Association between serum cotinine levels and electrocardiographic left atrial abnormality

Investigating the interplay of smoking, cardiovascular risk factors, and overall cardiovascular disease risk: NHANES analysis 2011-2018

BACKGROUND

This study explores the intricate relationship between smoking, cardiovascular disease (CVD) risk factors and their combined impact on overall CVD risk, utilizing data from NHANES 2011-2018.

METHODS

Participants were categorized based on the presence of CVD, and we compared their demographic, social, and clinical characteristics. We utilized logistic regression models, receiver operating characteristics (ROC) analysis, and the chi-squared test to examine the associations between variables and CVD risk.

RESULTS

Significant differences in characteristics were observed between those with and without CVD. Serum cotinine levels exhibited a dose-dependent association with CVD risk. The highest quartile of cotinine levels corresponded to a 2.33-fold increase in risk. Smoking, especially in conjunction with lower HDL-c, significantly increases CVD risk. Combinations of smoking with hypertension, central obesity, diabetes, and elevated triglycerides also contributed to increased CVD risk. Waist-to-Height Ratio, Visceral Adiposity Index, A Body Shape Index, Conicity Index, Triglyceride-Glucose Index, Neutrophil, Mean platelet volume and Neutrophil to Lymphocyte ratio demonstrated significant associations with CVD risk, with varying levels of significance post-adjustment. When assessing the combined effect of smoking with multiple risk factors, a combination of smoking, central obesity, higher triglycerides, lower HDL-c, and hypertension presented the highest CVD risk, with an adjusted odds ratio of 14.18.

CONCLUSION

Smoking, when combined with central obesity, higher triglycerides, lower HDL-c, and hypertension, presented the highest CVD risk, with an adjusted odds ratio of 14.18.

Harmful Impact of Tobacco Smoking and Alcohol Consumption on the Atrial Myocardium

Tobacco smoking and alcohol consumption are widespread exposures that are legal and socially accepted in many societies. Both have been widely recognized as important risk factors for diseases in all vital organ systems including cardiovascular diseases, and with clinical manifestations that are associated with atrial dysfunction, so-called atrial cardiomyopathy, especially atrial fibrillation and stroke. The pathogenesis of atrial cardiomyopathy, atrial fibrillation, and stroke in context with smoking and alcohol consumption is complex and multifactorial, involving pathophysiological mechanisms, environmental, and societal aspects. This narrative review summarizes the current literature regarding alterations in the atrial myocardium that is associated with smoking and alcohol.

Nicotine upregulates ACE2 expression and increases competence for SARS-CoV-2 in human pneumocytes

The coronavirus disease 2019 (COVID-19) pandemic has a variable degree of severity according to underlying comorbidities and life-style. Several research groups have reported an association between cigarette smoking and increased severity of COVID-19. The exact mechanism of action is largely unclear. We exposed low angiotensin-converting enzyme 2 (ACE2)-expressing human pulmonary adenocarcinoma A549 epithelial cells to nicotine and assessed ACE2 expression at different times. We further used the nicotine-exposed cells in a virus neutralisation assay. Nicotine exposure induces rapid and long-lasting increases in gene and protein expression of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor ACE2, which in turn translates into increased competence for SARS-CoV-2 replication and cytopathic effect. These findings show that nicotine worsens SARS-CoV-2 pulmonary infection and have implications for public health policies.

Serum Cotinine and Silent Myocardial Infarction in Individuals Free from Cardiovascular Disease

Serum cotinine is a sensitive and specific marker of tobacco exposure, including second-hand smoke exposure. We sought to explore the association of tobacco exposure determined by serum cotinine with electrocardiographic silent myocardial infarction (SMI). A total of 7,006 participants (59.0 ± 13.3 years; 52.6% women, 49.7% non-Hispanic whites) without cardiovascular disease from the Third National Health and Nutrition Examination Survey (NHANES III) were included in this analysis. SMI was defined as electrocardiographic evidence of MI in the absence of a history of MI. Multivariable logistic regression analysis was used to examine the association between SMI and serum cotinine tertiles. SMI was detected in 114 (1.63%) of the participants. The prevalence of SMI was higher among those with higher levels of serum cotinine (SMI prevalence was 1.25%, 1.49%, and 2.14% across serum cotinine lower [0.03 to 0.12 ng/ml], middle [0.12 to 1.39 ng/ml], and higher [1.40 to 1890 ng/ml] tertiles, respectively). In a model adjusted for potential confounders, participants within the highest serum cotinine tertile had significantly greater odds of SMI (odds ratio [95% confidence interval]: 2.51 [1.55 to 4.08]) compared with those with serum cotinine levels in the first tertile. Each 10 ng/ml increase in serum cotinine levels was associated with a 2% (p <0.0001) increase in the prevalence of SMI. This association was stronger in white than nonwhite participants (interaction p value = 0.05). In conclusion, elevated serum cotinine levels are associated with SMI. These findings further highlight the risk associated with passive and active smoking on cardiovascular health and underscore the potential utility of serum cotinine in identifying those at risk.

Association between serum cotinine levels and electrocardiographic left atrial abnormality

BACKGROUND

Although the harmful effect of tobacco exposure on cardiovascular disease (CVD) and its risk factors are well established, the constituents of cigarette-smoke and the pathophysiological mechanism involved are unknown. Recently, deep terminal negativity of P wave in V1 (DTNPV1) has emerged as a marker of left atrial abnormality that predicts atrial fibrillation, stroke, and death due to all-cause or CVD. Therefore, we examined the association between serum cotinine levels with abnormal DTNPV1 using the Third National Health and Nutrition Examination Survey.

METHODS

This analysis included 4,507 participants (mean age 58 ± 13 years, 53% women, 49% non-Hispanic white) of NHANES III, without history of CVD or major electrocardiographic abnormalities and not on heart rate modifying medications. Multivariable logistic regression analysis was used to examine the association between serum cotinine and abnormal DTNPV1-defined from automatically processed electrocardiograms as values of the amplitude of the terminal negative phase of P wave in lead V1 exceeding 100 μV.

RESULTS

Abnormal DTNPV1 was detected in 2.3% (n = 105) of the participants. In a model adjusted for demographics and CVD risk factors, each 10 ng/ml serum cotinine was associated with 2% increased odds of abnormal DTNPV1 (odds ratio 1.02, 95% confidence interval 1.01-1.03, p-value < 0.001). This association was consistent in subgroups stratified by age, sex, race, smoking status, hypertension, diabetes, dyslipidemia, and chronic obstructive pulmonary disease.

CONCLUSION

Elevated serum cotinine levels are associated with an abnormal DTNPV1. This suggests that nicotine exposure can lead to left atrial abnormalities, a possible mechanism for increased risk of CVD.