The impact of social networks and APOE ε4 on dementia among older adults: tests of possible interactions

OBJECTIVES: Emerging evidence suggests that social networks may protect against the development of dementia among older adults. In this study we analysed the association between social networks, the apolipoprotein E (APOE) ε4 allele, and dementia. We also investigated whether there were gender-specific patterns in this respect. METHOD: The analyses used population-based longitudinal data from Gothenburg, Sweden: the H70 Birth Cohort Study and the Prospective Population Study on Women (PPSW). A total of 580 individuals born in 1930 underwent semi-structured neuropsychiatric examinations in 2000-2001. Follow-up examinations were carried out in 2005-2006 and 2009-2010. The timing of dementia onset was analysed using Cox proportional hazards regression. RESULTS: The presence of the APOE ε4 allele affected the risk of developing dementia in both genders. Among women, distant social networks had a protective effect on dementia, while among men the significant associations between close social networks and dementia did not remain after controlling for covariates. Significant interactions between social networks and the APOE ε4 allele were not found. CONCLUSION: Strong social networks do not seem to moderate the increased risk of dementia implied by the APOE ε4 allele. Nevertheless, our results underline the importance of strong social networks in postponing dementia onset and indicate that their impact may differ among men and women

Socioeconomic status, gender and dementia: The influence of work environment exposures and their interactions with APOE ɛ4

It is a well-established fact that unfavourable social and economic conditions have a negative impact on health and longevity. Recent findings suggest that this is also true of age-related dementias. Yet most common indicators of socioeconomic status (SES) say very little about the actual mechanisms at play in disease development. The present paper explores five work exposure characteristics, all of which have a clear social gradient, that could potentially shed further light on the relationship between SES and dementia. Specifically, it investigates whether these exposures could moderate the impact of a well-known genetic risk factor: the APOE ɛ4 allele. The empirical analyses are based on data from a Swedish population study (n = 1019). Main occupation was linked to The Job Exposure Matrix to estimate the individuals’ exposure to the following work environment factors: work control, support, psychological demands, physical demands and job hazards. All analyses were conducted using binary logistic regression and focused specifically on gene-work exposure interactions. A significant main effect of work control on dementia risk was detected for males (OR = 0.68; p< 0.05), but not for females. However, control was found to significantly moderate the effect of APOE ɛ4 in both genders, albeit in different ways. These findings do not only underscore the importance of considering interactions between social and genetic risk factors to better understanding multifactorial diseases such as dementia. They also propose that gender- and class-based inequities interact, and hence must be considered simultaneously, also in relation to this particular disease

APOE ε₄ and the long arm of social inequity: estimated effects of socio-economic status and sex on the timing of dementia onset

It is well established that carriers of the apolipoprotein E (APOE) ε₄ allele run a greater risk of developing Alzheimer's disease, the most common form of dementia and a strongly age-related condition known to disproportionally affect women. Low educational attainment also stands out as a prominent risk factor, and it has been suggested that occupational class plays a similar role in disease susceptibility. Not yet fully explored, however, is the question of whether socio-economic status (SES) could moderate the effect of APOE ε₄. In the present paper, we address this issue. As substantial inequities in workforce participation and educational opportunities have existed between men and women in previous generations, we further examine whether SES-related moderations of the relationship between dementia and APOE ε₄ are sex-specific. Our analyses are based on a sample of 580 individuals from the H70 Birth Cohort Study and the Prospective Population Study on Women in Gothenburg, Sweden. Data were analysed using Cox proportional hazards regression, and the results suggest that while high SES postpones dementia onset among male APOE ε₄ carriers, this is not the case for women. These findings underscore the long-term impact of social inequity on health as well as the importance of considering potential interactions between social and genetic risk factors if we are to understand better the complex aetiology of dementia

Multiple Deprivation, Severity and Latent Sub-Groups:Advantages of Factor Mixture Modelling for Analysing Material Deprivation

Material deprivation is represented in different forms and manifestations. Two individuals with the same deprivation score (i.e. number of deprivations), for instance, are likely to be unable to afford or access entirely or partially different sets of goods and services, while one individual may fail to purchase clothes and consumer durables and another one may lack access to healthcare and be deprived of adequate housing . As such, the number of possible patterns or combinations of multiple deprivation become increasingly complex for a higher number of indicators. Given this difficulty, there is interest in poverty research in understanding multiple deprivation, as this analysis might lead to the identification of meaningful population sub-groups that could be the subjects of specific policies. This article applies a factor mixture model (FMM) to a real dataset and discusses its conceptual and empirical advantages and disadvantages with respect to other methods that have been used in poverty research . The exercise suggests that FMM is based on more sensible assumptions (i.e. deprivation covary within each class), provides valuable information with which to understand multiple deprivation and is useful to understand severity of deprivation and the additive properties of deprivation indicators