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Objectives This population-based cohort study was performed to assess the association between sleep disturbances and the risk of occupational accidents among women. Methods Data were collected by questionnaires on two different occasions (2000 and 2010) and data on work injuries were also collected from Swedish government records (ISA). Insomnia symptoms were defined as having severe or very severe problems with (i) difficulty initiating sleep, (ii) difficulty maintaining sleep, or (iii) early morning awakening. Symptom of obstructive sleep apnea syndrome (OSAS) was defined as reporting both snoring and daytime sleepiness. Working-age respondents (20-67 years of age) who responded to both baseline and follow-up questionnaires and had worked for part or all of the 10-year follow-up period (N=4320) were included in the study. Results Of the subjects responding to the questionnaire, 12.2% reported >= 1 accident and 6.3% reported an accident requiring sick leave in the government register. Blue-collar workers and night and shift work were more common in the group with occupational accidents. Subjects with insomnia symptoms both at baseline and follow-up (persistent insomnia symptoms) ran a higher risk of being involved in an self-reported occupational accident [adjusted OR (ORadj) 1.5, 95% confidence interval (95% CI) 1.2-2.0] after adjusting for age, body mass index, smoking, alcohol dependency, white- or blue-collar worker, years at work, night work, and physical activity. Persistent insomnia symptoms did not reach statistical significance as an independent predictor of register-reported occupational accident with sick leave (ORadj 1.4, 95% CI 0.99-2.1). No significant association was found between symptoms of OSAS and self-reported or register-based occupational accidents. Conclusions Persistent insomnia symptoms were associated with an increased risk of self-reported occupational accidents, while no significant association was found with occupational accidents with sick leave reported to government register.

OBJECTIVE: Daytime sleepiness is common in women and has negative health effects. Nocturnal gastroesophageal reflux (nGER) and snoring are risk factors for daytime sleepiness, but the effect of their interaction remains unknown. The aim of this study was to examine how nGER and snoring combined affected daytime sleepiness and involuntary falling asleep in women.

METHODS: A questionnaire was sent to randomly selected women in 2000 and 2010. Participants who answered questions regarding both nGER and snoring in both questionnaires were included (N = 4882). Daytime sleepiness was defined as severe or very severe problems with daytime sleepiness. Involuntary falling asleep was defined as sometimes, often or very often falling asleep involuntarily during the day. Respondents snoring loudly and disturbingly sometimes, often or very often were defined as snorers. Having nocturnal heartburn or acid reflux sometimes, often or very often was defined as having nGER.

RESULTS: Daytime sleepiness was reported by 14% of the participants, involuntary falling asleep by 11%. After adjustment for age, smoking, physical activity, caffeine intake and alcohol dependency, increased odd ratios (ORs) for both daytime sleepiness (adjusted OR 4.2, 95% confidence interval (CI): 1.9-9.2) and involuntary falling asleep (adjusted OR 3.1, 95% CI: 1.5-6.4) were seen in women with the combination of nGER and snoring at both baseline and follow-up. The association with daytime sleepiness was also strong for those with only persistent nGER but not for those with only persistent snoring.

CONCLUSION: Women with nGER were at increased risk of developing daytime sleepiness and snoring augmented this association. In addition, women with both nGER and snoring were also at increased risk of developing involuntary falling asleep.

Objectives

Smoking is associated with sleep disturbances. The aim of this study was to analyze whether sleep disturbances are predictors of smoking cessation and whether continued smoking is associated with the development of sleep disturbances.

Methods

A questionnaire was sent to randomly selected men and women in Northern Europe in 1999–2001 (RHINE II) and was followed up by a questionnaire in 2010–2012 (RHINE III). The study population consisted of 2568 participants who were smokers at baseline and provided data on smoking at follow-up. Insomnia symptoms were defined as having difficulty initiating and/or maintaining sleep and/or early morning awakening ≥3 nights/week. Multiple logistic regression analyses were performed to calculate odds ratios (OR).

Results

Subjects with difficulty initiating sleep (adjusted odds ratio; 95% confidence interval: 0.6; 0.4–0.8), difficulty maintaining sleep (0.7; 0.5–0.9), early morning awakening (0.6; 0.4–0.8), any insomnia symptom (0.6; 0.5–0.8) or excessive daytime sleepiness (0.7; 0.5–0.8) were less likely to achieve long-term smoking cessation after adjustment for age, BMI, pack-years, hypertension, diabetes, chronic bronchitis, rhinitis, asthma, gender and BMI difference. There was no significant association between snoring and smoking cessation. In subjects without sleep disturbance at baseline, continued smoking increased the risk of developing difficulty initiating sleep during the follow-up period compared with those that had quit smoking (adj. OR 1.7, 95% CI 1.2–2.3).

Conclusions

Insomnia symptoms and excessive daytime sleepiness negatively predict smoking cessation. Smoking is a risk factor for the development of difficulty initiating sleep. Treatment for sleep disturbances should be included in smoking-cessation programs.

Study objectives: Insomnia and snoring are common sleep disorders. The aim was to investigate the association of a combination of insomnia symptoms and snoring with comorbidity and daytime sleepiness. 

Methods: The study population consisted of 25,901 subjects (16-75 years, 54.4% women) from four Swedish cities, who answered a postal questionnaire that contained questions on snoring, insomnia symptoms (difficulties initiating and/or maintaining sleep and/or early morning awakening), smoking, educational level and respiratory and non-respiratory disorders. 

Results: Snoring was reported by 4,221 (16.2%), while 9,872 (38.1%) reported ≥ 1 insomnia symptom. A combination of insomnia symptoms and snoring was reported by 2,150 (8.3%). The association with hypertension (OR 1.4, 95% CI: 1.2-1.6), chronic obstructive pulmonary disease (COPD) (OR 1.8, 95% CI: 1.3-2.4), asthma (OR 1.9; 95% CI: 1.6-2.3), daytime sleepiness (OR 7.9, 95% CI 7.1-8.8) and the use of hypnotics (OR 7.5, 95% CI: 6.1-9.1) was highest for the group with both insomnia symptoms and snoring.

Conclusions: Subjects with snoring and insomnia combined run an increased risk of hypertension, COPD, asthma, daytime sleepiness and the use of hypnotics. It is important to consider snoring in patients seeking medical assistance for insomnia and, vice versa, in patients with snoring enquire about insomnia. 

Keywords:  Snoring, insomnia, daytime sleepiness, hypertension, COPD, asthma