Sleep Duration and Bedtime in the PURE Poland Cohort Study and the Link with Noncommunicable Diseases

Abstract

(1) Background: The objective was to investigate the association between sleep duration, bedtime, and noncommunicable diseases in the PURE Poland cohort study. (2) Methods: The baseline study was conducted in 2007–2010. The study group comprised 2023 adult inhabitants of urban and rural areas in Lower Silesia, Poland. The study protocol included questionnaires, blood pressure measurements, blood draws, and anthropometric measurements. Sleep duration and bedtime were self-reported. (3) Results: The median sleep duration of women was 30 min longer than men (8 h vs. 7.5 h; p = 0.001). The average time of sleep increased along with the age of the participants. A sleep duration of >8 h was more common in rural than in urban participants (40.2% vs. 27.1%; respectively; p < 0.001). The relative risk of diabetes, stroke, hypertension, cardiovascular diseases (CVD), and obesity was significantly higher in participants who went to bed between 6 p.m. and 10 p.m. in comparison to those who went to bed between 10 p.m. and 12 a.m. (RR 2.23, 95%CI 1.06–4.67; RR 2.52, 95%CI 1.28 to 4.97; RR 1.12, 95%CI 1.04–1.20; RR 1.36; 95%CI 1.1–1.68; RR 1.38; 95%CI 1.15–1.66, respectively). The relative risk of respiratory diseases was two-fold higher in those who went to bed after midnight in comparison to those who went to bed between 10 p.m. and 12 a.m. (RR 2.24; 95%CI 1.19–4.22). (4) Conclusions: In our study, an earlier bedtime was associated with a higher risk of diabetes, stroke, obesity, hypertension, and CVD.

Study of Sleep Parameters on Respiratory Health and School Performance in Urban Children

“…This could explain why children who used screens late at night had more difficulty waking up (76.6%) (Table 3). Consistent to a study conducted by Jakobsson et al [31], more than 30% of the study participants had wake-up difficulty. Many of the children who took part in the study had bedtime delays and sleep disturbances.…”

“…Furthermore, in the study, 95.9% of early sleepers had lesser sick days with respiratory illnesses (< 15 days in a year) than 66.8% of the late sleepers (P<0.05). A study conducted in 2022 by Katarzyna et al [19] found that the relative risk of respiratory diseases was two-fold higher in those who went to bed after midnight versus those who went to bed between 10 PM and 12 AM. Hence, late sleepers (>10 PM) increases the risk of respiratory illnesses as proven in our study as well the other studies.…”

The role of epidemiological research in public health using the PURE Poland study as an example

“…The main research directions in the analyses of the data collected in the Polish PURE cohort during the longterm follow-up period focused on dietary factors [8][9][10][11][12][13][14][15][16], the effect of CETP and PLTP protein activity on lipid disorders [17,18], overweight and obesity [19][20][21][22], atti- tudes toward tobacco smoking [23][24][25][26], alcohol consumption [27], sleep [28], quality of life [29], prevalence and determinants of hypertension [30,31], and carbohydrate metabolism disorders [32][33][34][35][36].…”