Pharmacological interventions for smoking cessation in Type 2 diabetes: A systematic review with meta-analysis and GRADE evaluation

Aims: To evaluate the efficacy and safety of pharmacological therapies for smoking cessation in individuals with Type 2 Diabetes Mellitus (T2DM) through a systematic review, meta-analysis, and GRADE evaluation. Methods: PubMed and Scopus were searched on 7 June 2024 using relevant keywords. Randomized controlled trials and prospective cohort studies involving adult smokers with T2DM receiving pharmacological treatments for smoking cessation were included. Data were extracted independently by two reviewers. Random-effects meta-analyses were conducted, and the certainty of evidence was assessed using GRADE. Results: Eighteen studies (19 publications) were included. Pharmacotherapy significantly increased continuous abstinence rates at 12 and 24 weeks (p < 0.001), with ORs of 4.17 (95 % CI: 2.71–6.42) and 3.80 (95 % CI: 2.52–5.72), respectively. At 52 weeks, varenicline was more effective than placebo (OR: 2.84, 95 % CI: 1.41–5.69, p = 0.003). Adverse events were more frequent with varenicline, but not significantly (OR: 1.40, 95 % CI: 0.98–1.98, p = 0.06). Conclusions: Varenicline appears effective for smoking cessation in T2DM, with an acceptable tolerability profile. Bupropion and NRT show potential efficacy. However, most evidence comes from post hoc analyses in which diabetes was not a predefined variable, warranting cautious interpretation.