Smokeless Tobacco as a Risk Factor for Type 2 Diabetes Mellitus in South East Asia Region: Systematic Review and Meta-Analysis

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder of which prevalence has been increasing steadily all over the world. There is a need of understanding the role of tobacco products in diabetes mellitus, especially smokeless tobacco (ST) products. OBJECTIVE: To analyze if ST is a determinant for T2DM among patients in South East Asia Region (SEAR) and secondly to obtain the pooled prevalence of use of ST in T2DM patients/participants from these studies. MATERIALS AND METHODS: PubMed, Google Scholar, EBSCO, and Scopus are the databases that were searched to find desired manuscripts, which fulfilled the inclusion criteria to undertake this systematic review and meta-analysis (SRMA). Meta-analysis was carried out to determine the pooled effect size for the odds ratio of ST use in T2DM with 95% CI. MedCalc statistical software was used followed by the DerSimonian and Laird method under the random effect model. RESULTS: A total of 8 manuscripts were involved in the systematic review and 7 in the meta-analysis. Odds of 1.39 indicating increased frequency of using ST among T2DM patients or survey participants was observed, which was not significant with C.I. 95% (0.843–2.288) and P < 0.001 with high heterogeneity. The pooled prevalence of use of ST in T2DM is 24.08% (CI 15.67 to 33.64) under random effect model with I(2) inconsistency of 97.16% in 8 studies from India and Bangladesh. CONCLUSION: This pooled analysis shows that ST use is not a risk factor for T2DM. The number of studies included in the SRMA from SEAR is limited having no representation from Myanmar, Bhutan, Timor Leste, and Sri Lanka.