الملخص الإنجليزي
Since the start of the industrial revolution, sleep patterns, duration, and quality have been continuously changing globally. This is associated with an emergence of sleep disturbances and increased prevalence of cardiometabolic risk worldwide. Aims and Objectives: This study aimed to investigate the association between sleep patterns and cardiometabolic risks in young adults and middle-aged group of Omanis in Muscat; the capital of Sultanate of Oman. The main objectives were: (1) to investigate the subjective and objective sleep patterns and their agreement levels; (2) to find any association between objective sleep patterns and cardiometabolic risks and biomarkers. Ethical approval: The study design and methods were approved by the Medical Research Ethic Committee at Sultan Qaboos University on 3rd April 2014 under MREC-878. Subjects & Methods: This is a cross-sectional study that strive for associations only. It was ethically approved by the Medical Research Committee at the College of Medicine at Sultan Qaboos University. Informed consent forms were obtained from all subjects before their enrollment in this study. A total of 1500 sleep questionnaires were distributed among Omani adults in Muscat area. The questionnaires included the Epworth Sleepiness Scale (ESS) to look for excessive daytime sleepiness and the Pittsburg Sleep Quality Index (PSQI), for sleep quality evaluation. Participants who successfully filled in the sleep questionnaires on the first day and fulfilled the inclusion criteria were categorized into two age groups based on the Ministry of health/WHO guidelines of age; (1) young adults of age (18-39 year), and (2) middle-aged group (40-59 years). In addition to the demographic and anthropometric data, participants were provided with an actigraphy device to wear it for one week at the same day of filling the questionnaires. A limited (home) sleep study was also performed for OSA diagnosis over night as a major confounding factor. The actigraphy device was returned at day (8) followed by fasting blood collection for cardiometabolic risks assessment, including metabolic syndrome and biomarkers investigation which included; high sensitivity C reactive protein (hs-CRP), malondialdehyde (MDA) and basal oxidizability status. Blood pressure was also measured three times and the average reading was noted. Statistical analysis: Data was collected and analyzed using Statistical Package for the Social Sciences (SPSS), version 21. A descriptive analysis, Chi-square test, Kruskal-Wallis test, Kappa test, Bland-Altman plot, linear and binary logistic regression analysis were implemented. Significant difference was reported at P value of 0.05. Results: A total of 946 participants [men: (n=405, 42.8%); women: (n=541, 57,2%)] were recruited (response rate=63.1%) and filled the sleep questionnaires. Out of which, only 321 subjects (men (n=171, 53.3%); women (n=150, 46.7%)], wore the actigraphy for one week and underwent fasting blood collection, amongst which 142 subjects agreed to use the limited (home) sleep study. Out of 321 participants, 69.5% (n=223) belonged to the young adults of age group (18-39 years) and only 30.5%(n=98) were of the middle aged group (40-59 years). Elderlies of>59 years were excluded from the study as they showed a very small percentage (<5%). The study sample consisted of subjects with an undergraduate education level (n=793; 82.8%) and were employed (n=898; 94.9%). The body mass index median was 25.7 kg/m2 (range: 42.4). The median for Systolic Blood Pressure (SBP) was 119 mmHg (range: 67.5), while for diastolic blood pressure it was 75 mmHg (range: 59). The sleep questionnaires revealed four sleep patterns among this study sample size; (1) monophasic (11.4%, n=108), biphasic-dawn (21.6%, n= 204), biphasic-siesta (21.2%, n=199) and polyphasic sleep pattern (46%, n=435). On the other hands, actigraphy analysis also showed the previous four sleep patterns throughout the week yet with different prevalence. Objectively, monophasic sleep pattern accounted for (24.3%, n=78), biphasic-dawn (9%, n=29), biphasic-siesta (36.1%, n=116) and polyphasic sleep pattern (30.5%, 11-98). Based on the actigraphy, both polyphasic and biphasic-siesta were the predominant sleep patterns and were significantly associated with short night sleep duration (<7 hours) (median= 6.8 hours) (P<0.0001, adjusted P=0.091), a long siesta (>60 minutes) (median=75.5 and 64 minutes respectively) (adjusted P<0.0001). Also, biphasic-siesta was practiced more by employed subjects as compared to unemployed participants who showed more polyphasic and biphasic-dawn sleep patterns. The sleep patterns varied with season too; in summer polyphasic sleep pattern prevailed over other patterns, while in winter, monophasic sleep pattern dominated over other sleep patterns. In addition, the ESS scores for polyphasic and biphasic-siesta sleep patterns were associated with higher normal daytime sleepiness (ESS median=9) (adjusted P<0.0001). Both patterns showed a higher prevalence of poor sleep quality (PSQI>5) (54.3% and 55.3% respectively), (PSQI score median=6) yet not significant after gender and age adjustments (P=0.032, adjusted P=0.372). In contrary, monophasic and biphasic-dawn sleep patterns showed night sleep duration within normal range (7-9 hours) (median=7.4 hours) and short siesta (560
