Objective: To determine the prevalence of risks habits, GSTM1 null genotype and oral mucosal lesions in Orang Asli populations and to investigate the correlation of the risk habits and GSTM1 null genotype.
Methods: Sociodemographic information was collected from 242 Orang Asli subjects via structured interview. Of the sample, 146 subjects had their mouth examined. Cells of buccal mucosa were collected using cytobrush and DNAs were extracted from 98 subjects. GSTM1 polymorphism was analysed using multiplex PCR.
Results: The prevalence of smoking in this population was 55.0%, alcohol drinking 4.2% and betel quid chewing 21.4%. Oral lesion/conditions namely leukoplakia, chewer's mucosa, lichen planus and oral submucous fibrosis were found in 8.8% with all of them indulging in risk habits. The overall prevalence of GSTM1 null genotype was 32.7%. Among subjects without risk habits, 21.1% (8/38) had GSTM1 null genotype while among subjects with risks habits the prevalence was 40.0% (24/60). Among those with risk habits, 47.8% (11/23) of quid chewers have GSTM1 null genotype as compared to 26.4% (19/72) of subjects who do not chew. These relationships were statistically significant [habits vs no habit (p = 0.051); quid chewers vs non quid chewers (p = 0.054)].
Conclusions: Smoking was the most common risk habits in the study population. The prevalence of GSTM1 null genotype was higher in those with risk habits especially those who chew betel quid.