Smoking-induced metabolic disorders: a review

Cardiovascular dysfunction induced by combined exposure to nicotine inhalation and high-fat diet

Smoking and high-fat diet (HFD) consumption are two modifiable risk factors for cardiovascular (CV) diseases, and individuals who are overweight or obese due to unhealthy diet are more likely to use tobacco products. In this study, we aim to investigate the combined effects of nicotine (the addictive component of all tobacco products) and HFD on CV health, which are poorly understood. C57BL/6N male mice were placed on either HFD (60 kcal% fat) or regular diet (22 kcal% fat) and exposed to air or nicotine vapor for 10-12 wk. CV function was monitored by echocardiography and radiotelemetry, with left ventricular (LV) catheterization and aortic ring vasoreactivity assays performed at end point. Mice on HFD exhibited increased heart rate and impaired parasympathetic tone, whereas nicotine exposure increased sympathetic vascular tone as evidenced by increased blood pressure (BP) response to ganglionic blockade. Although neither nicotine nor HFD alone or in combination significantly altered BP, nicotine exposure disrupted circadian BP regulation with reduced BP dipping. LV catheterization revealed that combined exposure to nicotine and HFD led to LV diastolic dysfunction with increased LV end-diastolic pressure (LVEDP). Moreover, combined exposure resulted in increased inhibitory phosphorylation of endothelial nitric oxide synthase and greater impairment of endothelium-dependent vasodilation. Finally, a small cohort of C57BL/6N females with combined exposure exhibited similar increases in LVEDP, indicating that both sexes are susceptible to the combined effect of nicotine and HFD. In summary, combined exposure to nicotine and HFD leads to greater CV harm, including both additive and new-onset CV dysfunction.NEW & NOTEWORTHY Nicotine product usage and high-fat diet consumption are two modifiable risk factors for cardiovascular diseases. Here, we demonstrate that in mice, combined exposure to inhaled nicotine and high-fat diet results in unique cardiovascular consequences compared with either treatment alone, including left ventricular diastolic dysfunction, dysregulation of blood pressure, autonomic dysfunction, and greater impairment of endothelium-dependent vasorelaxation. These findings indicate that individuals who consume both nicotine products and high-fat diet have distinctive cardiovascular risks.

Perceived Neighborhood Environment Impacts on Health Behavior, Multi-Dimensional Health, and Life Satisfaction

The impacts of perceived neighborhood environment on adults' health and life satisfaction have drawn increasing academic attention. However, previous studies usually examine multi-dimensional (physical, mental, and perceived) health and life satisfaction separately, and few studies dealt with them simultaneously. Moreover, limited research revealed the mechanisms behind the effects of perceived neighborhood environment on health and life satisfaction, as well as how such effects are moderated by socio-demographics. Therefore, employing the 2016 China Family Panel Study Dataset and using structural equation modeling, this study delves into the complicated relationships among perceived neighborhood environment, health behavior, health outcomes (i.e., body mass index, self-rated health status, and depression), and life satisfaction. Notably, it considers mediation and moderation simultaneously. It finds: (1) Better perceived neighborhood environment significantly promotes physical activity and reduces sedentary behavior, smoking, and drinking; (2) Health behavior fully mediates the effects of perceived neighborhood environment on health; (3) Perceived neighborhood environment significantly affects life satisfaction both directly and indirectly (through health behavior and health outcomes); (4) Socio-demographics moderate the above relationships. This study disentangles the complicated impacts of perceived neighborhood environment on adults' multi-dimensional health and life satisfaction, thus providing policy makers and practitioners with nuanced knowledge for intervention.

Association between waterpipe smoking and obesity: Population-based study in Qatar

INTRODUCTION

Over the past decade obesity prevalence has been increasing rapidly in the Gulf region (GR) including Qatar, becoming one of the major health issues in the region. Concomitantly, waterpipe (WP) smoking is increasing worldwide especially in the GR, and although the effect of cigarette smoking on body weight is well-established, studies indicating an association between WP smoking and obesity are scarce. Thus, we explored the association between WP smoking and obesity in comparison with cigarette smokers and healthy population in Qatar.

METHODS

We performed a cross-sectional study using data from Qatar Biobank and analyzed anthropometric measurements among 879 adults (aged 18-65 years) that included WP smokers, cigarette smokers, dual smokers and never smokers. Body composition was measured using bioelectrical impedance analysis and reported as lean mass, fat mass, and body fat percentage.

RESULTS

Overall, 12% (n=108) were WP smokers, 22% (n=196) were cigarette smokers, 9% (n=77) smoked both WP and cigarettes and 57% (n=498) were never smokers. Age, sex, history of diabetes, and hypertension, in addition to nationality were considered as confounding factors. Our analysis revealed that WP smokers had a significantly higher BMI (kg/m2) and fat mass when compared with cigarette smokers (p<0.05). Moreover, compared to cigarette smoking, WP smoking had a higher significant effect on BMI (β=3.8, SE=0.38; and β=5.5, SE=0.46; respectively), and fat mass (β=5.1, SE=0.79; and β=9.0, SE=0.97; respectively). However, WP users were similar to never-smokers in terms of body fat percent.

CONCLUSIONS

Our data indicate that compared to never smokers, daily WP users have higher BMI and fat mass, and are likely to be obese.

Organizational Justice and Long-term Metabolic Trajectories: A 25-Year Follow-up of the Whitehall II Cohort

CONTEXT

Organizational justice has been linked to lower risk of several chronic conditions among employees, but less is known about the long-term mechanisms underlying this risk reduction.

OBJECTIVE

To assess whether self-reported organizational justice is associated with individual and composite long-term metabolic trajectories.

DESIGN

Twenty-five-year follow-up of the Whitehall II prospective cohort study.

SETTING

Middle-aged public servants from the United Kingdom.

PARTICIPANTS

Data on 8182 participants were used.

MAIN OUTCOME MEASURES

Levels of 11 anthropometric, glycemic, lipid, and blood pressure biomarkers were measured at 5 timepoints (1991-2013). We used generalized estimating equations and group-based trajectory modeling to investigate the relationship between organizational justice and biomarker trajectories.

RESULTS

High vs low organizational justice were associated with lower waist (-1.7 cm) and hip (-1 cm) circumference, body mass index (-0.6 kg/m2), triglycerides (-1.07 mmol/L), and fasting insulin (-1.08 µIU/mL) trajectories. Two latent metabolic trajectory clusters were identified: a high- and a low-risk cluster. High organizational justice (vs low) were associated with belonging to the low-risk cluster (pooled odds ratio = 1.47). The low-risk cluster demonstrated lower baseline levels of most biomarkers and better glycemic control, whereas the high-risk cluster showed higher baseline levels of most biomarkers, glycemic deterioration, but also greater improvements in lipid levels over time.

CONCLUSIONS

People with high organizational justice had more favorable long-term cardiometabolic biomarker patterns than those with low organizational justice, indicating a potential mechanism contributing to the lower risk of chronic diseases in the first group. Further intervention studies are warranted to determine whether improvement of organizational justice might improve long-term health.

[Changes in tobacco and alcoholic beverage consumption among adolescents from Curitiba in the State of Paraná: a longitudinal study]

The scope of this study was to verify alterations in cigarette and alcohol consumption in a sample of adolescents from the state education system of the city of Curitiba in the State of Paraná between 2015 and 2017. It involved a longitudinal prospective cohort study conducted with 799 adolescents (11 to 15 years of age) between 2015 and 2017. The Youth Risk Behavior Surveillance System (YRBS) questionnaire evaluated mild and excessive alcohol and tobacco consumption. Modifications of alcohol and tobacco consumption were evaluated through Generalizable Estimating Equation (GEE) models with Poisson distribution to obtain Incidence Risk Ratios (IRR) with 95% confidence intervals (95%CI). The "time" variable was treated as an independent variable along with other possible predictors (gender, age bracket, nutritional status, socioeconomic level, head of household education, physical activity and screen time). Tobacco consumption (IRR= 1,32, 95%CI = 1,02; 1,71), mild (IRR= 1,32, 95%CI = 1,13; 1,53) and excessive (IRR= 1,21, 95%CI = 1,04; 1,40) alcohol consumption increased between 2015 and 2017. This study indicates that adolescents participating in this research are modifying their behaviors towards a less healthy lifestyle.

Dose-Dependent Effect of Smoking on Risk of Diabetes Remains after Smoking Cessation: A Nationwide Population-Based Cohort Study in Korea

BACKGROUND

This study aimed to evaluate the dose-dependent effects of smoking on risk of diabetes among those quitting smoking.

METHODS

We analyzed clinical data from a total of 5,198,792 individuals age 20 years or older who received health care check-up arranged by the national insurance program of Korea between 2009 and 2016 using the Korean National Health Insurance Service database. Cumulative smoking was estimated by pack-years. Smokers were classified into four categories according to the amount of smoking: light smokers (0.025 to 5 smoking pack-years), medium smokers (5 to 14 smoking pack-years), heavy smokers (14 to 26 smoking pack-years), and extreme smokers (more than 26 smoking pack-years).

RESULTS

During the study period, 164,335 individuals (3.2% of the total population) developed diabetes. Compared to sustained smokers, the risk of diabetes was significantly reduced in both quitters (hazard ratio [HR], 0.858; 95% confidence interval [CI], 0.838 to 0.878) and nonsmokers (HR, 0.616; 95% CI, 0.606 to 0.625) after adjustment for multiple risk factors. The risk of diabetes gradually increased with amount of smoking in both quitters and current smokers. The risk of diabetes in heavy (HR, 1.119; 95% CI, 1.057 to 1.185) and extreme smokers (HR, 1.348; 95% CI, 1.275 to 1.425) among quitters was much higher compared to light smokers among current smokers.

CONCLUSION

Smoking cessation was effective in reducing the risk of diabetes regardless of weight change. However, there was a potential dose-dependent association between smoking amount and the development of diabetes. Diabetes risk still remained in heavy and extreme smokers even after smoking cessation.

Smoking Affects the Patterns of Metabolic Disorders and Metabolic Syndrome in Patients With First-Episode Drug-Naive Schizophrenia: A Large Sample Study Based on the Chinese Han Population

OBJECTIVE

Although metabolic disorders and smoking are common in schizophrenia, few studies have investigated the effects of smoking on metabolic disorders or metabolic syndrome (MetS) in schizophrenia patients, especially in first-episode drug-naïve (FEDN) patients. We sought to investigate the differences in metabolic disorders and MetS between smoking and nonsmoking FEDN schizophrenia patients.

METHODS

A total of 428 FEDN schizophrenia patients and 435 controls were recruited. Blood pressure, waist circumference, body mass index (BMI), lipid profiles, and glucose metabolism were measured. The psychopathology was evaluated by Positive and Negative Syndrome Scale.

RESULTS

FEDN schizophrenia patients had a higher smoking rate than controls (23.8% vs 14.0%, P < .001). After adjusting for confounding variables, the prevalence of MetS, overweight, hypertension, hypertriglyceridemia, elevated insulin, and insulin resistance in smoking patients was higher than those in nonsmoking patients, while overweight and hypertension were higher in the smoking controls than in nonsmoking controls (all P < .05). In smoking patients, triglyceridemia, high-density lipoprotein cholesterol, and fasting blood glucose were the main contributing components to MetS, while in nonsmoking patients, waist circumference, systolic blood pressure, triglyceridemia, high-density lipoprotein cholesterol, and fasting blood glucose were the main contributing components to MetS. In smoking patients, BMI and homeostatic model assessment for insulin resistance were associated factors of MetS (both P < .05). In nonsmoking patients, sex, BMI, insulin, and homeostatic model assessment for insulin resistance were associated factors of MetS (all P < .05).

CONCLUSIONS

Our study indicates that smoking schizophrenia patients have a higher prevalence of MetS and metabolic disorders than nonsmoking patients. Moreover, smoking and nonsmoking patients have different contributing components and associated factors for MetS.

Chronic Gastritis Is Associated with a Decreased High-Density Lipid Level: Histological Features of Gastritis Based on the Updated Sydney System

Chronic gastritis could activate a systemic inflammatory response that could result in adverse lipid profiles. To determine the severity of chronic gastritis, Helicobacter pylori (HP), mononuclear cell (lymphocytes and plasma cells), and neutrophil scores were assessed on the basis of the updated Sydney system (USS), which is widely used for histological grading. The aim of this study was to assess the relationships between gastric histological features and lipid profile levels. This study included 15,322 males and 5929 females who underwent a health checkup and gastric biopsy at the Kangbuk Samsung Medical Center (KBSMC). We analyzed whether the HP, mononuclear cell, and neutrophil grades according to the USS were related to serum leukocyte count, unhealthy behaviors, and lipid profile levels. Gastritis with HP, neutrophils, or moderate to severe mononuclear cells was associated with an elevated serum leukocyte count. A high leukocyte count was related to increased low-density lipoproteins (LDL) and triglycerides/very-low-density lipoprotein (VLDL) and decreased high-density lipoproteins (HDL). In multivariate analyses, chronic gastritis with HP or moderate to severe mononuclear cells was significantly associated with decreased HDL in males, while mononuclear cells were significantly related to decreased HDL in females. Chronic gastritis was associated with an increased systemic inflammatory response, which was associated with unfavorable lipid profiles, especially low HDL levels.

Associations of tobacco smoking with body mass distribution; a population-based study of 65,875 men and women in midlife

BACKGROUND

Studies indicate an effect of smoking toward abdominal obesity, but few assess hip and waist circumferences (HC and WC) independently. The present study aimed to assess the associations of smoking status and volume smoked with HC and WC and their ratio in a population with low prevalence of obesity together with high prevalence of smoking.

METHODS

We used cross-sectional survey data from 11 of a total 19 Norwegian counties examined in 1997-99 including 65,875 men and women aged 39-44 years. Analysis of associations were adjusted for confounding by socioeconomic position, health indicators, and additionally for BMI.

RESULTS

Compared with never-smokers, when adjusting for confounders and in addition for BMI, mean HC remained lower while mean WC and waist-hip-ratio (WHR) were higher in current smokers. The finding of a lower HC and higher WHR level among smokers was consistent by sex and in strata by levels of education and physical activity, while the finding of higher WC by smoking was less consistent. Among current smokers, BMI-adjusted mean HC decreased whereas WC and WHR increased by volume smoked. Compared with current smokers, former smokers had higher BMI-adjusted HC, lower WHR and among women WC was lower.

CONCLUSIONS

The main finding in this study was the consistent negative associations of smoking with HC. In line with the hypothesis that lower percentage gluteofemoral fat is linked with higher cardiovascular risk, our results suggest that smoking impacts cardiovascular risk through mechanisms that reduce the capacity of fat storage in the lower body region.

Association of smoking and cardiometabolic parameters with albuminuria in people with type 2 diabetes mellitus: a systematic review and meta-analysis

AIMS

Smoking is a strong risk factor for albuminuria in people with type 2 diabetes mellitus (T2DM). However, it is unclear whether this sequela of smoking is brought about by its action on cardiometabolic parameters or the relationship is independent. The aim of this systematic review is to explore this relationship.

METHODS

Electronic databases on cross-sectional and prospective studies in Medline and Embase were searched from January 1946 to May 2018. Adult smokers with T2DM were included, and other types of diabetes were excluded.

RESULTS

A random effects meta-analysis of 20,056 participants from 13 studies found that the odds ratio (OR) of smokers developing albuminuria compared to non-smokers was 2.13 (95% CI 1.32, 3.45). Apart from smoking, the odds ratio of other risk factors associated with albuminuria were: age 1.24 (95% CI 0.84, 1.64), male sex 1.39 (95% CI 1.16, 1.67), duration of diabetes 1.78 (95% CI 1.32, 2.23), HbA1c 0.63 (95% CI 0.45, 0.81), SBP 6.03 (95% CI 4.10, 7.97), DBP 1.85 (95% CI 1.08, 2.62), total cholesterol 0.06 (95% CI - 0.05, 0.17) and HDL cholesterol - 0.01 (95% CI - 0.04, 0.02), triglyceride 0.22 (95% CI 0.12, 0.33) and BMI 0.40 (95% CI 0.00-0.80). When the smoking status was adjusted in a mixed effect meta-regression model, the duration of diabetes was the only statistically significant factor that influenced the prevalence of albuminuria. In smokers, each year's increase in the duration of T2DM was associated with an increased risk of albuminuria of 0.19 units (95% CI 0.07, 0.31) on the log odds scale or increased the odds approximately by 23%, compared to non-smokers. Prediction from the meta-regression model also suggested that the odds ratios of albuminuria in smokers after a diabetes duration of 9 years and 16 years were 1.53 (95% CI 1.10, 2.13) and 5.94 (95% CI 2.53, 13.95), respectively.

CONCLUSIONS

Continuing to smoke and the duration of diabetes are two strong predictors of albuminuria in smokers with T2DM. With a global surge in younger smokers developing T2DM, smoking cessation interventions at an early stage of disease trajectory should be promoted.

The prevalence of underweight, overweight and obesity and their related socio-demographic and lifestyle factors among adult women in Myanmar, 2015-16

BACKGROUND

The aim of the study was to estimate the prevalence of underweight and overweight or obesity and their socio-demographic and lifestyle factors in a female adult population in Myanmar.

MATERIAL AND METHODS

In a national cross-sectional population-based survey in the 2015-16 Myanmar Demographic and Health Survey, 12,160 women aged 18-49 years and not currently pregnant completed questionnaires and anthropometric measurements. Nutritional status was determined using Asian body mass index cut-offs: underweight (BMI<18.5 kg/m2), overweight (23.0-27.4 kg/m2), and obesity (≥27.5 kg/m2). Multinomial logistic regression modelling was used to determine the association between socio-demographic and lifestyle factors and weight status.

RESULTS

The prevalence of underweight was 14.1%, overweight 28.1% and obesity 13.1%. Among different age groups, the prevalence of underweight was the highest among 18 to 29 year-olds (20.2%), while overweight or obesity was the highest in the age group 30 to 49 years (around 50%). In multinomial logistic regression, being 30 to 49 years old, poorer and richer wealth status, living in all the other regions of Myanmar and ever contraceptive use were inversely and current tobacco use, not working and having less than two children ever born were positively associated with underweight relative to normal weight. Older age, having secondary education, urban residence, wealthier economic status, living with a partner, living in the Northern and Southern regions of Myanmar, having less than two children ever born and having ever used contraceptives were positively and current tobacco use was negatively associated with overweight or obesity relative to normal weight.

CONCLUSIONS

A dual burden of both underweight and overweight or obesity among female adults was found in Myanmar. Sociodemographic and health risk behaviour factors were identified for underweight and overweight or obesity that can guide public health interventions to address both of these conditions.

Diabetes-related behaviours among elderly people with pre-diabetes in rural communities of Hunan, China: a cross-sectional study

OBJECTIVE

To explore diabetes-related behaviours and their influencing factors among elderly individuals with pre-diabetes in rural areas of China.

DESIGN, SETTING AND PARTICIPANTS

A cross-sectional survey was conducted among elderly individuals (≥60 years) in rural communities in Yiyang City of China. Multistaged cluster random sampling was carried out to select 42 areas, and interviews were conducted among 434 elderly individuals with pre-diabetes (fasting plasma glucose 6.1-7.0 mmol/L and/or 2-hour post-glucose load of 7.8-11.1 mmol/L) using questionnaires on diabetes-related behaviours. The diabetes-related behaviours included eight categories: average daily sedentary time; frequency of physical activities per week; regular or irregular diet; whether paying attention to diet control or not; daily dietary preferences; frequency of physical examinations per year; current smoking status; and current consumption of alcohol. Each of the risky behaviours was scored -1 and each of the healthy behaviours was scored +1. Each individual's score of diabetes-related behaviours was the sum of the score for all behaviours.

MAIN OUTCOME MEASURES

Participants were asked about general information (age, gender, marital status, history of hyperglycaemia, family history of diabetes mellitus, presence of other diseases, body mass index, waist-to-hip ratio and education) and their diabetes-related behaviours. Multivariate linear regression analysis was performed to identify the risk factors for diabetes-related behaviour among elderly individuals with pre-diabetes.

RESULTS

The average score of diabetes-related behaviours of elderly individuals with pre-diabetes in rural China was 2.7. The prevalences of risky diabetes-related behaviours were as follows: <1 physical examination per year (57.6%), insufficient physical activities (55.3%), lack of attention paid to diet control (51.4%), high-salt and high-fat diets (41.0%), sedentary lifestyle (35.9%), smoking (22.8%), regular alcohol uptake (15.0%) and irregular diet (3.9%). Gender and a history of hyperglycaemia were found to be influencing factors of the diabetes-related behaviour score.

CONCLUSIONS

The prevalence of risky diabetes-related behaviours was high among pre-diabetic elderly individuals in rural China. More effort should be made to promote the prevention and control of diabetes in rural China. Future studies should be undertaken on diabetes prevention strategies tailored specially for this population.

TRIAL REGISTRATION NUMBER

ChiCTR-IOR-15007033; Results.

Current smoking is associated with a larger waist circumference and a more androgenic profile in young healthy women from high-risk breast cancer families

The purpose was to elucidate the interplay between current smoking, anthropometric measurements, and endogenous hormone levels in women ≤ 40 years. Questionnaires on lifestyle and reproductive factors were completed by 269 healthy women from high-risk breast cancer families between 1996 and 2006 in Sweden. Blood samples for analyses of plasma testosterone, estradiol, androstenedione, sex hormone-binding globulin, and body measurements were obtained 5–10 days before predicted onset of the next menstrual period. Women without smoking status, who were currently breastfeeding, or using hormonal contraception other than combined oral contraceptives (OCs) were excluded (n = 27). Current smokers (n = 57) had larger waist circumference (_adjp = 0.004) and waist-to-hip ratio (WHR) (_adjp = 0.007) than non-smokers (n = 185). In non-OC users, adjusted mean androstenedione levels were higher in current smokers compared with non-smokers (10.3 vs. 8.6 nmol/L; _adjp = 0.0002). While in current OC users estradiol levels were higher in smokers compared with non-smokers (22.5 vs. 17.4 pg/mL; _adjp = 0.012). In multivariable models, WHR was associated with both current smoking (_adjp ≤ 0.016) and higher levels of androstenedione (_adjp = 0.05) or bioavailable testosterone (_adjp = 0.001). Among non-OC users, a more androgenic profile was observed in current smokers compared with non-smokers, but not in current OC users. Irrespective of OC use, current smoking was associated with increased waist circumference.

Distinct Metabolic Profiles are Associated with Colorectal Adenomas and Serrated Polyps

OBJECTIVE

Prevention of colorectal cancer (CRC) by colonoscopy is recommended according to age and personal/familial history. Metabolic alterations are associated with colorectal adenomas, but data are scarce regarding serrated polyps and advanced polyps. The aim of this study was to evaluate the association between metabolic alterations and colorectal polyp type and advanced polyps.

METHODS

A case-control study was conducted among consecutive subjects, 40 to 70 years old, who underwent screening/diagnostic colonoscopy from 2010 to 2015. Subjects who were treated for diabetes, who had a family/personal history of CRC, and who were at high risk for CRC were excluded. Participants underwent anthropometric, laboratory, and ultrasonographic evaluations and a medical and lifestyle interview. Polyps were histologically classified as adenomatous or serrated polyps and divided into advanced and non-advanced categories.

RESULTS

The study included 828 participants (58.4 ± 6.6 years, 50.4% men). Abdominal obesity (odds ratio [OR] = 1.67, 95% CI: 1.20-2.30), hypertension (OR = 1.47, 95% CI: 1.03-2.09), and a high glycosylated hemoglobin percentage (HbA1c%) (OR = 1.57, 95% CI: 1.06-2.34) were independently associated with colorectal adenomas, whereas a high triglyceride to high-density lipoprotein cholesterol (TG/HDL) ratio was independently associated with serrated polyps (OR = 2.31, 95% CI: 1.32-4.03). A combination of three metabolic alterations was strongly associated with colorectal polyps.

CONCLUSIONS

Abdominal obesity, hypertension, and a high HbA1c% are independently associated with adenomas, whereas a high TG/HDL ratio is associated with serrated polyps. These parameters are easily accessible in clinical practice and may help define high-risk groups for CRC.

The impact of smoking on the development of diabetes and its complications

Diabetes is one of the most common metabolic disorders and emerges secondary to an interaction between genetic, environmental and lifestyle factors. This work provides an overview of the impact of smoking on the development of vascular complications in this condition and also provides an overview of the potential role of smoking in predisposition to diabetes. There are many studies documenting the impact of smoking on health (not focused on patients with diabetes), suggesting that the health exposure in these individuals is at least comparable to that observed in the general population. Distinct studies of smoking in patients with diabetes have unambiguously confirmed an increased prevalence and a higher risk of early death associated with the development of macrovascular complications. Smoking is also associated with premature development of microvascular complications and may contribute to the pathogenesis of type 2 diabetes. It has been shown that smoking is a predictor of the progression of glucose intolerance at both the transition from normoglycaemia to impaired glucose tolerance status and the increased risk of developing diabetes. The mechanisms explaining the relationship between smoking and the development of diabetes are not fully understood, although a number of hypotheses have been put forward. Current evidence indicates that smoking cessation is not only important to prevent macrovascular complications in diabetes, but also has a role in limiting microvascular disease and may also facilitate glycaemic management in this condition.

Occupational metal exposures, smoking and risk of diabetes and prediabetes

BACKGROUND

Metal exposure and tobacco smoking have been independently associated with diabetes, but no study has been conducted to investigate the interaction between them on the risk of diabetes.

AIMS

To investigate the effect of occupational exposure to metals, and potential effect modification by smoking, on the risk of diabetes and prediabetes in a cohort of Chinese male workers.

METHODS

We assessed metal exposure and tobacco smoking at baseline in the Jinchang Cohort of male workers. We used Poisson regression analyses to estimate the interaction between smoking and metal exposures based on occupations, which we grouped according to the measured urinary metal levels.

RESULTS

Among the 26008 study subjects, compared with non-smokers, the adjusted prevalence ratio (PR) for diabetes was 1.8 [95% confidence interval (CI) 1.3-2.4] for smokers of >40 pack-years. The adjusted PRs were 1.2 (95% CI 1.1-1.4) among mining/production workers and 2.7 (95% CI 2.4-3.0) among smelting/refining workers, both compared with office workers. There was significant effect modification under the additive model between smoking and metal exposure on the prevalence of diabetes (Pinteraction = 0.001), with an adjusted PR of 3.6 (95% CI 2.4-5.4) for those with >40 pack-years of smoking who had the highest metal exposures, whereas no significant interaction was observed for prediabetes.

CONCLUSIONS

Both exposure to metals and heavy smoking were associated with an increased prevalence of diabetes in this large cohort of male workers. There was also strong interaction between these two exposures in affecting diabetes risk that should be confirmed in future studies.

Electronic Cigarettes for Curbing the Tobacco-Induced Burden of Noncommunicable Diseases: Evidence Revisited with Emphasis on Challenges in Sub-Saharan Africa

Introduction. This review examines whether electronic cigarettes (e-cigs) implementation or vulgarization in sub-Saharan Africa (SSA) could be helpful in curtailing the toll of tobacco smoking in the region. Discussion. There are about 1.3 billion smokers worldwide, with nearly 80% of them living in developing countries where the burden of tobacco-related illnesses and deaths is the heaviest. Studies report that e-cigs may facilitate smoking cessation, reduction, or abstinence and may pose only a small fraction of the risks of traditional tobacco cigarettes; e-cigs may also considerably reduce second-hand smoking. Thereby, implementation of e-cig use could help to substantially reduce the burden driven by tobacco smoking in SSA, in a particular context of lack of regulations and control policies towards this threat. However, the evidence is not clear on whether e-cigs are risk-free, especially if used in the long term. Conclusions. On the whole, if e-cigs were to be introduced in SSA, they should be strictly recommended to current and/or ex-smokers as a method to quit smoking or prevent relapse and never-smokers should be strongly encouraged to avoid using these devices. Bans on sales of e-cigs to youngsters should be legislated, e-cig advertisements prohibited, and their usage continuously controlled and monitored.

Association between the Time of Length since Smoking Cessation and Insulin Resistance in Asymptomatic Korean Male Ex-Smokers

AIM

Smoking is a major risk factor for diabetes mellitus, mainly due to decreased insulin secretion and increased insulin resistance. However, there has been little research on the effects of smoking cessation period on changes in insulin resistance. In this study, we investigated the relationships between the length of time since smoking cessation period and insulin resistance in asymptomatic Korean male ex-smokers.

METHODS

A total of 851 male adults were included in this study. We considered several factors that can affect insulin resistance, and through multiple linear regression analysis, we assessed the effect the length of time since smoking cessation on insulin resistance in ex-smokers. Insulin resistance was represented as the insulin resistance index estimated by homeostasis model assessment.

RESULTS

HOMA-IR values showed a statistically significant negative correlation with the length of time since smoking cessation (p = 0.009) in ex-smokers. After performing multiple linear regression analysis using factors that could potentially influence insulin resistance, we found that waist circumference (p = 0.026) and the length of time since smoking cessation (p = 0.039) were independent predictors of HOMA-IR in asymptomatic male ex-smokers.

CONCLUSION

The longer the smoking cessation period, the more the insulin resistance tended to decrease in asymptomatic Korean male ex-smokers.

Smoking status and abdominal obesity among normal- and overweight/obese adults: Population-based FINRISK study

Several studies have reported direct associations of smoking with body mass index (BMI) and abdominal obesity. However, the interplay between them is poorly understood. Our first aim was to investigate the interaction between smoking status and BMI on abdominal obesity (waist circumference, WC). Our second aim was to examine how the association of smoking status with WC varies among normal and overweight/obese men and women. We examined 5833 participants from the National FINRISK 2007 Study. The interactions between smoking and BMI on WC were analyzed. Participants were categorized into eight groups according to BMI (normal weight vs. overweight/obese) and smoking status (never smoker, ex-smoker, occasional/light/moderate daily smoker, heavy daily smoker). The associations between each BMI/smoking status -group and WC were analyzed by multiple regressions, the normal-weight never smokers as the reference group. The smoking status by BMI-interaction on WC was significant for women, but not for men. Among the overweight/obese women, ex-smokers (β = 2.73; 1.99, 3.46) and heavy daily smokers (β = 4.90; 3.35, 6.44) had the highest estimates for WC when adjusted for age, BMI, alcohol consumption and physical activity. In comparison to never smoking overweight/obese women, the β-coefficients of ex-smokers and heavy daily smokers were significantly higher. Among men and normal weight women the β -coefficients did not significantly differ by smoking status. An interaction between smoking status and BMI on abdominal obesity was observed in women: overweight/obese heavy daily smokers were particularly vulnerable for abdominal obesity. This risk group should be targeted for cardiovascular disease prevention.

Relationship of cardiometabolic parameters in non-smokers, current smokers, and quitters in diabetes: a systematic review and meta-analysis

BACKGROUND

Smoking is associated with increased macrovascular and microvascular complications in people with diabetes. In addition to other concomitant vascular perturbations, it also seems to influence the cardiometabolic parameters, which may partly explain the accelerated rate of vascular complications in smokers with diabetes. While smoking cessation is advocated as a universal component of the management of diabetes, there is some anecdotal evidence that HbA1c could increase following smoking cessation. The aim of this review is to explore the relationship between smoking and its cessation on cardiometabolic parameters in diabetes.

METHODS

Searches were conducted on Medline, EMBASE and CINAHL up to March 2016. After screening 6866 studies (Additional file 1), 14 observational studies with a total of 98,978 participants' with either type 1 or type 2 diabetes were selected for review. Narrative synthesis and meta-analyses were carried out to explore the relationship between smoking and its cessation.

RESULTS

Meta-analysis showed that the pooled mean difference of HbA1c between non-smokers and smokers was -0.61% (95% CI -0.88 to -0.33, p < 0.0001). The difference in LDL cholesterol between non-smokers and smokers was -0.11 mmol/l (95% CI -0.21 to -0.01, p = 0.04). The difference in HDL cholesterol between non-smokers and smokers was 0.12 mmol/l (95% CI 0.08-0.15, p < 0.001). However, there was no statistically significant difference in blood pressure between the two groups. The difference in HbA1c between quitters and continued smokers was not statistically significant -0.10% (95% CI -0.42 to 0.21, p = 0.53). However, a narrative synthesis revealed that over a period of 10 years, the HbA1c was comparable between non-smokers and quitters.

CONCLUSION

Non-smokers have a statistically significant lower HbA1c and more favourable lipid profile compared to smokers. Smoking cessation does not lead to an increase in HbA1c in long-term and may reduce vascular complications in diabetes by its favourable impact on lipid profile.

Tobacco Use, Insulin Resistance, and Risk of Type 2 Diabetes: Results from the Multi-Ethnic Study of Atherosclerosis

INTRODUCTION

Tobacco use is associated with insulin resistance and incident diabetes. Given the racial/ethnic differences in smoking patterns and incident type 2 diabetes our objective was to evaluate the association between tobacco use and insulin resistance (IR) as well as incident type 2 diabetes mellitus in a contemporary multiethnic cohort.

METHODS AND RESULTS

We studied 5,931 Multi- Ethnic Study of Atherosclerosis (MESA) participants who at baseline were free of type 2 diabetes (fasting glucose ≥7.0 mmol/l (126 mg/dl) and/or use of insulin or oral hypoglycemic medications) categorized by self-reported tobacco status and reclassified by urinary cotinine (available in 58% of participants) as never, current or former tobacco users. The association between tobacco use, IR (fasting plasma glucose, insulin, and the homeostatic model assessment of insulin resistance (HOMA-IR)) and incident diabetes over 10 years was evaluated using multivariable linear regression and Cox proportional hazards models, respectively. Mean age of the participants was 62 (±10) years, 46% were male, 41% Caucasian, 12% Chinese, 26% African American and 21% Hispanic/Latino. IR biomarkers did not significantly differ between current, former, and never cigarette users (P >0.10) but showed limited unadjusted differences for users of cigar, pipe and smokeless tobacco (All P <0.05). Fully adjusted models showed no association between dose or intensity of tobacco exposure and any index of IR. When stratified into participants that quit smoking vs. those who continued smoking during the 10-year study there was no difference in serum glucose levels or frequency of diabetes. In fully adjusted models, there was no significant difference in diabetes risk between former or current cigarette smokers compared to never smokers [HR (95% CI) 1.02 (0.77,1.37) and 0.81 (0.52,1.26) respectively].

CONCLUSION

In a contemporary multi-ethnic cohort, there was no independent association between tobacco use and IR or incident type 2 diabetes. The role smoking plays in causing diabetes may be more complicated than originally thought and warrants more in-depth large contemporary multi-ethnic studies.

Metabolomic Profiles of Body Mass Index in the Framingham Heart Study Reveal Distinct Cardiometabolic Phenotypes

Background

Although obesity and cardiometabolic traits commonly overlap, underlying pathways remain incompletely defined. The association of metabolite profiles across multiple cardiometabolic traits may lend insights into the interaction of obesity and metabolic health. We sought to investigate metabolic signatures of obesity and related cardiometabolic traits in the community using broad-based metabolomic profiling.

Methods and Results

We evaluated the association of 217 assayed metabolites and cross-sectional as well as longitudinal changes in cardiometabolic traits among 2,383 Framingham Offspring cohort participants. Body mass index (BMI) was associated with 69 of 217 metabolites (P<0.00023 for all), including aromatic (tyrosine, phenylalanine) and branched chain amino acids (valine, isoleucine, leucine). Additional metabolic pathways associated with BMI included the citric acid cycle (isocitrate, alpha-ketoglutarate, aconitate), the tryptophan pathway (kynurenine, kynurenic acid), and the urea cycle. There was considerable overlap in metabolite profiles between BMI, abdominal adiposity, insulin resistance [IR] and dyslipidemia, modest overlap of metabolite profiles between BMI and hyperglycemia, and little overlap with fasting glucose or elevated blood pressure. Metabolite profiles were associated with longitudinal changes in fasting glucose, but the involved metabolites (ornithine, 5-HIAA, aminoadipic acid, isoleucine, cotinine) were distinct from those associated with baseline glucose or other traits. Obesity status appeared to “modify” the association of 9 metabolites with IR. For example, bile acid metabolites were strongly associated with IR among obese but not lean individuals, whereas isoleucine had a stronger association with IR in lean individuals.

Conclusions

In this large-scale metabolite profiling study, body mass index was associated with a broad range of metabolic alterations. Metabolite profiling highlighted considerable overlap with abdominal adiposity, insulin resistance, and dyslipidemia, but not with fasting glucose or blood pressure traits.

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.

Smoking, Smoking Cessation, and the Risk of Type 2 Diabetes among Japanese Adults: Japan Epidemiology Collaboration on Occupational Health Study

Aims

To examine the association of smoking status, smoking intensity, and smoking cessation with the risk of type 2 diabetes (T2D) using a large database.

Methods

The present study included 53,930 Japanese employees, aged 15 to 83 years, who received health check-up and did not have diabetes at baseline. Diabetes was defined as fasting plasma glucose ≥126 mg/dl, random plasma glucose ≥200 mg/dl, HbA1c ≥6.5% (≥48 mmol/mol), or receiving medication for diabetes. Cox proportional-hazards regression models were used to investigate the association between smoking and the risk of diabetes.

Results

During 3.9 years of median follow-up, 2,441 (4.5%) individuals developed T2D. The multivariable-adjusted hazard ratios (95% CI) for diabetes were 1 (reference), 1.16 (1.04 to 1.30) and 1.34 (1.22 to 1.48) for never smokers, former smokers, and current smokers, respectively. Diabetes risk increased with increasing numbers of cigarette consumption among current smokers (P for trend <0.001). Although the relative risk of diabetes was greater among subjects with lower BMIs (< 23 kg/m²), attributable risk was greater in subjects with higher BMIs (≥ 23 kg/m²). Compared with individuals who had never smoked, former smokers who quit less than 5 years, 5 to 9 years, and 10 years or more exhibited hazards ratios for diabetes of 1.36 (1.14 to 1.62), 1.23 (1.01 to 1.51), and 1.02 (0.85 to 1.23), respectively.

Conclusions

Results suggest that cigarette smoking is associated with an increased risk of T2D, which may decrease to the level of a never smoker after 10 years of smoking cessation.

Depressive and anxiety disorders: Associated with losing or gaining weight over 2 years?

This longitudinal study examines to what extent different depressive and anxiety disorders and clinical characteristics are associated with subsequent weight change, while controlling for baseline weight, sociodemographics, health status, psychotropic medication use and (un)healthy lifestyle factors. Data are from a sample of 2447 respondents aged 18-65 years of the Netherlands Study of Depression and Anxiety (NESDA). Baseline depressive disorders and anxiety disorders were determined with the Composite International Diagnostic Interview (CIDI). Weight at baseline and after 2 years was measured and analyzed as continuous change score (mean change in weight 1kg) and in categories of significant weight loss (<1S.D. weight change equaling <4kg), weight maintenance and weight gain (>1S.D., >6kg). After full adjustment for covariates baseline comorbid anxiety and depressive disorder and baseline Major Depressive Disorder (MDD) were associated with significant 2-year weight gain. Both current and remitted MDD at baseline and a baseline dysthymia, but none of the anxiety disorders, were associated with significant weight loss. This longitudinal study confirms a U-curved link between depression and weight change over 2 years. Furthermore, a dose-response effect of depression severity on 2-year weight gain was found.

Smoking is associated with impaired glucose regulation and a decrease in insulin sensitivity and the disposition index in first-degree relatives of type 2 diabetes subjects independently of the presence of metabolic syndrome

The aim of this study was to investigate glucose tolerance, insulin secretion and insulin resistance according to smoking habits in first-degree relatives of type 2 diabetes patients, a population at high risk for developing diabetes. One thousand three hundred (646 females and 654 males) subjects underwent an oral glucose tolerance test (OGTT) to investigate their glucose metabolism and answered questionnaires about their lifestyle habits. Smoker subjects showed significant impairment compared with non-smoker subjects in 2-h post-oral glucose tolerance test (2hOGTT, 129.3 ± 40.2 vs. 117.7 ± 37.6 mg/dl, p < 0.001), the OGTT insulin sensitivity (386.3 ± 54.9 vs. 400.5 ± 53.4 ml min(-1) m(2), p < 0.01) method and the insulin sensitivity and secretion index-2 (ISSI-2, 1.7 ± 0.8 vs. 2.0 ± 1.0, p < 0.005). Metabolic syndrome (MS) was higher in the smoker than in the non-smoker group (46.5 vs. 29.7 %, p < 0001), and smokers were more sedentary than non-smokers (3.94 ± 3.77 vs. 4.86 ± 4.41 h/week, p < 0.001). Smokers showed an increased risk of impaired glucose regulation (IGR: impaired glucose tolerance or diabetes mellitus) with a hazard ratio (HR) adjusted by gender, metabolic syndrome and physical activity of 1.78, 95 % CI 1.27-2.47 (p < 0.001). The association between smoking and MS conferred a risk of IGR that was five times higher (HR 5.495, 95 % CI 4.07-7.41, p < 0.001). Smoking habit was a significant explanatory variable in a multiple forward stepwise regression analysis performed using 2hOGTT and ISSI-2 as dependent variables (p < 0.0001, R = 0.313 and p < 0.0001, R = 0.347, respectively). In conclusions, our results show that tobacco smoking is tightly associated with impairments in glucose metabolism and insulin sensitivity and insulin secretion.

The relationship between waterpipe smoking and body weight: population-based findings from Syria

INTRODUCTION

Cigarette smoking has well known effects on body weight, with current smokers weighing less than never-smokers, and cessation producing weight gain. Use of waterpipe (or "hookah") is increasing in many parts of the world but its effects on body weight are not known.

METHODS

We compared body mass index (BMI) among 2,536 adults (age ≥ 18 years old), who were never, former, current nondaily, or current daily waterpipe smokers, drawn from 2 representative, population-based household surveys of adults in Aleppo, Syria.

RESULTS

Overall, 84.1% (n = 2,134) never-smoked waterpipe, 4.6% (n = 116) were former smokers, 9.9% (n = 251) were current nondaily smokers, and 1.4% (n = 35) were current daily smokers. Mean BMI of the sample was 30.2 kg/m(2) (SD = 6.3). Adjusted for cigarette smoking, number of chronic diseases, age, gender, income, and marital status, daily waterpipe users were 2.26 BMI units greater than never-smokers (beta = 2.26, 95% CI = 0.79-3.72), and had nearly threefold odds of being obese (odds ratio = 2.87, 95% CI = 1.06-7.76). Nondaily and former waterpipe users were similar to never-smokers in terms of BMI and obesity risk.

CONCLUSION

Results indicate that daily waterpipe users, compared to never-users, have higher BMI, translating into 6 extra kilograms of weight on average, and are 3 times as likely to be obese.

Cigarette smoking and gestational diabetes mellitus in Hispanic woman

AIMS

Hispanic women are at increased risk of gestational diabetes mellitus (GDM) as compared to non-Hispanic white women. While smoking has been associated with increased risk of type 2 diabetes, studies of smoking and GDM are sparse and conflicting. Therefore, we evaluated the relationship between cigarette smoking and GDM in Hispanic women.

METHODS

We conducted a pooled analysis of two Hispanic datasets based in Massachusetts: the UMass Medical Health Care dataset and the Proyecto Buena Salud dataset. A total of 3029 Hispanic prenatal care patients with singleton gestations were included. Cigarette smoking prior to and during pregnancy was collected via self-report. Diagnosis of GDM was abstracted from medical records and confirmed by study obstetricians.

RESULTS

One-fifth of participants (20.4%) reported smoking prior to pregnancy, and 11.0% reported smoking in pregnancy. A total of 143 women (4.7%) were diagnosed with GDM. We did not observe an association between pre-pregnancy cigarette smoking and odds of GDM (multivariable OR=0.77, 95% CI 0.47, 1.25). In contrast, smoking during pregnancy was associated with a 54% reduction in odds of GDM (OR=0.46, 95% CI 0.22, 0.95). However, this association was no longer statistically significant after adjustment for age, parity, and study site (OR=0.47, 95% CI 0.23, 1.00).

CONCLUSIONS

In this population of Hispanic pregnant women, we did not observe statistically significant associations between pre-pregnancy smoking and odds of GDM. A reduction in odds of GDM among those who smoked during pregnancy was no longer apparent after adjustment for important diabetes risk factors.

Smoking and diabetes: does the increased risk ever go away?

Recent studies reported that smoking cessation leads to higher short-term risk of type 2 diabetes than continuing to smoke. However, the duration of increased diabetes risk following smoking cessation needs further investigation. We followed 135,906 postmenopausal women aged 50-79 years enrolled in the Women's Health Initiative between September 1, 1993, and December 31, 1998, over an average of 11 years to examine the association between smoking cessation and risk of diabetes using Cox proportional hazard multivariable-adjusted regression models. Compared with that for never smokers, the risk for diabetes was significantly elevated in current smokers (hazard ratio = 1.28, 95% confidence interval: 1.20, 1.36) but was even higher in women who quit smoking during the first 3 years of follow-up (hazard ratio = 1.43, 95% confidence interval: 1.26, 1.63). Among former smokers, the risk of diabetes decreased significantly as the time since quitting increased and was equal to that of never smokers following a cessation period of 10 years. In new quitters with low cumulative exposure (<20 pack-years), diabetes risk was not elevated following smoking cessation. In conclusion, the risk of diabetes in former smokers returns to that in never smokers 10 years after quitting, and even more quickly in lighter smokers.

General and abdominal obesity parameters and their combination in relation to mortality: a systematic review and meta-regression analysis

Epidemiological studies assessing general and abdominal obesity measures or their combination for mortality prediction have shown inconsistent results. We aimed to systematically review the associations of body mass index (BMI), waist-to-hip ratio (WHR), waist circumference (WC) and waist-to-height ratio (WHtR) with all-cause mortality in prospective cohort studies. In this systematic review, which includes a meta-regression analysis, we analysed the associations with all-cause mortality of BMI, WHR, WC and WHtR in prospective cohort studies available in Medline, Embase, the Cochrane Database of Systematic Reviews and Esbiobase from inception through 7 May 2010. A total of 18 studies met the inclusion criteria, comprising 689, 465 participants and 48, 421 deaths during 5-24 years of follow-up. The studies were heterogeneous, mainly due to differences in categorization of anthropometric parameters (AP) and different approaches to statistical analysis. Both general and abdominal obesity measures were significantly associated with mortality. In analyses using categorical variables, BMI and WC showed predominantly U- or J-shaped associations with mortality, whereas WHR and WHtR demonstrated positive relationships with mortality. All measures showed similar risk patterns for upper quantiles in comparison to reference quantiles. The parameters of general and abdominal obesity each remained significantly associated with mortality when adjusted for the other. This evidence suggests that abdominal obesity measures such as WC or WHR, show information independent to measures of general obesity and should be used in clinical practice, in addition to BMI, to assess obesity-related mortality in adults.

Association of smoking cessation and weight change with cardiovascular disease among adults with and without diabetes

IMPORTANCE

Smoking cessation reduces the risks of cardiovascular disease (CVD), but weight gain that follows quitting smoking may weaken the CVD benefit of quitting.

OBJECTIVE

To test the hypothesis that weight gain following smoking cessation does not attenuate the benefits of smoking cessation among adults with and without diabetes.

DESIGN, SETTING, AND PARTICIPANTS

Prospective community-based cohort study using data from the Framingham Offspring Study collected from 1984 through 2011. At each 4-year examination, self-reported smoking status was assessed and categorized as smoker, recent quitter (≤ 4 years), long-term quitter (>4 years), and nonsmoker. Pooled Cox proportional hazards models were used to estimate the association between quitting smoking and 6-year CVD events and to test whether 4-year change in weight following smoking cessation modified the association between smoking cessation and CVD events.

MAIN OUTCOME MEASURE

Incidence over 6 years of total CVD events, comprising coronary heart disease, cerebrovascular events, peripheral artery disease, and congestive heart failure.

RESULTS

After a mean follow-up of 25 (SD, 9.6) years, 631 CVD events occurred among 3251 participants. Median 4-year weight gain was greater for recent quitters without diabetes (2.7 kg [interquartile range {IQR}, -0.5 to 6.4]) and with diabetes (3.6 kg [IQR, -1.4 to 8.2]) than for long-term quitters (0.9 kg [IQR, -1.4 to 3.2] and 0.0 kg [IQR, -3.2 to 3.2], respectively, P < .001). Among participants without diabetes, age- and sex-adjusted incidence rate of CVD was 5.9 per 100 person-examinations (95% CI, 4.9-7.1) in smokers, 3.2 per 100 person-examinations (95% CI, 2.1-4.5) in recent quitters, 3.1 per 100 person-examinations (95% CI, 2.6-3.7) in long-term quitters, and 2.4 per 100 person-examinations (95% CI, 2.0-3.0) in nonsmokers. After adjustment for CVD risk factors, compared with smokers, recent quitters had a hazard ratio (HR) for CVD of 0.47 (95% CI, 0.23-0.94) and long-term quitters had an HR of 0.46 (95% CI, 0.34-0.63); these associations had only a minimal change after further adjustment for weight change. Among participants with diabetes, there were similar point estimates that did not reach statistical significance.

CONCLUSIONS AND RELEVANCE

In this community-based cohort, smoking cessation was associated with a lower risk of CVD events among participants without diabetes, and weight gain that occurred following smoking cessation did not modify this association. This supports a net cardiovascular benefit of smoking cessation, despite subsequent weight gain.

Smoking is associated with reduced risk of autoimmune diabetes in adults contrasting with increased risk in overweight men with type 2 diabetes: a 22-year follow-up of the HUNT study

OBJECTIVE

To investigate the association between smoking habits and risk of autoimmune diabetes in adults and of type 2 diabetes.

RESEARCH DESIGN AND METHODS

We used data from the three surveys of the Nord-Trøndelag Health Study, spanning 1984-2008 and including a cohort of 90,819 Norwegian men (48%) and women (52%) aged ≥20 years. Incident cases of diabetes were identified by questionnaire and classified as type 2 diabetes (n = 1,860) and autoimmune diabetes (n = 140) based on antibodies to glutamic decarboxylase (GADA) and age at onset of diabetes. Hazard ratios (HRs) adjusted for confounders were estimated by Cox proportional hazards regression models.

RESULTS

The risk of autoimmune diabetes was reduced by 48% (HR 0.52 [95% CI 0.30-0.89]) in current smokers and 58% in heavy smokers (0.42 [0.18-0.98]). The reduced risk was positively associated with number of pack-years. Heavy smoking was associated with lower levels of GADA (P = 0.001) and higher levels of C-peptide (964 vs. 886 pmol/L; P = 0.03). In contrast, smoking was associated with an increased risk of type 2 diabetes, restricted to overweight men (1.33 [1.10-1.61]). Attributable proportion due to an interaction between overweight and heavy smoking was estimated to 0.40 (95% CI 0.23-0.57).

CONCLUSIONS

In this epidemiological study, smoking is associated with a reduced risk of autoimmune diabetes, possibly linked to an inhibitory effect on the autoimmune process. An increased risk of type 2 diabetes was restricted to overweight men.

Smoking and abdominal fat in blood donors

OBJECTIVE

To assess the association between smoking and abdominal fat among male blood donors.

METHODS

This was a cross-sectional study involving 1,235 adult male blood donors (age, 20-59 years) in the city of Cuiabá, Brazil. Socioeconomic, demographic, and anthropometric data, as well as information on the lifestyle of the participants, were collected. In this study, waist circumference and waist-to-hip ratio were used as markers of abdominal fat. The association between these two markers and smoking was analyzed by multiple linear regression in separate models, adjusted for potential confounders.

RESULTS

Of the 1,235 respondents, 273 (22.1%) reported being smokers, and, of those, 99 (36.3%) reported smoking more than 15 cigarettes per day. The average body mass index was lower among smokers than among nonsmokers (p < 0.001). In the multiple linear regression analyses, smoking was associated with waist circumference and waist-to-hip ratio for smokers of 6-10 cigarettes/day and of > 11 cigarettes/day.

CONCLUSIONS

In our sample, smoking was positively associated with indicators of abdominal fat, regardless of potential confounding factors, including the consumption of alcoholic beverages.

High consumption of smokeless tobacco ("snus") predicts increased risk of type 2 diabetes in a 10-year prospective study of middle-aged Swedish men

AIMS

Cigarette smoking increases the risk of type 2 diabetes (T2D). In Sweden and the US, people shift from smoking cigarettes to smokeless tobacco, i.e. oral moist snuff, "snus", to attain harm-reduction. There are limited and conflicting data as to whether snus increases the risk of T2D. The present study investigated if snus use predicts the risk of T2D incidence.

METHODS

This is a prospective population-based study where middle-aged Swedish men (n=2,383), without previously diagnosed T2D, were investigated with oral glucose tolerance test (OGTT) at baseline in 1992-94 and at follow-up 10 years later. Odds ratios (ORs) for newly diagnosed T2D at follow-up were assessed among those using snus, or cigarettes, at both baseline and follow-up, adjusted for major confounders.

RESULTS

The OR for T2D was not significantly increased in the whole group of snus users. However, the risk of diabetes increased with increasing weekly snus consumption; ORs (CIs) for >four boxes of snus/week were 2.1 (CI 0.9-4.9), and for >five boxes/week 3.3 (CI 1.4-8.1). For comparison, men smoking at baseline and still smoking at follow-up had an increased risk of diabetes compared with never smokers, OR 1.5 (CI 0.8-3.0), most evident for those smoking >15 cigarettes per day, OR 2.4 (CI 1.0-5.8). Tobacco use was associated with estimations of low insulin response (OGTT), but not low insulin sensitivity (HOMA).

CONCLUSIONS

High consumption of snus, like smoking, predicts risk of developing T2D. This should be considered when seeking harm-reduction by changing from use of cigarettes to snus. T2D risk from tobacco use may be mediated by effects on beta-cell function.

Six-minute walk test in non-insulin-dependent diabetes mellitus patients living in Northwest Africa

INTRODUCTION

International recommendations of the exploration of non-insulin-dependent diabetes mellitus (NIDDM) are focused on deficiency and not incapacity.

AIMS

(1) To estimate the incapacity of NIDDM patients through the 6-minute walk test (6MWT) data. (2) To determine their 6-minute walk distance (6MWD) influencing factors (3) To compare data of NIDDM patient group (PG; n = 100) with those of two control groups (CG): CG1 (n = 174, healthy nonobese and nonsmoker); CG2 (n = 55, obese nondiabetic free from comorbidities).

POPULATION AND METHODS

The anthropometric, socioeconomic, clinical, metabolic, and 6MWT data of 100 NIDDM patients (45 females) were collected.

RESULTS

Total sample means ± standard deviation of age, weight, and height were 54 ± 8 years, 81 ± 14 kg, and 1.64 ± 0.09 m. (1) Measured 6MWD (566 ± 81 m) was significantly lower than the theoretical 6MWD (90% ± 12%). The profile of the PG carrying the 6MWT, was as follows: 23% had an abnormal 6MWD; at the end of the 6MWT, 21% and 12% had, respectively, a low heart rate and a high dyspnea (>5/10), and 4% had desaturation during the walk. The estimated "cardiorespiratory and muscular chain" age (68 ± 16 years) was significantly higher than the chronological age. (2) The factors that significantly influenced the 6MWD (r(2) = 0.58) are included in the following equation: 6MWD (m) = -73.94 × gender (0, male; 1, female) - 3.25 × age (years) + 7.33 × leisure activity score - 35.57 × obesity (0, no; 1, yes) + 32.86 × socioeconomic level (0, low; 1, high) - 27.67 × cigarette use (0, no; 1, yes) + 8.89 × resting oxyhemoglobin saturation - 105.48. (3) Compared to the CGs, the PG had a significantly (P < 0.05) lower 6MWD (100%+9% and 100%+8%, respectively, for the CG1 and CG2).

CONCLUSION

NIDDM seems to accelerate the decline of the submaximal aerobic capacity evaluated through the 6MWD.

The endocrine effects of nicotine and cigarette smoke

With a current prevalence of approximately 20%, smoking continues to impact negatively upon health. Tobacco or nicotine use influences the endocrine system, with important clinical implications. In this review we critically evaluate the literature concerning the impact of nicotine as well as tobacco use on several parameters of the endocrine system and on glucose and lipid homeostasis. Emphasis is on the effect of smoking on diabetes mellitus and obesity and the consequences of smoking cessation on these disorders. Understanding the effects of nicotine and cigarettes on the endocrine system and how these changes contribute to the pathogenesis of various endocrine diseases will allow for targeted therapies and more effective approaches for smoking cessation.

Smoking Status and Metabolic Syndrome in the Multi-Ethnic Study of Atherosclerosis. A cross-sectional study

Background

Current smoking is associated with type 2 diabetes mellitus and impaired glucose tolerance but its association with the metabolic syndrome (metS), particularly with sufficiently sampled African American representation, has not been clearly established.

Objective

To assess whether a) metS is associated with smoking; b) any increased risk of metS among smokers is independent of body mass index (BMI) compared with non-smokers; c) smoking status is differentially associated with the metS and its components across different ethnic groups.

Methods

Cross sectional analysis of the Multi-Ethnic Study of Atherosclerosis (MESA) a community population-based sample free of cardiovascular disease.

Results

Current smokers (N = 769) had higher risk of metS (odds ratio [OR, 95% confidence interval]: 1.4, 1.1-1.7) versus never (reference, N = 2981) and former smokers (1.0, 0.8-1.1, N = 2163) and for metS components: high waist circumference (WC) (OR:1.9, 1.2-2.1), low high density lipoprotein cholesterol (HDL-C) (1.5, 1.3-1.8), elevated plasma triglycerides (TG) (OR:1.4, 1.2-1.7) as well as high C-reactive protein (CRP, an inflammatory marker) concentration (OR: 1.6,1.3-2.0) compared to never and former smokers after adjustment for BMI. A smoking status by ethnicity interaction occurred such that African American current and former smokers had greater likelihood of low HDL-C than White counterparts.

Conclusions

This study found that smoking is associated with the metS and despite the lower BMI of current smokers the prevalence of low HDL-C, elevated TG and CRP is higher among them than among non-smokers. African Americans generally have higher HDL-C than Whites but smoking wipes out this advantage.

Multi-Ethnic Study of Atherosclerosis (MESA) ClinicalTrials.gov Identifier: NCT00005487

Long working hours and metabolic syndrome among Japanese men: a cross-sectional study

Background

The link between long working hours and health has been extensively studied for decades. Despite global concern regarding metabolic syndrome, however, no studies to date have solely evaluated the relationship between long working hours and that syndrome. We therefore examined the association between long working hours and metabolic syndrome in a cross-sectional study.

Methods

Between May and October 2009, we collected data from annual health checkups and questionnaires from employees at a manufacturing company in Shizuoka, Japan. Questionnaires were returned by 1,601 workers (response rate: 96.2%; 1,314 men, 287 women). After exclusions, including women because of a lack of overtime work, the analysis was performed for 933 men. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for metabolic syndrome. Further, we conducted a stratified analysis by age-group (<40 years vs. ≥40 years).

Results

Metabolic syndrome was identified in 110 workers (11.8%). We observed a positive association between working hours and metabolic syndrome after adjusting for age, occupation, shift work, smoking status, frequency of alcohol consumption, and cohabiting status. Compared with subjects who worked 7–8 h/day, multivariate ORs for metabolic syndrome were 1.66 (95% CI, 0.91–3.01), 1.48 (95% CI, 0.75–2.90), and 2.32 (95% CI, 1.04–5.16) for those working 8–9 h/day, 9–10 h/day, and >10 h/day, respectively. Similar patterns were obtained when we excluded shift workers from the analysis. In age-stratified analysis, the corresponding ORs among workers aged ≥40 years were 2.02 (95% CI, 1.04–3.90), 1.21 (95% CI, 0.53–2.77), and 3.14 (95% CI, 1.24–7.95). In contrast, no clear association was found among workers aged <40 years.

Conclusions

The present study suggests that 10 h/day may be a trigger level of working hours for increased risk of metabolic syndrome among Japanese male workers.

Health disparities among occupations in Taiwan: a population study

OBJECTIVES

The first large-scale population survey was conducted in Taiwan to examine if and to what extent health disparities of four major chronic physical conditions exist among occupations.

METHODS

Face-to-face interviews about two risk behaviors (i.e., cigarette and alcohol use) and four major chronic physical conditions (i.e., cardiovascular disease, diabetes, liver disease and asthma) were conducted with 13,741 workers from nine major categories of occupations.

RESULTS

Health disparities among occupations were found based on a series of hierarchical logistic regression analyses after controlling for age, sex and two risk behaviors. In general, prevalence rates of cardiovascular disease among elementary occupations and skilled agricultural and fishery workers were approximately two to four times higher than those among other occupations. The above two occupations and plant and machine operators also had higher prevalence rates in diabetes and liver disease.

CONCLUSIONS

The results concerning health disparities among occupations provide policymakers and researchers with invaluable benchmarks of chronic physical conditions among occupations. The findings also suggest the importance of investigating causal relationship between these diseases and exposures at work, identifying and reducing unique risk factors and hazard exposures experienced by workers and conducting targeted surveillance and health promotion programs for at-risk occupations.

Weight gain and incident obesity among male snus users

Background

Snus is a moist smokeless tobacco product which has recently reached beyond its original market of Scandinavia. Snus is now being increasingly used in both the United States and South Africa. The effect of snus use on weight is unknown. This study has therefore investigated the relationship between the use of snus, weight gain (≥5%) and the incidence of obesity (body mass index ≥30 kg/m²).

Methods

The study participants (n = 9,954 males living in Stockholm County, Sweden) were recruited in 2002 and reassessed in 2007. Tobacco use was categorized according to information obtained in both the baseline and follow-up surveys. Outcomes were assessed by comparing self-reported weight and body mass index between the baseline and follow-up surveys.

Results

Stable current snus use (according to both surveys), compared to never having used any kind of tobacco, seemed to be associated with both weight gain (odds ratio = 1.31, 95% confidence interval: 1.04-1.65) and incident obesity (odds ratio = 1.93, 95% confidence interval: 1.13-3.30) after adjustment for age, baseline weight, alcohol consumption, physical activity, education, consumption of fruit and berries, and the frequency of having breakfast. No associations with incident obesity or weight gain were seen for stable former users of snus (according to both surveys) or among men who quit or began using snus during follow-up.

Conclusions

These data suggest that the use of snus is moderately associated with weight gain and incident obesity among men.

Smoking and risk for diabetes incidence and mortality in Korean men and women

OBJECTIVE

Mounting evidence suggests that smoking is a cause of type 2 diabetes. We explored the association of cigarette smoking with diabetes incidence and mortality in a large cohort of Koreans.

RESEARCH DESIGN AND METHODS

A 14-year prospective cohort study was performed on 1,236,443 Korean men and women, aged 30-95 years at baseline, who underwent standardized biennial medical examinations provided by the National Health Insurance Corporation (NHIC). Incident diabetes was identified on the basis of outpatient visits, hospitalization, or prescription medication treatment for diabetes, as captured in the NHIC database. Diabetes mortality was obtained through the national statistical office. Cox proportional hazards models were used to investigate associations of smoking with indicators of diabetes and diabetes mortality.

RESULTS

Smoking was significantly associated with increased risk for diabetic outpatient treatment, hospitalization, and mortality among both men and women, and the risk among current smokers increased modestly with the number of cigarettes smoked daily (P(trend) < 0.0001 for all associations). Compared with never smokers, current male smokers who smoked ≥ 20 cigarettes/day had increased risk for incident diabetes defined by outpatient treatment (adjusted hazard ratio 1.55 [1.51-1.60]), incident diabetes defined by ≥ 3 prescription medications for diabetes (1.71 [1.63-1.80]), and death from diabetes (1.60 [1.25-2.06]). The risks for outpatient treatment among smokers were higher in men than in women with evidence for effect modification by sex and age (P(interaction) < 0.0001).

CONCLUSIONS

Our study provides longitudinal evidence that smoking increases the risk of incident diabetes and mortality.

The effect of smoking on arterial stiffness

A systematic literature review was conducted using PubMed, Embase and the Cochrane Library to determine the effect of acute, chronic and passive smoking on arterial stiffness and to determine whether these effects are reversible after smoking cessation. A total of 39 relevant studies were identified and included. Acute smoking was found to cause an acute increase in arterial stiffness. Similarly, passive smoking increased arterial stiffness acutely and chronically. The majority of studies identified chronic smoking as a risk factor for increasing arterial stiffness. However, some studies found no statistical difference in arterial stiffness between nonsmokers and long-term smokers, although chronic smoking seems to sensitize the arterial response to acute smoking. In addition, whether arterial stiffness is reversed after smoking cessation and the timeline in which this may occur could not be determined from the identified literature. The effect of smoking discontinuation on arterial stiffness remains to be established by prospective smoking cessation trials.

Association of passive and active smoking with incident type 2 diabetes mellitus in the elderly population: the KORA S4/F4 cohort study

Active smoking is a risk factor for type 2 diabetes (T2DM), but it is unclear whether exposure to environmental tobacco smoke (ETS) is also associated with T2DM. The effect of passive and active smoking on the 7-year T2DM incidence was investigated in a population-based cohort in Southern Germany (KORA S4/F4; 1,223 subjects aged 55-74 years at baseline in 1999-2001, 887 subjects at follow-up). Incident diabetes was identified by oral glucose tolerance tests or by validated physician diagnoses. Among never smokers, subjects exposed to ETS had an increased diabetes risk in the total sample (odds ratio (OR) = 2.5; 95% confidence interval (CI): 1.1, 5.6) and in a subgroup of subjects having prediabetes at baseline (OR = 4.4; 95% CI: 1.5, 13.4) after adjusting for age, sex, parental diabetes, socioeconomic status, and lifestyle factors. Active smoking also had a statistically significant effect on diabetes incidence in the total sample (OR = 2.8; 95% CI: 1.3, 6.1) and in prediabetic subjects (OR = 7.8; 95% CI: 2.4, 25.7). Additional adjustment for components of the metabolic syndrome including waist circumference did not attenuate any of these associations. This study provides evidence that both passive and active smoking is associated with T2DM.

Destructive effects of smoking on molecular and genetic factors of periodontal disease

Many epidemiological evidences have proven the association between smoking and periodontal disease. The causality can be further established by linking findings of traditional epidemiological studies with the developments in molecular techniques that occurred in the last decade. The present article reviews recent studies that address the effect of smoking on molecular and genetic factors in periodontal disease. Most findings support the fact that tobacco smoking modulates destruction of the periodontium through different pathways: microcirculatory and host immune systems, connective tissue, and bone metabolism. Although smokers experience an increased burden of inflammatory responses to microbial challenges compared to non-smokers, understanding the association between smoking and periodontal diseases involves substantial problems with respect to accuracy of measurements, and particularly, sampling of many subjects. It remains unclear whether genetic susceptibility to periodontal disease is influenced by exposure to smoking or the effect of smoking on periodontal disease is influenced by genetic susceptibility. Employment of molecular techniques may play a key role in further elucidation of mechanisms linking smoking and periodontal destruction, the direct relationship as environmental factors and indirect relationship through genetic factors.

Endocrine and metabolic effects of smoking cessation

BACKGROUND

Cardiovascular, pulmonary, and oncological hazards of tobacco smoking have been well studied. Smoking may also have multiple effects on endocrine and metabolic systems affecting pituitary, thyroid, and adrenal glands; testicular and ovarian function; as well as energy balance; lipid, and glucose metabolism; and insulin resistance. Less is known about hormonal and metabolic effects that patients may experience while quitting smoking.

SCOPE

The objective of this article is to review systematically data on the endocrine and metabolic effects of smoking cessation. Articles based upon clinical trials, randomised controlled trials, and meta-analyses were obtained via a MEDLINE search (articles published between 1 August 1998 and 31 July 2008, inclusive; English language; human subjects; including abstracts) using key search terms relating to smoking cessation and endocrine or metabolic parameters. Additional studies were identified from the bibliographies of reviewed literature. Studies related to the search criteria were reviewed, 199 papers were identified, and 57 pertinent to this review were included.

FINDINGS

Limited data are available on the short- and long-term effects of smoking cessation on hypothalamic- and thyroid-pituitary-adrenal axes, sex hormones, energy homeostasis, and lipid and glucose metabolism. Initial data indicate that smoking cessation is associated with decreased cortisol levels and in the short-term, smoking cessation does not correct the diminished adrenocortical responses to stress caused by chronic smoking. Cessation reverses smoking's effects on thyroid disorders and may reduce the risk of osteoporosis. Finally, smoking cessation increases transiently food intake and sustained weight gain and is associated with increases in high-density lipoprotein cholesterol levels that occur rapidly on cessation.

CONCLUSION

Further research may provide insight into post-cessation endocrine changes that may be caused by alterations to central and peripheral systems. Such research may increase the understanding of underlying biological mechanisms that lead to symptoms and clinical features of smoking cessation.