The effectiveness of breath carbon monoxide analyzer in screening for environmental tobacco smoke exposure in Saudi pregnant women

Refinement of cg05575921 demethylation response in nascent smoking

The initiation of adolescent smoking is difficult to detect using carbon monoxide or cotinine assays. Previously, we and others have shown that the methylation of cg05575921 is an accurate predictor of adult smoking status. But the dose and time dependency of the demethylation response to smoking initiation in adolescents is not yet well understood. To this end, we conducted three consecutive annual in-person interviews and biological samplings of 448 high school students (wave 1 (W1)-wave 3 (W3)). At W1 (n = 448), 62 subjects reported using tobacco and 72 subjects reported using cannabis at least once in their life-time with 38 and 20 subjects having a positive cotinine and cannabinoid levels, respectively, at W1 intake. At W3 (n = 383), 67 subjects reported using tobacco and 60 subjects reported using cannabis at least once with 75 and 60 subjects having positive cotinine and cannabinoid levels, respectively, at W3. Subjects with undetectable cotinine levels at all three-time waves had stable levels of cg05575921 methylation throughout the study (88.7% at W1 and 88.8% at W3, n = 149), while subjects with positive cotinine levels at all 3 time points manifested a steady decrease in cg05575921 methylation (81.8% at W1 and 71.3% at the W3, n = 12). In those subjects with an affirmative smoking self-report at W3 (n = 17), the amount of demethylation at cg05575921 was correlated with time and intensity of smoking. We conclude that cg05575921 methylation is a sensitive, dose-dependent indicator of early stages of smoking, and may help to identify smokers in the early stages of smoking.

The Collection and Analysis of Carbon Monoxide Levels as an Indirect Measure of Smoke Exposure in Pregnant Adolescents at a Multidisciplinary Teen Obstetrics Clinic

STUDY OBJECTIVE

In this study we aimed to collect and analyze CO levels as an indirect measure of smoke exposure in pregnant adolescents.

DESIGN, SETTING, AND PARTICIPANTS

Participants included pregnant adolescents who received antenatal care over 18 months (2012-2013) at the Multidisciplinary Teen Obstetrics Clinic at a tertiary-care hospital in Southeastern Ontario.

INTERVENTIONS

The CO breath test is a noninvasive method that is used to assess smoke exposure, in which nonsmokers have levels of 0-6 ppm, and levels of 7-10, 11-20 and more than 20 ppm are consistent with light, typical, and heavy smokers, respectively. Expired CO, smoking status, cigarette number, and home secondhand smoke exposure were documented at 3 clinic visits.

MAIN OUTCOME MEASURES

To determine mean CO levels as a measure of smoke exposure and prevalence of secondhand smoke exposure.

RESULTS

The mean age of participants was 17.6 years. CO means (ppm) across 3 visits were 6.0, 5.9, and 4.8. Sixty-two percent of patients were self-reported nonsmokers, 38% were self-reported smokers (n = 93). CO means (standard error of the mean) were consistently different for nonsmokers vs smokers at visits 1 to 3, respectively: 2.9 (0.79) vs 9.7 (1.8); 3.0 (0.71) vs 12.9 (2.2), and 2.4 (0.71) vs 8.8 (1.5; P < .01, t test; n = 91). Of patient's highest CO (COmax), 62%, 9%, 15%, and 12% had levels of 6 or less, 7-10, 11-20, and greater than 20, respectively. Eighty-four percent of pregnant adolescents had home secondhand smoke exposure, which included 40% of nonsmokers and 100% of smokers (n = 57). Although most nonsmokers had a COmax of 6 or fewer ppm, 56% of smokers had COmax greater than 10 ppm (P < .05, χ(2)).

CONCLUSION

Emphasis on smoking cessation is imperative in pregnant adolescents and should particularly target partners and families, because secondhand smoke exposure was very prevalent.

Environmental Tobacco Smoke Exposure in Pregnancy is Associated With Earlier Delivery and Reduced Birth Weight

The association between maternal smoking and preterm birth (PTB) has been known for more than 50 years but the effect of passive smoking is controversial. This retrospective cohort study in Bristol, United Kingdom, examines the effect of environmental tobacco smoke exposure (ETSE) on gestational age at delivery, birth weight, PTB, and being small-for-gestational age (SGA). Environmental tobacco smoke exposure was defined by either self-report or exhaled carbon monoxide (eCO) levels, and exposed women were compared with unexposed controls. Two models were used: The first included all women with adjustment for maternal smoking, and the second considered nonsmokers alone. Both models were further adjusted for maternal age, body mass index, parity, ethnicity, employment status, socioeconomic position, asthma, preeclampsia, and offspring sex. Logistic regression and likelihood ratio tests were used to test for any association between exposure and the binary outcomes (PTB and SGA), while linear regression and F tests were used to test for associations between exposure and the continuous outcomes. There were 13 359 deliveries in 2012 to 2014, with complete data for 5066 and 4793 women in the self-reported and eCO-measured exposure groups, respectively. Self-reported exposure was associated with earlier delivery (-0.19 weeks; 95% confidence interval [CI]: -0.32 to -0.05) and reduced birth weight (-56 g, 95% CI: -97 to -16 g) but no increase in the risk of PTB or SGA. There was no evidence for an association between eCO-measured exposure and any of the outcome measures. This information is important when advising women and their families and adds further support to continued public health efforts to reduce exposure to tobacco smoke.

The Saudi Guidelines for the Diagnosis and Management of COPD

The Saudi Thoracic Society (STS) launched the Saudi Initiative for Chronic Airway Diseases (SICAD) to develop a guideline for the diagnosis and management of chronic obstructive pulmonary disease (COPD). This guideline is primarily aimed for internists and general practitioners. Though there is scanty epidemiological data related to COPD, the SICAD panel believes that COPD prevalence is increasing in Saudi Arabia due to increasing prevalence of tobacco smoking among men and women. To overcome the issue of underutilization of spirometry for diagnosing COPD, handheld spirometry is recommended to screen individuals at risk for COPD. A unique feature about this guideline is the simplified practical approach to classify COPD into three classes based on the symptoms as per COPD Assessment Test (CAT) and the risk of exacerbations and hospitalization. Those patients with low risk of exacerbation (<2 in the past year) can be classified as either Class I when they have less symptoms (CAT < 10) or Class II when they have more symptoms (CAT ≥ 10). High-risk COPD patients, as manifested with ≥2 exacerbation or hospitalization in the past year irrespective of the baseline symptoms, are classified as Class III. Class I and II patients require bronchodilators for symptom relief, while Class III patients are recommended to use medications that reduce the risks of exacerbations. The guideline recommends screening for co-morbidities and suggests a comprehensive management approach including pulmonary rehabilitation for those with a CAT score ≥10. The article also discusses the diagnosis and management of acute exacerbations in COPD.