Sedentary behaviours, cognitive function, and possible mechanisms in older adults: a systematic review

Abstract

Background

Physical activity can improve cognitive function of older adults, but the influence of sedentary behaviour on cognition is less clear. This systematic review investigated associations between sedentary behaviour and cognitive function in older adults without dementia, and possible mechanisms involved.

Methods

Major databases were searched for studies in English between 01/01/1999 and 31/10/2019. The systematic review followed COSMOS-E guideline and a pre-registered protocol (CRD42019122229). Risk of bias was assessed using NICE Quality appraisal checklist. Findings were narratively synthesized and presented.

Findings

Eighteen studies comprised of 13 cross-sectional and five longitudinal analyses (n = 40,228). Evidence suggested varied associations between varied sedentary behaviours and cognitive function in older adults. 50% of study analyses did not control for physical activity. 3/18 studies demonstrated associations between higher sedentary levels and lower levels of brain biomarkers, while 1/18 showed auto-regulatory effect in the left hippocampus. Conducting a meta-analysis was not justifiable due to considerable methodological, participant, outcome and exposure heterogeneity.

Conclusion

There is a lack of clarity about the overall and independent association between sedentary behaviour and cognition in older age. Underlying mechanisms are similar to physical activity and probably multi-modal. More studies with robust designs and methodology are needed to confirm effect of sedentary behaviour on cognition.

Appendices

Appendices

Appendix A: Nice quality appraisal checklist: quantitative studies reporting correlations and associations

Study	1.1	1.2	1.3	2.1	2.2	2.3	2.4	2.5	3.1	3.2	3.3	3.4	3.5	4.1	4.2	4.3	4.4	5.1 (IV)	5.2 (EV)
Bronas et al. [14]	+	+	++	+	++	NA	–	++	+	+	NA	NA	NA	NR	++	++	++	–	++
Da Ronch et al. [16]	++	+	++	++	++	NA	+	++	++	+	NA	NA	NA	NR	++	++	++	–	++
Edwards and Loprinzi [17]	++	+	++	++	++	NA	+	++	++	++	NA	NA	NA	NR	++	++	++	+	++
Falck et al. [11, 19]	++	++	++	+	++	NA	+	++	++	++	NA	NA	NA	NR	++	++	++	–	++
Fancourt and Steptoe [20]	++	+	+	+	++	NA	+	++	++	++	NA	NA	NA	NR	++	++	++	+	++
Garcia-Hermoso et al. [21]	++	+	+	++	++	NA	+	–	++	++	NA	NA	NA	NR	++	++	+	+	+
Hamer and Stamatakis [22]	+	+	+	+	++	NA	+	++	+	+	NA	NA	+	NR	++	++	++	–	++
Kesse-Guyot et al. [23]	+	+	+	+	++	NA	+	++	++	+	NA	NA	++	NR	++	++	++	–	++
Ku et al. [24]	++	++	++	++	++	NA	+	+	++	++	NA	NA	+	++	++	++	++	+	+
Kurita et al. [25]	++	+	+	+	++	NA	+	++	++	++	NA	NA	NA	NR	++	++	++	+	++
Maasakkers et al. [26]	++	+	+	+	++	NA	++	++	++	+	NA	NA	NA	NR	++	++	++	+	++
Nemoto et al. [8]	++	+	+	–	++	NA	+	++	++	++	NA	NA	NA	NR	++	++	++	–	+
Steinberg et al. [27]	++	++	++	+	++	NA	+	++	++	++	NA	NA	NA	NR	+	++	++	–	+
Vance et al. [28]	++	+	+	–	++	NA	–	++	++	++	NA	NA	NA	NR	++	++	+	–	+
Wanigatunga et al. [29]	+	+	+	+	++	NA	+	++	++	++	NA	NA	NA	NR	++	++	+	+	+
Engeroff et al. [18]	+	+	+	+	++	NA	+	++	++	++	NA	NA	NA	NR	++	++	++	–	++
Zlatar et al. [31]	++	+	+	+	++	NA	+	++	++	++	NA	NA	NA	NR	++	++	++	–	+
Zlatar et al. [30]	++	+	+	+	++	NA	+	++	++	++	NA	NA	NA	NR	++	++	++	–	+

1. (++) All or most of the checklist criteria have been fulfilled, where they have not been fulfilled the conclusions are very unlikely to alter
2. (+) Some of the checklist criteria have been fulfilled, where they have not been fulfilled, or not adequately described, the conclusions are unlikely to alter
3. (−) Few or no checklist criteria have been fulfilled and the conclusions are likely or very likely to alter
4. Internal Validity (IV); External Validity (EV); not reported (NR); not applicable (NA)

Appendix B: Search strategy

1. exp sedentary lifestyle/or sedentary.mp.

2. sedentar*.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

3. sedentary behaviour.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

4. sedentary activity.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

5. sedentary lifestyle.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

6. sitting.mp. or sitting/

7. supine position.mp. or supine position/

8. recline.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

9. television viewing.mp. or television/or television viewing/

10. computer time.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

11. desk bound.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

12. physical inactivity.mp. or exp physical inactivity/

13. cogniti*.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

14. cognitive function.mp. or exp cognition/

15. cognitive ability.mp.

16. memory test.mp. or memory test/

17. Neuropsychological test.mp. or neuropsychological test/

18. cognitive reserve.mp. or cognitive reserve/

19. biomarkers.mp. or biological marker/

20. biology/or biology.mp.

21. neuropathology.mp. or neuropathology/

22. genetic.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

23. mechanism.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

24. old$.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

25. older people.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

26. ageing.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

27. ageing/ep [Epidemiology]

28. older adult.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

29. older population.mp. [mp = title, abstract, heading word, drug trade name, original title, device manufacturer, drug manufacturer, device trade name, keyword, floating subheading word, candidate term word]

30. seniors.mp. or elderly care/

31. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12

32. 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 or 23

33. 24 or 25 or 26 or 27 or 28 or 29 or 30

34. 31 and 32 and 33

35. limit 34 to (English language and yr = ”1999 -Current” and (aged < 65 + years >))