The Impact of Obstructive Sleep Apnea and Tobacco Smoking on Endothelial Function

Association between smoking and obstructive sleep apnea based on the STOP-Bang index

Smoking is a risk factor for respiratory diseases, and it worsens sleep quality due to nicotine stimulation and sudden nicotine withdrawal during sleep. This can increase the severity of OSA through alterations upper airway inflammation and neuromuscular function, arousal mechanisms, and sleep architecture. Therefore, it may lead to sleep-disrupted breathing, particularly obstructive sleep apnea (OSA). Herein, this study aims to research the association between smoking and OSA through the STOP-Bang index. In this study, total sample of 3442 participants (1465 men and 1977 women) were analyzed. We used data from the Korea National Health and Nutrition Examination Survey in 2020 by classifying adults into current, ex-, and non-smokers. A multiple logistic regression analysis was used to investigate the association between smoking and OSA. Furthermore, multinomial regression analysis was used to investigate the effect of smoking cessation. For males, compared to the non-smokers, the odds ratios (OR) for the OSA were significantly higher in the ex-smokers (OR: 1.53, 95% confidence interval(CI) 1.01-2.32) and current smokers (OR: 1.79, 95% CI 1.10-2.89). In females, higher ORs were observed for OSA risk, similar to the non-smokers, smoking cessation, and pack-years. Among men, OSA was significantly associated with a moderate risk for ex-smokers (OR: 1.61, 95% CI 1.05-2.48) and a severe risk for current smokers (OR: 1.88, 95% CI 1.07-3.29). This study observed that smoking might contribute to OSA risk among adults. Smoking cessation can help to manage sleep quality properly.

Is it Mandatory to do a 24 hour ABPM in all Patients with Moderate to Severe Obstructive Sleep Apnoea?

Background  Obstructive sleep apnoea (OSA) has been described as a risk factor for arterial hypertension (HT). One of the proposed mechanisms linking these conditions is non dipping (ND) pattern in nocturnal blood pressure, however evidence is variable and based on specific populations with underlying conditions. Data for OSA and ND in subjects residing at high altitude are currently unavailable. Objective  Identify the prevalence and association of moderate to severe OSA with HT and ND pattern in hypertensive and non-hypertensive otherwise healthy middle-aged individuals in residing at high altitude (Bogotá:2640 mt) Methods  Adult individuals with diagnosis of moderate to severe OSA underwent 24 hour- ambulatory blood pressure monitoring (ABPM) between 2015 and 2017. Univariable and multivariable logistic regression analysis were performed to identify predictors of HT and ND pattern. Results  Ninety-three (93) individuals (male 62.4% and median age 55) were included in the final analysis. Overall, 30.1% showed a ND pattern in ABPM and 14.9% had diurnal and nocturnal hypertension. Severe OSA (higher apnea-hiponea index [AHI]) was associated with HT (p = 0.006), but not with ND patterns (p = 0.54) in multivariable regression. Smoking status and lowest oxygen saturation during respiratory events where independently associated with ND pattern (p = 0.04), whereas age (p = 0.001) was associated with HT. Conclusions  In our sample, one in three individuals with moderate to severe OSA have non dipping patterns suggesting lack of straight association between OSA and ND. Older individuals who have higher AHI are more likely to have HT, and those who smoke have a higher risk of ND. These findings add aditional information to the multiple mechanisms involved in the relationship between OSA and ND pattern, and questions the routine use of 24-hour ABPM, particullary in our region, with limited resources and healthcare acces. However, further work with more robust methodology is needed to draw conclusions.

Does Smoking Affect OSA? What about Smoking Cessation?

The connection between smoking and Obstructive sleep apnea (OSA) is not yet clear. There are studies that have confirmed the effect of smoking on sleep disordered breathing, whereas others did not. Nicotine affects sleep, as smokers have prolonged total sleep and REM latency, reduced sleep efficiency, total sleep time, and slow wave sleep. Smoking cessation has been related with impaired sleep. The health consequences of cigarette smoking are well documented, but the effect of smoking cessation on OSA has not been extensively studied. Smoking cessation should improve OSA as upper airway oedema may reduce, but there is limited data to support this hypothesis. The impact of smoking cessation pharmacotherapy on OSA has been studied, especially for nicotine replacement therapy (NRT). However, there are limited data on other smoking cessation medications as bupropion, varenicline, nortriptyline, clonidine, and cytisine. The aim of this review was to explore the current evidence on the association between smoking and OSA, to evaluate if smoking cessation affects OSA, and to investigate the possible effects of different pharmacologic strategies offered for smoking cessation on OSA.

Relevance of obstructive sleep apnea and smoking: Obstructive sleep apnea and smoking

BACKGROUND

The data concerning the association of smoking and obstructive sleep apnea (OSA) are limited. The effects of cigarette smoking on OSA still remain obscure.

OBJECTIVES

To reveal the impact of smoking on obstructive sleep apnea.

METHODS

About 384 patients with the diagnosis of OSA through full night polysomnographic (PSG) examination were included to the study. The demographic data (age, sex and BMI), complaints and medical history, status of smoking as non-smokers and smokers, smoking frequency (cigarettes/day), polysomnograhic data comprising apnea hypopnea index (AHI), non-REM sleep AHI (NREM AHI), REM sleep AHI (REM AHI), minimum oxygen saturation (min SaO2) were recorded for all the subjects. Non-smokers and smokers were compared in terms of severity of OSA.

RESULTS

The study population consisted of 384 subjects, 253 males and 131 females. Smoking frequency was not found correlated with OSA severity. Among smokers, males had higher severe OSA rate (P = 0.002, P < 0.05). In subjects with BMI < 30, severe OSA rate was higher in smokers (34.44% versus 21%) (P = 0.027, P < 0.05).

CONCLUSIONS

Our study detected higher rate of severe OSA in male smokers and smokers with BMI < 30. PSG data did not yield statistically significant difference in non-smokers and smokers. OSA severity was not found correlated with smoking frequency. Along with the study results, the impact of smoking on OSA is still controversial. Prospective studies with larger sample size may be contributive to further evaluation of the association of OSA with smoking.

Smoking history and its relationship with comorbidities in patients with obstructive sleep apnea

INTRODUCTION

Current knowledge on the correlation between smoking and comorbidities associated with obstructive sleep apnea (OSA) is limited. This study evaluated the smoking history of OSA patients and analyzed the association between smoking and OSA comorbidities.

METHODS

Retrospective analysis was performed in newly diagnosed OSA patients in our hospital, a tertiary medical center, from January 2016 to December 2019. In all, 1021 patients were enrolled and divided into two groups, non-smokers (n=796) and current/former smokers (n=225), in order to compare their clinical manifestations and polysomnographic results and to analyze the association between smoking and comorbidities.

RESULTS

Compared with the non-smokers, the current/former smokers had higher Epworth sleepiness scale (ESS) scores (9.3 ± 4.0 vs 8.5 ± 5.1; p<0.05), longer sleep latency (SL) [20.5 (12.3-39.3) vs 18.5 (10.0-34.0) minutes; p<0.05], and a lower nocturnal mean oxygen saturation (91.8 ± 3.6% vs 92.8 ± 3.4%; p<0.001). There was no significant difference in the apnea-hypopnea index (AHI) between the two groups. OSA patients with a history of smoking had significantly increased risk of hypertension (OR=2.09; 95% CI: 1.46- 3.01), chronic obstructive pulmonary disease (COPD) (OR=9.80; 95% CI: 4.73-20.33), gastroesophageal reflux disease (GERD) (OR=1.97; 95% CI: 1.19-3.27), and chronic pharyngitis (OR=1.83; 95% CI: 1.32-2.54).

CONCLUSIONS

No significant association was found between previous smoking history and current OSA severity. OSA patients with a history of smoking had an increased risk of hypertension, COPD, GERD, and chronic pharyngitis.

Accumulated nocturnal hypoxemia predict arterial endothelial function in patients with sleep-disordered breathing with or without chronic heart failure

ABTSRACT

Sleep-disordered breathing (SDB) is often accompanied with the chronic heart failure (CHF). Hypoxemia due to pulmonary congestion from CHF and concurrent SDB might synergistically impair endothelial function and worsen the prognosis. However, the main factors affecting deterioration of endothelial function are unknown and whether the influence of hypoxemia differs in SDB patients with and without CHF remains unclear. Fifty-three patients (CHF group, n = 23; non-CHF group, n = 30) underwent polysomnography to evaluate their SDB and flow-mediated vasodilation (FMD) measurements to assess arterial endothelial function. We examined the relationships between FMD and SDB-related parameters, including our original index of accumulated hypoxemia by SDB throughout one-night sleep: the time desaturation summation index (TDS), calculated as follows: (100% - averaged arterial oxygen saturation during sleep) × total sleep time. The mean age in the CHF and non-CHF groups was 59.0 ± 13.5 and 57.7 ± 11.4 years, respectively. Although the FMD in the 2 groups were not significantly different, well-known adverse factors for FMD such as serum lipid profiles, blood pressure levels, and conventional indices of SDB were worse in the non-CHF group. Only the TDS was not significantly different between 2 groups and associated with FMD as shown by the univariate analysis (CHF: p < 0.05, non-CHF: p < 0.01) and multivariate analysis (CHF: p < 0.05, non-CHF: p < 0.01). Accumulated hypoxemia (TDS) rather than the frequency of hypoxemia might more influence on the endothelial function irrespective of the cardiac state. Removal of accumulation of nocturnal hypoxemia might be a target for treatment equally in the patients with and without CHF.

Risk of Cardiovascular Disease Related to Smoking Is Greater Among Women With Sleep-Disordered Breathing

STUDY OBJECTIVES

Although both sleep-disordered breathing (SDB) and smoking are associated with cardiovascular disease (CVD), the potential for an interactive effect on CVD risk has not been explored. Our objective was to determine if smoking-related risk for CVD rises with greater SDB severity.

METHODS

Polysomnography and smoking history were obtained in 3,852 men and women in the Sleep Heart Health Study without baseline CVD. Fine-Gray proportional hazard models accounting for competing risk were used to calculate risk of incident CVD associated with SDB severity (defined by clinical cutoffs of the apnea-hypopnea index), smoking status (never, former, and current) and their interaction adjusting for potential confounders.

RESULTS

Over a mean (standard deviation) follow-up period of 10.3 (3.4) years, there were 694 incident CVD events. We found a significant three-way interaction of sex, current smoking, and moderate to severe SDB (P = .039) in the adjusted proportional hazards model. In adjusted analyses, women who were current smokers with moderate to severe SDB had a hazard ratio for incident CVD of 3.5 (95% confidence interval 1.6-8.0) relative to women who were nonsmokers without SDB. No such difference in CVD risk was observed in men or women of other strata of smoking and SDB.

CONCLUSIONS

In women, smoking-related risk for CVD is significantly higher among individuals with moderate to severe SDB.

Association between nondipping pattern and EndoPAT signal in patients with mild obstructive sleep apnea

OBJECTIVE

To compare vascular endothelial function between dipping (D) and nondipping (ND) patterns in patients with and without mild obstructive sleep apnea (OSA) using EndoPAT, a test of reactive hyperemia used to assess peripheral vascular endothelial function.

METHODS

The sample consisted of individuals of both genders between 18 and 65 years of age with a body mass index (BMI) of ≤35 kg/m² and apnea/hypopnea index (AHI) of ≤15. The nondipping pattern was considered present when the dip of nocturnal blood pressure (NBP) was <10%. All of the sample underwent clinical and physical evaluation, full polysomnography, 24-hour ambulatory blood pressure monitoring, and EndoPAT evaluation. A generalized linear model was used for statistical analysis.

RESULTS

The sample comprised 120 individuals, 35 in the control group and 85 in the mild OSA group. Four groups were formed: Control-ND, Control-D, Mild OSA-ND, and Mild OSA-D according to nocturnal ABPM patterns. The frequency of nondipping was (34.1%) in the Mild OSA group and (17.1%) in the Control group (p = 0.07). The Mild OSA-ND group had a higher augmentation index (AIx) than the Mild OSA-D group. Regression analysis showed that male gender, higher age, and nondipping status were associated with these results, whereas oxygen desaturation index (ODI) and AHI did not. With respect to the reactive hyperemia index (RHI), the Mild OSA-D group had lower values compared to the Control-ND group, but an association with OSA was not confirmed in the regression model.

CONCLUSION

Nondipping status was associated with a worse augmentation index in both groups independently of AHI or oxygen desaturation index. Male gender, higher age, and nondipping status were associated with augmentation index. ClinicalTrials.gov Identifier: NCT01461486.

Abnormal white matter microstructure among early adulthood smokers: a tract-based spatial statistics study

Objectives Cigarette smoking is an important risk factor of central nervous system diseases. However, the white matter (WM) integrity of early adulthood chronic smokers has not been attached enough importance to as it deserves, and the relationship between the chronic smoking effect and the WM is still unclear. The purpose of this study was to investigate whole - brain WM microstructure of early adulthood smokers and explore the structural correlates of behaviorally relevant features of the disorder. Methods We compared multiple DTI-derived indices, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD), between early adulthood smokers (n = 19) and age-, education- and gender-matched controls (n = 23) using a whole-brain tract-based spatial statistics approach. We also explored the correlations of the mean DTI index values with pack-years and Fagerström Test for Nicotine Dependence. Results The smokers showed increased FA in left superior longitudinal fasciculus (SLF), left anterior corona radiate, left superior corona radiate, left posterior corona radiate, left external capsule (EC), left inferior fronto-occipital fasciculus and sagittal stratum (SS), and decreased RD in left SLF. There were significant negative correlations among the average FA in the left external capsule and pack-years in smokers. In addition, significant positive correlation was found between RD values in the left SLF and pack-years. Discussion These findings indicate that smokers show microstructural changes in several white-matter regions. The correlation between the cumulative effect and microstructural WM alternations suggests that WM properties may become the new biomarkers in practice.

Smoking, obstructive sleep apnea syndrome and their combined effects on metabolic parameters: Evidence from a large cross-sectional study

Metabolic disorders have been separately associated with obstructive sleep apnea syndrome (OSAS) and smoking. However, no study has examined their interactions with metabolic parameters, including insulin resistance and dyslipidemia. To investigate whether the combination of OSAS and smoking results in an additive detriment in metabolic disorder parameters, we enrolled consecutive adult men during 2014–2015. Fasted blood samples were taken to determine glucose, insulin, and lipid levels. A questionnaire including an item on smoking pack-year exposure was administered, and the Epworth Sleepiness Scale and overnight polysomnography were performed. Smokers showed higher levels of glucose, insulin, total cholesterol (TC), triglycerides (TG), and low density lipoprotein-cholesterol (LDL-C), but lower high-density lipoprotein cholesterol (HDL-C) levels, than did non-smokers. In addition, the risks for insulin resistance increased with OSAS severity without fully adjustment. An OSAS × smoking interaction was found in insulin resistance after adjusting for potential confounding factors (p = 0.025). Although the difference was not significant, cessation of cigarette smoking seems to have a little benefit for smoking patients with OSAS. A synergistic effect was observed between smoking and OSAS on metabolic disorder parameters. Cessation of cigarette smoking may experience minor benefit for insulin resistance and lipid metabolism in patients with OSAS.