Associations between social relationship measures, serum brain‐derived neurotrophic factor, and risk of stroke and dementia

Abstract

IntroductionMechanisms underlying social determinants of stroke and dementia are unclear and brain-derived neurotrophic factor (BDNF) may contribute as a molecular link.MethodsUsing the Framingham Study, we examined social relationship measures as predictors of higher serum BDNF level and cumulative incidence of stroke and dementia.ResultsAmong 3294 participants, controlling for age and sex, isolation trended with lower BDNF (odds ratio = 0.69 [0.47–1.00]). Participants with more companionship had reduced risk for stroke (hazard ratio [HR] = 0.59 [0.41–0.83]) and dementia (HR = 0.67 [0.49–0.92]). Greater emotional support was associated with higher BDNF (odds ratio = 1.27 [1.04–1.54]), reduced dementia risk (HR = 0.69 [0.51–0.94], and among smokers, reduced stroke risk (HR = 0.23 [0.10–0.57]). Associations persisted after additional adjustments. BDNF partly mediated the total effect between emotional support and dementia risk.ConclusionsAvailability of social support appears to be associated with increased BDNF levels and, in certain subsets, reduce risk of subsequent dementia and stroke, thus warranting study of these pathways to understand their role in neuroprotection.

Systematic Review and Meta-Analysis of Psychosocial Risk Factors for Stroke

“…Single studies have shown that apathy rather than depression has the stronger association with stroke 5 , and another showed that lower life satisfaction is associated with an increased risk of stroke, especially in women 6 . Furthermore, depression is associated with other psychosocial risk factors such as reduced social support, which, in turn, have been associated with stroke 7 and atherogenesis 8 .…”

Preventive effects of an intergenerational program on age‐related hippocampal atrophy in older adults: The REPRINTS study

“…35 A recent community-based cohort study in fact reported an association between higher serum BDNF levels and emotional support, which is a specific type of social support. 36 Because the REPRINTS program Although there was no significant difference in results of cognitive assessments between the REPRINTS and control groups, greater decreases in hippocampal volume were correlated with greater decreases in scores of MMSE, delayed recall, picture completion, and semantic verbal fluency. Given that these tests partly assess learning and memory abilities, 37 correlation results are consistent with the involvement of the hippocampus in forming, storing, and retrieving semantic associations within the cognitive workspace of the memory system.…”

“…The hippocampus has the highest levels of BDNF expression, which can be increased by environmental enrichment, such as enhanced social interaction . A recent community‐based cohort study in fact reported an association between higher serum BDNF levels and emotional support, which is a specific type of social support . Because the REPRINTS program can increase social support, including emotional support, the selective effects of social engagement on hippocampal volume might be attributable to increased BDNF.…”

Fatherhood diminishes the hippocampal damaging action of excitotoxic lesioning in mice

“…Epidemiological studies in humans and a few studies in rodents have proposed a that social interaction has a protective effect on the development and recovery of neurodegenerative diseases, with a better outcome after brain damage. Affiliative interaction in mice subjected to middle carotid artery occlusion decreases ischaemic damage in male and female mice and improves the behavioural outcome and oxytocin has been proposed to mediate the neuroprotective effect of social interaction .…”