Influence of quitting smoking on diabetes-related complications: A scoping review with a systematic search strategy.

INTRODUCTION: Smoking in people with diabetes markedly elevates their risk of developing complications and increases the likelihood of cardiovascular mortality. This review is the first to specifically provide evidence-based analysis about the influence of quitting smoking on diabetes-related complications in people with type 2 diabetes. METHOD: The present review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews. All human clinical studies assessing the effects of stopping smoking cessation on diabetes-related complications were included. PubMed and Embase were screened until January 2024. References of primary studies and principal peer-reviewed scientific journals in the field were manually screened. RESULTS: We identified a total of 1023 studies. Only 26 met the criteria for eligibility. In general quitting smoking is associated with decreased risks of myocardial infarction and ischemic stroke. Regarding microvascular complications, the strongest evidence for the beneficial effects of smoking cessation is observed in diabetic nephropathy. However, the relationship between smoking cessation and retinopathy, neuropathy, diabetic foot complications and diabetic-related erectile dysfunction, is poorly investigated. CONCLUSION: Quitting smoking offers significant advantages in managing diabetes-related complications, significantly lowering the risks of myocardial infarction, ischemic stroke, and diabetic nephropathy. This underscores the importance of cessation. Providing evidence-based information on the benefits of stopping smoking for people with type 2 diabetes who smoke, can bolster smoking cessation efforts in the context of diabetes management.

A multicenter prospective randomized controlled trial investigating the effects of combustion-free nicotine alternatives on cardiovascular risk factors and metabolic parameters in individuals with type 2 diabetes who smoke: the DiaSmokeFree study protocol.

Stopping smoking is crucial for public health and especially for individuals with diabetes. Combustion-free nicotine alternatives like e-cigarettes and heated tobacco products are increasingly being used as substitutes for conventional cigarettes, contributing to the decline in smoking prevalence. However, there is limited information about the long-term health impact of those products in patients with diabetes. This randomized controlled trial aims to investigate whether switching from conventional cigarettes to combustion-free nicotine alternatives will lead to a measurable improvement in cardiovascular risk factors and metabolic parameters over a period of 2 years in smokers with type 2 diabetes. The multicenter study will be conducted in seven sites across four countries. A total of 576 smokers with type 2 diabetes will be randomly assigned (1:2 ratio) to either standard of care with brief cessation advice (Control Arm) or combustion-free nicotine alternatives use (Intervention Arm). The primary end point is the change in the proportion of patients with metabolic syndrome between baseline and the 2-year follow-up. Additionally, the study will analyze the absolute change in the sum of the individual factors of metabolic syndrome at each study time point. Patient recruitment has started in September 2021 and enrollment is expected to be completed by December 2023. Results will be reported in 2026. This study may provide valuable insights into cardiovascular and metabolic health benefits or risks associated with using combustion-free nicotine alternatives for individuals with type 2 diabetes who are seeking alternatives to tobacco cigarette smoking. The study protocol, informed consent forms, and relevant documents were approved by seven ethical review boards. Study results will be disseminated through articles published in high-quality, peer-reviewed journals and presentations at conferences.

Efficacy and Safety of Varenicline for Smoking Cessation in Patients With Type 2 Diabetes: A Randomized Clinical Trial.

Importance: Evidence of effective smoking cessation interventions in patients with diabetes is limited. The unique behavioral and metabolic characteristics of smokers with type 2 diabetes warrants a randomized clinical trial of the smoking cessation drug varenicline. Objective: To evaluate the efficacy and safety of varenicline in patients with type 2 diabetes with an intention to quit smoking. Design, Setting, and Participants: This multicenter, double-blind, placebo-controlled randomized clinical trial recruited patients from 6 outpatient clinics in 5 hospitals in Catania, Italy. Patients with type 2 diabetes, who were smoking at least 10 cigarettes a day, and who intended to quit smoking were screened for eligibility. Eligible patients were randomized to either varenicline or placebo treatment. The trial consisted of a 12-week treatment phase followed by a 40-week follow-up, nontreatment phase. Intention-to-treat data analysis was performed from December 2020 to April 2021. Interventions: Varenicline, 1 mg, twice daily or matched placebo administered for 12 weeks. Patients in both treatment groups also received smoking cessation counseling. Main Outcomes and Measures: The primary efficacy end point of the study was the continuous abstinence rate (CAR) at weeks 9 to 24. Secondary efficacy end points were the CAR at weeks 9 to 12 and weeks 9 to 52 as well as 7-day point prevalence of abstinence at weeks 12, 24, and 52. Results: A total of 300 patients (mean [SD] age, 57.4 [0.8] years; 117 men [78.0%] in varenicline group and 119 men [79.3%] in placebo group) were randomized to receive varenicline (n = 150) or placebo (n = 150). The CAR at weeks 9 to 24 was significantly higher for the varenicline than placebo group (24.0% vs 6.0%; odds ratio [OR], 4.95; 95% CI, 2.29-10.70; P < .001). The CARs at weeks 9 to 12 (31.3% vs 7.3%; OR, 5.77; 95% CI, 2.85-11.66; P < .001) and weeks 9 to 52 (18.7% vs 5.3%; OR, 4.07; 95% CI, 1.79-9.27; P < .001) as well as the 7-day point prevalence of abstinence at weeks 12, 24, and 52 were also significantly higher for the varenicline vs placebo group. The most frequent adverse events occurring in the varenicline group compared with the placebo group were nausea (41 [27.3%] vs 17 [11.4%]), insomnia (29 [19.4%] vs 19 [12.7%]), abnormal dreams (19 [12.7%] vs 5 [3.4%]), anxiety (17 [11.4%] vs 11 [7.3%]), and irritability (14 [9.4%] vs 8 [5.4%]). Serious adverse events were infrequent in both groups and not treatment-related. Conclusions and Relevance: Results of this trial showed that inclusion of varenicline in a smoking cessation program is efficacious in achieving long-term abstinence without serious adverse events. Varenicline should be routinely used in diabetes education programs to help patients with type 2 diabetes stop smoking. Trial Registration: ClinicalTrials.gov Identifier: NCT01387425.

International randomised controlled trial evaluating metabolic syndrome in type 2 diabetic cigarette smokers following switching to combustion-free nicotine delivery systems: the DIASMOKE protocol.

INTRODUCTION: Reducing exposure to cigarette smoke is an imperative for public health and for patients with diabetes. Increasingly, combustion-free nicotine delivery systems (C-F NDS) such as e-cigarettes and heated tobacco products are substituting conventional cigarettes and accelerating the downward trends in smoking prevalence. However, there is limited information about the long-term health impact in patients with diabetes who use C-F NDS. This randomised trial of type 2 diabetic cigarette smokers will test the hypothesis that following a switch from conventional cigarettes to C-F NDS a measurable improvement in metabolic syndrome (MetS) factors will be shown over the course of 2 years. METHODS AND ANALYSIS: The study is multicentre and thus will take place in five locations in four countries in an ambulatory setting. A total of 576 patients with diabetes will be randomised (1:2 ratio) to either a control arm (Study Arm A), in which they will be offered referral to smoking cessation programmes or to an intervention arm (Study Arm B) assigned to C-F NDS use. Participants will be at least 23 years old and of any gender. Patient recruitment will start in February 2021 and is expected to be completed by December 2021. Primary outcome measures include fasting plasma glucose, blood pressure, triglycerides, high-density lipoprotein and waist circumference, while secondary feature absolute change in the sum of the individual factors of MetS and change in each individual factor of MetS measured at each study time point. ETHICS AND DISSEMINATION: The approval of research ethics committee (REC) regarding the trial protocol, informed consent forms and other relevant documents is required to commence the study. Substantial amendments to the study protocol cannot be implemented until the REC grants a favourable opinion. The results of the study are intended to be published as articles in high quality peer-reviewed journals and disseminated through conference papers. TRIAL REGISTRATION NUMBER: NCT04231838. Pre-results stage.