BackgroundChronic feeding and sleep schedule disturbances are stressors that exert damaging effects on the organism. Practicing Muslims in Saudi Arabia go through strict Ramadan fasting from dawn till sunset for one month yearly. Modern era Ramadan practices in Saudi Arabia are associated with disturbed feeding and sleep patterns, namely abstaining from food and water and increasing daytime sleep, and staying awake and receiving food and water till dawn.HypothesisStrict Ramadan practices in Saudi Arabia may influence metabolism, sleep and circadian cortisol secretion.ProtocolYoung, male Ramadan practitioners were evaluated before and two weeks into the Ramadan. Blood samples were collected at 9.00 am and 9.00 pm for measurements of metabolic parameters and cortisol. Saliva was collected serially during the day for cortisol determinations.ResultsRamadan practitioners had relative metabolic stability or changes expected by the pattern of feeding. However, the cortisol circadian rhythm was abolished and circulating insulin levels and HOMA index were increased during this period.DiscussionThe flattening of the cortisol rhythm is typical of conditions associated with chronic stress or endogenous hypercortisolism and associated with insulin resistance.ConclusionsModern Ramadan practices in Saudi Arabia are associated with evening hypercortisolism and increased insulin resistance. These changes might contribute to the high prevalence of chronic stress-related conditions, such as central obesity, hypertension, metabolic syndrome and diabetes mellitus type 2, and their cardiovascular sequelae observed in the Kingdom.

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BACKGROUND: Over the next 20 yr, international market expansion will necessitate the production of new commercial airplanes and the recruitment of additional crewmembers and technicians. Research has proven that fatigue and lack of sleep are risk factors for impaired cognitive performance and human error. Pilots frequently report fatigue to their employers, which may be related to sleep disturbance. Airline pilots, in particular, often experience circadian desynchronization and other types of sleep disorders. Shift workers have been observed to be at higher risk of fatigue that affects their performance and alertness. In Saudi Arabia, sleep disorders among airline pilots are understudied and underreported. The primary objective of this study was to screen for and determine the risk of sleep disorders, fatigue, and depression among pilots.METHODS: A cross-sectional epidemiological study with national commercial pilots was conducted from March 2019 to March 2020 using validated questionnaires to screen for the risk of sleep disorders, fatigue, and depression.RESULTS: In total, 344 pilots participated in the study. Half the sample was at risk for insomnia and fatigue. Older and more experienced pilots were less likely to suffer impaired sleep quality, insomnia, sleepiness, fatigue, and depression. In total, 59 (17.2%) pilots were at high risk for sleep apnea.CONCLUSION: The current study found that pilots were at risk of developing sleep disorders. A more robust and objective assessment is warranted for screening.Alzehairi A, Alhejaili F, Wali S, Al Qassas I, Balkhyour M, Pandi-Perumal SR. Sleep disorders among commercial airline pilots. Aerosp Med Hum Perform. 2021; 92(12):937–944.

Background: Chronic feeding and sleep schedule disturbances are stressors that exert damaging effects on the organism. Practicing Muslims in Saudi Arabia go through strict Ramadan fasting from dawn till sunset for one month yearly. Modern era Ramadan practices in Saudi Arabia are associated with disturbed feeding and sleep patterns, namely abstaining from food and water and increasing daytime sleep, and staying awake and receiving food and water till dawn.Hypothesis: Strict Ramadan practices in Saudi Arabia may influence metabolism, sleep and circadian cortisol secretion.Protocol: Young, male Ramadan practitioners were evaluated before and two weeks into the Ramadan. Blood samples were collected at 9.00 am and 9.00 pm for measurements of metabolic parameters and cortisol. Saliva was collected serially during the day for cortisol determinations.Results: Ramadan practitioners had relative metabolic stability or changes expected by the pattern of feeding. However, the cortisol circadian rhythm was abolished and circulating insulin levels and HOMA index were increased during this period.Discussion: The flattening of the cortisol rhythm is typical of conditions associated with chronic stress or endogenous hypercortisolism and associated with insulin resistance.Conclusions: Modern Ramadan practices in Saudi Arabia are associated with evening hypercortisolism and increased insulin resistance. These changes might contribute to the high prevalence of chronic stress-related conditions, such as central obesity, hypertension, metabolic syndrome and diabetes mellitus type 2, and their cardiovascular sequelae observed in the Kingdom.

Purpose Positional obstructive sleep apnoea (POSA) is of important clinical significance, as positional treatment can augment or obviate continuous positive airway pressure. This study aimed to determine the prevalence of POSA and its characteristics using different definitions. Methods We retrospectively examined a cohort of patients who underwent polysomnography (PSG) between 2013 and 2019 at two sleep centres. Demographic data and PSG data were collected from 624 patients with an apnoea–hypopnea index (AHI) ≥ 5. POSA was defined using different criteria as follows: (1) AHI of at least twice as high in the supine position as in the lateral position (Cartwright’ s definition). (2) A supine AHI ≥ 10 and a lateral AHI < 10 (Marklun’s definition). (3) AHI of at least twice as high in the supine position than in the lateral position, with the lateral AHI not exceeding 5 (Mador’s definition or Exclusive POSA; e-POSA). (4) AHI ≥ 15/h; a supine AHI ≥ twice that of the nonsupine AHI ≥ 20 min of sleep in the supine and nonsupine positions; and a nonsupine AHI < 15 (Bignold’s definition). Results The prevalence of POSA was 54% (Cartwright), 38.6% (Mador), 33.8% (Marklund) and 8.3% (Bignold). Multivariate regression analysis showed a body mass index (BMI) < 35 kg/m2 was the only significant predictor of POSA. Mador’s definition had the highest diagnostic yield (sensitivity 63%; specificity 100%; area under the receiver operating characteristic curve 90.2%). Conclusion POSA is common, but its prevalence depends on the definition used. Low BMI was identified as a significant predictor.