Associations between Sedentary Duration and Cognitive Function in Older Adults: A Longitudinal Study with 2-Year Follow-Up

OBJECTIVES

This study aimed to investigate the association between different forms of sedentary behavior and cognitive function in Chinese community-dwelling older adults.

DESIGN

A longitudinal study with a 2-year follow-up.

SETTING AND PARTICIPANTS

Data from 5356 participants at baseline and 956 participants at the follow-up of the Anhui Healthy Longevity Survey (AHLS) were analysed.

MEASUREMENTS

Cognitive function was evaluated by the Mini-Mental State Examination (MMSE), and mild cognitive impairment (MCI) was classified according to education-specific criteria. Self-report questionnaires were used to assess the sedentary behavior of the participants.

RESULTS

The participants who reported longer screen-watching sedentary duration had higher MMSE scores (1-2 hours: β=0.758, 95% CI: 0.450, 1.066; > 2 hours: β=1.240, 95% CI: 0.917, 1.562) and lower likelihoods of MCI (1-2 hours: OR= 0.787, 95% CI: 0.677, 0.914; >2 hours: OR=0.617, 95% CI: 0.524, 0.726). The participants who had played cards (or mahjong) sedentary had higher MMSE scores (β= 1.132, 95% CI: 0.788, 1.476) and lower likelihoods of MCI (OR=0.572, 95% CI: 0.476, 0.687). However, the participants who reported longer other forms of sedentary duration had lower MMSE scores (1-2 hours: β=-0.409, 95% CI: -0.735, -0.082; > 2 hours: β=-1.391, 95% CI: -1.696, -1.087) and higher likelihoods of MCI (1-2 hours: OR=1.271, 95% CI: 1.081, 1.496; > 2 hours: OR=1.632, 95% CI: 1.409, 1.889). No significant association was detected between sedentary duration and MCI incidence.

CONCLUSION

Variations in the impact of diverse sedentary behaviors on the cognitive function were detected in Chinese older adults. However, such associations were cross-sectional and longitudinal associations were not found in the current study.

Living Environment, Built Environment and Cognitive Function among Older Chinese Adults: Results from a Cross-Sectional Study

BACKGROUND

Many studies have addressed the relationship between environmental factors and cognitive function; however, evidence from China is very rare.

OBJECTIVES

To discuss the relationship between the living and built environment and cognitive function among older Chinese adults.

DESIGN

The Anhui Healthy Longevity Survey (AHLS) was used to investigate the ability to control major non-communicable diseases through behavioural techniques among adults aged 60 or older dwelling in Anhui Province. A multistage sampling strategy was used to obtain a representative sample. Cross-sectional data were collected for the analyses.

SETTING

The included participants were recruited from four selected cities in Anhui Province, China.

PARTICIPANTS

The participants were adults aged 60 or older and resided in the selected urban or rural communities.

MEASUREMENTS

The Mini Mental State Examination was used to measure the cognitive status of the participants. Mild cognitive impairment (MCI) was defined as illiteracy with MMSE scores lower than 18, MMSE scores lower than 21 among those educated for 0-6 years, or MMSE scores lower than 25 among those with 6 or more years of education. The living environment was assessed by asking the participants about their daily living conditions. The distances between the participants' dwellings and the nearest facilities and the proportions of green/blue spaces within 800 m buffers were calculated based on the textural address to indicate the built environment.

RESULTS

The male participants who lived in a non-dusty environment had higher MMSE scores (β=0.828, 95% CI: 0.240, 1.416, p=0.006) and lower risks of mild cognitive impairment (MCI) (OR=0.651, 95% CI: 0.488, 0.868, p=0.003), and the male participants with no access to recreation spaces had lower MMSE scores (β=-1.107, 95% CI: -1.531, -0.684, p<0.001) and higher risks of MCI (OR=1.403, 95% CI: 1.134, 1.737, p=0.002). The female participants who lived far from a supermarket had significantly lower MMSE scores (Q3:β=-0.750, 95% CI: -1.266, -0.233, p adjusted=0.036; Q4: β=-1.184, 95% CI: -1.745, -0.624, p adjusted<0.001) than those who lived near a supermarket (Q1).

CONCLUSIONS

The living environment and built environment might have sex-specific associations with cognitive function among older adults.

Vegetable and Fruit Intake, Its Patterns, and Cognitive Function: Cross-Sectional Findings among Older Adults in Anhui, China

OBJECTIVES

To examine the associations of vegetable and fruit intake frequency, its patterns, and cognition among older Chinese adults.

DESIGN

Cross-sectional data obtained from the Anhui Province Healthy Longevity Survey.

SETTING

Urban and rural communities.

PARTICIPANTS

A total of 5410 older adults (aged 60 or older) were included from selected communities.

MEASUREMENTS

Data on the number of days in a typical week that vegetables and fruits were consumed were collected, and the four intake patterns were defined (V+/F+: daily intake of both vegetables and fruit; V+/F- or V-/F+: daily intake of vegetables or fruit; and V-/F-: no daily intake of either vegetables or fruit). Cognitive function was measured using the Mini-mental State Examination (MMSE), and mild cognitive impairment (MCI) was defined according to education-specific criteria.

RESULTS

Nondaily vegetable intake was associated with lower MMSE scores (β = -0.763, 95% confidence interval (CI): -1.463, -0.064) among males and a higher likelihood of having MCI (OR: 1.409, 95% CI: 1.037, 1.915) among females. Less frequent intake of fruit was associated with lower MMSE scores and a higher prevalence of MCI among both males and females (p for trends < 0.001 for both sexes). Compared with the V+/F+ group, male participants who were classified into the V+/F- and V-/F- groups had lower MMSE scores (V+/F-: β = -0.612, 95% CI: -1.094, -0.131; V-/F-: β = -1.273, 95% CI: -2.090, -0.455). Females classified in the V+/F- and V-/F- patterns had lower MMSE scores (V+/F-: β = -0.862, 95% CI: -1.320, -0.404; V-/F-: β = -1.293, 95% CI: -2.079, -0.507) and elevated risks of MCI (V+/F-: OR: 1.762, 95% CI: 1.386, 2.242; V-/F-: OR: 2.180, 95% CI: 1.505, 3.156).

CONCLUSION

Lower vegetable or fruit intake was associated with poorer cognitive performance among males and females, and the risk was even higher among those with a low intake of both vegetables and fruits. Healthy eating habits, including daily vegetable and fruit intake, are essential for cognition maintenance in both males and females.

Induction of the expression of SCF in mouse by lethal irradiation

To clarify what kinds of cytokines are actually contributing to proliferation of hemopoietic stem cells in vivo after lethal irradiation, we have investigated the expression of some cytokines by RT-PCR method. Above all, expression of the SCF was increased significantly in the bone marrow cells soon after lethal irradiation in both the Sca-1 (+) bone marrow cells injected and non-injected mice. The day 6 serum from the lethally irradiated mice could support the proliferation of the Sca-1 (+) bone marrow cells, even though the serum from normal mice could not. The quantification analyses have revealed the increase of the amounts of IL-6 and flt3-ligand in their serum, but not significant increase of the amount of SCF. Precise PCR analysis has revealed that the cell surface associated form of SCF was significantly induced in the bone marrow after lethal irradiation. These data indicate that the cell surface form of SCF mainly promotes the proliferation of hemopoietic stem cells with some soluble cytokines under sever lack of hemopoietic stem cells in vivo caused by lethal irradiation and also suggest the importance of direct cell-to-cell interaction on proliferation of hematopoietic stem cells in vivo.