Table 2.

Associations between relative telomere length (T:S) and personal exposures to air pollution in rural Chinese women using household biomass stoves. Results from mixed effects models.

Exposure	Women (n)a	Obs (n)	Difference in relative telomere length (95% CI)b
			Univariate	Multivariablec	Multivariablec plus temperature
${\mathrm{PM}}_{2.5}$ (per $10{\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$)
All exposures	132	195	$-0.02$ ($-0.04$, $-0.01$)	$-0.03$ ($-0.05$, $-0.01$)	$-0.01$ ($-0.03$, 0.01)
$<601{\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$	128	189	$-0.05$ ($-0.08$, $-0.02$)	$-0.06$ ($-0.08$, $-0.03$)	$-0.03$ ($-0.06$, 0.01)
$<472{\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$	128	185	$-0.06$ ($-0.09$, $-0.03$)	$-0.06$ ($-0.09$, $-0.03$)	$-0.03$ ($-0.06$, 0.01)
${\mathrm{PM}}_{2.5}$ (per IQR)
All exposures	132	195	$-0.36$ ($-0.64$, $-0.09$)	$-0.40$ ($-0.69$, $-0.12$)	$-0.09$ ($-0.41$, 0.22)
$<601{\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$	128	189	$-0.79$ ($-1.21$, $-0.38$)	$-0.83$ ($-1.26$, $-0.41$)	$-0.41$ ($-0.89$, 0.08)
$<472{\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$	128	185	$-0.88$ ($-1.36$, $-0.41$)	$-0.90$ ($-1.40$, $-0.41$)	$-0.39$ ($-0.96$, 0.17)
Black carbon (per $1{\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$)
All exposures	131	194	$-0.10$ ($-0.17$, $-0.03$)	$-0.09$ ($-0.16$, $-0.02$)	$-0.05$ ($-0.12$, 0.02)
$<13.9{\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$	127	188	$-0.21$ ($-0.35$, $-0.07$)	$-0.21$ ($-0.36$, $-0.07$)	$-0.09$ ($-0.24$, 0.07)
$<10.5{\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$	125	184	$-0.35$ ($-0.51$, $-0.18$)	$-0.35$ ($-0.53$, $-0.18$)	$-0.22$ ($-0.41$, $-0.03$)
Black carbon (per IQR)
All exposures	131	194	$-0.31$ ($-0.51$, $-0.10$)	$-0.27$ ($-0.48$, $-0.06$)	$-0.15$ ($-0.36$, 0.06)
$<13.9{\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$	127	188	$-0.65$ ($-1.08$, $-0.22$)	$-0.66$ ($-1.11$, $-0.21$)	$-0.27$ ($-0.75$, 0.20)
$<10.5{\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$	125	184	$-1.07$ ($-1.59$, $-0.56$)	$-1.10$ ($-1.63$, $-0.57$)	$-0.68$ ($-1.26$, $-0.10$)

Note: CI, confidence interval; IQR, interquartile range; obs, observations; ${\mathrm{PM}}_{2.5}$, particulate matter $\le 2.5\mathrm{\mu }\mathrm{m}$ in aerodynamic diameter; T:S, telomere repeat sequence copy number to single-copy gene ratio.

^a$N<137$ women due to unsuccessful extraction of DNA ($n=3$) or missing air pollution measurements due to filter damage or instrument error (${\mathrm{PM}}_{2.5}=2$, $\text{black carbon}=3$).

^bDifference in relative telomere length (T:S) associated with a $10{\text{-}\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$ increase in exposure to ${\mathrm{PM}}_{2.5}$ or $1{\text{-}\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$ increase black carbon with all observations and after excluding the highest 3% and 5% exposures, or with an IQR increase in exposure after excluding the highest 5% of exposures. IQRs for ${\mathrm{PM}}_{2.5}$ and black carbon were 151.3 and $3{.1\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$, respectively.

^cModel adjusted for age, waist circumference, socioeconomic status, exposure to environmental tobacco smoke, dietary sodium intake, physical activity, and the time of day and day of the week of DNA collection.