Antonio Sanna

Risk of Occupational Accidents in Workers With Obstructive Sleep Apnea: Systematic Review and Meta-analysis

STUDY OBJECTIVES Obstructive sleep apnea (OSA) is the single most important preventable medical cause of excessive daytime sleepiness (EDS) and driving accidents. OSA may also adversely affect work performance through a decrease in productivity, and an increase in the injury rate. Nevertheless, no systematic review and meta-analysis of the relationship between OSA and work accidents has been performed thus far. METHODS PubMed, PsycInfo, Scopus, Web of Science, and Cochrane Library were searched. Out of an initial list of 1,099 papers, 10 studies (12,553 participants) were eligible for our review, and 7 of them were included in the meta-analysis. The overall effects were measured by odds ratios (OR) and 95% confidence intervals (CI). An assessment was made of the methodological quality of the studies. Moderator analysis and funnel plot analysis were used to explore the sources of between-study heterogeneity. RESULTS Compared to controls, the odds of work accident was found to be nearly double in workers with OSA (OR = 2.18; 95% CI = 1.53-3.10). Occupational driving was associated with a higher effect size. CONCLUSIONS OSA is an underdiagnosed nonoccupational disease that has a strong adverse effect on work accidents. The nearly twofold increased odds of work accidents in subjects with OSA calls for workplace screening in selected safety-sensitive occupations. COMMENTARY A commentary on this article appears in this issue on page 1171.

Expiratory flow limitation during sleep in heavy snorers and obstructive sleep apnoea patients.

Inspiratory flow limitation (FL) during sleep has previously been reported both in obstructive sleep apnoea (OSA) patients and heavy snorers (HS). Recent results from this laboratory have shown the occurrence both of inspiratory and expiratory flow limitation during muscular relaxation in awake healthy subjects and OSA patients. In this study, we have investigated whether expiratory flow limitation occurs during sleep in heavy snorers and in patients with OSA. We studied four nonapnoeic, heavy snorers and five OSA patients. Airflow was measured with a pneumotachograph attached to a tight-fitting mask, and supraglottic pressure with a catheter placed at the supraglottic level. Scoring for flow limitation was achieved by visual inspection of 200 breaths recorded during sleep. About 20% of the respiratory cycles presented isolated inspiratory flow limitation. Approximately the same percentage was observed in heavy snorers and OSA patients. Isolated expiratory flow limitation was less frequently recorded. Coupled inspiratory and expiratory flow limitations were more numerous, especially in heavy snorers. We conclude that both in heavy snorers and obstructive sleep apnoea patients, inspiratory flow limitation is associated with expiratory flow limitation. This suggests that upper airway obstruction during sleep is both an inspiratory and expiratory event.

Motor vehicle accidents and obstructive sleep apnea syndrome: A methodology to calculate the related burden of injuries

The association between motor vehicle accidents (MVAs) and obstructive sleep apnea syndrome (OSAS) has always been quantified as risk of MVAs for individual drivers with OSAS. We evaluated the expected injured patients per year attributable to OSAS-dependent MVAs in a general population. By combining OSAS prevalence and OSAS-dependent MVAs odds ratio, we assessed the population attributable fraction (PAF), an epidemiological tool that can be used to quantify the proportion of road traffic injuries (RTIs) attributable to OSAS. For an apnea hypopnea index >5, the weighed median and combined average of OSAS prevalence were 4.4 (95% confidence interval (CI): 3.7–7.5) and 4.7 (95% CI: 4.2–5.2), respectively; values of risk of OSAS-dependent MVAs were 2.83 (95% CI: 2.72–3.08) and 2.52 (95% CI: 2.07–3.08), respectively. The PAF showed weighed median and combined average values of 6.6 (95% CI: 4.3–9.8) and 7.3% (95% CI: 6.0–13.5), respectively. Our results show that about 7% of RTIs for a population of male drivers involved in MVAs are attributable to OSAS. This value can be used to assess the potential impact, on the reduction of incidence of the motor vehicle injuries, of prevention programs aimed at reducing the number of subjects with an undiagnosed and/or untreated OSAS.

In long-term smokers and former smokers the bronchodilator response is not related to the fall in FEV1

Background: Cigarette smoking is the cardinal cause of chronic obstructive pulmonary disease (COPD), but only a relatively small percentage of smokers are developing clinically overt disease, suggesting, therefore, that other risk factors than smoking are involved. Several studies have shown that the bronchodilator response (BR) is related to the progress of COPD, as assessed by the fall in forced expiratory volume in 1 s (FEV1). However, the relationship between BR and fall in FEV1, is a disputed one. Objective: To assess the relationship between BR and fall in FEV1 in a group of long-term smokers and ex-smokers who were 60 years old on the average. Methods: Questionnaire, spirographic tests and BR were assessed in 56 smokers and ex-smokers of mean age 62.5 ± (SD) 2.7 years at the end of a 13-year follow-up period. BR was expressed as a percentage change of the prebronchodilator value (‘% initial’) and as a percentage change of predicted value (‘% predicted’). Results: The FEV1/VC vital capacity was 68.9 ± 7.6% at the start and 64.5 ± 11.3% at the end of the study. The average fall in FEV1 over 13 years was 26 ± 25 ml/year. The FEV1 increased after albuterol on the average with 5.9 ± 6.6%, 4.5 ± 3.9% of predicted, and the vital capacity with 2.5 ± 6.5%, 2.3 ± 6.4% of predicted. BR and fall in FEV1 were correlated: the greater the BR, the more rapid the fall in FEV1 (r = 0.4 and p < 0.01 for FEV1% and r = 0.3 and p < 0.05 for FEV1 predicted). However, when adjusting for prebronchodilator FEV1, the BR was no more related to the fall in FEV1 (r = 0.15, p > 0.05). Conclusions: In long-term smokers and ex-smokers, the BR measured at the end of the follow-up period was correlated with the fall in FEV1. However, after adjusting for prebronchodilator FEV1 values, BR was no more related to the decline in FEV1. The BR appears not to be associated with the development of COPD.

Obstructive sleep apnea syndrome and public health: the Italian way

Dear Editor, Obstructive sleep apnea syndrome (OSAS) is an underdiagnosed chronic disease with a very high prevalence in adults. Patients with untreatedOSAS are at significantly increased risk of comorbidities as well motor vehicle accidents and work accidents. In order to counteract the impact of OSAS on public health in Italy, the Italian Minister of Health has approved a new approach that is aimed at preventing and making an early diagnosis of OSAS in adults and children. To our knowledge, this is the first example of a holistic model planned by a national institution. OSAS is a chronic disease with an estimated prevalence of 23.4% in women and 49.7% in men over 40 years of age [1]. Patients with untreated OSAS are at significantly increased risk of cerebro-cardiovascular, metabolic and neurocognitive disease, motor vehicle accidents [2], and work accidents [3]. For these reasons, OSAS has an adverse impact on quality of life and life expectancy, with a substantial adverse impact on economic systems. Awareness of OSAS as being a health issue of great relevance is rising [4]. In order to prevent motor vehicles accidents and related injuries, countries with developed economies have either proposed or adopted protocols or mandatory testing for the screening and early diagnosis of OSAS in commercial and/or private vehicle drivers [5]. In order to counteract the impact of OSAS on public health in Italy, the Italian Minister of Health has approved a new approach that is aimed at preventing and making an early diagnosis of OSAS in adults and children. To our knowledge, this is the first example of a holistic model planned by a national institution that is aimed at improving the health of OSAS patients. There is a very significant gap between the estimated number of patients with OSAS (approximately 80% of them are undiagnosed) and the ability of the Italian health system to diagnose and care patients. This gap is likely to increase further for twomain reasons: (i) although normal-weight subjects may be affected by OSAS, the increase in the prevalence of OSAS is associated with increased obesity, with obesity being the highest risk factor for OSAS; (ii) according to the European Commission Directive 2014/85/EU, testing is mandatory for moderate or severe OSAS, both when associated with excessive daytime sleepiness (EDS) and before a driver’s license is granted or renewed, and applicants or drivers with moderate or severe OSAS who are undergoing treatment shall be subject to periodic medical review at intervals not exceeding 3 years for drivers of Group 1 and 1 year for drivers of Group 2 driving license [5]. As a result of the Commission Directive 2014/85/EU, adherence to treatment must be evaluated in an objective manner [5]. International statements on OSAS are as follows that: (i) the clinical suspicion should be confirmed by objective testing; (ii) home sleep testing (HST) is validated for the diagnosis of OSAS, titration of positive airway pressure (PAP), and oral appliance devices and is used * Desiderio Passali d.passali@virgilio.it

Le Sindrome dell’Apnea Ostruttiva nel Sonno (OSAS): i costi sanitari e sociali

Obstructive sleep apnea (OSA) syndrome is an underdiagnosed widespread chronic disease involving both sexes and all ages. Undiagnosed and untreated OSA is associated with workplace productivity losses and significant direct and indirect medical costs. A cost analysis of OSA was carried out in Italy ten years ago. Overall OSA medical costs, largely due to treatment of comorbidity, amounted to € 2,9 billion or 55% of total medical costs. Direct medical costs, due to diagnosis and treatment of OSA, were 6% of overall OSA costs, while medical costs due to the absence of diagnosis and of prevention of comorbidities represented 49% of the overall cost. Non-medical costs made up for the remaining 45%. € 1.5 billion could be saved by promoting screening campaigns aimed at detecting OSA that would otherwise remain undiagnosed and by improving adherence to treatment. Bearing in mind the increasing OSA prevalence and the recent quantification of avoidable OSA-related road accidents, the real cost of OSA is higher than estimated up to now.

OSA and Work-Related Injuries: Searching for Evidence

In a review published in CHEST (May 2015), Hirsch Allen et al 1 deal with a subject of great interest: the relationship between the common medical condition of OSA and accidents at work. Th is narrative review states, “Th ere is emerging evidence implicating OSA as an important factor in two important societal issues: work disability and work-related injuries.” 1 However, this evidence has not been included in the article.