A systematic review and meta-analysis of the association between social engagement, loneliness, and risk of dementia

Transcription

1 School of Psychiatry \ UNSW Medicine A systematic review and meta-analysis of the association between social engagement, loneliness, and risk of dementia Ross PENNINKILAMPI, Anne-Nicole CASEY, Maria FIATARONE-SINGH, Henry BRODATY

2 Acknowledgements Ross Penninkilampi 1 Prof Maria Fiatarone Singh 3,4 Prof Henry Brodaty 1,2,5 1 Dementia Centre for Research Collaboration, University of New South Wales (UNSW), Sydney, Australia 2 Centre for Healthy Brain Ageing, School of Psychiatry, UNSW Sydney, Australia 3 The University of Sydney, Faculty of Health Sciences and Sydney Medical School, Sydney, Australia 4 Hebrew SeniorLife and Jean Mayer USDA Human Nutrition Center on Aging, Tufts University, Boston, MA, USA 5 Academic Department for Old Age Psychiatry, Prince of Wales Hospital, Sydney, Australia

3 Background 1-6 Dementia affects people, their families, friends, the community & society 1-3 Shift in focus to risk reduction strategies 4-6 Which factors may increase risk? Which factors may be protective? Figure: Livingston G et al. Lancet 2017; 390: Prince MJ et al. World Alzheimer s Report 2015; 2 Wimo A et al. Alzheimers Dement 2017; 3 Livingston G et al. Lancet 2017; 4 Penninkilampi R et al. J Alzheimers Dis 2016; 5 Penninkilampi R et al. J Neuroimmune Pharmacol 2017; 6 Shah H et al. Lancet Neurol 2016

4 Cognitive Reserve Cognitive reserve enables people with brain changes typically seen in dementia to maintain better cognition longer, due to beneficial organisation of neurons in the brain

5 Cognitive Reserve 1-2 Larger brain volumes associated with larger social network size Maintenance of a larger social network is a cognitively complex task that may require more substantial brain resources Social engagement, which is cognitively complex, may stimulate cognitive reserve 1 Dunbar R. Trends Cogn Sci 2018; 2 Kwak S et al. Proc Biol Sci 2018

6 Photo: Celebrating 97 th birthday. St Louis Post Dispatch / Andrew Jansen If social engagement expands cognitive reserve, and cognitive reserve is associated with reduced dementia risk, then social engagement should reduce dementia risk

7 Social engagement has been investigated as a potential protective factor against cognitive decline and dementia 1,2 Previous review and meta-analysis to July 2012 (19 studies): 3 Factors associated with increased dementia risk low social participation less frequent contact greater loneliness 1 Fratiglioni L et al. Lancet Neurol 2004; 2 Fratiglioni L et al. Lancet 2000; 3 Kuiper JS et al. Ageing Res Rev 2015

8 Aim Update review of the literature and conduct meta-analysis to further address the question: Is social engagement (good, poor), and / or loneliness, associated with dementia risk?

9 Brief methods PRISMA guidelines PROSPERO registration (CRD ) Eight scientific databases searched Literature from Jan 2012 to May ,000+ citations screened, included 35 studies R for data analysis, metafor package 1 Penninkilampi R, Casey A-N, Fiatarone-Singh M, Brodaty H Under final review. 1 Viechtbauer, W. Conducting meta-analyses in R with the metafor package. J Stat Softw 2010; 36(3):1-48.

10 Inclusion criteria 1) Case control or cohort studies 2) Social engagement assessment, relating it to 3) Dementia diagnosis 4) Full-length, Englishlanguage journal articles

11 We investigated the associations with dementia risk for: good social engagement poor social engagement loneliness Good and poor social engagement each captured any facet of social engagement that could be considered positive or negative. Penninkilampi R, Casey A-N, Fiatarone-Singh M, Brodaty H. 2018

12 Good social engagement strong social networks high levels of social support high social satisfaction Poor social engagement social isolation lack of social support Having few social contacts Loneliness (objective, subjective) unpleasant feeling experienced when a social network does not meet expectations Penninkilampi R, Casey A-N, Fiatarone-Singh M, Brodaty H. 2018

13 Frequency of participation in social activities Frequency of contacts Marital status Social engagement and dementia risk Living situation Social network size Degree of social satisfaction Degree of social support Penninkilampi R, Casey A-N, Fiatarone-Singh M, Brodaty H. 2018

14 Study selection flow chart, with reasons for exclusion 35 studies with Penninkilampi R, Casey A-N, Fiatarone-Singh M, Brodaty H, 2018.

15 Forest plot of good and poor social engagement indicators Protective Increased dementia risk No effect Penninkilampi R, Casey A-N, Fiatarone-Singh M, Brodaty H. 2018

16 Associations with increased dementia risk Poor social engagement (16 studies; RR=1.42, 95% CI ) Unmarried (8 studies; RR=1.63, CI ) Poor social network (6 studies; RR=1.59, CI ) Greater magnitude of increased risk found in studies that controlled for depression than in those not adjusting for depression. Penninkilampi R, Casey A-N, Fiatarone-Singh M, Brodaty H. 2018

17 Associations with decreased dementia risk Good social engagement (18 studies; RR=0.80, 95% CI ) Married (1 study; RR=0.68, CI ) Many social contacts (8 studies; RR=0.85, CI ) High level of social activity (6 studies; RR=0.62, CI ) Good social engagement still protective against dementia adjusting for depression. Penninkilampi R, Casey A-N, Fiatarone-Singh M, Brodaty H. 2018

18 Sub-group analysis by follow-up time (<10 years vs. >=10 years) Good social engagement modestly protective (RR=0.88, 95% CI ) Pooled RR = 0.78, meaning 22% risk reduction Penninkilampi R, Casey A-N, Fiatarone-Singh M, Brodaty H. 2018

19 Summary & Significance of findings Poor social engagement in particular is related to an increased risk of dementia In high quality studies, pooled increased risk associated with poor engagement was 56% Good social engagement, pooled reduction in risk 22%--but significant publication bias Penninkilampi R, Casey A-N, Fiatarone-Singh M, Brodaty H. 2018

20 Significance of findings Depression + poor social engagement magnified risk, poor engagement depression Good social engagement and fewer depressive symptoms may overlap, not independent risk Inconclusive evidence for or against loneliness as a risk factor for dementia Penninkilampi R, Casey A-N, Fiatarone-Singh M, Brodaty H. 2018

21 Meta-analysis: Heterogeneity in some analyses Publication bias is a problem No effective way to correct for reverse causation Limitations Penninkilampi R, Casey A-N, Fiatarone-Singh M, Brodaty H. 2018

22 Future directions Potential preventative interventions may be most beneficial if they combat social isolation, and provide support to older individuals lacking social engagement rather than further increasing engagement of people who already have sufficient social support and integration Penninkilampi R, Casey A-N, Fiatarone-Singh M, Brodaty H. 2018

23 Conclusions We found evidence that poor social engagement was associated with an increased risk of dementia Good social engagement could not be conclusively associated with dementia risk Nonsignificant trend for loneliness increasing risk Well-designed studies investigating potential neurobiological, behavioral, and social mechanisms are needed to determine causation Penninkilampi R, Casey A-N, Fiatarone-Singh M, Brodaty H. 2018

24 Thank You!