Sleep Quality Of The Undergraduates In Qingdao And Its Dietary Influencing Factors

Objectives:Sleeping plays a critical role in maintaining homeostasis and promoting health.The dietary habits,dietary intake,and sleep patterns of the undergraduates,who are in the transition from adolescence to adulthood,are period-specific.The study aimed to describe the status of sleep quality among the undergraduates,to explore the relationship of dietary habits and mineral levels with sleep quality,and to further analyze the correlation between sleep quality and hematological indicators.The results could provide a theoretical basis for improving the sleep quality and health status of college students.Methods:With cluster random sampling,the study included 676 students from a university in Qingdao,and their basic demographic information through questionnaires and physical measurements were obtained,such as,living habits,dietary intake,height,and weight,etc.The Pittsburgh Sleep Quality Index(PSQI)was used to evaluate the sleep quality of college students from 7 dimensions such as subjective sleep quality,sleep onset time,sleep time,sleep efficiency,sleep disturbance,hypnotic drugs and daytime dysfunction.The included subjects were divided into poor sleep quality population and good sleep quality population according to the sleep quality evaluation criteria.The intake of breakfast,late-night snacks,snacks,grilled/fried food and instant food was obtained through the frequency of eating habits questionnaire.Logistic regression was used to analyze the relationship between dietary habits and the risk of poor sleep.The five eating habits were further evaluated comprehensively and a poor eating habit score was constructed.A score of 0 indicated no poor eating habit,and a score of 1-5 indicated that there are 1-5 bad eating habits,respectively.Logistic regression was used to analyze the relationship between the poor eating habits score and the risk of poor sleep quality.The intake of minerals and food groups was obtained through 24-h dietary recall and food frequency questionaire,and the relationship between the intake of minerals and the risk of poor sleep quality was analyzed through logistic regression.Moreover,for magnesium and calcium which were associated with sleep quality,the "magnesium-rich" and "calcium-rich" food pattern scores were established to explore the relationship between them and the risk of poor sleep quality.In addition,hematological and biochemical indicators were determined by automatic hematology analyzer and automatic biochemical analyzer,respectively.Serum 25(OH)D level was detected by high performance liquid chromatography tandem mass spectrometer.Spearman correlation analysis were used to explore the correlation of serum 25(OH)D levels and clinical indexes with sleep quality,respectively.Results:The average sleep duration of 676 college students was 7.76±0.73 hours.17.90% of the population had less than 7 hours of sleep.The average PSQI score of the subjects was4.93±2.54.38.82% of the population had poor sleep quality.Daytime dysfunction had the greatest effect on sleep quality,while hypnotic medications had the least effect.The PSQI score and percetage of poor sleep quality among those with the habit of staying up late to play mobile phones and being affected by roommates were higher(P values < 0.05 for all).The results of the association between dietary habits and sleep quality were showed as follows,compared with the group "eat breakfast every day",the odds ratios(ORs)and95% confidence intervals(CIs)of "eat breakfast ≤ 3 days per week" was 1.90(1.00,3.64).Compared with the group of "never snacking",the ORs(95% CIs)of "more than once a week" was 2.09(1.33,3.31).Compared with the group of "never/rarely eat fried/grilled food",the ORs(95% CIs)of "eat fried/grilled food more than once a week" was 2.99(1.81,4.94).Compared with the group of "never eating late-night snacks ",the ORs(95%CIs)of "eating late-night snacks more than once a month" was 2.53(1.43,4.48).Compared with the group of "never/rarely eat instant food",the ORs(95% CIs)of "eat instant food more than once a week" was 2.34(1.33,4.14).By establishing a poor dietary habit score,compared with the group with a score of 0,the ORs(95% CIs)of the group with 1 point,2-3 points,and 4-5 points were 1.56(0.59,4.12),2.41(0.98,5.91),and 4.37(1.85,12.11),respectively.The results of the association between mineral intake and sleep quality were showed as follows,the risk of poor sleep quality was marginally reduced by 31%(OR: 0.69,95%CI: 0.48–1.00)for each interquartile range of increased magnesium intake.The risk of poor sleep quality was marginally reduced by 15%(OR: 0.85,95% CI: 0.70–1.05)for each interquartile range of increased calcium intake.The ORs(95% CIs)of poor sleep quality across the quartiles of the magnesium-rich food pattern score were 1.00,0.61(0.36–1.05),0.62(0.36–1.07),and 0.40(0.22–0.73),respectively.The ORs(95% CIs)of poor sleep quality across the quartiles of the calcium-rich food pattern score were 1.00,0.70(0.41–1.21),0.58(0.33–1.00),and 0.50(0.27–0.94),respectively.In addition,the poor sleep quality was positively correlated with hemoglobin(r = 0.12,P = 0.01)and white blood cell account(r = 0.12,P = 0.02).The poor sleep quality was negatively correlated with the plasma 25(OH)D levels(r =-0.29,P = 0.04).Conclusion:The prevalence of poor sleep quality among college students in a university in Qingdao was relatively high.College students with poor eating habits such as skipping breakfast,snacking,grilling and fried foods,eating late-night snacks,and eating convenience foods might be at higher risk for poor sleep quality.College students with higher intakes of calcium-rich and magnesium-rich foods might have a lower risk of poor sleep quality.In addition,sleep quality was significantly correlated with several hematological indexes,and may affect the health status of college students.