Hypoxia and Sleep-disordered Breathing: Friend or Foe?

Prevalence of Sleep Disorders Among the General Population of the Jazan Region of Southwest Saudi Arabia

BACKGROUND

Sleep disorders impose a substantial burden on the global population, leading to an array of health complications. Understanding their prevalence and associated risk factors is crucial to formulating effective interventions.

OBJECTIVE

This study aimed to determine the prevalence and associated risk factors of sleep disorders among residents of the Jazan region of Saudi Arabia.

METHODS

This cross-sectional study conducted an online survey from December 2022 to March 2023. The sample comprised 670 respondents aged 18 years and older residing in Jazan. Demographic data, lifestyle habits, sleep patterns, and sleep disorder symptoms were assessed.

RESULTS

The participants were predominantly women (62.2%), with an average age of 30.99 years and a normal body mass index. The analyses revealed that 28.8% of the respondents reported experiencing sleep disorders, and 13.4% particularly had obstructive sleep apnea. Nearly half of the participants reported having primary insomnia, excessive daytime sleepiness, and restless leg syndrome. Significant associations were found between sleep disorders and older age (p = 0.012), obesity (p = 0.043), short or thin neck (p = 0.034), smoking (p = 0.003), caffeine use (p = 0.001), existing health conditions (p = 0.001), medication use (p = 0.013), lack of daytime naps (p = 0.043), and frequent nighttime awakenings to urinate (p = 0.001). The most common self-reported reasons for nightly awakenings were urination, anxiety or stress, discomfort or noise, and health conditions.

CONCLUSIONS

The findings suggest a high prevalence of sleep disorders among adults in Jazan, Saudi Arabia. Various demographic, lifestyle, and health-related factors are linked to these disorders. Therefore, targeted sleep health education and interventions could be instrumental in tackling this significant public health issue.

Potential Pathophysiological Pathways in the Complex Relationships between OSA and Cancer

Several epidemiological and clinical studies have suggested a relationship between obstructive sleep apnea (OSA) and a higher incidence or severity of cancer. This relationship appears to be dependent on a myriad of factors. These include non-modifiable factors, such as age and gender; and modifiable or preventable factors, such as specific comorbidities (especially obesity), the use of particular treatments, and, above all, the histological type or location of the cancer. Heterogeneity in the relationship between OSA and cancer is also related to the influences of intermittent hypoxemia (a hallmark feature of OSA), among others, on metabolism and the microenvironment of different types of tumoral cells. The hypoxia inducible transcription factor (HIF-1α), a molecule activated and expressed in situations of hypoxemia, seems to be key to enabling a variety of pathophysiological mechanisms that are becoming increasingly better recognized. These mechanisms appear to be operationally involved via alterations in different cellular functions (mainly involving the immune system) and molecular functions, and by inducing modifications in the microbiome. This, in turn, may individually or collectively increase the risk of cancer, which is then, further modulated by the genetic susceptibility of the individual. Here, we provide an updated and brief review of the different pathophysiological pathways that have been identified and could explain the relationship between OSA and cancer. We also identify future challenges that need to be overcome in this intriguing field of research.

Hypoxic Burden in Obstructive Sleep Apnea: Present and Future

Conventional measures of obstructive sleep apnea (OSA) severity, such as the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) are commonly used to quantify OSA severity and guide therapeutical decision-making processes. However, it is widely recognized that both AHI and ODI have important limitations and novel physiologically-informed metrics are needed to better capture the severity of OSA and characterize its physiological consequences, particularly the severity of recurrent nocturnal hypoxemia, ensuing the respiratory events. According to recent studies, the sleep apnea-specific "hypoxic burden (HB)", defined as the sum of individual areas under the oxygen desaturation curve, has shown some promise in identifying high risk individuals with OSA. In addition to the frequency of respiratory events, HB capture the depth and duration of OSA-related hypoxemia that may prove to be important disease characterizing features, not captured by the conventional "frequency-based" metrics, such as AHI and ODI. In this "perspective" paper the methods to quantify the HB, its characteristics, associations with health outcomes, and its limitations will be discussed.

Hypoxic Burden in Obstructive Sleep Apnea: Present and Future

Conventional measures of obstructive sleep apnea (OSA) severity, such as the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) are commonly used to quantify OSA severity and guide therapeutical decision-making processes. However, it is widely recognized that both AHI and ODI have important limitations and novel physiologically informed metrics are needed to better capture the severity of OSA and characterize its physiological consequences, particularly the severity of recurrent nocturnal hypoxemia, ensuing the respiratory events. According to recent studies, the sleep apnea-specific "Hypoxic Burden (HB)", defined as the sum of individual areas under the oxygen desaturation curve, has shown some promise in identifying high risk individuals with OSA. In addition to the frequency of respiratory events, HB capture the depth and duration of OSA-related hypoxemia that may prove to be important disease characterizing features, not captured by the conventional "frequency-based" metrics, such as AHI and ODI. In this "Perspective" paper the methods to quantify the HB, its characteristics, associations with health outcomes, and its limitations will be discussed.