Addressing the dual challenge: Managing smoking cessation in patients with diabetes

Abstract

Smoking increases complications and mortality in people with diabetes. Quitting delivers major benefits, but physiological (weight gain, insulin sensitivity shifts) and psychological barriers make cessation harder in this group. Our review article examined strategies tailored to people with diabetes. All smokers with diabetes should receive clear, personalized advice to quit, embedded in routine care. Among the available medications, varenicline has the strongest evidence in this population. Nicotine replacement therapy and bupropion may help but have limited diabetes-specific data, so they should be used with caution. Tobacco harm reduction (e-cigarettes, heated tobacco products) may facilitate switching away from combustible cigarettes and reduce exposure, although the long-term safety and efficacy in diabetes remain uncertain. Glucagon-like peptide-1 receptor agonists can aid weight and glycemic control and may indirectly support cessation. Digital tools (apps, wearables, and remote monitoring) offer real-time support and adherence tracking, although diabetes-specific effectiveness is still being established. Smoking cessation in people with diabetes requires urgent attention. Evidence-based interventions should be integrated into routine care, with particular attention given to early monitoring of glucose, body weight, and blood pressure after quitting, plus structured follow-up. More research should develop and test tailored, long-term strategies for this high-risk group, including pragmatic trials integrating harm reduction and digital support.

Key Words: Diabetes; Smoking cessation; Harm reduction; Glucagon-like peptide 1 analogues; Digital health technologies; Wearable sensors

Core Tip: This expert review addresses the dual challenge of smoking cessation in patients with type 2 diabetes - a high‐risk group experiencing synergistic vascular damage from chronic hyperglycemia and tobacco smoke toxicants. It underscores the evidence for (and limitations of) standard smoking cessation medications (i.e., nicotine replacement therapy, bupropion, and varenicline) while introducing emerging harm reduction strategies (i.e., e-cigarettes and heated tobacco products) and cutting-edge innovations (i.e., glucagon-like peptide-1 analogues and digital health tools). Adopting a holistic, patient-centered approach is crucial for improving the lives of people with diabetes who smoke, but further research to enhance long‐term cessation success and improve metabolic outcomes will be necessary.

INTRODUCTION

Diabetes is a chronic, metabolic disease characterized by elevated levels of blood glucose, which leads to severe damage to the heart, blood vessels, eyes, kidneys and nerves over time. It has become a major global health concern, with its prevalence rising dramatically over the past few decades. In 2022, an estimated 828 million adults worldwide were living with diabetes, marking a staggering increase of 630 million cases since 1990[1]. This rapid growth is driven by multiple factors, including population aging, urbanization, sedentary lifestyles, and rising obesity rates.

Smoking, in particular, poses a serious additional risk for people with diabetes. Globally, tobacco use affects 1.3 billion people and causes more than 7 million deaths annually from smoking-related diseases[2,3]. Smoking is a key driver of lung cancer, chronic obstructive pulmonary disease, and cardiovascular disease[4]. It also contributes to the onset of diabetes and worsens its complications[5-7]. Furthermore, in individuals with diabetes, smoking amplifies the harmful effects of elevated blood glucose levels, accelerating vascular damage[8,9].

While global age-standardized smoking prevalence among the general population declined significantly from 1990 to 2019[10], smoking prevalence among individuals with diabetes has not shown comparable reductions over the same period[11,12].

Smoking exacerbates health risks for individuals with diabetes, significantly increasing the likelihood of severe complications, including macrovascular and microvascular damage, and results in higher overall mortality rates than nonsmoking people with diabetes[6,13,14]. These complications place a heavy burden on healthcare systems, diminish productivity, and incur considerable economic costs[15,16].

At the organ and tissue level, smoking contributes to endothelial dysfunction, inflammation, and thrombosis, accelerating the progression of atherosclerosis, which is a major concern in diabetes[17]. Additionally, smoking negatively impacts glycemic control in diabetic patients. The combined effects of hyperglycemia and smoking-induced oxidative stress increase the risk of diabetes complications[7]. At the cellular level, tobacco exposure promotes insulin resistance by increasing oxidative stress and the production of inflammatory cytokines (e.g., tumor necrosis factor-α and interleukin-6)[18]. These inflammatory mediators interfere with insulin signaling, reducing glucose uptake in peripheral tissues. Dinardo et al[19] identified smoking as an independent factor for elevated glycated hemoglobin A1c (HbA1c) levels, while. Braffett et al[20] reported that HbA1c levels were 0.31% higher in people who smoke than in never smokers, with a further 0.22% increase in those with more than 10 pack-years of smoking vs less than 10 pack-years. Studies in animal models have shown that, at the molecular level, exposure to cigarette smoke can disrupt insulin production, processing, and secretion while also reducing β-cell viability and proliferation. These effects are linked to increased oxidative stress, endoplasmic reticulum stress, and ceramide accumulation[21], which may contribute to pancreatic dysfunction and the progression of diabetes.

Conversely, although the effects of smoking cessation on glycemic control, insulin resistance, and lipid parameters remain unclear[22], cessation has been shown to significantly reduce the risk of cardiovascular events, including myocardial infarction, ischemic stroke, and diabetic nephropathy[7,14,23].

Patients with type 2 diabetes who smoke may present a distinct clinical phenotype characterized by the combined harmful vascular effects of chronic hyperglycemia and toxicants from cigarette smoke, as well as adverse impacts on glycemic control and lipid profiles. These factors jointly accelerate vascular damage. Thus, while reducing exposure to cigarette smoke is a public health priority for everyone, it is especially critical for individuals with type 2 diabetes[24]. The latest American Diabetes Association guidelines emphasize that smoking cessation is an essential component of diabetes management, recognizing this high-risk phenotype with significant clinical, prognostic, and therapeutic implications[25].

A multidisciplinary approach is therefore vital, integrating behavioral counseling and pharmacological support. In addition, emerging strategies, such as novel pharmacotherapies and alternative nicotine delivery systems, offer potential harm-reduction approaches to aid cessation. Given the unique risks faced by this population when quitting smoking, this review highlights key health considerations and underscores the importance of individualized care strategies. Drawing on current evidence and clinical expertise, we propose a comprehensive framework to assist clinicians in addressing this pressing health challenge.

In view of the limited data on the health impacts of smoking cessation and complete cigarette substitution with combustion-free nicotine alternatives in individuals with diabetes, we conducted an expert review of available human studies on current and novel strategies to aid cessation in this vulnerable population. The primary goal of this review is to provide clinicians with up-to-date evidence on the potential health effects of stopping smoking and substituting conventional cigarettes with e-cigarettes (ECs) or heated tobacco products (HTPs) in the context of diabetes management, specifically examining how these products may influence glycemic control, lipid profiles, postcessation weight management, and vascular health. This evidence is intended to inform clinical recommendations and management strategies. A secondary objective is to improve health literacy among patients with type 2 diabetes, especially those considering or currently using potentially harm-reducing nicotine products, by clarifying how these alternatives might affect the metabolic and vascular outcomes that are critical to their health.

LITERATURE REVIEW

Although the article was conceptualized as an expert review, we applied the rigorous methodology of systematic review. Therefore, from October to November 2024, we conducted a thorough search of published English literature from the following databases: PubMed, EMBASE, Web of Science, and Scopus. A combination of keywords and Medical Subject Headings terms included “smoking cessation” AND “diabetes”, “tobacco use” AND “type 2 diabetes”, “nicotine replacement therapy” AND “diabetes”, “e-cigarettes” OR “electronic cigarettes” AND “diabetes”, “GLP-1 analogues” AND “smoking”, “digital health” AND “smoking cessation” AND “diabetes”, “weight gain after quitting smoking” AND “diabetes”, “glycemic control” AND “smoking cessation”. Additional search strings included terms such as “vaping”, “vape*”, “Alternative Nicotine Delivery Systems”, “Heated Tobacco Products”, and specific product names such as “IQOS”, “glo”, and “PLOOM”. The search was filtered to include only human studies published after January 2000. Exclusion criteria included studies involving adolescents or pregnant individuals and articles without full-text availability. Titles, abstracts, and full texts were sequentially screened by our team of reviewers independently, with any disagreements resolved through consensus. Several types of studies were identified, including cross-sectional, case-control, and cohort studies; randomized clinical trials; observational clinical studies; and systematic reviews and meta-analyses. Relevant studies were included in the expert review.

Considering the variety of interpretations and outcomes in the available clinical studies, this review does not aim to conclusively determine the positive or negative health impact of one intervention over the other in patients with diabetes. Instead, this article highlights the current gaps in the scientific literature and emphasizes the need for high-quality, controlled research to assess the long-term effects of smoking cessation and harm reduction on individuals with type 2 diabetes, especially in relation to vascular health, glycemic control, and lipid metabolism.

MANAGEMENT OF THE PATIENT WITH DIABETES WHO SMOKES

Health care providers, including diabetologists and endocrinologists, play a pivotal role in educating patients with diabetes about the heightened risks associated with smoking and actively supporting smoking cessation efforts. However, the addictive nature of tobacco smoking poses significant challenges, often requiring multiple attempts and extended treatment to achieve sustained abstinence. This difficulty is compounded by behavioral and psychological factors, such as stress, environmental triggers, and ingrained habits, which intensify over time and increase the risk of relapse[26]. Smoking relapse is particularly common among people with depression[27], a condition commonly associated with diabetes[28,29].

For many individuals with diabetes, smoking is perceived as a coping mechanism to manage weight, boredom, anxiety, depression, and stress, including stress specific to their condition[30,31], thereby contributing to the challenges associated with behavioral and psychological factors. Alarmingly, people with diabetes commonly fail to recognize the detrimental impact of smoking on their diabetes management and overall health[32,33]. These misconceptions contribute to the consistently low cessation rates observed within this population[34]. Addressing these barriers requires tailored interventions that acknowledge and address this interplay of psychological and behavioral challenges, coupled with comprehensive education to correct misconceptions.

Individuals with diabetes often struggle with chronic stress related to the daily management of their condition, monitoring blood glucose levels, adhering to dietary restrictions, and taking medications regularly[35]. This chronic stress can lead to increased levels of anxiety and depression, which can significantly hinder attempts to quit smoking. The stress associated with chronic illness, health concerns, and the need to follow strict guidelines can lead a person to seek relief by smoking and treating cigarettes to temporarily alleviate tension[36]. Diabetes, especially its chronic complications, can be associated with feelings of hopelessness and anxiety about the future, as well as concerns about deteriorating health. These emotions can lead to decreased motivation to take health-promoting actions, including quitting smoking.

The increased risk of failure in smoking cessation among individuals with chronic illnesses such as diabetes has been well documented in research[37,38]. People with diabetes may face greater challenges in quitting smoking, not only because of nicotine addiction but also because of psychological defense mechanisms that contribute to avoiding this issue. These mechanisms, such as denial, projection, or reversal, can prevent individuals from fully addressing their smoking habit[39]. These psychological factors can lead to a cycle of failed attempts at quitting, increasing feelings of frustration and hopelessness, which, in turn, reinforce the reliance on smoking as a coping mechanism.

Social stigmatization is a process in which individuals are perceived or treated negatively by others on the basis of traits or behaviors that are considered “different” or “unacceptable” in society. On average, four out of five adults with diabetes experience diabetes-related stigma, and one in five experiences discrimination (i.e., unfair and harmful treatment) due to diabetes, such as in healthcare, education, and employment[40]. Disease-related stigma can lead to many negative emotions, such as shame, guilt, and social isolation. The stigma of diabetes is associated with depressive and anxiety symptoms, as well as decreased overall emotional well-being[40]. For many individuals with diabetes, smoking may help them escape these difficult emotions. Smoking can serve as a form of “hidden” coping with anxiety, shame, or feelings of rejection. Nicotine affects the nervous system, providing a temporary sense of relief or relaxation. In this case, smoking becomes a mechanism that creates the illusion of control over emotions, although in reality, it worsens health and exacerbates problems related to diabetes. Individuals experiencing stigmatization may also avoid participating in smoking cessation therapy programs. They often fear being perceived as “worse” or “weaker” in the context of their health problems. They may feel ashamed of their lack of success in quitting smoking, leading to the avoidance of further support. To effectively support individuals with diabetes in the smoking cessation process, it is essential to address the psychological and emotional barriers related to stigma.

People with diabetes, especially those with lower income levels, may have difficulty accessing regular medical care or support for tobacco addiction treatment. In some cases, the lack of adequate health insurance or geographical distance from specialized medical centers can limit access to therapies. Nicotine addiction treatment programs, such as behavioral therapies, smoking cessation medications (e.g., nicotine replacement therapy or pharmacotherapy), and psychological support sessions or support groups, may be out of reach for individuals who lack the necessary financial resources.

Healthcare professionals can utilize structured frameworks to guide smoking cessation interventions effectively. One such model is the 5-A method (ask, advice, assess, assist, and arrange) framework, which involves five key steps: Ask about tobacco use, advise quitting, assess the willingness to quit, assist in providing support and resources, and arrange for follow-up. This approach helps healthcare professionals deliver comprehensive, personalized support to patients seeking to quit smoking.

Systematically identifying all patients who smoke during every clinical visit is crucial (ask). All identified smokers with diabetes should be encouraged to quit through clear and personalized advice. For example, “By quitting, you will not only enhance your overall health but also reduce the complications associated with diabetes. Did you know that?” (advice). Physicians should assess each patient’s readiness to make a serious quit attempt (assess). For patients unwilling to quit, a brief intervention aimed at increasing their motivation for future quit attempts should be provided. It is often more effective to wait until these patients feel ready and confident in their ability to quit rather than pressuring them prematurely. Smoking reduction can be a practical interim strategy to encourage eventual abstinence among smokers who are not prepared to make a quit attempt. Alternatively, physicians can suggest switching to less harmful nicotine products, such as ECs or HTPs, as a harm-reduction approach. Emerging options such as glucagon-like peptide-1 (GLP-1) analogues, digital health technologies, and wearable sensors may also support these patients. For patients ready to quit, physicians should promptly engage them in developing a tailored cessation plan (assist). This personalized plan should include setting a realistic quit date and identifying strategies to address nicotine addiction effectively. Such strategies may involve pharmacotherapy designed to manage common withdrawal symptoms such as cravings, irritability, anxiety, restlessness, depressed mood, and increased appetite, all of which are significant risk factors for relapse. Combining pharmacotherapy with intensive behavioral cessation support sessions has been shown to significantly increase abstinence rates among individuals with diabetes[41]. Additionally, addressing common concerns such as potential weight gain, poor glycemic control, and elevated blood pressure should be an integral part of the personalized plan. Providing patients with proactive strategies to manage these challenges can enhance their confidence and adherence to the cessation process, ultimately increasing the likelihood of sustained success. Regular follow-ups are essential to monitor progress and reinforce commitment (arrange). For patients facing more significant challenges, referral to specialized cessation centers should be considered. This structured, stepwise approach not only increases the likelihood of successful cessation but also ensures comprehensive support tailored to the unique needs of diabetic smokers. An algorithm for assisting patients with diabetes to quit smoking is provided in Figure 1.

Figure 1 A five-step algorithm for assisting people with diabetes who smoke. This flowchart outlines the decision-making process for addressing smoking cessation, relapse, and harm reduction in people with diabetes. It begins by identifying smoking behavior and progresses to personalized advice and interventions on the basis of the individual’s smoking status and preferences. A nonjudgmental, supportive approach is emphasized, focusing on the benefits of cessation, including reduced cardiovascular risk, improved glycemic control, and slower progression of diabetes complications such as nephropathy. Key steps include assessing readiness to quit and addressing concerns about cessation therapies, alternative nicotine products (e.g., e-cigarettes), weight gain, and stress management. For patients ready to quit, the framework advocates a quit plan combining psychological counseling with pharmacological support, adjusting antidiabetic medications, and incorporating weight management strategies such as exercise or glucagon-like peptide-1 receptor agonists. For patients who relapse, the framework recommends re-engagement with renewed support and referral to specialized cessation services when needed. For those not ready to quit, maintaining open dialogue, offering harm-reduction strategies (e.g., e-cigarettes), and preparing for future cessation support are emphasized. CV: Cardiovascular; HTP: Heated tobacco product; ONP: Oral nicotine pouches; CO: Carbon monoxide; GLP-1: Glucagon-like peptide-1.

In the general population, smoking cessation rates can be doubled or tripled when smoking cessation counseling is combined with pharmaceutical interventions such as varenicline[42], bupropion[43], nicotine replacement therapy[44], and cytisine[45]. However, the efficacy and tolerability of these treatments in individuals with diabetes remain insufficiently studied, with some interventions, such as cytisine, lacking efficacy data specific to diabetic populations.

For patients with diabetes, only a moderate recommendation can be made for nicotine replacement therapy and bupropion due to limited evidence, with much of the supporting data derived from a single study[46], thereby reducing confidence in the reproducibility of the results. Conversely, robust evidence supports the use of varenicline as a smoking cessation aid in individuals with diabetes. Findings from three key studies[47-49] demonstrated that varenicline at least triples the likelihood of sustained abstinence during the critical early phase of cessation, when the risk of relapse is highest[50,51]. The commonly reported side effects of varenicline, including nausea and abnormal dreams, align with observations in the general population and are generally mild, rarely leading to treatment discontinuation[42]. This finding suggests that varenicline is a particularly promising intervention for people with diabetes seeking to quit smoking.

The presence of polycyclic aromatic hydrocarbons in cigarette smoke has been shown to affect the metabolism of antidiabetic drugs by altering the activity of critical biotransformation enzymes via cytochrome P450 1A1/1A2/1B1 induction and uridine diphosphate glucuronosyltransferase detoxification activity[52,53]. This necessitates vigilant patient monitoring and, where appropriate, dosage adjustments for both active smokers and those in the process of quitting to ensure optimal pharmacotherapy[54].

Generally, smoking cessation treatments exhibit no clinically significant interactions with antidiabetic medications[54]. However, certain safety considerations must be taken into account when these treatments are prescribed. Caution should be used with nicotine replacement therapy in patients with acute cardiovascular events, such as recent myocardial infarction, serious cardiac arrhythmias, worsening or unstable angina pectoris, or accelerated hypertension. Bupropion is contraindicated in patients with a seizure disorder, a current or prior diagnosis of anorexia nervosa or bulimia, or those undergoing abrupt discontinuation of benzodiazepines, barbiturates, or antiepileptic drugs. Varenicline should be avoided in patients with a history of psychiatric illness, epilepsy, or a predisposition to seizures. Careful patient assessment, tailored treatment plans, close monitoring, and clear communication with patients are essential to minimize risks and optimize smoking cessation outcomes.

EMERGING ALTERNATIVE STRATEGIES

Further personalized approaches to smoking cessation may provide a viable solution for individuals who face challenges with conventional methods.

GLP-1 analogues

In recent decades, significant progress has been made in the development of pharmacological treatments for diabetes. Among the most notable innovations are the use of GLP-1 receptor agonists and sodium-glucose cotransporter 2 inhibitors. These medications not only improve glycemic control but also provide additional benefits, including cardiovascular and renal protection. For individuals with diabetes, who are often at high risk for complications such as heart disease and kidney dysfunction, these treatments offer a promising approach to reduce overall morbidity and improve long-term health outcomes.

Emerging evidence suggests that GLP-1 analogues may play a role in addiction physiology, appetite regulation, and weight control[55,56]. Experimental studies in mice have shown that the GLP-1 analogue exenatide can abolish nicotine reward and reduce nicotine intake[56]. In humans, a preliminary study evaluating extended-release exenatide combined with a nicotine patch in individuals with prediabetes and/or overweight demonstrated higher smoking abstinence rates at six weeks compared to placebo (46.3% vs 26.8%)[57]. Additionally, abstainers in the exenatide group experienced reductions in cravings, withdrawal symptoms, and weight gain. However, findings from a larger randomized, double-blind, placebo-controlled trial of the GLP-1 analogue dulaglutide revealed no significant effect on smoking abstinence rates[58]. The interpretability of this trial is limited due to coadministration with varenicline, which likely enhanced efficacy in the control group. Additionally, very few participants had diabetes. One notable limitation of GLP-1 analogues is their temporary impact on postcessation weight gain, with a high rate of weight regain observed after discontinuation of the medication[59]. These findings underscore the need for further research to evaluate the utility of GLP-1 analogues in smoking cessation, particularly in diabetic populations, where weight management and sustained abstinence are critical.

Inhaled nicotine

Nicotine substitution products, such as ECs, which vaporize a solution typically containing propylene glycol and/or vegetable glycerin with nicotine and flavors, have gained popularity as a smoking cessation tool. While not entirely risk-free, ECs expose users to significantly fewer harmful substances than do conventional tobacco cigarettes[60-62]. Chronic smokers who switch to ECs have demonstrated early improvements in blood pressure, heart rate, and myocardial and vascular function[63,64]. Whether these changes are sustained in the longer term is unclear. Regulatory agencies, including the United States Food and Drug Administration, have authorized ECs as harm reduction options for individuals unable or unwilling to quit smoking through other means[65]. Similarly, the United Kingdom’s National Institute for Health and Care Excellence recognized that switching to nicotine-containing ECs is likely far less harmful than continued smoking and should be included in cessation interventions[66]. A recent Cochrane review further underscored the efficacy of ECs, suggesting that they are more effective than nicotine replacement therapy and bupropion in stopping smoking[67]. HTPs and oral nicotine products, resembling oral nicotine replacement therapies, are also designed to deliver nicotine without combustion. In an initial open-label, actual-use study of nicotine pouches, self-reported 7-day smoking cessation rates of 27% were reported after one week of product trial followed by six weeks of use[68]. However, clinical evidence supporting the use of combustion-free nicotine products specifically for smoking cessation in diabetic populations is lacking. In a large global internet-based survey of EC users, 574 respondents with diabetes were included, with 40.1% reporting improvements in their condition after switching to ECs[69]. This underscores the urgent need for more rigorous research to confirm these observations and guide healthcare providers in counseling patients with diabetes who are using or considering the use of ECs.

Combination therapy

Compared with monotherapy, combining smoking cessation treatments has demonstrated incremental benefits in the general population. Specifically, the combination of varenicline with ECs has shown promising results in randomized controlled trials (RCTs). One RCT assessed the combination of ECs, which provide rapid nicotine delivery, with varenicline, which provides basal partial agonism of nicotinic acetylcholine receptors[70]. This combination trended toward greater efficacy than did varenicline alone, with a 43% lower hazard of relapse in the combination group. Similarly, another RCT focusing on individuals who dual-used conventional tobacco cigarettes and ECs reported that adding varenicline significantly increased continuous smoking abstinence rates between week 4 and week 24 (49% vs 14% for placebo)[71]. Interestingly, EC e-liquid consumption increased in the varenicline group but not in the placebo group, suggesting a synergistic interaction between ECs and varenicline. These findings highlight the potential of combination therapy as a more effective approach for smoking cessation, particularly for individuals struggling with monotherapy. However, further research is needed to confirm these benefits and optimize treatment protocols.

Digital and mobile health technologies

While pharmacologic approaches remain valuable in smoking cessation, complementary digital and mobile health technologies provide innovative solutions for smoking detection and cessation. Examples include smartphone cessation apps, portable carbon monoxide monitors, and wearable technologies, which leverage real-time data and personalized feedback to support users. These technologies, combined with advancements in wearable sensors, machine learning models, and smartphone applications, have demonstrated significant promise for smoking detection and cessation. By providing real-time feedback and personalized support, digital health solutions have the potential to increase user motivation and adherence, ultimately improving quit rates[72-74]. Furthermore, integrating remote carbon monoxide monitoring into smoking cessation programs may parallel the success of remote glucose monitoring in diabetes care. Tools such as the SmokeBeat app, SmokeWatch, and Pivot provide real-time feedback and personalized support, significantly assisting in smoking abstinence by increasing awareness, counteracting habitual behaviors, and fostering adherence[75,76]. These approaches are particularly advantageous in optimizing the limited time and resources available to physicians during office visits while extending their reach to patients’ homes through continuous monitoring, 365 days a year. Despite these advancements, evidence on the effectiveness of digital and mobile health technologies specifically for smoking cessation among patients with diabetes remains limited, warranting further research to explore their potential in this population.

HEALTH CONCERNS FOR PATIENTS WITH DIABETES QUITTING SMOKING

When individuals with diabetes decide to quit smoking, they may encounter specific health challenges that require careful attention. Increased appetite, weight gain, fluctuations in glucose levels, poor glycemic control, and elevated blood pressure can complicate diabetes management. To address these concerns effectively, it is essential for individuals with diabetes to collaborate with healthcare professionals to develop a comprehensive quitting strategy that addresses their specific health concerns and optimizes diabetes management.

Weight gain

Quitting smoking often leads to weight gain, which can be particularly challenging for individuals who smoke as a strategy for weight control, particularly for those concerned about weight gain. This is a significant concern for many people with type 2 diabetes, as they are often overweight or obese[77], which results in a proatherogenic metabolic profile that is associated with increased cardiovascular risk and all-cause mortality. Weight gain following smoking cessation is common among people with diabetes and significantly greater than that in comparable nondiabetic individuals[78,79]. Weight gain is a cause of concern for many individuals with diabetes[30,31], because it is associated with increased cardiovascular risk and all-cause mortality[79,80]. For example, while quitters without weight gain exhibit a significantly reduced risk of cardiovascular disease compared with people who smoke (hazard ratio = 0.77, 95% confidence interval: 0.62-0.95), this benefit is nullified in those who gain more than 5 kg (hazard ratio = 0.99; 95% confidence interval: 0.70-1.41)[79]. The analysis of weight change from the varenicline clinical trials of Tonstad and Lawrence[47] and Russo et al[49] provides important additional insight into the broader implications of smoking cessation for individuals with diabetes. Specifically, both studies suggest that varenicline may help prevent significant postcessation weight gain, offering reassurance to clinicians and patients that the metabolic and cardiovascular benefits of quitting are not undermined.

Glycemic control

Postcessation weight gain and the resulting increase in insulin resistance can also raise concerns about glycemic control[81,82]. A United Kingdom-based retrospective cohort study of 10692 adults with type 2 diabetes reported a modest (0.21%) increase in HbA1c levels among individuals who quit smoking and remained abstinent for at least one year, with HbA1c levels returning to baseline after prolonged abstinence[83]. Conversely, studies in Asiatic populations suggest that quitting smoking is associated with a gradual improvement in glycemic control, although the observed differences in HbA1c rarely exceed 0.5%[84,85]. The overall impact of smoking cessation on glycemic control in people with diabetes is unpredictable, emphasizing the need for careful monitoring and potential therapeutic adjustments.

Arterial hypertension

Hypertension is prevalent among individuals with diabetes and is a critical component of comprehensive care[86]. However, the interaction between smoking cessation and blood pressure is complex and not fully understood[87]. Recent studies suggest a reduced risk of hypertension following smoking cessation[88], whereas older research indicates the opposite[89]. Similar discrepancies have been reported when comparing cross-sectional with prospective studies. For example, a Spanish nationwide cross-sectional study revealed no significant difference in blood pressure between smokers and ex-smokers with type 2 diabetes[90]. However, a one-year prospective study revealed better blood pressure control among quitters than among those who continued smoking, despite modest weight gain[91]. Given these discrepancies, the impact of smoking cessation on blood pressure in people with diabetes remains unclear. However, the avoidance of tobacco-related toxicants and their impacts on longer-term endothelial function and vascular stiffness are unequivocally beneficial. Postcessation weight gain may act as an important confounder, necessitating a precautionary approach that includes careful blood pressure monitoring throughout the cessation process. Future studies are needed to clarify these interactions and guide best practices for managing blood pressure in diabetic patients during smoking cessation.

SUPPLEMENTAL CLINICAL GUIDANCE

Unpleasant surprises can undermine smoking cessation efforts, so it is essential to prepare patients with knowledge of what to expect. Healthcare providers should discuss potential withdrawal symptoms, emphasizing that while some individuals may experience no symptoms, others may experience several. The severity and duration of withdrawal symptoms vary greatly between individuals; most people find that symptoms peak within the first few days and subside within 2 weeks to 4 weeks. Additionally, patients should be informed that smoking cessation may temporarily affect glycemic control and advised about the importance of more frequent glucose monitoring and the possibility of requiring therapeutic adjustments in the initial months after quitting smoking[75]. For individuals experiencing glycemic instability, a temporary increase in antidiabetic medication may be necessary to maintain control. Equipping patients with this knowledge and providing proactive strategies to manage withdrawal symptoms and glycemic changes can significantly improve their chances of successful smoking cessation.

In clinical practice, identifying risk factors that predict relapse is essential for tailoring smoking cessation interventions; this can help identify individuals who may benefit from more comprehensive support or emerging alternative strategies to sustain motivation and prevent relapse[65]. Common predictors of failure include an early age of smoking onset, short duration of prior quit attempts, coexisting depression, a high degree of nicotine dependence, alcohol-related problems, and a lack of sustained motivation[92]. While these predictors have been well documented in the general population, they have not been specifically studied in people with diabetes.

CONCLUSION

Smoking cessation for individuals with diabetes demands a critical and urgent solution because of the heightened health risks posed by these coexisting conditions. The complex relationships among smoking, cardiovascular risk, weight management, and glycemic control require a multifaceted and personalized approach.

Evidence-based strategies, such as behavioral counseling and smoking cessation medications, should be routinely offered to people with diabetes as part of their diabetes care. While varenicline has demonstrated robust efficacy in diabetic populations, the limited number of high-quality trials underscores the need for further research to evaluate its long-term safety and effectiveness.

Diabetes education programs must be strengthened to provide healthcare professionals with the skills and knowledge needed to maximize their patients’ chances of successfully quitting smoking. These programs should focus on addressing the unique challenges faced by diabetic smokers, including weight gain, psychological stress, and misconceptions about smoking’s impact on diabetes management.

There remains a significant unmet need for effective alternative options for patients with diabetes who struggle to quit smoking or are not yet ready to attempt cessation. While complete cessation is the ideal outcome, it may not always be the optimal goal if it leads to failure or relapse. Physicians should explore all available pathways and tailor interventions to reduce exposure to combustible cigarettes and increase the likelihood of sustained abstinence. Emerging strategies include tobacco harm reduction approaches (i.e., ECs and HTPs) as well as the use of GLP-1 analogues, digital health technologies, and wearable sensors. For some patients with diabetes, transitioning to vaping or the long-term use of GLP-1 analogues may represent an acceptable trade-off, balancing minimal residual risk with a greater chance of achieving successful and sustainable cessation outcomes. Furthermore, the incorporation of innovative technologies, such as wearable sensors and digital health platforms, offers new avenues for personalized and continuous support.

Despite the well-documented health risks associated with continued smoking in this vulnerable group, smoking cessation in individuals with diabetes remains a largely neglected area, with only 135 cessation studies published over the past 30 years. Many individuals with diabetes continue to smoke, underscoring the urgent need for advancements in technology and pharmacology to address this dual challenge effectively. Future research must prioritize the unique needs of this vulnerable group, refine cessation interventions to achieve significantly higher quit rates and improve long-term health outcomes. Adopting a holistic, patient-centered approach is crucial to improving the lives of people with diabetes who smoke and addressing this pressing public health issue.