Association Of Sleep Fragmentation With Obesity And Abnormal Body Fat Distribution In College Students

Objectives This study aims to Describe the current situation of sleep fragmentation in college students,evaluate the correlation effect of sleep fragmentation with obesity and abnormal body fat distribution,so as to provide theoretical guidance and intervention framework for the prevention of health hazards caused by sleep fragmentation and provide new ways for the prevention and control of obesity.MethodsResearchers randomly recruited college students who volunteered to participate in the project in 2 colleges and universities in Hefei,Anhui Province through online and onsite recruitment.The researchers initially recruited 520 college students in 2019 and2018.A week after the establishment of the university student queue,the baseline questionnaire and physical examination were carried out.The questionnaire was filled out in the classrooms of each school to collect basic demographic data,daily activities and other information.Physical examination(including height,weight,blood pressure and body composition measurement)is carried out uniformly in the laboratory.Finally,457 volunteers completed the questionnaire and 469 students completed the physical examination.After the completion of the questionnaire and physical examination,the sleep status of400 volunteers was measured continuously for 7 days using the wrist strap triaxial accelerometer(GT3X-BT;Acti Graph),and the sleep fragmentation data of 389volunteers(139 males,accounting for 35.7%)were included in the analysis.The sleep parameters measured by the triaxial accelerometer include: sleep efficiency(SE);Wake after sleep onset(WASO);Total sleep time(TST);Sleep fragmentation index(SFI);Activity index(MI);(6)Fragmentation index(FI).In this study,sleep fragmentation index(SFI)was used as an index to evaluate sleep fragmentation.Pearson correlation was used to analyze the correlation between sleep parameters(SFI,MI,WASO,SE,TST)and obesity parameters(BMI,PBF,FM,WC,VFA)of college students.Univariate analysis of variance was used to compare the distribution of sleep parameters of college students in different weight states(normal,overweight,obesity),and the distribution of obesity parameters of college students at different sleep fragmentation levels.Univariate and multivariate linear regression models were used to analyze the relationship between sleep fragmentation and obesity parameters of college students.Among them,sleep fragmentation(SFI)was both a continuous variable and a categorical variable(grouped by SFI quartile,with the lowest quartile array of SFI as the reference group).Multiple logistic regression analysis was used to analyze the increase of overweight and obesity risk of college students for each unit of increase in sleep fragmentation(SFI)ResultsAmong 389 college students included in the analysis,139(35.7%)were male students.The average value of the participants’ sleep fragmentation index was(23.1 ± 6.0).According to BMI,college students were divided into three groups.Compared with the normal weight group,the obese group had significantly higher MI and SFI levels [MI:(17.9 ± 20.8 vs.11.8 ± 3.0;P<0.01),SFI:(27.3 ± 4.7 vs.22.7 ± 5.9;P<0.01)].Sleep fragmentation index was positively correlated with obesity parameters: BMI(r=0.17,P<0.01),PBF(r=0.12,P<0.05),FM(r=0.18,P<0.01),WC(r=0.17,P<0.01),VFA(r=0.18,P<0.01).There was no statistically significant difference in other sleep parameters(TST,SE,WASO)among college students in different weight status groups(P values were all greater than 0.05)College students were divided into four groups according to the SFI quartile.Compared with SFI Q1 group(the lowest quartile array),the BMI,PBF,FM WC and VFA levels were significantly higher [BMI:(22.4 ± 3.7 kg/m2 vs 20.9 ± 2.3 kg/m2;P<0.01),PBF:(29.6 ± 7.3% vs 27.2 ± 7.0%;P<0.05),FM:(18.2 ± 6.6 kg vs 15.5 ± 4.6 kg;P<0.01),WC:(75.9 ± 8.6 cm vs 72.4 ± 5.7 cm;P<0.01),VFA:(74.6 ± 32.3 cm2 vs 61.0 ± 22.9cm2;P<0.01)].There was no significant difference in obesity parameters(BMI,PBF,FM,WC,VFA)among college students in SFI Q1,Q2 and Q3 groups(P>0.05).After adjusting for covariates such as age,sex,socio-economic status,sleep duration,smoking and drinking status,physical activity,sugary drink intake,and video time,SFI increased by 1 unit,BMI,PBF,FM WC and VFA levels increased [BMI: 0.09 kg/m2(95% CI: 0.02,0.14;P=0.001),PBF: 0.14%(95% CI: 0.04,0.24;P=0.005),FM: 0.17kg(95% CI: 0.07,0.26;P=0.001),WC: 0.20 cm(95% CI: 0.09,0.32;P=0.001),VFA:0.83 cm2(95% CI: 0.37,1.29;P<0.001)].Similarly,the SFI quartile divided college students into four groups.Compared with the SFI Q1 group,the levels of BMI,PBF,FM,WC and VFA in the SFI Q4 group increased [BMI: 0.50 kg/m2(95% CI: 0.21,0.79;P=0.001),PBF: 0.76%(95% CI: 0.21,1.32;P=0.007),FM: 0.91 kg(95% CI:0.36,1.46;P=0.001),WC: 1.09 cm(95% CI: 0.42,1.76;P=0.002),VFA: 4.50 cm2(95% CI: 1.83,7.17;P=0.001)].Compared with SFI Q1 group,the changes of obesity parameters(BMI,PBF,FM,WC,VFA)of college students in Q2 and Q3 groups were not statistically significant(P>0.05).After adjusting for covariates such as age,sex,socio-economic status,length of sleep,smoking and drinking status,physical activity,sugary drink intake,and video time,the risk of overweight and obesity among college students increases with each unit of SFI increase [overweight: 3%(95% CI: 0.97,1.08;P=0.444),obesity: 16%(95% CI: 1.06,1.26;P=0.001)]ConclusionCollege students are faced with sleep fragmentation,which is related to obesity and abnormal body fat distribution.Sleep fragmentation is a risk factor for obesity and abnormal body fat c distribution.Individuals with high sleep fragmentation have significantly higher obesity and central body fat distribution,suggesting that sleep fragmentation may have cumulative effects on obesity and central body fat distribution.Future research should strengthen the discussion of the total regulatory factors and biological mechanism of sleep fragmentation environment,and provide information for the development of intervention programs for adolescent sleep fragmentation.