TY - JOUR
T1 - Leveraging naturally occurring variation in financial stress to examine associations with inflammatory burden among older adults
AU - Samuel, Laura
AU - Szanton, Sarah L.
AU - Fedarko, Neal S.
AU - Simonsick, Eleanor M.
N1 - Publisher Copyright:
© 2020 Royal Society Publishing. All rights reserved.
PY - 2020/11/1
Y1 - 2020/11/1
N2 - Background Financial strain is associated with earlier disability and mortality, but causal links are underexplored, partly because it is unethical to randomise people to financial stress. This study leverages naturally occurring random variation in days since monthly Social Security payment arrival among older adults to test associations with inflammatory biomarkers. Methods Biomarker data, including tumour necrosis factor (TNF)-α, interleukin (IL)-6 and C reactive protein (CRP), was collected from 2155 non-working healthy adults aged 70-79 years, participating in the Health, Aging and Body Composition Study. Days since payment arrival was independent of all demographic, socioeconomic or health characteristics measured in this study. Restricted cubic spline models estimated associations separately for each week of the month, stratified by financial strain status (interaction term p value for TNF-α model <0.05). Results Among financially strained older adults, more days since payment arrival was associated with higher TNF-α levels during the first week of the month (coefficient=0.102). Associations with IL-6 and CRP differed depending on the degree of financial strain (interaction term p values <0.05). Those with low, but not high, strain had lower levels of IL-6 (coefficient=-0.152) and CRP (coefficient=-0.179) during the first week. Conclusions Days since monthly payments were associated with inflammatory cytokines among older adults who have difficulty making ends meet financially and associations depended on financial strain severity, suggesting that results are attributable to monthly variation in financial stress. Future research should examine whether more frequent Social Security disbursement would modify financial strain and inflammatory biomarkers.
AB - Background Financial strain is associated with earlier disability and mortality, but causal links are underexplored, partly because it is unethical to randomise people to financial stress. This study leverages naturally occurring random variation in days since monthly Social Security payment arrival among older adults to test associations with inflammatory biomarkers. Methods Biomarker data, including tumour necrosis factor (TNF)-α, interleukin (IL)-6 and C reactive protein (CRP), was collected from 2155 non-working healthy adults aged 70-79 years, participating in the Health, Aging and Body Composition Study. Days since payment arrival was independent of all demographic, socioeconomic or health characteristics measured in this study. Restricted cubic spline models estimated associations separately for each week of the month, stratified by financial strain status (interaction term p value for TNF-α model <0.05). Results Among financially strained older adults, more days since payment arrival was associated with higher TNF-α levels during the first week of the month (coefficient=0.102). Associations with IL-6 and CRP differed depending on the degree of financial strain (interaction term p values <0.05). Those with low, but not high, strain had lower levels of IL-6 (coefficient=-0.152) and CRP (coefficient=-0.179) during the first week. Conclusions Days since monthly payments were associated with inflammatory cytokines among older adults who have difficulty making ends meet financially and associations depended on financial strain severity, suggesting that results are attributable to monthly variation in financial stress. Future research should examine whether more frequent Social Security disbursement would modify financial strain and inflammatory biomarkers.
KW - Epidemiology of ageing
KW - health inequalities
KW - socio-economic
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U2 - 10.1136/jech-2020-213807
DO - 10.1136/jech-2020-213807
M3 - Article
C2 - 32665370
AN - SCOPUS:85092750586
SN - 0143-005X
VL - 74
SP - 892
EP - 897
JO - Journal of epidemiology and community health
JF - Journal of epidemiology and community health
IS - 11
ER -