Association Of Dietary Diversity Scores Changes With Cognitive Impairment And Activities Of Daily Living Disability Among Older People:a Cohort Study

ObjectivesTo investigate the association between dietary diversity scores(DDS)changes with cognitive impairment and activities of daily living(ADL)disability among older people.MethodsBased on the Chinese Longitudinal Health Longevity Survey(CLHLS),food groups were collected at baseline and follow-up using simplified food frequency questionnaire(FFQ),and then overall,plant-based and animal-based dietary diversity score(DDS)were calculated.DDS changes were calculated using DDS at baseline and the first follow-up.We calculated the DDS at baseline and first follow-up survey from nine food groups and categorized into three groups:high,medium,and low.Then,9 DDS change patterns were created as follows:high-to-high,high-to-medium,high-tolow,medium-to-high,medium-to-medium,medium-to-low,low-to-high,low-tomedium,and low-to-low.The absolute change scores of the DDS were calculated using DDS at baseline and the first follow-up,including extreme decline,moderate decline,stable,moderate improvement,and large improvement.Cognitive function and ADL were measured using Mini-Mental State Examination and Katz Functional Index of Daily Living,respectively,and the association between three DDS changes(total,plantbased,and animal-based DDS)and cognitive impairment and ADL disability was assessed using a multivariable adjusted Cox proportional risk regression model.Results(1)We documented 2,805 cognitive impairments during 52,325 person-years of follow-up.The incidence of cognitive impairments was the lowest in high-to-high overall DDS change patterns(34.4 per 1000 person-years),while,low-to-low group owns the highest(89.7 per 1000 person-years).Compared to high-to-high overall DDS change patterns,the multivariable adjusted HR(95%CI)for high-to-medium,mediumto-medium,medium-to-low,low-to-medium and low-to-low DDS change patterns were 1.33(1.12-1.57),1.11(0.94-1.32),1.61(1.39-1.86),2.00(1.66-2.40),2.30(1.90-2.78)and 2.80(2.23-3.53),respectively.Compared with participants with stable DDS change pattern,those who in large improvement of DDS had a 13%lower risk of cognitive impairment(HR=0.87;95%CI:0.78-0.98).The associations of plant-based DDS and animal-based DDS with cognitive impairment were in a similar direction to the main result.Age,regular exercise and ADL disability interacted with DDS change patterns on cognitive impairment(P<0.05).(2)We documented 2,151 ADL disability during 53,306 person-years of followup.The incidence of ADL disability was the lowest in high-to-high overall DDS change patterns(25.1 per 1000 person-years),while,low-to-medium group owns the highest(54.2 per 1000 person-years).Compared to high-to-high overall DDS change patterns,the multivariable adjusted HR(95%CI)for high-to-medium,medium-to-high,mediumto-medium,medium-to-low,low-to-high,low-to-medium and low-to-low DDS change patterns were 1.54(1.18-2.00),2.04(1.56-2.66),2.20(1.73-2.79),1.96(1.51-2.54),2.23(1.29-3.86),2.97(2.28-3.88)and 2.61(1.97-3.47).The associations of plant-based DDS and animal-based DDS with cognitive impairment were in a similar direction to the main result.Age,marital and regular exercise interacted with DDS change patterns on cognitive impairment(P<0.05).ConclusionsIn conclusion,among Chinese older adults,we observed the protective associations between maintaining higher DDS and a reduced risk of cognitive impairment and ADL disability.It emphasizes that maintaining higher DDS in old age has a protective effect on cognitive function and ADL,and complements the existing basis on the association between DDS changes and impaired cognitive function and ADL disability in the elderly.