Relationship of psychosocial resources with allostatic load : A systematic review

Objective
Allostatic load (AL) represents cumulative wear-and-tear on the body and is operationalized as a multisystem index of biomarkers. Allostatic load is associated with morbidities and mortality, leading to a growing body of literature that uses AL as an outcome in its own right. Psychosocial resources (PSRs), such as mastery and social support, may influence health outcomes in part via AL, and the current review seeks to characterize the relations between PSRs and AL.

Methods
A systematic review was conducted by searching PubMed, CINAHL Plus, PsycINFO, Scopus, and Embase for studies examining the relation between PSR(s) and AL in humans. From 1,417 abstracts screened, 60 full-text articles were reviewed, and 24 studies met inclusion criteria.

Results
Mixed evidence exists for a relationship between PSRs and AL. Most (14/24) studies used a cross-sectional design, and only one study investigated whether a PSR predicted change in AL. Compared to cross-sectional studies, longitudinal studies were more likely to report a significant relationship (8/14 versus 8/10, respectively). Studies with statistically significant main or moderated effects had larger sample sizes than those reporting null effects. Whether a study reported a significant main or moderated relationship did not differ by whether psychological (8/11) or social (10/16) resources were assessed.

Conclusions
Evidence for a relationship between PSRs and AL is equivocal, and obtained significant relationships are generally small in magnitude. Gaps in the current literature and directions for future research are discussed. Longitudinal studies are needed that repeatedly assess PSRs and AL.