Exposure to second-hand smoke among secondary school-going adolescents: Findings from the Malaysian Adolescent Health Risk Behaviour (MyAHRB) study

Background:

Exposure to second-hand smoke (SHS) is one of the main causes of morbidity and it has been proven to be associated with an increased likelihood of smoking initiation among adolescents. Nonetheless, evidence on SHS exposure among Malaysian adolescents is scarce. Therefore, this article aims to demonstrate the magnitude and factors associated with SHS exposure among school-going adolescents in selected secondary schools in Peninsular Malaysia.

Methods:

Data were derived from the Malaysian Adolescent Health Risk Behaviour (MyAHRB) study conducted in 2013. A total of 2599 adolescent were recruited into the study using a two-stage proportionate-to-size sampling method. Data were obtained from self-administered questionnaires. Descriptive analysis and multivariable logistic regression were performed to determine the risk factors/predictors associated with SHS.

Results:

More than half of the respondents had been exposed to SHS during the last one week (56.4%), and SHS exposure was significantly higher among respondents who smoked (94.0% vs. 49.9%, p <0.001). Multivariable analysis revealed that the likelihood of exposure to SHS was higher among those who smoked (adjusted odds ratio (aOR) 12.90, 95% confidence interval (CI): 8.01–20.4), had at least one parent/guardian who smoked (aOR 5.49, 95% CI: 4.41–6.94) and adolescents of Malay descent (aOR 2.10, 95% CI: 1.68–2.63).

Conclusion:

Our findings suggested that the effectiveness of anti-smoking measures implemented in recent years to protect adolescents from the health risks of passive smoking were less evident. Therefore, educational and awareness programmes that emphasize the negative health impacts of SHS exposure on Malaysian adolescents, particularly when among smoking adults, should be intensified to help in preventing adoption of smoking behaviours among adolescents.

Histological maturity of healed duodenal ulcers and ulcer recurrence after treatment with colloidal bismuth subcitrate or cimetidine

The relationship between histological maturity of healed duodenal ulcers and ulcer recurrence after 6 weeks of treatment with colloidal bismuth subcitrate or cimetidine was investigated. There was no significant difference in healing rates between colloidal bismuth subcitrate- and cimetidine-treated patients (85.7% and 71.8%, respectively; P greater than 0.05). Histologically, the regenerating mucosa of healed ulcers was divided into three categories--good, fair, and poor--according to pattern. Sixty percent of healed colloidal bismuth subcitrate-treated and 30.9% of healed cimetidine-treated ulcers had a good pattern; the difference was statistically significant (P = 0.027). The difference in recurrence rates between healed colloidal bismuth subcitrate-treated and healed cimetidine-treated patients was statistically significant at 3 months (3.45% and 20%, respectively; P = 0.044). All recurrent ulcers in both groups had fair or poor patterns of regenerating mucosa. It was concluded that the greater histological maturity of the regenerating mucosa may contribute to the lower recurrence rate in colloidal bismuth subcitrate-treated patients than in cimetidine-treated patients.

In vivo cell kinetics studies of the duodenum during and after healing of cysteamine-induced duodenal ulcer in rats using bromodeoxyuridine incorporation

The present study investigated the defect of duodenal defence responsible for the tendency of recurrence of duodenal ulcer. Male Wistar rats were treated with cysteamine-HCl subcutaneously to induce duodenal ulcer, and bromodeoxyuridine (BrdU) was given intraperitoneally 1 h before laparotomy. Serial tissue sections and immunocytochemical staining of BrdU were done to study the cell kinetics during and after healing. Deep ulcers developed in the proximal part of the duodenum 24 h after cysteamine injection, and the ulcer was replaced by scar tissue 1 week later. BrdU-labelling index of normal duodenal mucosa in control rats was 30-34%. On the peripheral part of the regenerative mucosa, BrdU-labelling index increased from 1.5% to 26-27%, 1-4 weeks after injection and remained at this level thereafter. On the central part, except the most central area, the labelling index remained at 0% until 3 weeks, and was 15% 6 weeks after cysteamine treatment. It never achieved the level seen in control normal mucosa. The labelling rate of fibrous cells in scar tissue decreased from 28% to nearly 0% 1-4 weeks after the injection. It is concluded that both the ulcer scar and the regenerative mucosa do not achieve a mature state in the initial scarred stage; they need more time to reach a relatively mature condition. Moreover, the regenerative mucosa will be the weak, easily damaged part of the duodenum.