Awareness and use of smoking cessation treatments among diabetic patients

Effectiveness of pharmacotherapies for diabetes on nicotine, food, and water intake in insulin-resistant rats

The intersectionality between diabetes medications and nicotine consumption was assessed in female and male rats. Briefly, the rats were fed a high-fat diet (HFD) or regular diet (RD) for 4 weeks. Then separate groups received vehicle or a low dose of streptozotocin (STZ; 25 mg/kg). Three days later, insulin resistance was assessed by measuring plasma glucose levels for 180 min following an injection of insulin (0.75 U/kg). The rats were then prepared with jugular catheters, and they were given 23 h access to nicotine intravenous self-administration (IVSA) in 4 days cycles with 3 days of forced abstinence in their home cages where they consumed their respective diet. During the IVSA sessions, operant responses for food and water and changes in body weight were recorded. Prior to administration of the pharmacotherapies, the rats were given access to two doses of nicotine (0.015 then 0.03 mg/kg for the remainder of the study). Then, daily injections of the pharmacotherapies were given at the onset of dark cycle (6 p.m.) in the following order: 1) dapagliflozin (3.0 then 10.0 mg/kg), 2) insulin (0.75 U/kg twice), and 3) bromocriptine (3.0 then 10.0 mg/kg). The results suggest that our HFD+STZ regiment induced insulin resistance in female and male rats. Also, the HFD-fed rats displayed higher nicotine intake than RD controls, regardless of sex. Administration of insulin, but not dapagliflozin or bromocriptine, normalized nicotine intake in HFD-fed rats to control levels. These results have clinical implications regarding the potential efficacy of insulin to control excessive nicotine intake in persons with diabetes.

Central and peripheral actions of nicotine that influence blood glucose homeostasis and the development of diabetes

Cigarette smoking has long been recognized as a risk factor for type 2 diabetes (T2D), although the precise causal mechanisms underlying this relationship remain poorly understood. Recent evidence suggests that nicotine, the primary reinforcing component in tobacco, may play a pivotal role in connecting cigarette smoking and T2D. Extensive research conducted in both humans and animals has demonstrated that nicotine can elevate blood glucose levels, disrupt glucose homeostasis, and induce insulin resistance. The review aims to elucidate the genetic variants of nicotinic acetylcholine receptors associated with diabetes risk and provide a comprehensive overview of the available data on the mechanisms through which nicotine influences blood glucose homeostasis and the development of diabetes. Here we emphasize the central and peripheral actions of nicotine on the release of glucoregulatory hormones, as well as its effects on glucose tolerance and insulin sensitivity. Notably, the central actions of nicotine within the brain, which encompass both insulin-dependent and independent mechanisms, are highlighted as potential targets for intervention strategies in diabetes management.

Examination of nicotine and saccharin reward in the Goto-Kakizaki diabetic rat model

Morbidity and mortality attributed to type 2 diabetes have exponentially increased in the US. At exceptionally high risk is a subpopulation of persons with type 2 diabetes who smoke, which are shown to have decreased success rates of smoking cessation than euglycemic smokers. Preclinical research in our laboratory has shown that the rewarding effects of nicotine are enhanced in the streptozotocin and high-fat diet rodent model of diabetes. It is presently unclear whether this enhancement of nicotine reward can be demonstrated in other insulin resistant rat models. This study aimed to determine if a similar increase in nicotine reward is found in Goto-Kakizaki (GK) rats, a model of the spontaneous formation of insulin resistance in an inbred sub-strain of Wistar rat. Nicotine conditioned place preference (CPP) was examined in Sprague-Dawley (SD), Wistar, and GK rats. A robust nicotine CPP was found in SD and Wistar rats, but nicotine CPP was not detected in GK rats. Locomotor activity was also evaluated in all three strains, and GK rats demonstrated significantly less activity as compared to SD and Wistar rats. To further assess reward behavior in GK rats, consumption of saccharin solution was measured over a 48 -h period. GK rats showed a significant increase in saccharin intake compared to SD rats. These findings suggest that GK rats experience an enhanced hedonic processing as compared to SD rats. The lack of nicotine CPP in GK rats may be due to deficits in learning and memory, thus hindering their ability to acquire or express a place preference.

Insulin modulates the strong reinforcing effects of nicotine and changes in insulin biomarkers in a rodent model of diabetes

This study examined whether the strong reinforcing effects of nicotine and changes in insulin biomarkers observed in diabetic rats are modulated via insulin. A model of diabetes was employed involving administration of streptozotocin (STZ), which produces hypoinsulinemia in rats. The present study included vehicle- or STZ-treated rats that received sham surgery or insulin pellets. Two weeks later, the rats were given extended access to intravenous self-administration (IVSA) of saline or nicotine. Concomitant changes in food intake, water responses, and body weight were assessed during 12 days of IVSA. After the last session, plasma levels of insulin, leptin, amylin, and glucagon-like peptide-1 (GLP-1) were assessed using Luminex^® technology. In a separate cohort, phosphorylated insulin receptor substrate-2 (pIRS-2) and insulin growth factor-1 receptor β (IGF-1Rβ) were assessed in the nucleus accumbens (NAc) and ventral tegmental area (VTA) of vehicle- or STZ-treated rats that received sham surgery or an insulin pellet. STZ-treated rats displayed an increase in glucose levels, a decrease in body weight, and an increase in nicotine, food, and water intake relative to controls. STZ-treated rats also displayed a decrease in plasma insulin and leptin levels and an increase in amylin and GLP-1 levels relative to controls. Importantly, all of the STZ-induced changes in behavior and insulin biomarkers were prevented by insulin supplementation. STZ-treated rats also displayed a decrease in pIRS-2 and IGF-1Rβ in the NAc (but not VTA), an effect that was also prevented by insulin. These data suggest that insulin systems in the NAc modulate the strong reinforcing effects of nicotine in male diabetic rats.

Cigarette smoking, type 2 diabetes mellitus, and glucagon-like peptide-1 receptor agonists as a potential treatment for smokers with diabetes: An integrative review

Tobacco use disorder (TUD), in particular cigarette smoking, contributes significantly to the macro- and micro-vascular complications of type 2 diabetes mellitus (DM). Persons with DM who regularly use tobacco products are twice as likely to experience mortality and negative health outcomes. Despite these risks, TUD remains prevalent in persons with DM. The objective of this integrative review is to summarize the relationship between TUD and DM based on epidemiological and preclinical biological evidence. We conclude with a review of the literature on the glucagon-like peptide-1 (GLP-1) as a potential treatment target for addressing comorbid TUD in smokers with DM.

Effects of nicotine on homeostatic and hedonic components of food intake

Chronic tobacco use leads to nicotine addiction that is characterized by exaggerated urges to use the drug despite the accompanying negative health and socioeconomic burdens. Interestingly, nicotine users are found to be leaner than the general population. Review of the existing literature revealed that nicotine affects energy homeostasis and food consumption via altering the activity of neurons containing orexigenic and anorexigenic peptides in the brain. Hypothalamus is one of the critical brain areas that regulates energy balance via the action of these neuropeptides. The equilibrium between these two groups of peptides can be shifted by nicotine leading to decreased food intake and weight loss. The aim of this article is to review the existing literature on the effect of nicotine on food intake and energy homeostasis and report on the changes that nicotine brings about in the level of these peptides and their receptors that may explain changes in food intake and body weight induced by nicotine. Furthermore, we review the effect of nicotine on the hedonic aspect of food intake. Finally, we discuss the involvement of different subtypes of nicotinic acetylcholine receptors in the regulatory action of nicotine on food intake and energy homeostasis.

Enhanced vulnerability to tobacco use in persons with diabetes: A behavioral and neurobiological framework

Tobacco use significantly magnifies the negative health complications associated with diabetes. Although tobacco use is strongly discouraged in persons with diabetes, clinical evidence suggests that they often continue to smoke and have more difficulty quitting despite serious contraindications. Here, we suggest that a potential reason for enhanced vulnerability to tobacco use in persons with diabetes is greater rewarding effects of nicotine. This review summarizes pre-clinical evidence indicating that the rewarding effects of nicotine are enhanced in rodent models of type 1 and type 2 diabetes. We also provide a framework of neurobiological mechanisms that are posited to promote tobacco use in persons with diabetes. This framework suggests that diabetes induces a disruption in insulin signaling that leads to a suppression of dopamine systems in the mesolimbic reward pathway. Lastly, we consider the clinical implications of enhanced rewarding effects of nicotine that may promote tobacco use in persons with diabetes. The clinical efficacy of smoking cessation medications that enhance dopamine are important to consider, given that persons with diabetes may display disrupted dopaminergic mechanisms. Future work is needed to better understand the complex interaction of dopamine and insulin in order to develop better smoking cessation medications for persons with diabetes.

Continued smoking abstinence in diabetic patients in primary care: a cluster randomized controlled multicenter study

AIMS

To assess the effectiveness of an intensive smoking cessation intervention based on the transtheoretical model of change (TTM) in diabetic smokers attending primary care.

METHODS

A cluster randomized controlled clinical trial was designed in which the unit of randomization (intervention vs. usual care) was the primary care team. An intensive, individualized intervention using motivational interview and therapies and medications adapted to the patient's stage of change was delivered. The duration of the study was 1 year.

RESULTS

A total of 722 people with diabetes who were smokers (345 in the intervention group and 377 in the control group) completed the study. After 1 year, continued abstinence was recorded in 90 (26.1%) patients in the intervention group and in 67 (17.8%) controls (p=0.007). In patients with smoking abstinence, there was a higher percentage in the precontemplation and contemplation stages at baseline in the intervention group than in controls (21.2% vs. 13.7%, p=0.024). When the precontemplation stage was taken as reference (OR=1.0), preparation/action stage at baseline showed a protective effect, decreasing 3.41 times odds of continuing smoking (OR=0.293 95% CI 0.179-0.479, p<0.001). Contemplation stage at baseline also showed a protective effect, decreasing the odds of continuing smoking (OR=0.518, 95% CI 0.318-0.845, p=0.008).

CONCLUSIONS

An intensive intervention adapted to the individual stage of change delivered in primary care was feasible and effective, with a smoking cessation rate of 26.1% after 1 year.

Enhanced nicotine self-administration and suppressed dopaminergic systems in a rat model of diabetes

Patients with diabetes display a heightened propensity to use tobacco; however, it is unclear whether they experience enhanced rewarding effects of nicotine. Thus, this study examined the reinforcing effects of nicotine in a rodent model of diabetes involving administration of streptozotocin (STZ), a drug that is toxic to pancreatic insulin-producing cells. The first study compared STZ- and vehicle-treated rats that had 23-hour access to intravenous self-administration (IVSA) of nicotine or saline and concomitant access to food and water. In order to examine the contribution of dopamine to our behavioral effects, dopamine transporter (DAT), D1 and D2 receptor levels were compared in the nucleus accumbens (NAc) following 10 days of nicotine or saline IVSA. Dopamine levels in the NAc were also compared following nicotine administration. Lastly, nicotine metabolism and dose-dependent effects of nicotine IVSA were assessed. The results revealed that STZ-treated rats displayed enhanced nicotine intake and a robust increase in food and water intake relative to controls. Protein analysis revealed an increase in DAT and a decrease in D1 receptor levels in the NAc of STZ- versus vehicle-treated rats regardless of IVSA condition. STZ-treated rats also displayed suppressed NAc dopamine levels during baseline and in response to nicotine. STZ treatment did not alter our assessment of nicotine metabolism. Furthermore, STZ treatment increased nicotine IVSA in a dose-dependent manner. Our findings suggest that STZ-treatment increased the rewarding effects of nicotine. This suggests that strong reinforcing effects of nicotine may contribute to greater tobacco use in patients with diabetes.

Insulin resistant rats display enhanced rewarding effects of nicotine

BACKGROUND

Tobacco use among persons with Type II diabetes exponentially increases negative health consequences and mortality rates. It is especially troubling that diabetic persons who smoke have a greater difficulty with tobacco cessation as compared to non-diabetic smokers. Diabetes is a metabolic syndrome that consists of insulin resistance due to disruptions in insulin signaling. We have previously shown that insulin depletion enhances the motivational effects of nicotine.

METHODS

The present study expands our previous work by examining whether insulin resistance, produced by a high-fat diet (HFD) regimen, enhances the rewarding effects of nicotine, as measured by the conditioned place preference (CPP) paradigm. Rats were placed on either a regular diet (RD) or a HFD for 5 weeks, after which they were assessed for insulin resistance via blood glucose measurements after an insulin challenge. Rats then underwent a nicotine CPP study.

RESULTS

The findings revealed that HFD produced insulin resistant and non-insulin resistant animals. Interestingly, the magnitude of nicotine CPP was larger in insulin resistant rats versus RD rats. Nicotine CPP was absent in non-insulin resistant animals. A similar increase in body weight was observed in insulin resistant and non-insulin resistant rats as compared to RD rats. These findings suggest that neither the increased body weight nor the HFD per se in the insulin resistant rats contributed to the enhanced nicotine reward.

CONCLUSION

These present study suggests that insulin resistant rats undergo unique neurobiological changes related to a disruption in insulin signaling that promotes the rewarding effects of nicotine.

Use and effectiveness of quitlines for smokers with diabetes: cessation and weight outcomes, Washington State Tobacco Quit Line, 2008

INTRODUCTION

Having diabetes and smoking increases the risk of morbidity and mortality. However, cessation-related weight gain, a common side effect during quitting, can further complicate diabetes. Evidence-based telephone quitlines can support quitting but have not been studied adequately in populations with chronic diseases such as diabetes. The purpose of this study was to evaluate the use and effectiveness of a tobacco quitline among tobacco users with diabetes. Cessation-related weight concerns and weight gain were also assessed.

METHODS

We administered a telephone-based follow-up survey to tobacco users with and without diabetes 7 months after their enrollment in a quitline. We collected and analyzed data on demographics, tobacco use, dieting, weight concern, quitting success (7- and 30-day point prevalence), and weight gain. We computed summary statistics for descriptive data, χ(2) and t tests for bivariate comparisons, and multivariable analyses to determine correlates of cessation.

RESULTS

Tobacco users with diabetes used the quitline in a greater proportion than they were represented in the general population. Quit rates for those with and without diabetes did not differ significantly (24.3% vs 22.5%). No significant differences existed between groups for weight gain at follow-up, regardless of quit status. However, participants with diabetes reported more weight gain in previous quit attempts (34.2% vs 22.4% gained >20 lbs, P = .03). Weight concern was a significant correlate of continued smoking, regardless of diabetes status.

CONCLUSIONS

Results suggest that quitlines are effective for participants with diabetes, but tailored interventions that address weight concerns during cessation are needed.

Smoking, smoking cessation and smoking relapse patterns: a web-based survey of current and former smokers in the US

AIM

The aim of this study was to characterise the natural course of smoking cessation behaviour in a web-based survey of current and former cigarette smokers (CS and FS) in the United States.

METHODS

A web-based survey of CS and FS was conducted in April 2009; demographic and socioeconomic characteristics and smoking history (including the number of lifetime and length of latest quit attempts, aids used and time to relapse) were collated. The surveyed cohort was selected from prescreened CS and FS panellists and matched for age, race and education, to be representative of the US population. Descriptive statistics and time-to-event analyses using Kaplan-Meier curves were applied in the analysis of this report.

RESULTS

The final cohort comprised 512 CS and 566 FS (n = 1078). A larger proportion of FS than CS reported a longest smoke-free period of > 1 year (78.8% vs. 22.4%, respectively). As a greater variety of smoking cessation products became available over time, the proportion of unassisted quit attempts decreased from 76.1% prior to 1983 to 43.9% after 2006 for CS and from 79.3% to 50.3% for FS. The cumulative proportion of subjects relapsing was 31.3% by 1 week and 79.3% by 6 months. The estimated median time to next quit attempt was approximately 360 days.

CONCLUSIONS

These data confirm that relapse is common and that as the variety of cessation modalities increase, the proportion of unassisted quit attempts decreases. Self-help or cold-turkey methods still provide significant alternatives even when pharmacotherapy is available. This study provides data related to the smoking history and smoking cessation patterns of a large, nationally representative sample of CS and FS.

Examining why smokers do not want behavioral support with stopping smoking

OBJECTIVE

This article delineates theory-based determinants of the low use of behavioral stop-smoking support with a view to inform interventions to address the low use.

METHODS

Study 1 comprised interviews with 27 smokers recruited from a primary care centre in England. Study 2 used a nationwide sample of 212 smokers who completed a questionnaire informed by Study 1. Multiple regression and mediation analyses were used in Study 2 to discern the determinants of smokers' motivation to use behavioral stop-smoking support.

RESULTS

The best predictors of low motivation to use (a) group support, and (b) one-to-one support were expectations that stop-smoking support is ineffective at increasing chances of stopping smoking. In turn, expectations of ineffectiveness were predicted by expectations that both services provide insufficient support, as well as smokers' low self-efficacy to use them. A negative image of those attending groups was another predictor of group support.

CONCLUSION

A substantial proportion of smokers hold expectations about stop-smoking support that are unlikely to facilitate motivation to use such support.

PRACTICE IMPLICATIONS

Intervention studies are now needed targeting such expectations.

Results of the application of the American Diabetes Association guidelines regarding tobacco dependency in subjects with diabetes mellitus

The objective of the study was to evaluate the stages of change for cessation in smoking after the application of American Diabetes Association recommendations in diabetic patients who smoke. This longitudinal descriptive study involved smokers with diabetes mellitus (DM) who were attended for their DM between September 2003 and December 2006. Intervention used was dependent on the stage of change for cessation (according to Prochaska and Di Clemente). For precontemplation subjects, a brief session was carried out where information regarding the risks of smoking in conjunction with DM was given. Patients at the contemplation stage of smoking cessation were offered the chance to participate in a cessation program. Later evaluation was carried out after a follow-up of more than 6 months. Seven hundred thirty-three subjects with DM were evaluated, including 156 smokers (21.28%): 103 (66.02%) in the precontemplation stage, 25 (16.02%) in the contemplation stage, 12 (7.69%) in the preparation stage, 12 (7.69%) in the action stage, and 4 (2.56%) in the maintenance stage. By the last follow-up, 65 (41.6%) subjects had quit smoking (36 ex-smokers), of whom 20 (30.77%) had subsequently relapsed. The use of the American Diabetes Association recommendations for the treatment of tobacco dependence in diabetes treatment results in an increased change of smoking cessation stages in subjects with DM as well as a higher overall percentage in abstinence.

Cigarette smoking, smoking cessation, and diabetes

There is evidence for increased risk of developing type 2 diabetes among cigarette smokers. In addition, smoking-associated health risks can exacerbate major conditions that precede or accompany diabetes, such as cardiovascular and kidney diseases. Smoking cessation can result in weight gain and a short-term worsening of some diabetic symptoms that may deter smokers with diabetes from attempting to quit. Additionally, there is limited evidence regarding the efficacy/safety of smoking cessation pharmacotherapies in this population and the general effects of smoking cessation, particularly for type 1 diabetes. Smoking cessation in diabetes therefore remains a highly relevant subject for further research.

Educational disparities in rates of smoking among diabetic adults: the translating research into action for diabetes study

OBJECTIVES

We assessed educational disparities in smoking rates among adults with diabetes in managed care settings.

METHODS

We used a cross-sectional, survey-based (2002-2003) observational study among 6538 diabetic patients older than 25 years across multiple managed care health plans and states. For smoking at each level of self-reported educational attainment, predicted probabilities were estimated by means of hierarchical logistic regression models with random intercepts for health plan, adjusted for potential confounders.

RESULTS

Overall, 15% the participants reported current smoking. An educational gradient in smoking was observed that varied significantly (P<.003) across age groups, with the educational gradient being strong in those aged 25 to 44 years, modest in those aged 45 to 64 years, and nonexistent in those aged 65 years or older. Of particular note, the prevalence of smoking observed in adults aged 25-44 years with less than a high school education was 50% (95% confidence interval: 36% to 63%).

CONCLUSIONS

Approximately half of poorly educated young adults with diabetes smoke, magnifying the health risk associated with early-onset diabetes. Targeted public health interventions for smoking prevention and cessation among young, poorly educated people with diabetes are needed.

Difficulties of smoking cessation in diabetic inpatients benefiting from a systematic consultation to help them to give up smoking

AIM

To assess the value of systematic smoking cessation consultations for diabetic smokers admitted to hospital.

METHODS

All diabetic smokers admitted to the Diabetes Department of Georges Pompidou European Hospital between February 2003 and February 2004 were systematically offered a consultation with a physician specialised in tobacco cessation. Follow-up visits at three, six and nine months were planned.

RESULTS

Of the 306 diabetic patients admitted, 38 (12.4%) were smokers. There were more men than women in the group of smokers and the diabetic smokers were younger than the non-smokers. The smokers had fewer micro-angiopathic complications than the non-smokers, but there was no difference in the frequency of macro-angiopathic complications. The level of nicotine physical dependence was moderate or high for 60% of the smokers. Although all the smokers agreed to the consultation, less than half agreed to drug-based treatments to help them to give up smoking and only 15% returned for the six-month visit. Only one patient had stopped smoking at the six-month visit.

CONCLUSION

This study demonstrates the difficulties in systematic interventions to help diabetic patients to stop smoking. Diabetic smokers probably constitute a specific population for which the barriers to giving up smoking should be explored.