Additional file 1: Tables S1. of Systematic review of lung function and COPD with peripheral blood DNA methylation in population based studies

Search terms (n = 92) used within MEDLINE, EMBASE and Web of Science. (DOCX 13 kb

Characteristics of the study population (N = 1552).

<p>ETS indicates environmental tobacco smoke exposure; SBP, systolic blood pressure; DBP, diastolic blood pressure; BMI, body mass index;</p>a<p>Annual average over 10 years previous to the study.</p>b<p>average over 3 days previous to the HRV measurement.</p

Adjusted^a estimates of the mean percent difference of HRV associated with a 1 µg/m³ increase in average exposure to traffic-related PM10^b by <i>IL6</i>-174 G/C genotypes (N = 1549).

<p>HRV indicates heart rate variability: SDNN indicates standard deviation of all NN intervals (units ms); TP, total power (ms²); HF, high frequency power (ms²); LF, low frequency power (ms²).</p>a<p>adjusted for gender, age, age squared, BMI, BMI squared, smoking status, environmental tobacco smoke exposure, alcohol consumption, physical activity, high-sensitivity C-reactive protein, uric acid levels, hypertension, heart disease, diabetes, street and railway noise, seasonal effects and area.</p>b<p>Annual average over 10 years previous to the study.</p>c<p>p-values for the genotype- specific TPM₁₀ effect estimate.</p>d<p>p-values of interaction effects of the <i>IL6</i>-174 G/C polymorphism with TPM₁₀ on HRV were tested for additive, dominant and recessive genetic models; p-values of the most significant mode of inheritance are presented (additive¹ or dominant²).</p

Unadjusted and adjusted^a geometric means of the HRV indices and percent differences in HRV indices by traffic-related PM₁₀ (TPM₁₀) and by <i>IL6</i>-174G/C genotypes (N = 1549).

<p>HRV indicates heart rate variability: SDNN indicates standard deviation of all NN intervals (units ms); TP, total power (ms²); HF, high frequency power (ms²); LF, low frequency power (ms²).</p>a<p>adjusted for gender, age, age squared, BMI, BMI squared, smoking status, environmental tobacco smoke exposure, alcohol consumption, physical activity, high-sensitivity C-reactive protein, uric acid levels, hypertension, heart disease, diabetes, street and railway noise, seasonal effects and area.</p>b<p>p-values of genotype-specific main effects of the <i>IL6</i>-174G/C polymorphism and TPM₁₀ on HRV (codominant genetic model).</p>c<p>p-values of main effects of the <i>IL6</i> -174G/C polymorphism on HRV indices were tested for additive, dominant and recessive genetic models; p-values of the most significant mode of inheritance are presented (¹additive or ²dominant).</p>d<p>per 1 µg/m³ TPM₁₀ increase.</p>e<p>compared to reference genotype G/G.</p

Effect modification by vigorous physical activity.

<p>MetS-W: Metabolic syndrome according to World Health Organization. MetS-I: Metabolic syndrome according to International Diabetes Federation. MetS-A: Metabolic syndrome according to Adult Treatment Panel-III criteria. Active defined as vigorous physical activity ≥30 minutes per week. Inactive defined as vigorous physical activity <30minutes per week. Fully adjusted models include age, sex, educational attainment, neighbourhood socio-economic index, occupational exposure to vapours, gases, dusts and fumes, smoking status, smoked pack-years, exposure to passive smoke, consumption of fruits and raw vegetables, and body mass index. PM₁₀: particulate matter <10μm in diameter from all sources. All analyses were done with four-hour fasting participants. Participants’ study area was treated as a random effect in all models. Odds ratio values refer to increments of 10μg/m³ in PM₁₀ exposure. Total N = 3684; N(physically-active) = 2115.</p

Effect modification by smoking status.

<p>MetS-W: Metabolic syndrome according to World Health Organization. MetS-I: Metabolic syndrome according to International Diabetes Federation. MetS-A: Metabolic syndrome according to Adult Treatment Panel-III criteria. Fully adjusted models include age, sex, educational attainment, neighbourhood socio-economic index, occupational exposure to vapours, gases, dusts and fumes, exposure to passive smoke, consumption of fruits and raw vegetables, physical activity and body mass index. PM₁₀: particulate matter <10μm in diameter from all sources. All analyses were done with four-hour fasting participants. Participants’ study area was treated as a random effect in all models. Odds ratio values refer to increments of 10μg/m³ in PM₁₀ exposure. Total N = 3684; N(never-smoker) = 1623.</p

Sensitivity Analyses.

<p>Fully adjusted models include age, sex, educational attainment, neighbourhood socio-economic index, occupational exposure to vapours, gases, dusts and fumes, smoking status, smoked pack-years, exposure to passive smoke, consumption of fruits and raw vegetables, physical activity and body mass index. MI: multiple imputations. IPW: inverse probability weighting. PM₁₀: particulate matter <10μm in diameter from all sources. NO₂: nitrogen dioxide. OR: odds ratio. CI: confidence interval. OR refer to increments of 10μg/m³ in PM₁₀, and NO₂ exposure respectively. All analyses were done with four-hour fasting participants.</p><p>Sensitivity Analyses.</p

Effect modification by sex.

<p>MetS-W: Metabolic syndrome according to World Health Organization. MetS-I: Metabolic syndrome according to International Diabetes Federation. MetS-A: Metabolic syndrome according to Adult Treatment Panel-III criteria. Fully adjusted models include age, educational attainment, neighbourhood socio-economic index, occupational exposure to vapours, gases, dusts and fumes, smoking status, smoked pack-years, exposure to passive smoke, consumption of fruits and raw vegetables, physical activity and body mass index. PM₁₀: particulate matter <10μm in diameter from all sources. NO₂: nitrogen dioxide. All analyses were done with four-hour fasting participants. Participants’ study area was treated as a random effect in all models. Odds ratio values refer to increments of 10μg/m³ in PM₁₀ exposure. Total N = 3684; N(males) = 1746.</p

Effect modification by age group.

<p>MetS-W: Metabolic syndrome according to World Health Organization. MetS-I: Metabolic syndrome according to International Diabetes Federation. MetS-A: Metabolic syndrome according to Adult Treatment Panel-III criteria. Fully adjusted models include sex, educational attainment, neighbourhood socio-economic index, occupational exposure to vapours, gases, dusts and fumes, smoking status, smoked pack-years, exposure to passive smoke, consumption of fruits and raw vegetables, physical activity and body mass index. PM₁₀: particulate matter <10μm in diameter from all sources. All analyses were done with four-hour fasting participants. Participants’ study area was treated as a random effect in all models. Odds ratio values refer to increments of 10μg/m³ in PM₁₀ exposure. Total N = 3684; N(age≤50) = 1393.</p

Background Characteristics of participants.

<p>MetS-W: World Health Organization-defined metabolic syndrome. MetS-I: International Diabetes Federation-defined metabolic syndrome. MetS-A: Adult Treatment Panel III-defined metabolic syndrome. ETS: environmental tobacco smoke. VGDF: vapours, gases, dusts or fumes. SEI: socio-economic index expressed as a percentage. PM₁₀: particulate matter <10μm in diameter from all sources. NO₂: nitrogen dioxide.</p><p>^adefined as IFG and any two of central obesity, hypertension, low HDL and high triglycerides.</p><p>^bdefined as central obesity and any two of IFG, hypertension, low HDL and high triglycerides.</p><p>^cdefined as any three of IFG, central obesity, hypertension, low HDL and high triglycerides.</p><p>^d defined as not having a, b and c.</p><p>^edefined by WHO as fasting blood glucose≥6.1mmol/L and/or diagnosis of type2diabetes; and by IDF and ATP-III as fasting blood glucose≥5.6mmol/L and/or diagnosis of type2diabetes. High triglycerides defined as fasting triglycerides≥1.7mmol/L or treatment for this condition.</p><p>^f defined by WHO as ≤ 0.9 mmol/L (males), ≤ 1.0 mmol/L (females); and by IDF and ATP-III as < 1.03 mmol/L (males), < 1.29 mmol/L (females), or treatment for this condition.</p><p>^gdefined by WHO as ≥140/90, or treatment of previously diagnosed hypertension; and by IDF and ATP-III as blood pressure >130/85 mm Hg or previously diagnosed hypertension.</p><p>^hproportion in controls according to MetS-W/ MetS-I or MetS-A criteria respectively.</p><p>Background Characteristics of participants.</p