting with genetic factors.

Ambient air pollution, bone mineral density and osteoporosis: Results from a national population-based cohort study

Evidence concerning the associations of ambient air pollution exposure with bone mineral density and osteoporosis has been mixed. We conducted cross-sectional and prospective analysis of the associations between air pollution exposure and osteoporosis using data from UK Biobank study. Estimated bone mineral density (eBMD) of each participant at baseline survey was calculated using quantitative ultrasound data, and incident osteoporosis cases were identified during the follow-up period according to health-related records. Air pollution concentrations were assessed using land use regression models. We fitted multivariable linear and logistic regression models to estimate the associations of air pollution with eBMD and osteoporosis prevalence at baseline. We applied cox proportional hazard regression models to assess the relationships between air pollution and osteoporosis incidence. Among the 341,311 participants at baseline, higher air pollution exposure was associated with lower eBMD levels and increased odds of osteoporosis prevalence. For example, an IQR increase in PM_2.5, PM_2.5 absorbance, PM₁₀, NO₂ and NO_x levels were associated with 0.0018 (95% CI: 0.0012, 0.0023) to 0.0052 (95% CI: 0.0046, 0.0058) g/cm² decrease in eBMD. A total of 330,988 participants without osteoporosis were followed up for an average of 12.0 years. We identified 8105 incident osteoporosis cases (456 cases with pathological fracture and 7634 cases without pathological fracture) during the follow-up. The hazard ratios for an interquartile range increase in PM_2.5, PM_2.5 absorbance, PM₁₀, NO₂ and NO_x were 1.09 (95% CI: 1.06, 1.12), 1.04 (95% CI: 1.02, 1.07), 1.04 (95% CI: 1.01, 1.07), 1.07 (95% CI: 1.04, 1.10), and 1.06 (95% CI: 1.03, 1.09), respectively. Our study suggests that ambient air pollution might be a risk factor of decreased bone mineral density and osteoporosis incidence.

Association of air pollutants and osteoporosis risk: The modifying effect of genetic predisposition

BACKGROUND

Limited studies have examined the association between air pollutants and osteoporosis incidence; however, the results are conflicting. We aimed to quantify the effects of selected air pollutants on osteoporosis risk and explore the modifying effect of genetic predisposition.

METHODS

A total of 422,955 subjects who did not have osteoporosis at baseline in the UK Biobank were included from 2006 to 2010. We conducted a Cox proportional hazards model with adjustment for covariates to examine the association between air pollutant scores and individual air pollutants and incident osteoporosis. Furthermore, a polygenic risk score (PRS) of osteoporosis was built and examined to determine whether genetic susceptibility modified the effect of air pollutants on osteoporosis. The relationship between air pollutants and osteoporosis was examined by using a restricted cubic spline (RCS) method.

RESULTS

After confounder adjustment, the results showed a remarkable increase in the risk of osteoporosis with each 10 unit increase in exposure to air pollution (hazard ratio: 1.06, 95 % confidence interval: 1.03-1.08), PM_2.5 (1.94, 1.52-2.48), NO₂ (1.06, 1.02-1.10), and NO_X (1.03, 1.01-1.04). However, no significant association was observed between PM₁₀ or PM_2.5-10 exposure and osteoporosis. Subjects with high air pollutant exposure levels and a high PRS had a noteworthy increase in osteoporosis risk compared to those with low air pollutant exposure levels and a low PRS. Air pollutants and genetic variants exerted additive effects on the risk of osteoporosis. Positive correlations were observed between osteoporosis and PM_2.5 (P < 0.001), NO₂ (P = 0.001), and NOx (P = 0.002) exposure.

CONCLUSIONS

Exposure to PM_2.5, NO₂ and NOx was associated with an increase in osteoporosis risk, and this effect was more pronounced in populations with high genetic risk. The association between PM_2.5, NO₂ and NOx exposure and osteoporosis is modified by genetic variations.

Long-term exposure to air pollution might decrease bone mineral density T-score and increase the prevalence of osteoporosis in Hubei province: evidence from China Osteoporosis Prevalence Study

We hypothesized that air pollution could cause oxidative damage and inflammation in the human body, which was linked to bone loss. Our result showed that long-term exposure to air pollution might decrease bone mineral density (BMD) T-score and increase the prevalence of osteoporosis in Hubei province.

INTRODUCTION

Osteoporosis is becoming an increasingly serious public health problem with the advent of global aging. Long-term exposure to air pollution has been linked to multitudinous adverse health outcomes, but evidence is still relatively limited and inconsistent for BMD T-score and osteoporosis. This study aimed at exploring the associations between long-term exposure to air pollution and BMD T-score and osteoporosis.

METHODS

The Hubei part of the China Osteoporosis Prevalence Study was extracted. Data on air pollutants were collected by the national air quality real-time release platform of China Environmental Monitoring Station. Linear mixed models and multilevel logistic regression analyses were performed to assess the associations between air pollution and BMD T-score and osteoporosis, respectively. Subgroup analyses were conducted to identify vulnerable populations.

RESULTS

A total of 1845 participants were included in this cross-section study. Per 10 ug/m³ increase in PM_2.5 and SO₂ were associated with 0.20 (95% CI: 0.04, 0.36) and 0.31 (95% CI: 0.11, 0.51) decrease in BMD T-score of the neck of femur, respectively. Per 10 ug/m³ increase in CO was linked with 0.03 (95% CI: 0.02, 0.05) decrease in BMD T-score of the total hip. Per 1 ug/m³ increase in PM_2.5 was associated with 5% increase in the prevalence of osteoporosis in all participants. In general, the higher concentrations of PM_2.5 with the more adverse effect on osteoporosis (P for trend = 0.01). The impact of PM_2.5 on osteoporosis in males was higher than that in females [1.29, 95% CI (1.11, 1.50) vs 1.01, 95% CI (0.95, 1.07)]. Per 1 ug/m³ increase in PM₁₀ corresponded with 4% elevation in the risks of osteoporosis in rural population. The ORs (95% CI) for the association of osteoporosis and NO₂ in ever/current smoking and drinking population were 1.07 (1.01, 1.13) and 1.05 (1.00, 1.09), respectively. SO₂ had a statistically significant positive effect on people with comorbidity [OR = 1.10, (95% CI: 1.00 to 1.21)], while none in people without comorbidity [OR = 0.96, (95% CI: 0.88 to 1.05)].

CONCLUSION

Our study provided evidence that long-term exposure to PM_2.5 was linked with the decreased BMD T-score and increased risk of osteoporosis among all participants. The adverse impacts of PM_2.5, PM₁₀, and NO₂ were larger in males than in females. People having comorbidity, living in rural areas, and current/ever smoking or drinking were more vulnerable to air pollution. Public health departments should consider air pollution to formulate better preventive measures for osteoporosis.

Epidemiological characteristics of fractures of spine, hip, proximal humerus and forearm during the haze epidemic period

BACKGROUND

Air pollutants have an impact on the occurrence of spine fractures, hip fractures, proximal humerus fractures and forearm fractures. This study aimed at evaluating the short-term impact of particulate matter with aerodynamic diameters of less than 2.5 µm (PM_2.5) on the occurrence of those fractures in Shijiazhuang, Hebei, China.

METHODS

The daily meteorological, pollution, and fracture data of Shijiazhuang from 2014 to 2019 were collected. Distribution characteristics of fractures were described using descriptive epidemiological methods. The distributed lag nonlinear model (DLNM) was used to reveal the description of those fractures in the exposed and lag dimensions at the same time. Based on gender and age (<18 years old, 18-69 years old and >69 years old), stratified analysis was performed. Sensitivity analysis was performed to ascertain the robustness of the results.

RESULTS

Between 2014 and 2019, fracture incidences in Shijiazhuang exhibited an overall increasing trend, with an obvious seasonality. PM_2.5 was positively related to daily fracture cases and the effects were more obvious in women, adolescents and people of working age. When PM_2.5 concentrations increased by one interquartile range (IQR) (70 μg/m³), RR exhibited a unimodal distribution. Its peak appeared on the 16th day of lag (RR=1.005987, 95% CI:1.002472,1.009652), and the RRs were also statistically significant from the 10th to 22nd day of lag. Similarly, cumulative effects of each increase in the concentration of PM_2.5 IQR also showed a unimodal distribution. The largest cumulative effect occurred on the 28th day of lag (RR=1.084457, 95% CI:1.012207,1.161864), and the cumulative RRs were also statistically significant from the 19th day to 30nd days. In the dose-response relationship, as PM_2.5 concentrations increased, RR increased.

CONCLUSION

Year by year, fractures in Shijiazhuang City exhibited an increasing trend. PM_2.5 can affect the occurrence of those fractures. The impact on women, adolescents and people of working age is even greater. The supervision of PM_2.5 should be strengthened while large-scale emissions should be limited.

Long-term exposure to air pollution increases hip fracture incidence rate and related mortality: analysis of National Hip Fracture Database

To explore the association of air pollution and hip fracture and related mortality in the UK. The average levels of PM2.5, PM10, and NO2 exhibited a positive association with hip fracture and short-term mortality while O₃ did not. Our study highlights the association of air pollution and hip fracture.

INTRODUCTION

Until now, the influence of air pollution on bone mineral density and associated fractures has drawn little attention, and the consequences are controversial. To investigate the association between air pollution and hip fracture incidence and related short-term mortality.

METHODS

We constructed a cohort of all the National Hip Fracture Database beneficiaries (513,540 patients) in the UK from 2013 to 2018. Per year averages of PM_2.5, PM₁₀, O₃, NO₂, and SO₂ were estimated according to the person's residence. The incidence rate ratio with 95% confidence interval and all-cause mortality within 30-day post-fracture (ACM30D) rate ratios were estimated using generalized additive models.

RESULTS

The average levels of PM_2.5, PM₁₀, and NO₂ exhibited a positive association with the incidence rate of hip fracture (IHF) and ACM30D. Whereas, this association was negative for O₃ levels. Each increase of 5 μg per cubic meter in PM_2.5, PM₁₀, and NO₂ leads to 9.5%, 9.2%, and 4.1% higher hip fracture rate, respectively, and also 9.3%, 8.3%, and 2.9% higher ACM30D, respectively. When we restricted the analysis to low-level exposure of air pollutants, similar results were obtained.

CONCLUSION

Our study found a moderate, positive association between IHF, ACM30D, and the levels of specific air pollutants in the entire National Hip Fracture Database population. A reduction in the levels of PM_2.5, PM₁₀, and NO₂ may decrease the hip fracture incidence rate and associated short-term mortality in older adults. Our study highlights the influence of air pollution on hip fracture.

The potential osteoporosis due to exposure to particulate matter in ambient air: Mechanisms and preventive methods

Air pollution and health consequences associated with exposure to air pollutants, such as particulate matter, are of serious concerns in societies. Over the recent years, numerous studies have investigated the relation of many diseases with air pollutants. This review used a search strategy to provide the comprehensive information on the relationship between particle matters and osteoporosis. To this end, three search databases were used to find the articles focused on particle matters and osteoporosis. After the screening process, 13 articles related to the purpose of the study were selected and the relevant data were extracted. The results indicated that osteoporosis is significantly associated with PM₁₀. However, this association with PM_2.5 remains unclear. In addition, particle materials indirectly lead to the osteoporosis and bone fractures as a consequence of reduced UV-B, reduced adsorption of vitamin D. Furthermore, they can lead to other diseases by use of drugs with adverse effects on bone health, and creating conditions that may increase the risk of falling in the elderly. This review shows that although more accurate research is needed to determine the mechanism and risk of exposure to particulate matter in the air on bone health, the negative effects of this pollutant on bone mineral density (BMD) are evident.Implications: PM is usually classified by its size or aerodynamic diameter; PM10 denotes particles < 10 µm in diameter; PM2.5 particles are <2.5 µm in diameter. Many epidemiological studies have shown that short-term exposure to PM might reduce lung function. However, short-term effects might be reversible, and the main concern is attributed to long-term exposure. A major public health concern that may be affected by numerous metabolic and even environmental risk factors is osteoporosis. The purpose of this systematic review was to investigate the role of PM in the occurrence or exacerbation of osteoporosis in citizens.

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

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 years) 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.

Prevalence, Characteristics, and Associated Risk Factors of Wrist Fractures in Americans Above 50: The Cross-Sectional NHANES Study

SUMMARY

By analyzing data from NHANES, we aimed to evaluate the prevalence, characteristics, and associated factors of wrist fractures in Americans aged 50 and above.

INTRODUCTION

Wrist fractures, whose prevalence increases with age, are one of the most common fractures in the United States. However, epidemiological studies on the prevalence of wrist fractures of certain ages were limited.

METHODS

The data of Americans aged 50 or above from 2013-2014 and 2017-2018 in NHANES were extracted and analyzed.

RESULTS

The prevalence of wrist fractures among Americans whose age was 50 or above was 12%, which was similar between men and women (men 12.8% vs. women 11.4%, p = 0.267). Among those who had experienced their first wrist fracture, 17.8% of the population experienced a second wrist fracture. The top two causes of the first wrist fracture were a fall from a standing height (56%) or a hard fall (34.8%). The prevalence of wrist fractures was higher in men than in women (13.7% versus 8.7%, p = 0.023) aged < 60, but higher in women than in men aged ≥ 60 (11.8% versus 14.3%, p = 0.007). Multivariate analysis showed that obesity, frequent drinking, current smoking, high serum phosphate level, non-Hispanic white women, and osteoporosis were independently associated with wrist fractures. Stratified by race, osteoporosis, frequent drinking, and high serum phosphate level were risk factors for wrist fractures in all races. As for Mexican Americans, non-Hispanic whites, and other races including multi-racial, current smoking was a risk factor of wrist factures. Furthermore, obesity was positively associated with wrist fractures in Mexican Americans, other Hispanics, and non-Hispanic whites.

CONCLUSION

The prevalence of wrist fractures in Americans aged 50 and above was 12%. Falling from a standing height was the main cause of the first wrist fracture. Frequent drinking, current smoker, high serum phosphate level, osteoporosis, obesity, and non-Hispanic women were more likely to experience wrist fractures.

The Association Between Long-term Exposure to Ambient Air Pollution and Bone Strength in China

CONTEXT

Evidence regarding the association of long-term exposure to air pollution on bone strength or osteoporosis is rare, especially in highly polluted low- and middle-income countries. Little is known about whether the association between air pollution and bone strength changes at different bone strength distributions.

OBJECTIVE

Using the baseline data from the China Multi-Ethnic Cohort, we investigated the association between long-term air pollution exposure and bone strength.

METHODS

We used multiple linear models to estimate the association between air pollution and bone strength, and we conducted quantile regression models to investigate the variation of this association in the distribution of bone strength. The 3-year concentrations of PM1, PM2.5, PM10, and NO2 for each participant were assessed using spatial statistical models. Bone strength was expressed by the calcaneus quantitative ultrasound index (QUI) measured by quantitative ultrasound, with higher QUI values indicating greater bone strength.

RESULTS

A total of 66 598 participants were included. Our analysis shows that every 10 μg/m3 increase in 3-year average PM1, PM2.5, PM10, and NO2 was associated with -5.38 units (95% CI: -6.17, -4.60), -1.89 units (95% CI: -2.33, -1.44), -0.77 units (95% CI: -1.08, -0.47), and -2.02 units (95% CI: -2.32, -1.71) changes in the QUI, respectively. In addition, populations with higher bone strength may be more susceptible to air pollution.

CONCLUSION

Long-term exposure to PM1, PM2.5, PM10, and NO2 was significantly associated with decreased bone strength in southwestern China adults. Air pollution exposure has a more substantial adverse effect on bones among populations with higher bone strength.

Incidence of osteoporosis and ambient air pollution in South Korea: a population-based retrospective cohort study

Background

This study investigated the associations between exposure to ambient air pollutants and the incidence of osteoporosis using the Korean National Insurance Service–National Sample Cohort.

Methods

This nationwide, population-based, retrospective cohort study included 237,149 adults aged ≥40 years that did not have a diagnosis of osteoporosis at baseline between January 1, 2003, and December 31, 2015. Osteoporosis was defined as claim codes and prescriptions of bisphosphonates or selective estrogen receptor modulators at least twice annually. After matching values for PM₁₀, NO₂, CO, and SO₂ during the 2002–2015 time period and PM_2.5 in 2015 with residential areas, the incidence of osteoporosis was analyzed using a Cox proportional hazards regression model according to the quartile of average yearly concentrations of pollutants.

Results

Overall 22.2% of the study subjects, 52,601 (male: 5.6%, female: 37.6%) adults in total, were newly diagnosed with osteoporosis and treated. Exposure to PM₁₀ was positively associated with incidence of osteoporosis (Q4: 1798 per 100,000 person-years vs. Q1: 1655 per 100,000 person-years). The adjusted hazard ratio (HR) with 95% confidence interval (CI) of Q4 in PM₁₀ was 1.034 (1.009–1.062). The effect of PM₁₀ on osteoporosis incidence was distinct in females (adjusted sub-HR: 1.065, 95% CI: 1.003–1.129), subjects aged < 65 years (adjusted sub-HR: 1.040, 95% CI: 1.010–1.072), and for residents in areas with low urbanization (adjusted sub-HR: 1.052, 95% CI: 1.019–1.087). However, there was no increase in osteoporosis based on exposure to NO₂, CO, SO₂, or PM_2.5.

Conclusions

Long-term exposure to PM₁₀ was associated with newly diagnosed osteoporosis in Korean adults aged ≥40 years. This finding can aid in policy-making that is directed to control air pollution as a risk factor for bone health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11866-7.

Association between outdoor particulate air pollution and the risk of osteoporosis: a systematic review and meta-analysis

Air pollution is a major threat to global health, which is associated with several adverse health outcomes and increased mortality. Few studies have investigated the association between air pollution and osteoporosis, and their findings were inconclusive. Our objective is to determine whether exposure to outdoor air pollution is causally associated with risk of osteoporosis. A systematic literature search of PubMed, Web of Science, Embase, and Cochrane Library for publications up to December 2020 was conducted for studies reporting the association between air pollution and osteoporosis. Meta-analysis was performed to estimate the pooled effect size of air pollution on osteoporosis using the relative risk (RR) and 95% confidence intervals (95% CI). Quality assessment was conducted, and all statistical analyses were performed by RevMan 5.3 software. Our search identified 9 eligible studies involving 9,371,212 patients. Meta-analysis revealed that there was an increased risk of osteoporosis (total body BMD and hip fracture) as a result of exposure to air pollution including PM_2.5 and NO₂. However, no significant excess risk of osteoporosis was found regardless of PM₁₀, NO, and O₃. In spite of a few number of epidemiological studies selected in the present literature review, this study indicated that the increased exposure to air pollutants was positively associated with high risk of osteoporosis. Further cohort studies with large sample sizes are needed to investigate different constituents and the duration of exposure of air pollutants.

Current status and distribution of hip fractures among older adults in China

China is a middle-risk country for hip fracture at present, which differs from previous data that it was low-risk. By 2050, the total number of hip fractures in people older than 65 years is predicted to be 1.3 million.

INTRODUCTION

To assess hip fracture incidence in China and examine the heterogeneity of hip fracture in seven geographical regions of China.

METHODS

There were 238,230 hip fracture patients aged 65 years or older from 2013 to 2016 from a large national in-patients database (HQMS) involving 30.6 million hospitalizations. Taking into account the total national hospitalization rate per calendar year, we estimated the incidence of hip fracture per 100,000 residents older than 65 years in China overall and in seven geographical Chinese regions.

RESULTS

The proportion of men and women older than 65 years with hip fractures was 1.00:1.95. Between 2013 and 2016, the number of hip fractures per 100,000 people age 65+ was 278. China has vast territories; the number of hip fractures per 100,000 people over 65 years old was 202 in Northeast China and 374 in Northwest China. Northwest has higher altitude, lower population density, is less developed with lower urbanization than Northeast China which is low altitude, and highly urbanized.

CONCLUSIONS

China should no longer be regarded as a low-risk country for hip fracture. By 2050, the total number of hip fractures in people older than 65 years in China is predicted to be 1.3 million. Higher altitude areas had higher hip fracture rates than lower altitude, higher urbanized areas.

Exposure to Air Pollution and Risk of Hip Fracture: A Population-Based Cohort Study With a 6-Year Follow-Up in South Korea

OBJECTIVES

We aimed to investigate whether exposure to air pollutants was associated with the risk of hip fracture.

METHODS

We extracted data on a 2010 cohort of the adult population (more than or equal to 30 years old) from a South Korean database.

RESULTS

A total of 178,147 individuals were included in the analysis, and hip fracture had occurred in 919 individuals (0.5%). In a multivariable logistic regression model, a 1 mcg/m increase in concentrations of particulate matter measuring of less than or equal to 10 μm was associated with 2% increase in hip fracture risk (odds ratio [OR]: 1.02, 95% confidence interval [CI]: 1.01 to 1.03; P = 0.039); there were no significant associations between hip fracture risk and exposure to SO2 (P = 0.076), ozone (P = 0.220), carbon monoxide (P = 0.698), or sulfur dioxide (P = 0.114).

CONCLUSIONS

Particular matter air concentration may be a modifiable risk factor for hip fracture.

Particulate Air Pollution and Osteoporosis: A Systematic Review

Air pollution is associated with inflammation and oxidative stress, which predispose to several chronic diseases in human. Emerging evidence suggests that the severity and progression of osteoporosis are directly associated with inflammation induced by air pollutants like particulate matter (PM). This systematic review examined the relationship between PM and bone health or fractures. A comprehensive literature search was conducted from January until February 2021 using the PubMed, Scopus, Web of Science, Google Scholar and Cochrane Library databases. Human cross-sectional, cohort and case-control studies were considered. Of the 1500 papers identified, 14 articles were included based on the inclusion and exclusion criteria. The air pollution index investigated by most studies were PM2.5 and PM10. Current studies demonstrated inconsistent associations between PM and osteoporosis risk or fractures, which may partly due to the heterogeneity in subjects' characteristics, study design and analysis. In conclusion, there is an inconclusive relationship between osteoporosis risk and fracture and PM exposures which require further validation.

Effect of meteorological factors and air pollutants on fractures: a nationwide population-based ecological study

OBJECTIVE

To determine the association of meteorological factors and air pollutants (MFAPs) with fracture and to estimate the effect size/time lag.

DESIGN

This is a nationwide population-based ecological study from 2008 to 2017.

SETTING

Eight large metropolitan areas in Korea.

PARTICIPANTS

Of 8 093 820 patients with fractures reported in the Korea National Health Insurance database, 2 129 955 were analysed after the data set containing patient data (age, sex and site of fractures) were merged with MFAPs. Data on meteorological factors were obtained from the National Climate Data Center of the Korea Meteorological Administration. Additionally, data on air pollutants (atmospheric particulate matter ≤2.5 µm in diameter (PM_2.5), PM₁₀, ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide) were obtained from the Air Korea database.

PRIMARY AND SECONDARY OUTCOME MEASURES

We hypothesised that there would be an association between MFAPs and the incidence of fracture. A generalised additive model was used while factoring in the non-linear relationship between MFAPs and fractures as well as a time lag ≤7 days. Multivariate analysis was performed. Backward elimination with an Akaike information criterion was used to fit the multivariate model.

RESULTS

Overall, in eight urban areas, 2 129 955 patients with fractures were finally analysed. These included 370 344, 187 370, 173 100, 140 358, 246 775, 6501, 228 346, 57 183 and 719 978 patients with hip, knee, shoulder, elbow, wrist, hand, ankle, foot and spine fractures, respectively. Various MFAPs (average temperature, daily rain, wind speed, daily snow and PM_2.5) showed significant association with fractures, with positive correlations at time lags 7, 5-7, 5-7, 3-7 and 6-7 days, respectively.

CONCLUSIONS

Various MFAPs could affect the occurrence of fractures. The average temperature, daily rain, wind speed, daily snow and PM_2.5 were most closely associated with fracture. Thus, improved public awareness on these MFAPs is required for clinical prevention and management of fractures.

Long-term exposure to fine particulate matter and osteoporotic fracture: A case-control study in Taiwan

Few studies have explored the relationship between long-term exposure to particulate matter with an aerodynamic diameter of ≤2.5 μm (PM_2.5) and osteoporotic fracture, particularly in high PM_2.5 level areas. The aim of this study was to assess the association between long-term exposure to PM_2.5 and osteoporotic fracture. We performed a matched case-control study of 16,175 participants obtained from a hospital registry during 2005-2014 in Taiwan. A major osteoporotic fracture was defined as a fracture of the spine, hip, proximal humerus, and forearm. We applied satellite-based spatiotemporal models with 1-km resolution to individually calculate the 1-year average PM_2.5 concentration before the index date which was defined as the first visit date for the osteoporotic fracture. Logistic regression models with and without potential confounding factors were used to estimate odds ratios (OR) and 95% confidence intervals (CI) between PM_2.5 and osteoporotic fracture, whereas a restricted cubic spline model was used to estimate the dose-response relationship. The sample's median age was 44.7 years (interquartile range: 30.7, 63.1 years). We observed that long-term PM_2.5 exposure was associated with osteoporotic fracture, the OR was 1.12 (95% CI: 1.03, 1.22) per 10-μg/m³ increase in PM_2.5 in women. In the dose-response association, the OR of osteoporotic fracture was significantly increased for PM_2.5 exposures more than 41 μg/m³. We did not find a significant association between PM_2.5 (per 10-μg/m³ increase) and osteoporotic fracture among overall population (adjusted OR, 1.02 [95% CI, 0.97 to 1.08]) and men (adjusted OR, 0.94 [95% CI, 0.86 to 1.02]). The results of the stratified analysis showed that women were more sensitive to the adverse impact of PM2.5 that were men, and evidence was obtained of sex-based effect modification (P for interaction = 0.002). Our findings suggest that long-term exposure to PM_2.5 is associated with osteoporotic fracture, particularly among women.

Air Pollutants Interaction and Gender Difference on Bone Mineral Density T-Score in Taiwanese Adults

Osteoporosis is defined as a systemic skeletal disease characterized by a reduction in bone mass and microarchitectural deterioration of bone tissue. Previous studies have reported associations between air pollution and lower bone mineral density; however, few studies have investigated the association between air pollution and osteoporosis. In this study, we combined two databases, the first including 5000 individuals registered in the Taiwan Biobank, and the second containing detailed daily data on air pollution. After multivariable adjustments, ozone (O3) (unstandardized coefficient β, 0.015; p = 0.008) was significantly positively associated with T-score, whereas carbon monoxide (CO) (unstandardized coefficient β, -0.809; p < 0.001), sulfur dioxide (SO2) (unstandardized coefficient β, -0.050; p = 0.005), nitric oxide (NO) (unstandardized coefficient β, -0.040; p < 0.001), nitrogen dioxide (NO2) (unstandardized coefficient β, -0.023; p < 0.001), and nitrogen oxide (NOx) (unstandardized coefficient β, -0.017; p < 0.001) were significantly negatively associated with T-score. The interactions between CO and NOx (p = 0.001) and SO2 and NO2 (p = 0.004) on T-score were statistically significant. An increase in exposure to CO, NO and NOx was associated with a faster decline in T-score in the female participants compared to the male participants. In addition, an increase in O3 was associated with a faster increase in T-score in the female participants compared to the male participants. In conclusion, the air pollutants CO, SO2, NO, NO2, and NOx were associated with osteoporosis. In addition, there were interaction and synergetic effects between CO and NOx and SO2 and NO2 on T-score. We also observed differences in the associations between air pollutants and T-score between the female and male participants.

Association of air pollution with osteoporotic fracture risk among women over 50 years of age

INTRODUCTION

Air particulate matter (PM) is an environmental exposure associated with oxidation and inflammation. Whether particulate matter is associated with risk of osteoporotic bone fracture is unclear. We investigated the association between exposure to PM and risk of bone fractures.

MATERIALS AND METHODS

We collected data of 44,602 participants living in three metropolitan cities in Republic of Korea from National Health Insurance Service database. We examined the association of 2 year averaged concentrations of PM and osteoporotic fracture over 4 years. Exposure to 2-year averaged air pollution [PM2.5 (< 2.5 μm in aerodynamic diameter), PM10 [< 10 μm in aerodynamic diameter], PM coarse (PM ranging from 2.5 μm to 10 μm)] concentrations were estimated from 2008 to 2009 in Air Korea data. The adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for osteoporotic fractures were calculated using the multivariate Cox proportional hazards model.

RESULTS

After adjusting for age, household income, and Charlson Comorbidity Index, PM 2.5 in one pollutant model increased the risk of osteoporotic fractures, compared to the first quartile group (4th quartile group aHR = 1.13, 95% CI 1.02-1.24). Also, PM 2.5 increased the risk of spine and non-spine fractures compared to the first quartile group (4th quartile group aHR = 1.17, 95% CI 1.00-1.38, aHR = 1.16, 95% CI 1.01-1.33). We found no association between PM10/PM coarse and osteoporotic fractures.

CONCLUSION

We found that PM2.5 is a risk factor for osteoporotic bone fractures.

Association of ambient PM2·5 exposure with maternal bone strength in pregnant women from Mexico City: a longitudinal cohort study

BACKGROUND

Pregnancy is associated with deteriorations in maternal bone strength and heightened susceptibility to bone fractures. We aimed to investigate whether ambient particulate matter (PM)_2·5 concentrations were associated with bone strength during pregnancy.

METHODS

In this longitudinal cohort study, we analysed longitudinal data from women participating in the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) cohort in Mexico City, Mexico. Eligible women were aged 18 years or older, at less than 20 weeks' gestation at the time of recruitment, planning to stay in Mexico City for the next 3 years, without heart or kidney disease, did not use steroids or anti-epileptic drugs, were not daily consumers of alcohol, and had access to a telephone. Daily ambient PM_2·5 concentrations were estimated from a spatio-temporal model that was based on the individual's address. Trabecular bone strength was measured using quantitative ultrasound from the radius of the middle finger and cortical bone strength from the proximal phalanx of the middle finger, during the second trimester, third trimester, and 1 and 6 months post partum. Bone strength T scores were modelled with PM_2·5 concentrations using linear mixed models and distributed lag models.

FINDINGS

Adjusting for multiple exposure windows, each 10 ug/m³ increase in PM_2·5 exposure concentrations in the first trimester was associated with a 0·18 SD decrease (95% CI -0·35 to -0·01; p=0·033) in ultrasound speed-of-sound (SOS) T score of trabecular bone strength from the second trimester until 6 months post partum. Similarly, each 10 μg/m³ increase in third trimester PM_2·5 exposure was associated with a 0·18 SD decrease (-0·36 to -0·01; p=0·044) in the SOS T score of trabecular bone strength from the third trimester until 6 months post partum. PM_2·5 exposure in the first month post partum was associated with a 0·20 SD decline (-0·39 to -0·01; p=0·043) in cortical bone strength until 6 months post partum.

INTERPRETATION

Ambient PM_2·5 exposure during and after pregnancy was associated with diminished trabecular and cortical bone strength. Early pregnancy PM_2·5 exposure was associated with a greater decline in bone strength later during pregnancy. Late pregnancy and early post-partum exposures adversely affected the post-partum bone strength recovery. Technological and policy solutions to reduce PM_2·5 pollution could improve public health by reducing bone fracture risk.

FUNDING

US National Institute of Environmental Health Sciences.

Molecular and cellular mechanisms linking air pollution and bone damage

Air pollution is the second most important risk factor associated with noncommunicable diseases after smoking. The effects of pollution on health are commonly attributable to particulate matter (PM), a complex mixture of particles suspended in the air. PM can penetrate the lower respiratory tract and has harmful direct and indirect effects on different organs and tissues. Direct effects are caused by the ability of PM components to cross the respiratory membrane and enter the bloodstream; indirect effects are systemic consequences of the local airway response. Recent work suggests that PM is an independent risk factor for low bone mineral density and osteoporosis-related fractures. Osteoporosis is a common age-related disease closely linked to bone fractures, with severe clinical consequences affecting quality of life, morbidity, and mortality. In this review, we discuss potential mechanisms behind the association between outdoor air pollution, especially PM, and bone damage. The discussion features four main mechanisms: 1) several different atmospheric pollutants can induce low-grade systemic inflammation, which affects bone metabolism through a specific effect of cytokines such as TNFα, IL-1β, IL-6, and IL-17 on osteoblast and osteoclast differentiation and function; 2) some pollutants, particularly certain gas and metal compounds, can cause oxidative damage in the airway and bone cells; 3) different groups of pollutants can act as endocrine disruptors when binding to the receptors in bone cells, changing their functioning; and 4) air pollution can directly and indirectly cause vitamin D deficiency. Characterizing these mechanisms will better define the physiopathology of bone damage, and recognizing air pollution as a modifiable risk factor for osteoporosis will inform environmental policies. Such knowledge will also guide the prevention of fractures due to fragility and help reduce health-related costs.

Long-term exposure to air pollution might increase prevalence of osteoporosis in Chinese rural population

OBJECTIVES

The associations of long-term exposure to air pollution with osteoporosis are rarely reported, especially in rural China. This study aimed to explore the association among rural Chinese population.

METHODS

A total of 8033 participants (18-79 years) derived from the Henan Rural Cohort Study (n = 39,259) were included in this cross-sectional study. Exposure to air pollutants was estimated using machine learning algorithms with satellite remote sensing, land use information, and meteorological data [including particulate matter with aerodynamic diameters ≤1.0 μm (PM₁), ≤2.5 μm (PM_2.5), and ≤10 μm (PM₁₀), and nitrogen dioxide (NO₂)]. The bone mineral density of each individual was measured by using ultrasonic bone density apparatus and osteoporosis was defined based on the T-score ≤ -2.5. Multiple logistic regression models were used to examine the association of air pollution and osteoporosis prevalence.

RESULTS

We observed that per 1 μg/m³ increase in PM₁, PM_2.5, PM₁₀ and NO₂ were associated with a 14.9%, 14.6%, 7.3%, and 16.5% elevated risk of osteoporosis. Compared with individuals in the first quartile, individuals in the fourth quartile had higher odds ratio (OR) of osteoporosis (P-trend < 0.001), the ORs (95% confidence interval) were 2.08 (1.72, 2.50) for PM₁, 2.28 (1.90, 2.74) for PM_2.5, 1.93 (1.60, 2.32) for PM₁₀, and 2.02 (1.68, 2.41) for NO₂. It was estimated that 20.29%-24.36% of osteoporosis cases could be attributable to air pollution in the rural population from China.

CONCLUSIONS

Long-term exposure to air pollutants were positively associated with high-risk of osteoporosis, indicated that improving air quality may be beneficial to improve rural residents health.

Association of Ambient and Household Air Pollution With Bone Mineral Content Among Adults in Peri-urban South India

IMPORTANCE

Air pollution is a major threat to global health. Osteoporosis is responsible for a substantial burden of disease globally and is expected to increase in prevalence because of population aging. Few studies have investigated the association between air pollution and bone health, and their findings were inconclusive.

OBJECTIVE

To quantify the association between ambient and household air pollution and bone mass in a sample of the general population in peri-urban India.

DESIGN, SETTING, AND PARTICIPANTS

This was a population-based cross-sectional analysis of the Andhra Pradesh Children and Parents Study cohort, which recruited participants from 28 villages near Hyderabad, South India, during 2009 to 2012. Separate linear mixed models were fitted with nested random intercepts (household within villages) for each exposure-outcome pair and were sequentially adjusted for potential confounders. Data analysis was conducted between April 2019 and July 2019.

EXPOSURES

Annual mean ambient particulate matter air pollution less than 2.5 µm in aerodynamic diameter (PM2.5) and black carbon (BC) levels at the residence estimated by land-use regression and self-reported use of biomass cooking fuel.

MAIN OUTCOMES AND MEASURES

The primary outcome was bone mineral content (BMC) measured in grams, corrected by bone area at the lumbar spine and left hip, as measured by dual-energy x-ray absorptiometry. The secondary outcome was bone mineral density measured in grams per centimeters squared.

RESULTS

A total of 3717 participants were analyzed (mean [SD] age, 35.7 [14.0] years; 1711 [46.0%] women). The annual mean (SD) PM2.5 exposure was 32.8 (2.5) μg/m3, and the annual mean (SD) BC exposure was 2.5 (0.2) μg/m3; 57.8% of participants used biomass cooking fuels. In fully adjusted models, PM2.5 was associated with lower BMC in the spine (mean difference, -0.57 g per 3 μg/m3 increase in PM2.5; 95% CI, -1.06 to -0.07 g per 3 μg/m3 increase in PM2.5) and hip (mean difference, -0.13 g per 3 μg/m3 increase in PM2.5; 95% CI, -0.3 to 0.03 g per 3 μg/m3 increase in PM2.5). After confounder adjustment, exposure to PM2.5 was also associated with lower bone mineral density in the spine (mean difference, -0.011 g/cm2 per 3 μg/m3 increase in PM2.5; 95% CI, -0.021 to 0 g/cm2 per 3 μg/m3 increase in PM2.5) and hip (mean difference, -0.004 g/cm2 per 3 μg/m3 increase in PM2.5; 95% CI, -0.008 to 0.001 g/cm2 per 3 μg/m3 increase in PM2.5). Exposure to BC was associated with lower BMC in the spine (mean difference, -1.13 g per 1 μg/m3 increase in BC; 95% CI, -2.81 to 0.54 g per 1 μg/m3 increase in BC) and hip (mean difference, -0.35 g per 1 μg/m3 increase in BC; 95% CI, -0.96 to 0.25 g per 1 μg/m3 increase in BC), although the confidence intervals were wider. There was no association between biomass fuel use and spine BMC (mean difference, 0.12 g; 95% CI, -0.45 to 0.68 g).

CONCLUSIONS AND RELEVANCE

In a cross-sectional analysis of a population-based cohort, ambient air pollution was associated with lower BMC in a young adult population in a peri-urban area of South India.

Air Pollution and Noncommunicable Diseases: A Review by the Forum of International Respiratory Societies' Environmental Committee, Part 2: Air Pollution and Organ Systems

Although air pollution is well known to be harmful to the lung and airways, it can also damage most other organ systems of the body. It is estimated that about 500,000 lung cancer deaths and 1.6 million COPD deaths can be attributed to air pollution, but air pollution may also account for 19% of all cardiovascular deaths and 21% of all stroke deaths. Air pollution has been linked to other malignancies, such as bladder cancer and childhood leukemia. Lung development in childhood is stymied with exposure to air pollutants, and poor lung development in children predicts lung impairment in adults. Air pollution is associated with reduced cognitive function and increased risk of dementia. Particulate matter in the air (particulate matter with an aerodynamic diameter < 2.5 μm) is associated with delayed psychomotor development and lower child intelligence. Studies link air pollution with diabetes mellitus prevalence, morbidity, and mortality. Pollution affects the immune system and is associated with allergic rhinitis, allergic sensitization, and autoimmunity. It is also associated with osteoporosis and bone fractures, conjunctivitis, dry eye disease, blepharitis, inflammatory bowel disease, increased intravascular coagulation, and decreased glomerular filtration rate. Atopic and urticarial skin disease, acne, and skin aging are linked to air pollution. Air pollution is controllable and, therefore, many of these adverse health effects can be prevented.

Short-term association between outdoor air pollution and osteoporotic hip fracture

This study examines the association of the levels of different airborne pollutants on the incidence of osteoporotic hip fracture in a southern European region. Association was detected between SO₂ and NO₂ and hospital admissions due to hip fracture.

INTRODUCTION

To examine the short-term effects of outdoor air pollution on the incidence of osteoporotic hip fracture in a southern European region.

METHODS

This is an ecological retrospective cohort study based on data obtained from three databases. In a time-series analysis, we examined the association between hip fracture incidence and different outdoor air pollutants (sulfur dioxide (SO₂), monoxide (NO), nitrogen dioxide (NO₂), ozone (O₃), and particulate matter in suspension < 2.5 (PM_2.5) and < 10-μm (PM₁₀) conditions by using general additive models (Poisson distribution). The incidence rate ratio (IRR), crude and adjusted by season and different weather conditions, was estimated for all parameters. Hip incidence was later analyzed by sex and age (under or over age 75) subgroups. The main outcome measure was daily hospital admissions due to fracture.

RESULTS

Hip fracture incidence showed association with SO₂ (IRR 1.11 (95% CI 1.04-1.18)), NO (IRR 1.01 (95% CI 1.01-1.02)), and NO₂ (IRR 1.02 (95% CI 1.01-1.04)). For O₃ levels, this association was negative (IRR 0.97 (95% CI 0.95-0.99)). The association persisted for SO₂ and NO₂ when the models were adjusted by season. After adjusting by season and weather conditions, the association persisted for NO₂. When participants were stratified by age and sex, associations persisted only in women older than 75 years.

CONCLUSIONS

A short-term association was observed with several indicators of air pollution on hip fracture incidence. This is the first study that shows these associations.

Impact of air pollution on vitamin D deficiency and bone health in adolescents

The association between air pollution and bone health was evaluated in adolescents in the city of Tehran. This study is essentially ecological. Vitamin D deficiency among adolescents has been reported at higher rates in polluted areas than in non-polluted areas. Additionally, residence in polluted areas is associated with lower levels of bone alkaline phosphatase.

PURPOSE

The aim of this study was to evaluate the association between ambient air pollution and bone turnover in adolescents and to compare the prevalence of vitamin D deficiency between polluted and non-polluted areas of Tehran.

METHODS

This cross-sectional population-based study was conducted on 325 middle- and high-school students (both girls and boys) in Tehran in the winter. During the study period, detailed daily data on air pollution were obtained from archived data collected by Tehran Air Quality Control Company (AQCC). Serum levels of calcium, phosphorus, parathyroid hormone (PTH), bone-specific alkaline phosphatase, 25(OH) vitamin D, osteocalcin, cross-linked C-telopeptide (CTX), total protein, albumin, and creatinine were obtained from the study group.

RESULTS

Vitamin D deficiency was more prevalent in polluted areas than in non-polluted areas. After adjustment for age and sex, residence in the polluted area showed a statistically significant positive association with vitamin D deficiency and a statistically significant negative association with bone turnover. Interestingly, high calcium intake (>5000 mg/week) protects against the effects of air pollution on bone turnover.

CONCLUSIONS

Air pollution is a chief factor determining the amount of solar UVB that reaches the earth's surface. Thus, atmospheric pollution may play a significant independent role in the development of vitamin D deficiency.

Association of air particulate pollution with bone loss over time and bone fracture risk: analysis of data from two independent studies

BACKGROUND

Air particulate matter (PM) is a ubiquitous environmental exposure associated with oxidation, inflammation, and age-related chronic disease. Whether PM is associated with loss of bone mineral density (BMD) and risk of bone fractures is undetermined.

METHODS

We conducted two complementary studies of: (i) long-term PM <2.5 μm (PM_2.5) levels and osteoporosis-related fracture hospital admissions among 9.2 million Medicare enrollees of the Northeast/Mid-Atlantic United States between 2003-2010; (ii) long-term black carbon [BC] and PM_2.5 levels, serum calcium homeostasis biomarkers (parathyroid hormone, calcium, and 25-hydroxyvitamin D), and annualized BMD reduction over a 8-year follow-up of 692 middle-aged (46.7±12.3 yrs), low-income BACH/Bone cohort participants.

FINDINGS

In the Medicare analysis, risk of bone fracture admissions at osteoporosis-related sites was greater in areas with higher PM_2.5 levels (Risk ratio [RR] 1.041, 95% Confidence Interval [CI], 1.030, 1.051). This risk was particularly high among low-income communities (RR 1.076; 95% CI, 1.052, 1.100). In the longitudinal BACH/Bone study, baseline BC and PM_2.5 levels were associated with lower serum PTH (Estimate for baseline one interquartile increase in 1-year average BC= -1.16, 95% CI -1.93, -0.38; Estimate for baseline one interquartile increase in 1-year average PM_2.5= -7.39; 95%CI -14.17, -0.61). BC level was associated with higher BMD loss over time at multiple anatomical sites, including femoral neck (-0.08%/year per one interquartile increase; 95% CI -0.14, -0.02%/year) and ultradistal radius (-0.06%/year per one interquartile increase; 95% CI -0.12, -0.01%/year).

INTERPRETATION

Our results suggest that poor air quality is a modifiable risk factor for bone fractures and osteoporosis, especially in low-income communities.

Exposure to air pollution increases the risk of osteoporosis: a nationwide longitudinal study

Several studies have indicated that air pollution induces systemic as well as tissue-specific inflammation. Chronic inflammatory diseases such as rheumatoid arthritis and chronic obstructive pulmonary disease reduce bone mineral density (BMD), leading to increased release of immune cells from the bone marrow. However, the association between air pollution and osteoporosis remains poorly defined. Therefore, we conducted this population-based retrospective cohort study to evaluate the risk of osteoporosis in Taiwanese residents exposed to air pollution.We combined 2 nationwide databases in this study. The National Health Insurance Research Database of Taiwan was available from 2000 to 2010. Detailed daily data on air pollution were collected by Taiwan Environmental Protection Agency (EPA) from 1998 to 2010. We calculated the yearly average concentrations of air pollutants from the study start to the date of osteoporosis occurrence, or withdrawal from the NHI program, or December 31, 2010. The yearly average concentrations of air pollutants were categorized into quartiles, and the risks of osteoporosis were evaluated among 4 stages of air pollutants.Among Q1, Q2, Q3, and Q4 of pollutants in all subjects, the adjusted hazard ratios (HRs) of osteoporosis in Q2, Q3, and Q4 were compared with Q1. For carbon monoxide (CO), the adjusted HRs were 1.05 (95% confidence interval [CI], 0.97-1.14), 1.78 (95% CI, 1.65-1.92), and 1.84 (95% CI, 1.71-1.98), respectively. For nitrogen dioxide (NO2), the adjusted HRs were 1.35 (95% CI, 1.25-1.45), 1.24 (95% CI, 1.15-1.35), and 1.60 (95% CI, 1.48-1.73), respectively, in all subjects.The findings of the present study show that CO and NO2 exposure is associated with an increased risk of osteoporosis in the Taiwanese population.

Associations between ambient air pollution and bone turnover markers in 10-year old children: results from the GINIplus and LISAplus studies

Negative associations between bone turnover markers and bone mineral density have been reported. In order to study the association between ambient air pollution and bone turnover markers, as indicators of bone loss, we investigated associations between land-use regression modeled air pollution (NO2, PM2.5 mass, PM2.5 - 10 [coarse particles], PM10 mass and PM2.5 absorbance) and bone turnover markers in 2264 children aged 10 years. Serum osteocalcin and C-terminal telopeptide of type I collagen (CTx), measured by Modular-System (Roche), were the two bone turnover markers considered in this analysis. In total population, NO2, PM2.5 - 10 and PM10 mass exposure were positively and significantly associated with both osteocalcin and CTx. A 2.5 (95% CI: 0.6, 4.4) ng/ml increase in osteocalcin and a 24.0 (95% CI: 6.7, 41.3) ng/L increase in CTx were observed per IQR (6.7μg/m(3)) increase in NO2, independent of socioeconomic status, sex, age, pubertal status, fasting status and total physical activity. The estimated coefficients were 3.0 (95% CI: 0.1, 5.8) for osteocalcin and 32.3 (95% CI: 6.1, 58.5) for CTx with PM2.5 - 10; 3.2 (95% CI: 0.0, 6.4) for osteocalcin and 30.7 (95% CI: 1.7, 59.7) for CTx with PM10. Children living close to a major road (≤ 350m) had higher levels of both osteocalcin (1.4 [-1.2, 4.0] ng/ml) and CTx (16.2 [-7.4, 39.8] ng/L). The adverse impact of ambient air pollution on bone turnover rates observed in one of the study areas showed stimulation of more such studies.