Objective To study the age-dependent relationship between body mass index(BMI)and cognitive impairment in rural population aged 40 years and above.Methods From October 2014 to March 2015,people aged 40 years and above,who lived in two natural villages in Huyi District of Xi'an,were selected as the research subjects.Their general demographic information,lifestyle,medical history,family history,physical examination,and biochemical examination were collected.Mini-Mental State Examination(MMSE)was used to evaluate global cognitive function.Cognitive impairment was defined as an MMSE score lower than the cutoff value,specifically,scores ≤17 for subjects who were illiterate,scores ≤20 for subjects with primary school education,and scores ≤24 for subjects with junior high school education or above.The age-dependent relationship between BMI and cognitive impairment was discussed using stratified analysis,restricted cubic spline(RCS),and multivariate Logistic regression.Results We included a total of 1 792 subjects in the analysis,of whom 230(12.8％)were diagnosed with cognitive impairment.There were 726 males(40.5％);the average age was(55.53±9.92)years,ranging from 40 to 85 years,1 193 subjects aged 40-59 years(66.6％),and 599 subjects aged ≥60 years(33.4％).The average BMI was(25.29±3.14)kg/m2.In the total population,BMI index was fitted as restricted cubic splines in the Logistic regression model,and other confounding factors were corrected.The results showed that BMI index was significantly correlated with cognitive impairment(Poverall=0.023),and there was a trend of nonlinear relationship(P nonlinear=0.097).The specific relationship was that with BMI=25 kg/m2 as the reference(OR=1),when BMI index was＜25 kg/m2,the OR value increased as BMI index decreased.However,when BMI index was ≥25 kg/m2,the OR value did not change significantly as BMI index increased.The population was divided into two subgroups according to age(40-59 years vs.≥60 years).Stratified analysis showed that in the ≥60 years old subgroup,cognitive impairment had significant correlation with BMI index(Poverall=0.038,Pnonlinear=0.097),and the changing trend of the correlation was similar to that of the overall population.By contrast,in the 40-59 years old subgroup,BMI index was not significantly associated with cognitive impairment(Poverall=0.722,Pnonlinear=0.738).Conclusion The relationship between BMI and cognitive impairment is affected by age.No significant association is found in the middle-aged population of 40-59 years old,but there may be a nonlinear association in the elderly population over 60 years old.Specifically,with BMI=25 kg/m2 as the boundary,as BMI decreases,the risk of cognitive impairment gradually increases.As BMI further increases,the risk of cognitive impairment does not change significantly even though it reaches the obesity level.

Objective To study the age-dependent relationship between body mass index(BMI)and cognitive impairment in rural population aged 40 years and above.Methods From October 2014 to March 2015,people aged 40 years and above,who lived in two natural villages in Huyi District of Xi'an,were selected as the research subjects.Their general demographic information,lifestyle,medical history,family history,physical examination,and biochemical examination were collected.Mini-Mental State Examination(MMSE)was used to evaluate global cognitive function.Cognitive impairment was defined as an MMSE score lower than the cutoff value,specifically,scores ≤17 for subjects who were illiterate,scores ≤20 for subjects with primary school education,and scores ≤24 for subjects with junior high school education or above.The age-dependent relationship between BMI and cognitive impairment was discussed using stratified analysis,restricted cubic spline(RCS),and multivariate Logistic regression.Results We included a total of 1 792 subjects in the analysis,of whom 230(12.8％)were diagnosed with cognitive impairment.There were 726 males(40.5％);the average age was(55.53±9.92)years,ranging from 40 to 85 years,1 193 subjects aged 40-59 years(66.6％),and 599 subjects aged ≥60 years(33.4％).The average BMI was(25.29±3.14)kg/m2.In the total population,BMI index was fitted as restricted cubic splines in the Logistic regression model,and other confounding factors were corrected.The results showed that BMI index was significantly correlated with cognitive impairment(Poverall=0.023),and there was a trend of nonlinear relationship(P nonlinear=0.097).The specific relationship was that with BMI=25 kg/m2 as the reference(OR=1),when BMI index was＜25 kg/m2,the OR value increased as BMI index decreased.However,when BMI index was ≥25 kg/m2,the OR value did not change significantly as BMI index increased.The population was divided into two subgroups according to age(40-59 years vs.≥60 years).Stratified analysis showed that in the ≥60 years old subgroup,cognitive impairment had significant correlation with BMI index(Poverall=0.038,Pnonlinear=0.097),and the changing trend of the correlation was similar to that of the overall population.By contrast,in the 40-59 years old subgroup,BMI index was not significantly associated with cognitive impairment(Poverall=0.722,Pnonlinear=0.738).Conclusion The relationship between BMI and cognitive impairment is affected by age.No significant association is found in the middle-aged population of 40-59 years old,but there may be a nonlinear association in the elderly population over 60 years old.Specifically,with BMI=25 kg/m2 as the boundary,as BMI decreases,the risk of cognitive impairment gradually increases.As BMI further increases,the risk of cognitive impairment does not change significantly even though it reaches the obesity level.

Objective:To explore the latent classes of emotional behavior of children with mental disorders, and their relationship with parents' sense of parenting competence and psychological distress.Methods:A survey of 327 parents of children with mental disorders was conducted from September to December 2022 using the general information questionnaire, the sense of parenting competence scale, the Kessler psychological distress scale, and the strengths and difficulties questionnaire (parent version). Mplus 8.0 and SPSS 25.0 softwares were used for statistical analysis.The latent class analysis was used to identify subgroups of children with mental disorders based on their emotional behavior.Multinomial logistic regression was used to analyze the related factors.Results:Latent class analysis showed that the emotional behaviors of children with mental disorders were divided into 3 categories: emotion-conduct problem prominent group (38.53%(126/327)), simple emotional problem group (44.65%(146/327)), and emotion-peer interaction significant group (16.82%(55/327)). The differences among the 3 latent classes were statistically significant (all P<0.05) in terms of parents' parenting competence, satisfaction, and psychological distress scores.Compared with the emotion-conduct problem prominent group, the higher the parental parenting knowledge and parenting competence, the emotional behavior of children with mental disorders tended to be in the simple emotional problem group ( B=0.699, OR=2.011, 95% CI=1.046-3.868; B=0.088, OR=1.092, 95% CI=1.017-1.173). Compared with the " emotion-conduct problem prominent group" , the emotional behavior of children with mental disorders aged 13 to 18 years old tended to be in the " emotion-peer interaction significant group" ( B=1.982, OR=7.255, 95% CI=1.637-32.141). Conclusion:The emotional behavior of children with mental disorders is heterogeneous, and there are differences in sense of parenting competence and psychological distress of parents among different latent classes of children with mental disorders.