METHOD: This cross-sectional study was carried out to measure salivary cotinine concentrations among 1064 schoolchildren (10-11 years) attending 24 schools in Malaysia following recent partial smoke-free restrictions. Parents completed questionnaires and schoolchildren provided saliva samples for cotinine assay.
RESULTS: The geometric mean (GM) salivary cotinine concentrations for 947 non-smoking schoolchildren stratified by household residents' smoking behaviour were: for children living with non-smoking parents 0.32 ng/ml (95% CI 0.28-0.37) (n = 446); for children living with a smoker father 0.65 ng/ml (95% CI 0.57-0.72) (n = 432); for children living with two smoking parents 1.12 ng/ml (95% CI 0.29-4.40) (n = 3); for children who live with an extended family member who smokes 0.62 ng/ml (95% CI 0.42-0.89) (n = 33) and for children living with two smokers (father and extended family member) 0.71 ng/ml (95% CI 0.40-0.97) (n = 44). Parental-reported SHS exposures showed poor agreement with children's self-reported SHS exposures. Multiple linear regression demonstrated that cotinine levels were positively associated with living with one or more smokers, urban residence, occupation of father (Armed forces), parental-reported exposure to SHS and education of the father (Diploma/Technical certificate).
CONCLUSIONS: This is the first study to characterise exposures to SHS using salivary cotinine concentrations among schoolchildren in Malaysia and also the first study documenting SHS exposure using salivary cotinine as a biomarker in a South-East Asian population of schoolchildren. Compared to other populations of similarly aged schoolchildren, Malaysian children have higher salivary cotinine concentrations. The partial nature of smoke-free restrictions in Malaysia is likely to contribute to these findings. Enforcement of existing legislation to reduce exposure in public place settings and interventions to reduce exposure at home, especially to implement effective home smoking restriction practices are required.
STUDY DESIGN: This was a cross-sectional comparative study in a Malaysian tertiary obstetric hospital involving 200 non-smoking pregnant women at term, of whom 100 were secondhand smokers and 100 were non-secondhand smokers. Those with multiple pregnancies, with a body mass index (BMI) of more than 30kg/m2or who delivered by Caesarean section were excluded. The participants' basic demographic details, delivery details, neonatal outcome and placental weight were recorded. Umbilical cord blood samples were obtained, and cord blood cotinine levels were measured with a Cotinine ELISA kit. The primary outcomes were baby's birth weight, length, and head circumference, Apgar score at 5min and placental weight. The secondary outcome was difference in cord blood cotinine levels between the two groups and the correlation of these differences with the neonatal outcome.
RESULTS: The secondhand smoker group had significantly lower baby weight (2.94±0.31kg vs 3.05±0.40kg), head circumference (30.87±2.35cm vs 37.13±2.36cm), length (46.58±1.95cm vs 51.53±2.05cm) and placental weight (520±73.5g vs 596±61.3g) and significantly higher cord blood cotinine levels (16.35±12.84ng/mL vs 0.56±0.22ng/mL). Cord blood cotinine levels had significant negative correlations with placental weight (r=-0.461), baby's weight (r=-0.297), baby's head circumference (r=-0.501) and baby's length (r=-0.374).
CONCLUSION: Secondhand smoke increases the incidence of adverse pregnancy outcomes (newborns'anthropometric measurements and placental weight) and causes higher cord blood cotinine levels.
METHODS: A total of 26 pre-schools in Seremban, Malaysia were randomly selected using the probability proportional to size sampling. Dental examination was performed by a dentist to record the number of decayed teeth (dt). Weight and height of the pre-schoolers were measured. The mother-administered questionnaire was used to gather information pertaining to the sociodemographic characteristics and second-hand smoke exposure. Total sugar exposure was calculated from a 3-day food record.
RESULTS: Among the 396 participating pre-schoolers, 63.4% of them had at least one untreated caries, with a mean ± SD dt score of 3.56 ± 4.57. Negative binomial regression analysis revealed that being a boy (adjusted mean ratio = 1.42, 95% CI = 0.005-0.698, p = 0.047), exposed to second-hand smoke (adjusted mean ratio = 1.67, 95% CI = 0.168-0.857, p = 0.004) and those who had more than 6 times of daily total sugar exposure (adjusted mean ratio = 1.93, 95% CI = 0.138-0.857, p = 0.013) were significantly associated with dental caries among pre-schoolers.
CONCLUSION: A high prevalence of dental caries was reported in this study. This study highlights the need to reduce exposure to second-hand smoke and practice healthy eating behaviours in reducing the risk of dental caries among pre-schoolers.
METHODS: A total of 715 incident PD cases were ascertained in a cohort of 220 494 individuals from NeuroEPIC4PD, a prospective European population-based cohort study including 13 centres in eight countries. Smoking habits were recorded at recruitment. We analysed smoking status, duration, and intensity and exposure to passive smoking in relation to PD onset.
RESULTS: Former smokers had a 20% decreased risk and current smokers a halved risk of developing PD compared with never smokers. Strong dose-response relationships with smoking intensity and duration were found. Hazard ratios (HRs) for smoking <20 years were 0.84 [95% confidence interval (CI) 0.67-1.07], 20-29 years 0.73 (95% CI 0.56-0.96) and >30 years 0.54 (95% CI 0.43-0.36) compared with never smokers. The proportional hazard assumption was verified, showing no change of risk over time, arguing against a delaying effect. Reverse causality was disproved by the consistency of dose-response relationships among former and current smokers. The inverse association between passive smoking and PD, HR 0.70 (95% CI 0.49-0.99) ruled out the effect of unmeasured confounding.
CONCLUSIONS: These results are highly suggestive of a true causal link between smoking and PD, although it is not clear which is the chemical compound in cigarette smoking responsible for the biological effect.
METHODS: A structured questionnaire was used to collect data on a child's current and previous illnesses, oral health behaviours, dietary habits, parental smoking behaviours and parents' dental history. The intraoral examination recorded dental caries (dmfs), enamel defects, gingival health, melanin pigmentation and soft tissue health. Stimulated saliva was collected. Total sIgA levels were quantified using indirect competitive ELISA with a SalimetricsTM kit.
RESULTS: The 44 children (aged 15-69 months) recruited were divided into two groups: ETS and non-ETS (control). There were 22 children in each: 16 who were exposed to ETS during and after gestation were identified as the ETSB subgroup. Participants exposed to ETS were more likely to have had upper respiratory tract and middle ear infections during the neonatal period and had higher mean dmft, mean dmfs, mean percent of surfaces with demarcated opacities and mean GI than the non-ETS participants. The children exposed to ETS before and after birth had the highest occurrence of enamel opacities showed a higher risk for dental caries even though more children in this group used the recommended fluoride toothpaste (1000 ppm fluoride). Mothers who smoked either never breastfed their children or breastfed their children for less than the recommended period of 6 months. Children exposed to ETS were shown to have higher mean total sIgA (μg/ml) than the children in the control group.
CONCLUSIONS: Associations between ETS exposure before and after gestation and oral health, including salivary changes in young children were shown in the present study. Dental health professionals should include a question about household smoking in children's dental histories, which would allow opportunities to discuss the impact of smoking on child oral health. Longitudinal oral health studies should include a history of maternal smoking during pregnancy and afterwards.
METHODS: We analyzed data from the Global Youth Tobacco Survey (GYTS) 2003, GYTS 2009, and the Tobacco and Electronic Cigarette Survey among Malaysia Adolescents (TECMA) 2016. The surveys employed multistage sampling to select representative samples of adolescents attending secondary school in Malaysia. Data were collected using a pre-validated self-administered anonymous questionnaire adopted from the GYTS.
RESULTS: Between 2003 and 2016, major changes occurred in which there were reductions in the prevalence of ever smoking, current smoking, and susceptibility to smoking. Reductions were also observed in exposure to SHS in public places and in the home. The proportion of school-going adolescents who support a ban on smoking in public places increased between 2013 to 2016, and there was a significant reduction in the proportion of respondents that were offered 'free' cigarettes by tobacco company representatives. However, there was no difference in the proportion of adolescents who initiated smoking before the age of 10 years and current smokers seeking advice to quit smoking across the time period.
CONCLUSIONS: Our study indicates that the smoking policies and measures have been effective in reducing smoking prevalence, secondhand smoke exposure, and access to cigarettes, among school-going adolescents in Malaysia. However, measures to reduce smoking initiation and increase smoking cessation need to be strengthened to reduce the burden of smoking-related diseases in Malaysia in the long-term.
METHODS: A multistage sampling was performed across rural primary schools in Kuala Krai, Kelantan, Malaysia. Data were collected using self-administered questionnaires and the children aged 10-11 years (n=312) were subjected to cognitive tests including digit span, letter-number sequencing, coding, and symbol search. Cognitive performance was tested using subscales derived from the Wechsler Intelligence Scale for Children.
RESULTS: The prevalence of SHS exposure at home was 55.8%, where 11.9% of children lived with one smoker, while 43.9% of children lived with ≥2 smokers. There was a significant difference in the mean score of the combined cognitive tests between SHS-exposed and non-exposed children after adjustment for sex, parental educational level, family income and academic performance [Pillai's Trace=0.084, F statistic (df)=6.803 (4302), p<0.001].
CONCLUSIONS: More than half of the primary school children in rural Kuala Krai were exposed to SHS from at least one smoker at home. There was a significant association between SHS exposure at home and cognitive performance.