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Objectives: Although continuous positive airway pressure (CPAP) effectively prevents sleep apnea and reduces blood pressure, many patients do not use CPAP every night. This trial investigates cardiovascular effects after sleeping five nights without CPAP.

Methods: We randomized 100 patients (67 men and 33 women with a mean age 64±9 years) using CPAP treatment for moderate-to-severe sleep apnea to either withdraw treatment for five nights (n=50) or to continue with CPAP (n=50). The primary outcomes were arterial stiffness and 24h blood pressure.

Results: The 24h SBP increased by a mean of 2.8mmHg [95% confidence interval (CI) 0.2-5.4mmHg] (P=0.035) and DBP increased by a mean of 1.7mmHg (95% CI 0.1-3.3mmHg) (P=0.032) in the group without CPAP compared to the CPAP group. There was a significant effect on blood pressure in women but not in men. In women, SBP increased by 5.1mmHg (95% CI 1.0-9.5mmHg) (P=0.017) and DBP by 2.9mmHg (95% CI 0.4-5.6mmHg) (P=0.029). Arterial stiffness remained unaffected. Secondary outcomes that worsened in patients without CPAP included apnea-hypopnea index, oxygen desaturation index, hemoglobin levels, and daytime sleepiness.

Conclusion: Blood pressure is affected after five nights of CPAP interruption, along with a rapid return of sleep apneas, nocturnal hypoxic events, daytime sleepiness and increased hemoglobin levels, but arterial stiffness was not affected. Blood pressure was affected in women only, suggesting a sex-related CPAP effect on blood pressure.

Objectives: Sleep apnea is suggested to be associated with cancer risk, but results are heterogenous, and few studies are population-based. We aimed to assess risk associations between self-reported witnessed apnea during sleep and specific cancers in a population-based cohort.

Methods: This retrospective cohort study analyzed questions on witnessed sleep apnea in relation to incident cancer in the Northern Sweden Health and Disease Study. Cancer diagnoses were derived from the Swedish Cancer Registry and characterized as 12 different cancer types. Cox regression models adjusted for age, sex, ever smoking, body mass index, and education were used to assess risk associations.

Results: In total, 82,059 participants were included, and 10,668 (13 %) reported witnessed sleep apnea. They were followed for 9.0 (SD 4.7) years and 4030 incident cancers were diagnosed. Self-reported witnessed sleep apnea was independently associated with incident lung cancer with an adjusted hazard ratio (aHR), 1.78 (95 %CI 1.16, 2.73) p = 0.008 and breast cancer aHR, 1.39 (95 %CI 1.04, 1.84) p = 0.023. The risk for lung cancer was driven by an association with lung adenocarcinoma aHR, 2.16 (95 %CI 1.19, 3.91) p = 0.01. There was a multiplicative effect on ever smoking and reporting witnessed apnea for lung cancer with an aHR, 5.27 (95 %CI 3.07, 9.05) p < 0.001.

Conclusions: Self-reported witnessed sleep apnea is associated with an increased risk of developing lung- and breast cancer. There is a multiplicative effect of reporting witnessed sleep apnea and ever-smoking with an over 5 times increase on the hazard for lung cancer.

Excessive daytime sleepiness (EDS) is a common complaint in the general population and is associated with cardiovascular disease and increased mortality. We aimed to investigate whether sleep duration is related to excessive daytime sleepiness in the general population, both in itself and in combination with other factors. We performed a cross-sectional analysis in the population-based Swedish CArdioPulmonary bioImage Study (SCAPIS) cohort (n = 27,976; 14,436 females; aged 50–64 years) to assess how sleep-related factors along with anthropometric, lifestyle, socioeconomic factors as well as somatic disease and psychological distress, were related with EDS assessed by the Epworth sleepiness scale (ESS). Analyses were performed using logistic regression modelling with EDS defined by an ESS score of ≥11 as the main outcome. Both short and long sleep duration were related to EDS with increasing ORs for decreasing sleep duration (7 h vs. reference (8 h): OR 1.2, 95% CI 1.02–1.3 to ≤4 h: 1.9; 1.4–2.5). In addition to sleep-related factors such as insomnia (1.3; 1.2–1.4), poor sleep quality (1.2; 1.04–1.4), snoring (1.5; 1.4–1.6), and nocturnal gastro-oesophageal reflux (1.5; 1.21–1.8), psychological distress showed a strong association with EDS. This included sadness/depression (1.2; 1.1–1.3), stress (some stress: 1.4; 1.1–1.7 to constant stress over 5 years: 1.7; 1.3–2.2), and self-rated "control in life" (lowest quartile: 1.7; 1.6–2.0). Daytime sleepiness is multifactorial and associated with both sleep duration and sleep quality. Strong associations were also established with factors related to psychological distress. Further research may investigate interventions targeting both sleep and psychological health to reduce daytime sleepiness at the societal level.