TY - JOUR
AU - Budakoglu, Isıl, Irem
AB - Abstract Objective To objectively investigate the effect of passive smoking on pneumonia and disease severity in children aged less than 5 years by using cotinine as an indicator of passive smoking. Methods Between December 2015 and April 2016, children aged less than 5 years with pneumonia and age-matched healthy controls were included in this study, which was conducted at three tertiary pediatric pulmonology centers. A questionnaire was given to the parents regarding demographic data and smoking status at home. Urinary cotinine/creatinine ratio (CCR) was measured. The data from the pneumonia and control groups, as well as children with mild and severe pneumonia within the pneumonia group, were compared. Results A total of 227 subjects were included in the study; there were 74 children in the pneumonia group and 153 in the control group. The mean age of all the children was 33.4 ± 1.28 months. Of all subjects, 140 were male and 102 were exposed to passive smoking by their parents at home. There were statistically significant differences in age, number of people in the home, and mother’s and father’s age between the control and pneumonia groups (p < 0.05). No difference was found in the CCR in the control and pneumonia group (p > 0.05). Age and urinary CCR were significantly different between children with mild and severe pneumonia (p < 0.05). Conclusion We showed that passive smoking exposure was associated with the development of severe pneumonia in children. Further studies are needed to examine the underlying cause in detail. passive smoking, pneumonia, children INTRODUCTION Pneumonia is the one of the leading causes of death in children worldwide. Every year nearly two million children die due to pneumonia [1]. Smoking is one of the predisposing factors for lower respiratory tract infections (LRTI) [2]. Smoking causes various diseases, LRTI, several types of cancer, cardiac diseases and psychiatric diseases in adults [3–6]. Children are usually exposed to tobacco smoking by their parents in the home [7]. Passive smoking may harm children more than adults because children do not have fully developed immune systems [8]. Passive smoking increases the risk of LRTI, asthma, bronchiolitis, pneumonia, middle ear infection, inflammatory bowel disease, sleep disturbances and leukemia in children, as well as being related to sudden infant death syndrome [9–14]. Smoking affects both humoral and cellular immunity by affecting lymphocyte proliferation and differentiation and induces apoptosis of lymphocytes [14, 15]. It also reduces mucociliary activity and changes the amount, consistency and permeability of the mucus [16, 17]. Serum immunoglobulin levels, T-lymphocyte helper/suppressor cell ratio and cytotoxic activity of natural killer cells decrease by smoking, which may cause decreased immune response to infections [14, 18]. Cotinine is the major metabolite of nicotine and can be measured in urine, hair and saliva. Cotinine is one of the objective and reliable markers of passive smoking [19]. There are several studies about passive smoking and respiratory system diseases in children; most were done by using questionnaires to detect passive smoking. In this study, we aimed to investigate the effect of passive smoking on pneumonia and disease severity in children under 5 years of age by using cotinine as an objective indicator of passive smoking. MATERIALS AND METHODS Between December 2015 and April 2016, this study was conducted in three pediatric pulmonology centers which are tertiary and referral centers. Children under 5 years of age diagnosed with pneumonia for the first time were included as the pneumonia group. Age-matched healthy controls from general pediatric clinics were included as the control group. Subjects who had symptoms and signs of respiratory system infection such as cough, increased respiratory rate, presence of sputum, cyanosis in the last month were not included in the control group. Subjects who had a history of premature delivery, incomplete immunization, recurrent LRTI, underlying diseases such as cystic fibrosis, congenital heart diseases, malnutrition, diabetes, asthma, immunodeficiency or any other chronic disease were excluded from both pneumonia and control groups. Pneumonia was defined with acute respiratory symptoms such as cough, fever and tachypnea. Tachypnea was defined as an increase in respiratory rate according to age [20]. A body temperature above 38°C was considered high fever. Subcostal, intercostal and suprasternal retractions and nasal flaring, if present, and oxygen saturations were recorded. Lung auscultation findings were recorded as rales, rhonchi, decreased respiratory sounds and prolonged expiration. Presence of consolidation with/without effusion on the chest X-ray was noted. Clinical, laboratory and radiological findings, treatment and hospitalization were noted. The pneumonia patients were grouped as mild and severe according to disease severity [21]. A questionnaire was given to the all subjects’ parents about demographic data and smoking status at home. At least 10 ml urine was obtained from each subject. Urine samples were stored at −70°C after they were centrifuged. Urine cotinine levels were analyzed using an LC-MS/MS (liquid-chromatography mass spectrometry) method. Urinary creatinine levels were determined by colorimetric method using ready kits. To compensate for the effect of variable dilution in the spot concentration of urinary cotinine, the CCR was calculated. The data from control and pneumonia groups and mild and severe groups within the pneumonia group were compared. SPSS v.20.0 for Windows (Chicago, IL, USA) was used for the statistical analysis. The χ2 test was used for nominal variables. The data are expressed as mean ± standard error of the mean. analysis of variance and Student’s t-test were used if parametric conditions were obtained. If not, the Mann–Whitney U-test and Kruskal–Wallis test were used. A two-tailed p-value of less than 0.05 was considered significant. To distinguish passive smokers from nonsmokers, urinary CCR cutoff values were established by receiver operating characteristic (ROC) analysis of our overall samples. The optimal values were selected, being those that exhibited the highest classification rates. This report was performed using the principles of the Declaration of Helsinki and approved by Gazi University Faculty of Medicine Ethics Committee (Date: 14/12/2015, number: 123). Informed consent was obtained from all subjects’ parents. RESULTS Overall, 274 subjects enrolled in the study, and 47 subjects were excluded because of absent urine sample and/or incomplete questionnaires. In total, 227 subjects were included in the study, with 74 children in the pneumonia group and 153 in the control group. Mean age of all children was 33.4 ± 1.28 months, and 140 (61%) were male. It was reported by parents that 102 (44%) of all subjects were exposed to passive smoking by their parents in the home. Urinary CCR of children who were exposed to passive smoking were higher than unexposed children. Urinary CCR of children who were exposed to passive smoking by more than 10 cigarettes in a day were significantly higher than unexposed children (p < 0.05). Clinical, laboratory and radiological findings and treatment of patients in the pneumonia group are shown in Table 1. Hospitalization was needed in 71% of these patients and two patients needed intensive care hospitalization. Demographic features and cotinine levels of pneumonia and control groups are shown in Table 2. Parent-reported passive smoking exposure and urinary CCR levels were similar in two groups. However, there were statistically significant differences in age, number of people in the home, mother’s age and father’s age between the two groups (p < 0.05). Table 1 Clinical, laboratory, radiological findings and treatment of pneumonia patients n = 74 % Symptoms  Fever 49 66  Cough 73 98  Tachypnea 46 62  Feeding difficulties 37 50  Moderate to severe recession 57 77 Physical examination  Tachypnea 48 64  Oxygen saturation <93% 16 21  Rales 56 75  Rhonchi 38 51  Decreased respiratory sounds 3 4  Prolonged expiration 1 1  Retractions 35 47 Laboratory  Increased white blood cell 33 44  CRP >6 mg/la 48 78  ESR >20 mm/ha 19 73 Radiology  Infiltration 64 86  Effusion 0 0 Treatment  Antibiotic 65 87  Hospitalization 53 71  Oxygen support 23 31  Mechanical ventilation 2 2  Intensive care unit 2 2  Treatment duration (day), mean ± SD 7.44 ± 0.56 n = 74 % Symptoms  Fever 49 66  Cough 73 98  Tachypnea 46 62  Feeding difficulties 37 50  Moderate to severe recession 57 77 Physical examination  Tachypnea 48 64  Oxygen saturation <93% 16 21  Rales 56 75  Rhonchi 38 51  Decreased respiratory sounds 3 4  Prolonged expiration 1 1  Retractions 35 47 Laboratory  Increased white blood cell 33 44  CRP >6 mg/la 48 78  ESR >20 mm/ha 19 73 Radiology  Infiltration 64 86  Effusion 0 0 Treatment  Antibiotic 65 87  Hospitalization 53 71  Oxygen support 23 31  Mechanical ventilation 2 2  Intensive care unit 2 2  Treatment duration (day), mean ± SD 7.44 ± 0.56 Note: CRP, C-reactive protein; ESR, Erythrocyte sedimentation rate; SD, standard deviation. a CRP was measured in 61 and ESR in 26 patients. Open in new tab Table 1 Clinical, laboratory, radiological findings and treatment of pneumonia patients n = 74 % Symptoms  Fever 49 66  Cough 73 98  Tachypnea 46 62  Feeding difficulties 37 50  Moderate to severe recession 57 77 Physical examination  Tachypnea 48 64  Oxygen saturation <93% 16 21  Rales 56 75  Rhonchi 38 51  Decreased respiratory sounds 3 4  Prolonged expiration 1 1  Retractions 35 47 Laboratory  Increased white blood cell 33 44  CRP >6 mg/la 48 78  ESR >20 mm/ha 19 73 Radiology  Infiltration 64 86  Effusion 0 0 Treatment  Antibiotic 65 87  Hospitalization 53 71  Oxygen support 23 31  Mechanical ventilation 2 2  Intensive care unit 2 2  Treatment duration (day), mean ± SD 7.44 ± 0.56 n = 74 % Symptoms  Fever 49 66  Cough 73 98  Tachypnea 46 62  Feeding difficulties 37 50  Moderate to severe recession 57 77 Physical examination  Tachypnea 48 64  Oxygen saturation <93% 16 21  Rales 56 75  Rhonchi 38 51  Decreased respiratory sounds 3 4  Prolonged expiration 1 1  Retractions 35 47 Laboratory  Increased white blood cell 33 44  CRP >6 mg/la 48 78  ESR >20 mm/ha 19 73 Radiology  Infiltration 64 86  Effusion 0 0 Treatment  Antibiotic 65 87  Hospitalization 53 71  Oxygen support 23 31  Mechanical ventilation 2 2  Intensive care unit 2 2  Treatment duration (day), mean ± SD 7.44 ± 0.56 Note: CRP, C-reactive protein; ESR, Erythrocyte sedimentation rate; SD, standard deviation. a CRP was measured in 61 and ESR in 26 patients. Open in new tab Table 2 Demographic features and cotinine levels of pneumonia and control groups Control (n = 153) Pneumonia (n = 74) p Age (month) 38.0 ± 1.4 23.8 ± 2.1 <0.001 Male gender (%) 64.1 56.8 >0.05 People living at home 4.1 ± 0.9 4.5 ± 1.5 0.012 Age of mother 32.2 ± 0.4 29.6 ± 0.7 0.004 Age of father 35.6 ± 0.4 33.5 ± 0.7 0.023 Smoking mother (%) 20.9 20 >0.05 Smoking father (%) 47.7 47.3 >0.05 Smoking exposure 54.2 52.7 >0.05 Urinary CCR (ng/mg) 7.30 ± 1.4 7.62 ± 1.4 >0.05 Control (n = 153) Pneumonia (n = 74) p Age (month) 38.0 ± 1.4 23.8 ± 2.1 <0.001 Male gender (%) 64.1 56.8 >0.05 People living at home 4.1 ± 0.9 4.5 ± 1.5 0.012 Age of mother 32.2 ± 0.4 29.6 ± 0.7 0.004 Age of father 35.6 ± 0.4 33.5 ± 0.7 0.023 Smoking mother (%) 20.9 20 >0.05 Smoking father (%) 47.7 47.3 >0.05 Smoking exposure 54.2 52.7 >0.05 Urinary CCR (ng/mg) 7.30 ± 1.4 7.62 ± 1.4 >0.05 Bold number indicates statistically significant value. Open in new tab Table 2 Demographic features and cotinine levels of pneumonia and control groups Control (n = 153) Pneumonia (n = 74) p Age (month) 38.0 ± 1.4 23.8 ± 2.1 <0.001 Male gender (%) 64.1 56.8 >0.05 People living at home 4.1 ± 0.9 4.5 ± 1.5 0.012 Age of mother 32.2 ± 0.4 29.6 ± 0.7 0.004 Age of father 35.6 ± 0.4 33.5 ± 0.7 0.023 Smoking mother (%) 20.9 20 >0.05 Smoking father (%) 47.7 47.3 >0.05 Smoking exposure 54.2 52.7 >0.05 Urinary CCR (ng/mg) 7.30 ± 1.4 7.62 ± 1.4 >0.05 Control (n = 153) Pneumonia (n = 74) p Age (month) 38.0 ± 1.4 23.8 ± 2.1 <0.001 Male gender (%) 64.1 56.8 >0.05 People living at home 4.1 ± 0.9 4.5 ± 1.5 0.012 Age of mother 32.2 ± 0.4 29.6 ± 0.7 0.004 Age of father 35.6 ± 0.4 33.5 ± 0.7 0.023 Smoking mother (%) 20.9 20 >0.05 Smoking father (%) 47.7 47.3 >0.05 Smoking exposure 54.2 52.7 >0.05 Urinary CCR (ng/mg) 7.30 ± 1.4 7.62 ± 1.4 >0.05 Bold number indicates statistically significant value. Open in new tab In the pneumonia group, 64.1% of the children with smoking exposure had severe pneumonia and 35.9% had mild pneumonia. There were statistically significant differences in age and urinary CCR between the two groups (p < 0.05). Demographic features and cotinine results of mild and severe pneumonia patients in the pneumonia group are shown in Table 3. CCR was compared in control, mild and severe pneumonia group and there was no difference in CCR between the three groups (p > 0.05). Table 3 Comparison of mild and severe pneumonia patients Mild pneumonia (n = 21) Severe pneumonia (n = 53) p Age (month) 31.4 ± 3.7 30.8 ± 2.4 0.026 Male gender (%) 47.6 60.4 >0.05 People living at home 4.6 ± 0.3 4.5 ± 0.1 >0.05 Age of mother 30.0 ± 1.5 29.5 ± 0.8 >0.05 Age of father 33.9 ± 1.5 33.3 ± 0.9 >0.05 Smoking mother (%) 23.8 37.5 >0.05 Smoking father (%) 61.9 41.5 >0.05 Smoking exposure (%) 66.7 47.2 >0.05 Urinary CCR (ng/mg) 3.3 ± 0.75 9.3 ± 1.9 0.005 Mild pneumonia (n = 21) Severe pneumonia (n = 53) p Age (month) 31.4 ± 3.7 30.8 ± 2.4 0.026 Male gender (%) 47.6 60.4 >0.05 People living at home 4.6 ± 0.3 4.5 ± 0.1 >0.05 Age of mother 30.0 ± 1.5 29.5 ± 0.8 >0.05 Age of father 33.9 ± 1.5 33.3 ± 0.9 >0.05 Smoking mother (%) 23.8 37.5 >0.05 Smoking father (%) 61.9 41.5 >0.05 Smoking exposure (%) 66.7 47.2 >0.05 Urinary CCR (ng/mg) 3.3 ± 0.75 9.3 ± 1.9 0.005 Open in new tab Table 3 Comparison of mild and severe pneumonia patients Mild pneumonia (n = 21) Severe pneumonia (n = 53) p Age (month) 31.4 ± 3.7 30.8 ± 2.4 0.026 Male gender (%) 47.6 60.4 >0.05 People living at home 4.6 ± 0.3 4.5 ± 0.1 >0.05 Age of mother 30.0 ± 1.5 29.5 ± 0.8 >0.05 Age of father 33.9 ± 1.5 33.3 ± 0.9 >0.05 Smoking mother (%) 23.8 37.5 >0.05 Smoking father (%) 61.9 41.5 >0.05 Smoking exposure (%) 66.7 47.2 >0.05 Urinary CCR (ng/mg) 3.3 ± 0.75 9.3 ± 1.9 0.005 Mild pneumonia (n = 21) Severe pneumonia (n = 53) p Age (month) 31.4 ± 3.7 30.8 ± 2.4 0.026 Male gender (%) 47.6 60.4 >0.05 People living at home 4.6 ± 0.3 4.5 ± 0.1 >0.05 Age of mother 30.0 ± 1.5 29.5 ± 0.8 >0.05 Age of father 33.9 ± 1.5 33.3 ± 0.9 >0.05 Smoking mother (%) 23.8 37.5 >0.05 Smoking father (%) 61.9 41.5 >0.05 Smoking exposure (%) 66.7 47.2 >0.05 Urinary CCR (ng/mg) 3.3 ± 0.75 9.3 ± 1.9 0.005 Open in new tab The ROC analysis revealed that urinary CCR was 2.47 ng/mg (area under the curve 0.629, sensitivity 62.7%, and specificity 53.4%) for passive smoking exposure in children (Fig. 1). Fig. 1. Open in new tabDownload slide ROC curve analysis for passive smoking exposure (green line indicates CCR). Fig. 1. Open in new tabDownload slide ROC curve analysis for passive smoking exposure (green line indicates CCR). DISCUSSION There are many studies about passive smoking and respiratory diseases in children, but there is insufficient knowledge about disease severity and passive smoking in children with pneumonia. Herein, we objectively examined the association of passive smoking and disease severity in pneumonia in children. In this study, 44% of all children were exposed to passive smoking at home, and patients with severe pneumonia had higher CCRs than those in the mild group. Our study had some limitations. The need for intensive care unit hospitalization and mechanical ventilation were low, and we could not compare children with very severe pneumonia with the others in the pneumonia group. We found significant differences between the pneumonia and control groups in terms of age, crowded living conditions and lower maternal age, compatible with the literature [22, 23]. In a previous meta-analysis, the risk of serious respiratory infection in early life was found higher in children whose parents smoked, especially in those aged less than 2 years [24]. Parents’ smoking status, rate of exposure to passive smoking and CCR were very similar between the two groups in our study, which may be related with the older ages of our patients. In the pneumonia group, age was lower in the severe group than in the mild group, which in line with the literature [25]. The rate of exposure to passive smoking and the smoking rates of fathers were high in the mild group; however, urinary CCR was found to be significantly higher in the severe group. We believe that patients with severe pneumonia were more likely to spend more time at home because of their young age, and mothers who smoked had a stronger influence than fathers on the children’s exposure [26]. Mothers should be warned about this risk. Although there was a statistically significant difference, the ages of both groups were very close and the differences of CCR between two groups were prominent. In a previous study, passive smoking was found related with longer hospital stay and a greater requirement of intensive care in hospitalized children with pneumonia who had household smokers numbering more than two. We could not compare the requirement for intensive care due to the low sample number, but compatible with this study, patients with severe pneumonia had higher CCRs, which show a greater exposure to passive smoking in our study [27]. These were also compatible with other studies that showed an association between the intensity of exposure to passive smoking and disease severity in other respiratory illnesses such as asthma, bronchiolitis and RSV infection in children [28–34]. In another study conducted in a pediatric emergency department, more severe illness was found in bronchiolitis and asthma among children who were exposed to passive smoking; however, no difference was found in severity of pneumonia [35]. The authors could not explain this situation and further research was recommended to understand this situation. In our study, we objectively found that severe pneumonia was associated with exposure to passive smoking. In conclusion, we objectively showed that passive smoking exposure was associated with the development of severe pneumonia in children. Parents should be informed about the damage related with exposing children to passive smoking. 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Google Scholar Crossref Search ADS PubMed WorldCat © The Author(s) [2019]. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)
TI - Passive Smoking and Disease Severity in Childhood Pneumonia Under 5 Years of Age
JF - Journal of Tropical Pediatrics
DO - 10.1093/tropej/fmz081
DA - 2011-12-01
UR - https://www.deepdyve.com/lp/oxford-university-press/passive-smoking-and-disease-severity-in-childhood-pneumonia-under-5-j13Kn0ize8
SP - 1
VL - Advance Article
IS - 
DP - DeepDyve
ER -