Time to first cigarette and serum cholesterol levels

More precise method of low-density lipoprotein cholesterol estimation for tobacco and electronic cigarette smokers: A cross-sectional study

Smoking is associated with elevated low-density lipoprotein cholesterol (LDL-C) levels. However, the accuracies of the Friedewald, Sampson, and Martin LDL-C-estimating equations based on smoking status are unclear. We analyzed the accuracy of LDL-C levels estimated using these three equations based on tobacco and electronic cigarette smoking status. Data on LDL-C and other lipid components were obtained from the Korea National Health and Nutrition Examination Survey from January 2009 to December 2021. Direct LDL-C (dLDL-C) levels and smoking data of 12,325 participants were evaluated. Current smokers had higher triglyceride levels than never smokers. Electronic cigarette smokers had higher triglyceride and dLDL-C levels than never smokers. The Martin equation yielded more accurate mean absolute deviations than the other equations for the group with triglyceride levels <400 mg/dL as well as more accurate median absolute deviation values, except for the group with dLDL-C levels <40 mg/dL. Similar estimates were derived from the equations when the triglyceride levels were <150 mg/dL. However, the Martin equation may lead to the overestimation of LDL-C levels. In conclusion, the Martin equation is suitable for triglyceride levels <400 mg/dL regardless of the electronic cigarette/tobacco smoking status; if the triglyceride level is <150 mg, the Friedewald equation could also be considered, regardless of the electronic cigarette/tobacco smoking status.

Time from waking to the first cigarette and mortality and incident cardiovascular disease

BACKGROUND

This study aimed to investigate the associations of time from waking to the first cigarette (TWFC) with all-cause mortality, cardiovascular disease (CVD) mortality and incident CVD among people smoking.

METHODS

Data were from the UK Biobank, including 32 519 people smoking aged 40-70 years. TWFC was investigated using a touch-screen questionnaire. Outcomes included all-cause mortality and mortality from and incidence of CVD, ischemic heart disease (IHD) and stroke.

RESULTS

Compared with participants reporting TWFC >120 min, those reporting TWFC between 61 and 120 min (HR, 1.30; 95% CI, 1.10-1.53), TWFC between 5 and 60 min (1.48, 1.30-1.70) and TWFC <5 min (1.65, 1.42-1.93) had a higher risk of all-cause mortality. Compared with participants reporting TWFC >120 min, those reporting TWFC between 5 and 60 min and TWFC <5 min had higher risks of CVD and IHD mortality and incident CVD and IHD, but those reporting TWFC between 61 and 120 min did not. The associations of TWFC with stroke mortality and incident stroke were not observed.

CONCLUSION

In this cohort study, a shorter TWFC was associated with higher risks of all-cause mortality, mortality from CVD and IHD, as well as incident CVD and IHD.

Smoking timing, genetic susceptibility, and the risk of incident atrial fibrillation: a large prospective cohort study

AIMS

Although smoking is a well-known risk factor for atrial fibrillation (AF), the association of smoking timing with AF risk remains unclear. This study aimed to prospectively investigate the association of smoking timing with risk of incident AF, and test the modification effect of genetic susceptibility.

METHODS AND RESULTS

A total of 305,627 participants with detailed information for time from waking to first cigarette were enrolled from UK Biobank database. Cox proportional hazard model was employed to assess the relationship between smoking timing and AF risk. Weighted genetic risk score for AF was calculated. Over a median 12.2-year follow-up, 13,410 AF cases were documented. Compared to non-smokers, time from waking to the first cigarette showed gradient inverse associations with risk of incident AF (P-trend <0.001). The adjusted hazard ratio related to smoking timing was 1.13 (95% CI: 0.96-1.34) for >120 minutes, 1.20 (95% CI: 1.01-1.42) for 61-120 minutes, 1.34 (95% CI: 1.19-1.51) for 30-60 minutes, 1.43 (95% CI: 1.26-1.63) for 5-15 minutes, and 1.49 (95% CI: 1.24-1.63) for <5 minutes, respectively. Additionally, we found that the increased risk of AF related to shorter time from waking to the first cigarette was strengthened by the genetic susceptibility to AF.

CONCLUSIONS

Our findings suggest gradient inverse association between time from waking to the first cigarette and risk of incident AF, and the association is strengthened by the genetic susceptibility to AF.

Smoking timing, genetic susceptibility and the risk of incident type 2 diabetes: A cohort study from the UK Biobank

AIM

To prospectively assess the association of smoking timing with the risk of type 2 diabetes (T2D) and examine whether smoking amount or genetic susceptibility might modify the relationship.

MATERIALS AND METHODS

A total of 294 815 participants without diabetes from the UK Biobank, including non-smokers and smokers with data on the time from waking to first cigarette, were included. Cox proportional hazards models were used to evaluate the association between smoking timing and the risk of incident T2D.

RESULTS

During a median follow-up time of 12 years, a total of 9937 incident cases of T2D were documented. Compared with non-smokers, a shorter time from waking to first cigarette was significantly associated with a higher risk of incident T2D (P for trend < .001). In the fully adjusted model, the hazard ratios (HRs) (95% confidence interval) associated with smoking timing were 1.46 (1.17-1.81) for more than 2 hours, 1.51 (1.21-1.87) for 1-2 hours, 1.58 (1.34-1.85) for 30-60 minutes, 1.86 (1.57-2.21) for 5-15 minutes and 2.01 (1.60-2.54) for less than 5 minutes. We found that even among those who reported being light smokers, those with the shortest time from waking to first cigarette had a 105% higher risk of T2D with an HR of 2.05 (1.52-2.76), which was comparable with heavy smokers. The genetic risk score for T2D did not modify this association (P-interaction = .51).

CONCLUSIONS

Our findings indicate that shorter time from waking to first cigarette is significantly associated with a higher risk of incident T2D.

Smoking Timing, Healthy Diet, and Risk of Incident CKD Among Smokers: Findings From UK Biobank

RATIONALE & OBJECTIVE

Although smoking is a recognized risk factor for chronic kidney disease (CKD), the relationship between the time smoking is initiated after awakening each day and CKD remains largely unstudied. This study examined the association between this timing and the risk of CKD, and the potential interactions of smoking timing with other risk factors for the occurrence of CKD.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

A total of 32,776 participants in the UK Biobank with complete data on the time from waking to the first cigarette and free of prevalent CKD were included.

EXPOSURE

Time from waking to the first cigarette.

OUTCOME

Incident CKD cases.

ANALYTICAL APPROACH

Cox proportional hazards regression was used to investigate the associations between the time smoking is initiated each day and the risk of CKD. The potential interactions of smoking timing with risk factors in relationship to CKD risk were assessed on both multiplicative and additive scales.

RESULTS

During a median follow-up period of 12 years, 940 incident CKD cases occurred. Shorter durations of time from waking to the first cigarette were associated with a higher risk of incident CKD (P trend=0.01). Compared with>120 minutes, the adjusted hazard ratio (HR) associated with smoking timing was 1.28 (95% CI, 0.92-1.80) for 61-120 minutes, 1.48 (95% CI, 1.11-1.96) for 30-60 minutes, 1.36 (95% CI, 1.01-1.88) for 5-15 minutes, and 1.70 (95% CI, 1.22-2.37) for<5 minutes, respectively. Furthermore, there was a significant additive interaction and multiplicative interactions between the timing of smoking and a healthy diet score (P for additive interaction=0.01; P for multiplicative interaction = 0.004).

LIMITATIONS

Generalizability, possible residual confounding, limiting causal inference.

CONCLUSIONS

These findings reveal a significant association between the shorter time from waking to the first cigarette and a higher CKD risk. The magnitude of these associations was greater in the setting of an unhealthy diet.

PLAIN-LANGUAGE SUMMARY

This study explored the association of the daily timing of first cigarette smoking and the occurrence of kidney disease. Further, we addressed whether this association was influenced by the quality of the diet. The study found that smoking very soon after waking, especially when combined with a poorer quality diet, was associated with a significantly increased risk of developing chronic kidney disease. This research emphasizes the value of healthier lifestyle choices for kidney health.

Effect of cigarette smoking on smoking biomarkers, blood pressure and blood lipid levels among Sri Lankan male smokers

Study purpose

The aim of this study was to determine the fractional exhaled nitric oxide (FeNO) levels, exhaled breath carbon monoxide (eCO) levels, blood pressure, blood lipid levels between smokers and non-smokers and to determine the association of smoking intensity with the above parameters.

Methods

This descriptive study was conducted in selected periurban areas of the Colombo District, Sri Lanka. Adult male current tobacco smokers (n=360), aged between 21 and 60 years were studied and compared with anthropometrically matched male non-smokers (n=180). Data were collected by interviewer-administered questionnaire, clinical assessment and measurement of FeNO by FENO monitor and eCO bySmokerlyser.

Results

Smokers had significantly lower mean FeNO levels and higher mean eCO values compared with non-smokers. Presentation of palpitations was higher among the smokers and a significantly positive correlation was identified between palpitations and eCO levels. There was a significantly positive correlation between the systolic blood pressure of smokers with the duration of smoking (DS), Brinkman Index (BI), Body Mass Index (BMI) and there was a significantly negative correlation with FeNO levels. The mean arterial pressure was positively correlated with the DS, BI and BMI. There was a significantly negative correlation between FeNO and the number of cigarettes smoked per day, DS and BI of smokers. Significantly higher total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), very LDL-C, TC: HDL ratio and low high density lipoprotein cholesterol (HDL-C) level was observed among smokers compared with the non-smokers.

Conclusions

Tobacco smoking was found to impact blood pressure and serum lipid levels thus enhancing the cardiovascular risk among smokers. The levels of eCO and FeNO are useful biomarkers for determining the intensity of smoking. The results indicate the necessity for urgent measures to stop cigarette smoking in Sri Lanka.

Lipid profiles in users of combustible and electronic cigarettes

Electronic cigarette use has especially risen among adolescents and young adults. The aim of this study was to investigate fasting blood glucose and lipid profiles in chronic combustible cigarette and electronic cigarette users. We evaluated participants aged 21 to 45 (n = 525, mean age 31 ± 7 years, 45% women) without established cardiovascular disease or risk factors who were combustible cigarette users (n = 290), electronic cigarette users (n = 131; 65 sole users and 66 dual users), or never users (n = 104). In the first wave of enrollment (2014-2017), electronic cigarette users reported their products as first, second and third generation devices (e-cig users) and were all largely current (i.e., dual) or former (sole) combustible cigarette users, whereas in the second wave of enrollment (2019-2020), electronic cigarette users all reported pod-based device use (pod users) and included more sole users who were never smokers. In multivariable-adjusted analyses comparing to never users, both sole e-cig users and combustible cigarette users had higher glucose and triglycerides and lower high-density lipoprotein (HDL) cholesterol levels. Dual e-cig users showed higher triglycerides and very-low-density lipoprotein cholesterol, and lower HDL cholesterol compared to never users. In contrast, pod users (both sole and dual) had lipid profiles and glucose levels similar to never users. Overall, users of early generation electronic cigarettes display adverse metabolic profiles. In contrast, pod-based electronic cigarette users have similar lipid profiles to never users. Future studies are needed to understand the cumulative effects of electronic cigarette use on cardiometabolic health.

Association between Time to First Cigarette and Health-Related Quality of Life of Middle-Aged Male Current Smokers: A Nationwide Representative Study in Korea

BACKGROUND

Although many studies have demonstrated that the first cigarette in the morning increases the prevalence of smoking-related morbidity, limited studies have examined the impact of time to first cigarette (TTFC) on the health-related quality of life (HRQoL). Thus, we assessed this relationship using nationally-representative data from the Korea National Health and Nutrition Examination Survey VII-1 (2016).

METHODS

We conducted a cross-sectional study using data from 577 current male smokers aged 30-59 years, after excluding those with a certain disease. Participants were divided into four categories according to TTFC (≤5 min, 6-30 min, 31-60 min, >60 min). HRQoL was measured using self-reported EuroQol-5 (EQ-5D). The relationship between TTFC and EQ-5D index was analyzed using a multivariate-adjusted generalized linear model to assess how HRQoL varies according to TTFC. After adjusting for confounders, a multivariate-adjusted logistic regression analysis was performed to identify which of the five dimensions of the EQ-5D affected the HRQoL according to TTFC.

RESULTS

The generalized linear analysis indicated that as TTFC decreased (6-30 min, 31-60 min vs. >60 min), the EQ-5D index score decreased significantly (P=0.037). Shorter TTFC (≤5 min vs. >60 min) was associated with higher pain/discomfort (odds ratio [OR], 3.82; 95% confidence interval [CI], 1.39-10.48) and anxiety/depression (OR, 7.58; 95% CI, 1.75-32.88).

CONCLUSION

Higher nicotine dependence was associated with impaired HRQoL. These results may be used to improve smoking cessation treatment outcomes.

Cigarette smoke extract stimulates PCSK9 production in HepG2 cells via ROS/NF‑κB signaling

Cigarette smoke (CS) exposure is a risk factor for dyslipidemia and atherosclerosis. Reduced expression of low-density lipoprotein receptor (LDLR) in hepatocytes may be one of the underlying mechanisms for these disorders. The aim of the present study was to investigate the molecular mechanism underlying the regulatory effect of CS extract (CSE) on proprotein convertase subtilisin/kexin type 9 (PCSK9) and low LDLR expression in HepG2 cells. PCSK9 and LDLR mRNA and protein expression levels in HepG2 cells were evaluated after CSE treatment via reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. In addition, total intracellular reactive oxygen species (ROS) production was determined via 2,7-dichlorofluorescein diacetate fluorescence. CSE significantly increased PCSK9 expression and inhibited LDLR expression in a time- and concentration-dependent manner. Furthermore, CSE significantly induced ROS production and nuclear factor κB (NF-κB) activation. However, pretreatment with a ROS scavenger or an NF-κB inhibitor significantly attenuated the CSE-induced changes in PCSK9 and LDLR expression. In addition, pretreatment with melatonin markedly reduced ROS production, NF-κB activation and PCSK9 expression, and increased LDLR expression in the CSE-treated cells. These data suggest that melatonin inhibits CSE-regulated PCSK9 and LDLR production in HepG2 cells via ROS/NF-κB signaling.

'Time to first tobacco cigarette soon after waking' occurs more often among underage newly incident smokers in the United States, 2004-2017

AIMS

Time to first cigarette (TTFC) after waking is a highly regarded and readily measured manifestation of a tobacco dependence process. We aim to estimate short TTFC as it occurs very soon after the onset of cigarette smoking (CS) in a community sample of newly incident smokers, all 12-21 years of age, and to study risk variation with the age of CS onset.

METHODS

United States National Surveys on Drug Use and Health, 2004-2017, drew large nationally representative samples of 12-to-21-year-old community residents, and used computerized self-interviews to measure tobacco cigarette smoking, the Fagerstrom TTFC construct, and related variables. A 'short' TTFC was defined as smoking the first cigarette after waking up within 30 min vs. 'long' TTFC or smoking more than 30 min. We studied 8188 newly incident smokers, all assessed within six months after the first puff. Estimated age-specific cumulative incidence proportions (CIP) and odds ratios (OR) are estimated and compared, with due attention to complex survey design and weights.

RESULTS

Among underage newly incident smokers (12-17 years old), an estimated 5.2% experienced short TTFC within 6 months after CS onset (95% CI = 4.4%, 6.2%), versus 3.7% for older new smokers (18-21 years; 95% CI = 2.8%, 4.6%). Underage smokers are 1.5 times more likely to develop short TTFC compared to older initiates (95% CI = 1.1, 2.1). No male-female variations are seen, but exploratory analysis disclosed findings that involve Census-defined race-ethnicity subgroups. Non-Hispanic African-American initiates are twice as likely to develop short TTFC, and Hispanic initiates are less likely to develop short TTFC, as compared with non-Hispanic White smokers.

CONCLUSIONS

Based on US community samples our study offers new evidence about TTFC formation observed within six months after the first puff when cigarette smoking starts before age 18 years.

A key indicator of nicotine dependence is associated with greater depression symptoms, after accounting for smoking behavior

INTRODUCTION

Depression is a global burden that is exacerbated by smoking. The association between depression and chronic smoking is well-known; however, existing findings contain possible confounding between nicotine dependence (ND), a latent construct measuring addiction, and objective smoking behavior. The current study examines the possible unique role of ND in explaining depression, independently of smoking behavior.

METHODS

A nationally-representative sample of current adult daily smokers was drawn by pooling three independent, cross-sectional, biennial waves (spanning 2011-16) of the National Health and Nutrition Examination Survey (NHANES). The association between ND (operationally defined as time to first cigarette (TTFC) after waking) and the amount of depression symptoms was examined after adjusting for both current and lifetime smoking behaviors (cigarettes per day and years of smoking duration) and sociodemographic factors (gender, age, race, education and income to poverty ratio).

RESULTS

Earlier TTFC was associated with more depression symptoms, such that those smoking within 5 minutes of waking had an approximately 1.6-fold higher depression score (PRR = 1.576, 95% CI = 1.324-1.687) relative to those who smoke more than 1 hour after waking. This relationship remained significant after adjusting for current and lifetime smoking behavior as well as sociodemographic factors (PRR = 1.370, 95% CI = 1.113, 1.687).

CONCLUSIONS

The latent construct of ND, as assessed by TTFC, may be associated with an additional risk for depression symptoms, beyond that conveyed by smoking behavior alone. This finding can be used for more refined risk prediction for depression among smokers.

Smoking Habits in Human Immunodeficiency Virus-Infected People from Italy: A Cross-Sectional Analysis of the STOPSHIV Cohort

In a nationwide Italian sample of people living with HIV (PLWH), the prevalence of smoking, nicotine dependence, propensity to stop smoking, and cardiovascular profile were investigated. The nicotine dependence by Fagerström test and the propensity to stop according to the stages of change were evaluated. Associations between smoking habits and patients' characteristics were analyzed using an unconditional logistic regression model. Among 1,087 PLWH (age 47.9 ± 10.8 years, men 73.5%), the prevalence of current smokers was 51.6%. The median of Fagerström test was 4 (interquartile range 2-6); 60.1% of the smokers were in precontemplation, 17.6% in contemplation, 18.7% in preparation, and 3.6% in action. In a logistic multivariate model, current smoking was associated with male sex, being divorced/widowed, Caucasian ethnicity, dyslipidemia, atherosclerotic cardiovascular disease risk, psychiatric comorbidity, hepatitis C virus infection, and alcohol abuse. Low high-density lipoprotein cholesterol level was associated with high nicotine dependence. More than 50% of PLWH were current smokers, one-third of them showed a high or very high degree of dependence. Our findings draw attention to the need of smoking cessation strategies for PLWH.

Time to First Cigarette and Self-Reported Health Among US Adult Smokers

Background:

Numerous studies have reported that shorter time to first cigarette (TTFC) is linked to elevated risk for smoking-related morbidity. However, little is known about the influence of early TTFC on self-reported health among current smokers. Hence, the objective of this study was to examine the association between TTFC and self-reported health among US adult smokers.

Methods:

Data came from the 2012-2013 National Adult Tobacco Survey (NATS). Current smokers aged 18 years and older (N = 3323) were categorized into 2 groups based on TTFC: ≤ 5 minutes (n = 1066) and >5 minutes (n = 2257). Propensity score matching (PSM) was used to control selection bias.

Results:

After adjusting for sociodemographic and smoking behavior factors, current smokers with early TTFC had higher odds for poor health in comparison with current smokers with late TTFC in the prematching (adjusted odds ratio [AOR] = 1.65; 95% confidence interval [CI] = 1.31-2.08) and postmatching (AOR = 1.60; 95% CI = 1.22-2.09) samples.

Conclusions:

In conclusion, smokers with early TTFC were associated with increased risk of poor health in the United States. To reduce early TTFC, elaborate efforts are needed to educate people about harms of early TTFC and benefits of stopping early TTFC.

Nicotine dependence as an independent risk factor for atherosclerosis in the National Lung Screening Trial

Background

Atherosclerosis and COPD are systemic inflammatory diseases that share common risk factors including cigarette smoking. A high level of nicotine dependence is emerging as a recently identified risk factor for pulmonary impairment, chronic obstructive pulmonary disease and tobacco-related cancers. We hypothesized that nicotine dependence is associated with the risk of atherosclerosis in long-term cigarette smokers.

Methods

A nested case-control study was conducted within the National Lung Cancer Screening Trial- American College of Radiology Imaging Network. Cases were defined as having a new diagnosis of any type of atherosclerosis. Controls were matched on a 2:1 basis by age, sex, race, study center, smoking status, years of smoking, and frequency of smoking. Dependence was measured by the time to first cigarette after awakening (TTFC).

Results

The study included 166 cases and 286 controls. Compared to participants who smoked within 5 min after waking, the risk of atherosclerosis for participants who smoked an hour or more after waking was borderline non-significant (odds ratio = 0.49, 95% confidence intervals [CI] 0.23, 1.00). Findings were similar for men and women. For aortic atherosclerosis, the corresponding odds ratio was 0.24 (95% CI 0.08, 0.69). Hypertension was associated with an increased risk and body mass index was associated with a decreased risk of aortic atherosclerosis. The TTFC was unrelated to coronary atherosclerosis.

Conclusions

Compared to smoking immediately after waking, delaying an hour or more reduces the risk of aortic atherosclerosis even among long-term heavy smokers. Possible mechanisms that explain this association are intensity of smoking, inflammation and oxidative stress, and elevated lipid levels.

Time to First Cigarette and the Risk of Hypertension: A Nationwide Representative Study in Korea

BACKGROUND

Although previous studies have explored the effect of smoking on blood pressure, little is still known about the role of time to first cigarette (TTFC)-an indicator of nicotine dependence-in hypertension. Therefore, we evaluated this association using representative nationwide data.

METHODS

Current daily smokers (N = 941; aged 19-79 years) who participated in the 7th version of the Korea National Health and Nutrition Examination Survey I (2016) were included. We categorized participants into 4 groups according to their TTFC. Furthermore, we categorized participants into hypertensive and nonhypertensive groups based on whether they were taking antihypertensive medications or had high blood pressure (≥140/90 mm Hg). The association of daily TTFC and hypertension was examined without adjusting for any covariates; after adjusting for smoking behaviors; and after adjusting for demographic characteristics, socioeconomic status, health-related behaviors, and comorbidities.

RESULTS

In the fully adjusted weighted regression analysis, participants reporting TTFC ≤ 5 minutes (vs. >60 minutes) had roughly twice the odds of having hypertension (95% confidence interval [CI] = 1.07-4.16) and the adjusted odds ratios compared with TTFC of >60 minutes were 1.53 (95% CI = 0.81-2.86) for 6-30 minutes and 1.31 (95% CI = 0.68-2.50) for 31-60 minutes (Ptrend = 0.03).

CONCLUSIONS

Hypertension risk increases with shorter TTFC. Especially, TTFC of ≤5 minutes may prove valuable in assessing the risk of hypertension. Screening smokers based on their TTFC might be useful in assessing their risk of hypertension and smoking cessation programs.

Effect of exclusive cigarette smoking and in combination with waterpipe smoking on lipoproteins

Objective:

A significant increase in total cholesterol and LDL-C is well shown in tobacco users, as compared to non-tobacco users. The additive effects of waterpipe and cigarette smoking on LDL levels have not been studied. The study’s objective was to assess the correlation between cigarette smoking and LDL levels in Lebanese cigarette smokers and to check the interaction effect of waterpipe and cigarette smoking on LDL levels.

Methods:

This cross-sectional study was conducted between October 2016 and February 2017 in 4 different laboratories, enrolling 308 patients (188 non-smokers, 105 cigarette smokers, 15 previous smokers).

Results:

Current cigarette smoking (Beta = 25.57; p < 0.0001) was significantly associated with higher LDL levels and higher total cholesterol levels (Beta = 53.29; p < 0.0001) in exclusive cigarette smokers. Among current cigarette smokers who were current waterpipe smokers, a significant increase in LDL level was observed relative to current cigarette smokers who were not waterpipe smokers (Beta = 66.64 vs Beta = 37.37; p < 0.0001).

Conclusion:

Among Lebanese current cigarette smokers, LDL levels increased relative to nonsmokers, consistent with findings in other populations. In addition, among Lebanese current cigarette smokers, current waterpipe smoking might increase adverse lipid profiles associated with adverse coronary effects more than cigarette smoking alone. The direct cause responsible for these observed variations in our study remains unidentified, with the hope that future research will reveal it.