BACKGROUND: Ozone has heterogeneous effects on lung function. We investigated whether obesity and airways hyperresponsiveness (AHR) modify the acute effects of ozone on lung function in the elderly. METHODS: We studied 904 elderly men from the Normative Aging Study whose lung function (FVC, FEV1) was measured approximately every 3 years from 1995 to 2005. We defined obesity as a body mass index of at least 30 kg/m2. Using a standardized methacholine challenge test, we defined AHR as a FEV1 decline of 20% after inhalation of a cumulative dosage of 0 to 8.58 micromol of methacholine. Ambient ozone in the Greater Boston area was measured continuously. We estimated effects using mixed linear models, adjusting for known confounders. RESULTS: An increase in ozone of 15 parts per billion during the previous 48 h was associated with a greater decline in FEV1 in the obese (-2.07%; 95% confidence interval [CI], -3.25 to -0.89%) than in the nonobese (-0.96%; 95% CI, -1.70 to - 0.20%). The same exposure was also associated with a greater decline in FEV1 for those with AHR (-3.07%; 95% CI, -4.75 to -1.36%) compared to those without AHR (-1.32%; 95% CI, -2.06 to -0.57%). A three-way interaction trend test demonstrated a multiplicative effect of those two risk factors (p < 0.001). We found similar associations for FVC. CONCLUSIONS: Our results indicate that both obesity and AHR modify the acute effect of ozone on lung function in the elderly, with evidence of interaction between AHR and obesity that causes a greater than additive effect.
BACKGROUND:Ozone has heterogeneous effects on lung function. We investigated whether obesity and airways hyperresponsiveness (AHR) modify the acute effects of ozone on lung function in the elderly. METHODS: We studied 904 elderly men from the Normative Aging Study whose lung function (FVC, FEV1) was measured approximately every 3 years from 1995 to 2005. We defined obesity as a body mass index of at least 30 kg/m2. Using a standardized methacholine challenge test, we defined AHR as a FEV1 decline of 20% after inhalation of a cumulative dosage of 0 to 8.58 micromol of methacholine. Ambient ozone in the Greater Boston area was measured continuously. We estimated effects using mixed linear models, adjusting for known confounders. RESULTS: An increase in ozone of 15 parts per billion during the previous 48 h was associated with a greater decline in FEV1 in the obese (-2.07%; 95% confidence interval [CI], -3.25 to -0.89%) than in the nonobese (-0.96%; 95% CI, -1.70 to - 0.20%). The same exposure was also associated with a greater decline in FEV1 for those with AHR (-3.07%; 95% CI, -4.75 to -1.36%) compared to those without AHR (-1.32%; 95% CI, -2.06 to -0.57%). A three-way interaction trend test demonstrated a multiplicative effect of those two risk factors (p < 0.001). We found similar associations for FVC. CONCLUSIONS: Our results indicate that both obesity and AHR modify the acute effect of ozone on lung function in the elderly, with evidence of interaction between AHR and obesity that causes a greater than additive effect.
Authors: Mary B Rice; Petter L Ljungman; Elissa H Wilker; Diane R Gold; Joel D Schwartz; Petros Koutrakis; George R Washko; George T O'Connor; Murray A Mittleman Journal: Am J Respir Crit Care Med Date: 2013-12-01 Impact factor: 21.405
Authors: Ming Zhu; Christopher Hug; David I Kasahara; Richard A Johnston; Alison S Williams; Norah G Verbout; Huiqing Si; Jordan Jastrab; Amit Srivastava; Erin S Williams; Barbara Ranscht; Stephanie A Shore Journal: Am J Respir Cell Mol Biol Date: 2009-11-13 Impact factor: 6.914
Authors: Kyung Hwa Jung; Matthew Perzanowski; Andrew Rundle; Kathleen Moors; Beizhan Yan; Steven N Chillrud; Robin Whyatt; David Camann; Frederica P Perera; Rachel L Miller Journal: Environ Res Date: 2013-12-27 Impact factor: 6.498
Authors: Joel A Mathews; Nandini Krishnamoorthy; David I Kasahara; John Hutchinson; Youngji Cho; Jeffrey D Brand; Alison S Williams; Allison P Wurmbrand; Luiza Ribeiro; Frank Cuttitta; Mary E Sunday; Bruce D Levy; Stephanie A Shore Journal: Am J Respir Cell Mol Biol Date: 2018-03 Impact factor: 6.914