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

Abstract

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 (PM 2.5) 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 dualenergy 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) PM 2.5 exposure was 32.8 (2.5) μg/m 3 , and the annual mean (SD) BC exposure was 2.5 (0.2) μg/m 3 ; 57.8% of participants used biomass cooking fuels. In fully adjusted models, PM 2.5 was associated with lower BMC in the spine (mean difference, −0.57 g per 3 μg/m 3 increase in PM 2.5 ; 95% CI, −1.06 to −0.07 g per 3 μg/m 3 increase in PM 2.5) and hip (mean difference, −0.13 g per 3 μg/m 3 increase in PM 2.5 ; 95% CI, −0.3 to 0.03 g per 3 μg/m 3 increase in PM 2.5). After confounder adjustment, exposure to PM 2.5 was also associated with lower bone mineral density in the spine (mean difference, −0.011 g/cm 2 per 3 μg/m 3 increase in PM 2.5 ; 95% CI, −0.021 to 0 g/cm 2 per 3 μg/m 3 increase in PM 2.5) and hip (mean difference, −0.004 g/cm 2 per 3 μg/m 3 increase in PM 2.5 ; 95% CI, −0.008 to 0.001 g/cm 2 per 3 μg/m 3 increase in PM 2.5). Exposure to BC was associated with lower BMC in the spine (mean difference, −1.13 g per 1 μg/m 3 increase in BC; 95% CI, −2.81 to 0.54 g per 1 μg/m 3 increase in BC) and hip (mean difference, −0.35 g per 1 μg/m 3 increase in BC; 95% CI, −0.96 to 0.25 g per 1 μg/m 3 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).

Particulate Air Pollution and Osteoporosis: A Systematic Review

“…However, some studies have validity, 81 , 82 , 86 , 87 , 94 confounding factor 83 , 91 and subjects follow-up issues. 93 , 94 Four studies were conducted in North and South America (the United States, 85 , 93 Chile 91 and Mexico 94 ); 4 studies were conducted in Europe (Norway, 81 , 82 Romania 83 and Spain 90 ), and the remaining 6 studies were conducted in Asia (Taiwan, 84 , 86 Henan province of China, 87 India 88 and South Korea 89 , 92 ). The total number of participants was 1,024,864, wherein 68,861 were from cross-sectional studies and 956,003 were from cohort studies.…”

“…Two cohort studies had a sample size >100,000 participants, 92 , 93 whereas 8 studies had a sample size of 1000–100,000 participants, 82 , 85–91 and the remaining 5 studies enrolled <1000 patients. 81 , 83 , 84 , 93 , 94 The participants were mainly elderly, 81–84 , 89–91 , 93 followed by middle-aged adults, 86 , 87 , 89 , 92 , 93 young adults 85 , 88 , 93 and pregnant women. 94 …”

“…The bone health status was reported either as fracture incidence, 82 , 89–93 BMC and BMD assessed via DXA 81–85 , 88 , 93 or QUS method. 86 , 87 , 94 BMDs of total body, 81 , 83 , 85 pelvic, 85 hip, 84 , 88 , 93 femoral neck, 83 , 84 , 93 lumbar spine, 83 , 84 , 88 , 93 distal forearm, 82 distal radius 93 and ultradistal radius 93 were measured. Besides, Lin et al 86 Qiao et al 87 and Wu et al 94 measured bone health via QUS method without DXA validation.…”

“… An estimated 20.29% (PM 1 ), 23.20% (PM 2.5 ) and 24.36% (PM 10 ) osteoporosis cases could be prevented by reducing the exposed PMs below their respective first quartile limit. 7 Ranzani et al 2020 88 2009–2012 Hyderabad, South India Cross-sectional study 3717 subjects with men (n= 2006) and women (n= 1711) aged 35.7 ± 14 years old Annual mean exposures of PM 2.5 was estimated from sampling data and land-use regression models BMC, and BMD at left hip and lumbar spine L1-L4 were measured via DXA PM 2.5 (for every 3 μg/m 3 increase) was negatively associated with lumbar spine BMC [mean difference= −0.57 g, 95% CI= (−1.06, −0.07)] after adjusting for the bone area, DXA type, age, sex, sex-by-age interaction, percentage lean, percentage fat body mass, fruit intake, vegetable intake, calcium intake, physical activity, smoking, household cooking fuel, occupation, education and standard of living index. NS association between PM 2.5 and lumbar spine BMD, hip BMC and hip BMD.…”

Effects of sulfur dioxide, ozone, and ambient air pollution on bone metabolism related biochemical parameters in a rat model

“…Evidences evaluating the association between AAP and bone health related biochemical factors is limited [ 4 ]. Some previous studies have concluded associations between air pollution and bone mineral density loss and increased risk of osteoporotic fracture [ 12 , 13 ].…”