Cigarette Smoking Is Associated with Prolongation of the QTc Interval Duration in Patients with Type 2 Diabetes Mellitus

Investigating the impact of smoking habits through photoplethysmography analysis

Smoking is widely recognized as a significant risk factor in the progression of arterial stiffness and cardiovascular diseases. Valuable information related to cardiac arrhythmias and heart function can be obtained by analyzing biosignals such as the electrocardiogram (ECG) and the photoplethysmogram (PPG). The PPG signal is a non-invasive optical technique that can be used to evaluate the changes in blood volume, and thus it can be linked to the health of the vascular system.Objective. In this study, the impact of three smoking habits-cigarettes, shisha, and electronic cigarettes (e-cigarettes)-on the features of the PPG signal were investigated.Approach. The PPG signals are measured for 45 healthy smokers before, during, and after the smoking session and then processed to extract the morphological features. Quantitative statistical techniques were used to analyze the PPG features and provide the most significant features of the three smoking habits. The impact of smoking is observed through significant changes in the features of the PPG signal, indicating blood volume instability.Main results. The results revealed that the three smoking habits influence the characteristics of the PPG signal significantly, which presentseven after 15 min of smoking. Among them, shisha has the greatest impact on PPG features, particularly on heart rate, systolic time, augmentation index, and peak pulse interval change. In contrast, e-cigarettes have the least effect on PPG features. Interestingly, smoking electronic cigarettes, which many participants use as a substitute for traditional cigarettes when attempting to quit smoking, has nearly a comparable effect to regular smoking.Significance. The findings suggest that individuals who smoke shisha are more likely to develop cardiovascular diseases at an earlier age compared to those who have other smoking habits. Understanding the variations in the PPG signal caused by smoking can aid in the early detection of cardiovascular disorders and provide insight into cardiac conditions. This ultimately contributes to the prevention of the development of cardiovascular diseases and the development of a health screening system.

Smoking-associated Electrocardiographic Abnormalities Predict Cardiovascular Mortality: Insights from NHANES

Background—

Smoking is associated with arrhythmia and sudden cardiac death, but the biological mechanisms remain unclear. Abnormal electrocardiogram (ECG) durations of ventricular repolarization (QT interval), atrial depolarization (P wave), and atrioventricular depolarization (PR interval and segment), predict cardiac arrhythmia and mortality.

Objectives—

To elucidate how smoking affects cardiac excitation, we assessed in a nationally representative sample (NHANES III) associations between cotinine, abnormalities in P duration, PR interval, PR segment, rate-corrected QT (QTc), QRS duration, and JT interval, and long-term mortality.

Methods—

We analyzed data from 5,633 adults using survey-weighted multinomial logistic regression to estimate associations between tobacco use (>15 ng/ml serum cotinine) and short (<5th percentile) or long (>95th percentile) ECG intervals, relative to reference (5 - 95th percentile).

Results—

After adjustment for demographics, risk factors, and conduction-altering medications, smoking was associated with a higher odds of short PR interval, PR segment, and QRS, and long JT. Broader ECG effects of smoking were also assessed by survey-weighted linear regression of continuous cotinine and ECG intervals, which revealed cotinine inversely associated with PR segment and QTc. Over a 22-year follow-up, many ECG abnormalities predicted cardiovascular mortality in smokers, including long JT, QRS, and QTc, and short QRS.

Conclusions—

Smoking increases likelihood for rapid atrioventricular conduction, rapid ventricular depolarization, and slow ventricular repolarization. The ventricular electrophysiologic abnormalities associated with smoking also predict cardiovascular mortality in smokers; however, traditional ECG measures of cardiac risk like QTc can overlook these ventricular defects and their independent predictive value in smokers.

Modelling the relationship between continuously measured glucose and electrocardiographic data in adults with type 1 diabetes mellitus

INTRODUCTION

Type 1 diabetes mellitus (T1DM) is associated with earlier onset of cardiovascular disease. Recent evidence has found hyperglycaemia appears to play a greater role in this association among T1DM compared to T2DM. This study investigates the relationship between glucose and QTc (a key cardiovascular measure) using data from continuous electrocardiogram (ECG) and glucose monitors.

METHODS

Seventeen adults with T1DM were recruited at a clinical facility in Ireland. A continuous glucose monitoring system was fitted to each participant that measured glucose every 5 min for 7 days. The participants simultaneously wore a vest with sensors to measure 12-lead ECG data every 10 min for 7 days. Area under the glucose curve (AUC), proportion of time spent in hypoglycaemia and hyperglycaemia, and mean daily absolute deviation of glucose were calculated. Mixed effects ANOVA and functional regression models were fitted to the data to investigate the aggregate and time-dependent association between glucose and QTc.

RESULTS

All participants were male with an average age of 52.5 (SD 3.8) years. Those with neuropathy had a significantly higher mean QTc compared to their counterparts. Mean QTc was significantly longer during hyperglycaemia. There was a significant positive association between QTc and time spent in hyperglycaemia. A negative association was found between QTc and time spent in hypoglycaemia. A functional model suggested a positive relationship between glucose and QTc at several times during the 7-day follow-up.

CONCLUSION

This study used sensor technology to investigate, with high granularity, the temporal relationship between glucose and ECG data over one week. QTc was found to be longer on average during hyperglycaemia.

Association between Triglyceride Glucose Index and Corrected QT Prolongation in Chinese Male Steelworkers

Objectives: Increased triglyceride glucose (TyG) index appears to be linked to carotid and coronary atherosclerosis and calcifications and possesses an elevated future risk of developing cardiovascular disease. Corrected QT (QTc) interval prolongation is associated with ventricular arrhythmias and sudden cardiac death, and a high prevalence of prolonged QTc interval was previously reported in blue-collar workers. The purpose of this study was to find the possible causal inter-relationship between TyG index and QTc interval in a large population of Chinese male steelworkers. Methods: A total of 3189 male workers from two steel plants were enrolled. They responded to a cross-sectional questionnaire on basic attributes and lifestyle, including sleep patterns. All workers in the two plants underwent periodic health checkups, including twelve-lead electrocardiography. Structural equation modeling (SEM) was used to assess the direct and indirect effects of TyG index on QTc interval. Results: With increasing TyG index tertile, the male steelworkers had an increased QTc interval. Applying multivariate analysis, TyG index was associated independently with the odds of QTc prolongation (adjusted odds ratio = 2.73, 95% confidence interval = 1.39–5.24, p = 0.004). SEM revealed that TyG index, hypertension, obesity, lifestyle, white blood cell (WBC) count, and liver function had statistically significant direct effects on QTc interval. Furthermore, TyG index also had an indirect effect on QTc interval through hypertension, obesity, WBC count, and liver function. Moreover, lifestyle had an indirect effect on QTc interval through TyG index. The final model explained 14% of the variability in QTc interval. Conclusions: An increased TyG index was associated with QTc interval prolongation in this study, and SEM delineated possible causal pathways and inter-relationships of the risk factors contributing to the occurrence of QTc prolongation among Chinese male steelworkers.

Relationship between Plasma Adiponectin Level and Corrected QT Interval in Smoker and Non-smoker Adult Male Subjects

Objective

This study determined the relationship between plasma adiponectin level and corrected QT interval (QTc) in smokers and non-smokers.

Methodology

This cross-sectional analytical study was undertaken in 30 smokers and 30 non-smokers. Plasma adiponectin level was determined by enzyme-linked immunosorbent assay (ELISA). The QT interval was measured by routine 12-lead ECG with Lead II rhythm and QTc was calculated.

Results

Mean plasma adiponectin level was significantly lower in smokers (27.89±15 μg/ml) than that of non-smokers (52.13±21.57pg/ml) (p<0.001). Mean QTc interval was significantly longer in smokers than that of non-smokers (415.37±29.9 versus 395.63±26.13 ms, p<0.01). Higher risk of low adiponectin level (odds ratio [OR],8.1; 95% confidence interval [CI],1.61-40.77) and QTc interval prolongation (OR,6; 95%CI,1.17-30.73) were observed in smokers. There was weak significant negative correlation between plasma adiponectin level and QTc interval in the study population (n=60, r=-0.407, p=0.001). Moreover, low plasma adiponectin level was significantly associated with prolonged QTc interval in the study population (n=60, Fisher's exact p value<0.05). Risk of QTc interval prolongation was 4.3 times higher in subjects with low plasma adiponectin level (OR,4.27; 95% CI,1.05-17.46).

Conclusion

Smokers have greater risk for low plasma adiponectin level and prolonged QTc interval. There is a relationship between plasma adiponectin level and QTc interval.

Cardiovascular injury induced by tobacco products: assessment of risk factors and biomarkers of harm. A Tobacco Centers of Regulatory Science compilation

Although substantial evidence shows that smoking is positively and robustly associated with cardiovascular disease (CVD), the CVD risk associated with the use of new and emerging tobacco products, such as electronic cigarettes, hookah, and heat-not-burn products, remains unclear. This uncertainty stems from lack of knowledge on how the use of these products affects cardiovascular health. Cardiovascular injury associated with the use of new tobacco products could be evaluated by measuring changes in biomarkers of cardiovascular harm that are sensitive to the use of combustible cigarettes. Such cardiovascular injury could be indexed at several levels. Preclinical changes contributing to the pathogenesis of disease could be monitored by measuring changes in systemic inflammation and oxidative stress, organ-specific dysfunctions could be gauged by measuring endothelial function (flow-mediated dilation), platelet aggregation, and arterial stiffness, and organ-specific injury could be evaluated by measuring endothelial microparticles and platelet-leukocyte aggregates. Classical risk factors, such as blood pressure, circulating lipoproteins, and insulin resistance, provide robust estimates of risk, and subclinical disease progression could be followed by measuring coronary artery Ca2+ and carotid intima-media thickness. Given that several of these biomarkers are well-established predictors of major cardiovascular events, the association of these biomarkers with the use of new and emerging tobacco products could be indicative of both individual and population-level CVD risk associated with the use of these products. Differential effects of tobacco products (conventional vs. new and emerging products) on different indexes of cardiovascular injury could also provide insights into mechanisms by which they induce cardiovascular harm.

The association of long-term glycaemic variability versus sustained chronic hyperglycaemia with heart rate-corrected QT interval in patients with type 2 diabetes

Objectives

Prolonged heart rate-corrected QT(QTc) interval is related to ventricular arrhythmia and cardiovascular mortality, with considerably high prevalence of type 2 diabetes. Additionally, long-term glycaemic variability could be a significant risk factor for diabetic complications in addition to chronic hyperglycaemia. We compared the associations of long-term glycaemic variability versus sustained chronic hyperglycaemia with the QTc interval among type 2 diabetes patients.

Methods

In this cross-sectional study, 2904 type 2 diabetes patients were recruited who had undergone at least four fasting plasma glucose (FPG) and 2-hour postprandial plasma glucose (PPG) measurements (at least once for every 3 months, respectively) during the preceding year. Long-term glycaemic variabilities of FPG and 2-hour PPG were assessed by their standard deviations (SD-FPG and SD-PPG, respectively), and chronic fasting and postprandial hyperglycaemia were assessed by their means (M-FPG and M-PPG, respectively). HbA1c was also determined upon enrolment to assess current overall glycaemic control. QTc interval was estimated from resting 12-lead electrocardiograms, and more than 440 ms was considered abnormally prolonged.

Results

Patients with prolonged QTc interval (≥440 ms) had greater M-FPG, M-PPG, SD-PPG and HbA1c than those with normal QTc interval but comparable SD-FPG. QTc interval was correlated with M-FPG, M-PPG, SD-PPG and HbA1c (r = 0.133, 0.153, 0.245 and 0.207, respectively, p = 0.000) but not with SD-FPG (r = 0.024, p = 0.189). After adjusting for metabolic risk factors via multiple linear regression analysis, SD-PPG, M-PPG and HbA1c (t = 12.16, 2.69 and 10.16, respectively, p = 0.000) were the major independent contributors to the increased QTc interval. The proportion of prolonged QTc interval increased significantly from 10.9% to 14.2% to 26.6% for the first (T1) to second (T2) to third (T3) tertiles of SD-PPG. After adjusting via multiple logistic regression analysis, the odd ratios of prolonged QTc interval of the T2 and T3 versus the T1 of SD-PPG were 1.15 (95% CI, 0.82–1.60) and 2.62 (1.92–3.57), respectively.

Conclusions

Increased long-term variability of PPG is a strong independent risk factor for prolonged QTc interval in type 2 diabetes patients, in addition to long-term postprandial hyperglycaemia and current HbA1c.

The relationship between insulin sensitivity and heart rate-corrected QT interval in patients with type 2 diabetes

BACKGROUND

Reduced insulin sensitivity not only contributes to the pathogenesis of type 2 diabetes but is also linked to multiple metabolic risk factors and cardiovascular diseases (CVD). A prolonged heart rate-corrected QT interval (QTc interval) is related to ventricular arrhythmias and CVD mortality and exhibits a high prevalence among type 2 diabetes patients. The aim of the study was to investigate the relationship between insulin sensitivity and the QTc interval in patients with type 2 diabetes.

METHODS

This cross-sectional observational study recruited 2927 patients with type 2 diabetes who visited the Affiliated Haian Hospital and Second Affiliated Hospital of Nantong University. The insulin sensitivity index (Matsuda index, ISI_Matsuda) derived from 75-g OGTT and other metabolic risk factors were examined in all patients. The QTc interval was estimated using a resting 12-lead electrocardiogram, and an interval longer than 440 ms was considered abnormally prolonged.

RESULTS

The QTc interval was significantly and negatively correlated with the ISI_Matsuda (r = -0.296, p < 0.001), and when the multiple linear regression analysis was adjusted for anthropometric parameters, metabolic risk factors, and current antidiabetic treatments, the QTc interval remained significantly correlated with the ISI_Matsuda (β = -0.23, t = -12.63, p < 0.001). The proportion of patients with prolonged QTc interval significantly increased from 12.1% to 17.9%, 25.6% and 37.9% from the fourth to third, second and first quartile of the ISI_Matsuda, respectively. After adjusting for anthropometric parameters by multiple logistic regression analysis, the corresponding odd ratios (ORs) for prolonged QTc interval of the first, second and third quartiles versus the fourth quartile of ISI_Matsuda were 3.11 (95% CI 2.23-4.34), 2.09 (1.51-2.88) and 1.53 (1.09-2.14), respectively, and p for trend was <0.001.

CONCLUSIONS

Reduced insulin sensitivity is associated with an increase in the QTc interval in patients with type 2 diabetes.

Prevalence of diabetes and impaired fasting glucose among residents in the Three Gorges Reservoir Region, China

BACKGROUND

The Three Gorges Dam in China is the world's largest hydro-electric scheme in the contemporary world. After the construction of the Dam, great changes took place on the residents' lifestyles characterized by reduced physical activity due to the loss of arable land and a series of psychological problems caused by resettlement, which might be regarded as contributing factors to the development of diabetes in Three Gorges Reservoir Region (TGRR). However, there is no study that has been conducted targeting large population samples with the aim of determining the prevalence of diabetes in TGRR. This study purposed to estimate the prevalence of diabetes and impaired fasting glucose (IFG) in the adult population ≥18 years in TGRR and to evaluate the associated risk factors.

METHODS

A total of 3721 randomly selected adults, aged ≥18 years and having lived in TGRR for at least one year, participated in questionnaire-based interview from April to May 2013 and had their physical examinations and standard glucose taken. 75 g oral glucose tolerance test (OGTT) was conducted on the subjects with fasting glucose levels being ≥ 5.6 mmol/L. Diabetes and IFG were defined according to WHO 1999 criteria.

RESULTS

The age-standardized prevalence of diabetes and IFG were 7.6% (7.9% among men and 7.4% among women) and 9.0% (9.1% among men and 8.9% among women), respectively. Among the identified cases of diabetes in this study, 54.46% (171/314) were newly diagnosed. The prevalence of diabetes cases rose with age (4.0%, 4.5%, 8.1%, 11.2%, 12.4% and 12.9% among persons who were 18 to 29, 30 to 39, 40 to 49, 50 to 59, 60 to 69 and ≥ 70 years of age, respectively). The results of multivariate logistic-regression analyses showed that the diabetes was significantly linked to age, family history of diabetes, central obesity, educational level and hypertension for both men and women. In addition, smoking was significantly associated with diabetes in men.

CONCLUSIONS

Diabetes has become a major public health problem in the TGRR with a large number of the cases undiagnosed. These results suggest that regular population-based diabetes screening should be conducted to identify early-stage diabetes and integrated strategies aimed at the prevention and treatment of diabetes initiated.

Tobacco smoking, epilepsy, and seizures

Tobacco smoking is considered the greatest risk factor for death caused by noncommunicable diseases. In contrast to extensive research on the association between tobacco smoking and diseases such as heart attack, stroke, and cancers, studies on the association between tobacco smoking and seizures or epilepsy are insufficient. The exact roles tobacco smoking and nicotine use play in seizures or epilepsy have not been well reviewed. We reviewed available literature and found that 1) there are vast differences between tobacco smoke and nicotine based on their components and their effects on seizures or epilepsy; 2) the seizure risk in acute active tobacco smokers, women who smoke during pregnancy, electronic cigarette smokers, and the role of smoking in sudden unexplained/unexpected death in epilepsy remain unclear; 3) seizure risks are higher in acute secondhand smokers, chronic active smokers, and babies whose mothers smoke; 4) tobacco smoke protects against seizures in animal models whereas nicotine exerts mixed effects in animals; and 5) tobacco smoking agents can be noneffective, proconvulsant, or anticonvulsant. Finally, the opportunities for future research on this topic is discussed.