Epilepsy and tobacco smoking: a cross-sectional study

Multimorbidity in People with Epilepsy

Multimorbidity is an emerging priority in healthcare due to associations with the ageing population, frailty, polypharmacy, health and social care demands. It affects 60-70% of adults and 80% of children with epilepsy. Neurodevelopmental conditions are commonly seen in children with epilepsy, while cancer, cardiovascular and neurodegenerative conditions often afflict older people with epilepsy. Mental health problems are common across the lifespan. Genetic, environmental, social and lifestyle factors contribute to multimorbidity and its consequences. Multimorbid people with epilepsy (PWE) are at higher risk of depression and suicide, premature death, suffer lower health-related quality of life, and require more hospital admissions and health care costs. The best management of multimorbid PWE requires a paradigm shift from the traditional single disease-single comorbidity approach and a refocus on a person-centred approach. Improvements in health care must be informed by assessing the burden of multimorbidity associated with epilepsy, delineating disease clusters, and measuring the effects on health outcomes.

Current Cigarette Smoking Is Associated With a High Seizure Frequency and Anxiety Symptoms in People With Epilepsy

Purpose

This study aims to answer the following questions: how many people with epilepsy (PWE) have cigarette smoking habits? Which demographic or clinical characteristics are associated with cigarette smoking? Is cigarette smoking related to depressive and anxiety symptoms in PWE?

Methods

A total of 524 PWE were included in the final analysis. Demographic and clinical data were gathered and recorded. Smoking status was identified. The associations of smoking status with the clinical features of epilepsy and depressive and anxiety symptoms were evaluated by logistic regression models.

Results

The overall prevalence of cigarette smoking was 23.5% (123 PWE) in this sample. In the multivariate logistic regression model, men (adjusted OR = 10.414, 95% CI: 5.552–19.535, P < 0.001), high seizure frequency (adjusted OR = 1.474, 95% CI: 1.043–2.084, P = 0.028), and anxiety symptoms (adjusted OR = 2.473, 95% CI: 1.483–4.112, P = 0.001) were shown to have independent associations with cigarette smoking in PWE.

Conclusion

Our findings suggested that the overall prevalence of cigarette smoking was 23.5% in adults with epilepsy, which is slightly lower than that (26.6%) in general adults in China. In the present study, cigarette smoking was associated with men, high seizure frequency, and anxiety symptoms in PWE. Further prospective clinical studies with larger sample sizes are required to confirm our findings.

Smokers with and without Epilepsy show Similar Smoking Rate, Dependence Level, Cessation Attempts, and Motives

BACKGROUND

Individuals with epilepsy are up to twice as likely to be current cigarette smokers compared to those without. Moreover, one study showed current smoking is associated with an increased likelihood of seizures. However, outside of this one study, there is limited data on the presentation of specific smoking-related behaviors and cognitions in people with epilepsy, inhibiting our understanding of the severity of this behavior and our ability to formulate effective treatments for this population.

PURPOSE

The current study examined smoking-related behaviors and cognitions among smokers with epilepsy compared to smokers without epilepsy.

METHODS

Participants were 43 smokers with (Mage = 43.4, SD = 11.6) and 43 smokers without (Mage = 45.5, SD = 8.8) epilepsy recruited from an urban, academic setting within the U.S. Separate Analyses of Covariance (ANCOVAs) were conducted to evaluate differences between smokers with and without epilepsy in terms of smoking behavior (i.e., daily smoking rate, nicotine dependence, number of quit attempts, smoking duration, age of smoking onset) and smoking-related cognitive processes (i.e., smoking motives, perceived barriers to smoking cessation, cessation motives) after controlling for race and problematic alcohol use.

RESULTS

Smokers with epilepsy did not differ from smokers without epilepsy in terms of smoking rate (p = .51, ηp2 = .01), nicotine dependence (p = .12, ηp2 = .03), age of smoking onset (p = .42, ηp2 = .01), number of quit attempts (p = .43, ηp2 = .01), barriers to cessation (p = .30 to .80, ηp2 = .00 to .01), or cessation motives (p = .28 to .60, ηp2 = .00 to .02). Smokers without epilepsy reported higher levels of smoking for sensorimotor manipulation reasons (p = .03, ηp2 = .06) and longer smoking duration (p = .03, ηp2 = .06) than smokers with epilepsy.

CONCLUSIONS

Smokers with epilepsy do not appear to differ significantly from smokers without epilepsy in terms of smoking-related behaviors and cognitions, and may therefore benefit from current evidence-based treatments for smoking cessation that are not contraindicated for epilepsy (i.e., bupropion, varenicline).

Understanding cardiovascular disease in older adults with epilepsy

OBJECTIVE

This study was undertaken to investigate the distribution of social, lifestyle/behavior, and chronic disease risk factors for cardiovascular disease (CVD) in people with epilepsy as compared to the general population. We also measured the cross-sectional association between epilepsy and CVD in older adults, with and without adjustments for a history of stroke.

METHODS

We analyzed data for 44 817 participants in the Canadian Longitudinal Study on Aging, including 751 individuals with a lifetime history of epilepsy. We modeled associations using ordinal and binomial logistic regression, as well as log-binomial regression, with multiple imputation for missing data. We measured the attributable fraction of CVD burden due to stroke.

RESULTS

The majority of the CVD risk factors were significantly more prevalent in people with epilepsy as compared to the general population without epilepsy, independent of age and sex. After adjusting for a history of stroke, people with epilepsy had a significantly higher prevalence of heart disease (prevalence ratio [PR] = 1.27, 95% confidence interval [CI] = 1.02-1.57) and peripheral vascular disease (PR = 1.88, 95% CI = 1.50-2.36). Stroke accounted for 36% (95% CI = 19.85-48.76) of the increased prevalence of any CVD among people with epilepsy, similar to the 32% (95% CI = 27.82-36.25) among people without epilepsy. After adjustment for all other CVD risk factors, peripheral vascular disease remained significantly more prevalent (PR = 1.65, 95% CI = 1.28-2.12) in people with epilepsy as compared to those without.

SIGNIFICANCE

CVD risk factors are more prevalent in people with epilepsy, independent of age and sex, and the association between epilepsy and CVD is independent of the association between epilepsy and stroke. The association between peripheral vascular disease and epilepsy may differ from the associations with other types of CVD. These findings are important steps in more comprehensively understanding the origins of CVD in people with epilepsy.

Modifiable risk factors for epilepsy: A two-sample Mendelian randomization study

INTRODUCTION

We conducted a two-sample Mendelian randomization study to determine the associations of modifiable risk factors with epilepsy.

METHODS

Fourteen potential risk factors for epilepsy were selected based on a systematic review of risk factors for epilepsy. Single-nucleotide polymorphisms associated with each exposure at the genome-wide significance threshold (p < 5×10^-8 ) were proposed as instrumental variables from corresponding genome-wide association studies. Summary-level data for epilepsy were obtained from the FinnGen consortium (4,588 cases and 144 780 noncases). Potential causal associations (p < .05) were attempted for replication using UK Biobank data (901 cases and 395 209 controls).

RESULTS

Among 14 potential risk factors, 4 showed significant associations with epilepsy in FinnGen. All associations were directionally similar in UK Biobank and associated with epilepsy at p ≤ .004 in meta-analyses of FinnGen and UK Biobank data. The odds ratios of epilepsy were 1.46 (95% CI, 1.18, 1.82) for one unit increase in log odds ratio of having depression, 1.44 (95% CI, 1.13, 1.85) for one standard deviation increase in serum ferritin, 1.12 (95% CI, 1.04, 1.21) for one standard deviation increase in transferrin saturation, and 1.25 (95% CI, 1.09, 1.43) for one standard deviation increase in the prevalence of smoking initiation. There were suggestive associations of serum iron and magnesium with epilepsy. No association was observed for insomnia, blood pressure, alcohol consumption, or serum vitamin B12, 25-hydroxyvitamin D and calcium levels.

CONCLUSION

This MR study identified several modifiable risk factors for adulthood epilepsy. Reducing prevalence of depression and smoking initiation should be considered as primary prevention strategies for epilepsy.

Antiseizure drugs and risk of developing smoking-related chronic obstructive pulmonary disease or lung cancer: A population-based case-control study

AIMS

To determine whether enzyme-inducing antiseizure drugs (ASDs) affect the risk of developing chronic obstructive pulmonary disease (COPD) or lung cancer in smokers.

METHODS

Cases of COPD and lung cancer and matched controls without these conditions were identified from a population of smokers with ≥1 prescription for any type of ASD in the Clinical Practice Research Datalink UK database of patients managed in primary care (1995-2016). A matched case-control study was performed utilising multivariate logistic regression analyses of exposure to enzyme-inducing ASDs compared to non-enzyme-inducing ASDs. The duration of ASD exposure and level of tobacco exposure were also assessed.

RESULTS

We identified 5952 incident COPD and 1373 incident lung cancer cases, and 59 328 and 13 681 matched controls, respectively. Compared with never use, ever use of enzyme-inducing ASDs was associated with slightly decreased risk estimates of COPD (adjusted odds ratio: 0.85, 95% confidence interval: 0.81-0.89) and lung cancer (adjusted odds ratio: 0.82, 95% confidence interval: 0.73-0.92). These risk estimates were attenuated in heavy smokers.

CONCLUSION

We found slightly decreased risk estimates of COPD and lung cancer among smokers taking enzyme-inducing ASDs and hypothesise that this may be related to induction of detoxification of tobacco-specific lung toxins.

Expression profile of cytochrome P450s and effects of polycyclic aromatic hydrocarbons and antiepileptic drugs on CYP1 expression in MOG-G-CCM cells

AIMS

This study was performed to investigate the expression profile of cytochrome P450 (CYP) isoforms and effects of polycyclic aromatic hydrocarbons (PAHs) and antiepileptic drugs on CYP1 expression in human astrocytoma MOG-G-CCM cells.

MAIN METHODS

CYP1A1 and CYP1B1 expression were determined by quantitative real-time polymerase chain reaction, Western blotting, and immunocytochemistry.

KEY FINDINGS

MOG-G-CCM cells expressed various CYP isoforms. Among the CYP isoforms analyzed, CYP1B1 showed the highest expression level, followed by CYP1A1. Furthermore, CYP1B1 was localized in both the endoplasmic reticulum and mitochondria. 3-Methylcholanthrene (3-MC), benz[a]anthracene (B[a]A), benzo[a]pyrene (B[a]P), and valproic acid (VPA) increased the expression of CYP1B1 and CYP1A1. The potent aryl hydrocarbon receptor antagonist GNF351 significantly suppressed the 3-MC- and VPA-mediated upregulation of CYP1B1 and CYP1A1. In addition, VPA potentiated the induction of CYP1B1 and CYP1A1 by 3-MC, B[a]A, and B[a]P, although the augmentation of CYP1A1 was more remarkable than that of CYP1B1. In contrast, other antiepileptic drugs (carbamazepine, lamotrigine, levetiracetam, phenytoin) did not affect the 3-MC-mediated upregulation of CYP1B1 and CYP1A1. VPA is known to act as a histone deacetylase (HDAC) inhibitor. Therefore, the effects of trichostatin A, a representative HDAC inhibitor, on CYP1 induction by 3-MC were examined. Trichostatin A enhanced the 3-MC-mediated upregulation of CYP1A1 but not CYP1B1.

SIGNIFICANCE

These results partially indicated that VPA may augment the PAH-mediated induction of CYP1B1 and CYP1A1 through the activation of transcription by HDAC inhibition.

The role of cigarette smoking in epilepsy severity and epilepsy-related quality of life

Empirical evidence suggests that cigarette smoking is common among individuals with epilepsy. However, little is known about relationship between smoking and clinical features of epilepsy. Thus, the aim of the current study was to examine the differences between smokers (n = 43; 58.1% female, M_age = 43.4 years, SD = 11.6) and nonsmokers (n = 49; 63.3% female, M_age = 48.5 years, SD = 15.9) with epilepsy in terms of epilepsy severity (i.e., presence of seizures in the past year, refractory epilepsy status) and epilepsy-related quality of life. As hypothesized, smokers with epilepsy, compared with nonsmokers with epilepsy, were at an increased risk to have experienced seizures in the past year after controlling for the effect of Medicaid status as a proxy for socioeconomic status (odds ratio [OR] = 3.61). Positive smoking status was also associated with lower levels of epilepsy-related quality of life; however, this finding did not remain significant when Medicaid status was taken into consideration. Contrary to the hypotheses, smokers with epilepsy were not at an increased risk of having refractory epilepsy compared with nonsmokers with epilepsy. These findings suggest that cigarette smoking is associated with at least one aspect of epilepsy severity. Thus, in addition to the broader health benefits, smokers with epilepsy should be advised of the increased seizure risk associated with current cigarette smoking. Future work should examine the longitudinal impact of smoking on epilepsy severity, including whether successful smoking cessation ameliorates the seizure risk found in this cross-sectional study.

Smoking prevalence and seizure control in Chinese males with epilepsy

Smoking has a negative effect on most diseases, yet it is under-investigated in people with epilepsy; thus its role is not clear in the general population with epilepsy. We performed a retrospective pilot study on males with epilepsy to determine the smoking rate and its relationship with seizure control using univariate analysis to calculate odds ratios (ORs) and also used a multi-variate logistic regression model. The smoking rate in our sample of 278 individuals was 25.5%, which is lower than the general Chinese population smoking rate among males of 52.1%. We used two classifications: the first classified epilepsy as generalized, or by presumed topographic origin (temporal, frontal, parietal and occipital). The second classified the dominant seizure type of an individual as generalized tonic clonic seizure (GTCS), myoclonic seizure (MS), complex partial seizure (CPS), simple partial seizure (SPS), and secondary GTCS (sGTCS). The univariable analysis of satisfactory seizure control profile and smoking rate in both classifications showed a trend towards a beneficial effect of smoking although most were not statistically significant. Considering medication is an important confounding factor that would largely influence seizure control, we also conducted multi-variable analysis for both classifications with drug numbers and dosage. The result of our model also suggested that smoking is a protective factor. Our findings seem to suggest that smoking could have a potential role in seizure control although confounders need exploration particularly in view of the potential long term health effects. Replication in a much larger sample is needed as well as case control studies to elucidate this issue.