The Relationship Between Sleep Time And Bone Mineral Density

Objective To explore the relationship between sleep time and bone mineral density in middle-aged and elderly population.Methods Residents aged 40 to 75 years who met the requirements in Lanzhou community were studied by using the baseline data of the“REACTION”study in the Lanzhou.Questionnaires(sleep time,time of getting up,nap duration)?physical examination?laboratory examination?bone mineral density and its T value were extracted from the study population.The sleep time is divided into 5 groups:~21:00?~22:00?~23:00?~24:00?>24:00.The sleep duration at night is divided into 5 groups:~6h?~7h?~8h?~9h?>9h.The nap duration was divided into 4 groups:0h?~0.5h?~1h?>1h.One-way analysis of variance was used to compare the differences in bone mineral density between different groups during different sleep time,different sleep duration at night,and different nap duration.Partial correlation analysis was used to investigate the relationship between sleep time,sleep duration at night,nap duration and bone mineral density.Binary logistic regression analysis was used to investigate the risk of sleep time,sleep duration at night,nap duration and osteoporosis.Results(1)A total of 8886 subjects were enrolled in the study,with an average age of(57.8±8.5)years.The average bone mineral density was(0.53±0.13)g?cm~2,which was higher in men than in women(0.56±0.13 vs 0.53±0.13)g?cm~2(P<0.05).(2)The average sleep time,the average sleep duration at night,and the average nap duration were(22:47±0:53),(7.66±1.14)h,and(0.56±0.64)h.33.5%of the residents slept for?7h at night,5.3%residents slept for>9h,2.7%residents fell asleep after 24:00,59.0%residents had naps.(3)One-way analysis of variance showed that in the general population and female population,the bone mineral density of the sleepers was lowest at~22:00(P<0.05),and the bone mineral density of men who fell asleep after 24:00 was lower than those who fell to sleep at~23:00(P<0.05).women who had a nap had lower bone mineral density than those who did not have a nap(P<0.05),there was no significant difference in bone mineral density between men under different nap duration groups(P>0.05);There was no significant difference in bone mineral density between different sleep duration groups at night(P>0.05).(4)Partial correlation analysis showed that after adjusting for age,menopause(adjusted only to female population)and other confounding factors,male's sleep time was negatively correlated with bone mineral density(r=-0.049,P<0.05),there was no correlation between women's sleep time and bone mineral density(P>0.05);There was no correlation between sleep duration at night and nap duration and bone mineral density(P>0.05).(5)The results of binary logistic regression analysis showed that the sleep time~23:00 as control group,after adjusting for a variety of confounding factors,falling asleep after 24:00 is positively associated with the risk of osteoporosis for woman(OR=2.972,P<0.05),there was no correlation between men's sleep time and the risk of osteoporosis(P>0.05);There was no correlation between sleep duration at night and nap duration and the risk of osteoporosis(P>0.05).Conclusions Among the middle-aged and elderly people in Lanzhou,the later the man falls asleep,the lower the bone mineral density.Falling asleep after 24:00may be an independent risk factor for osteoporosis in women.