Allostatic load and physical performance in older adults: Findings from the International Mobility in Aging Study (IMIAS).

• Elevated Allostatic Load Index determines worse physical performance states in older adults. • Distributions of Allostatic Load Averages do not differ significantly among the cities evaluated. • Total and Indirect Mediation Effects between Allostatic Load and the variables of age, socioeconomic and chronic conditions on physical performance scores were evidenced. This study aimed to evaluate the association between Allostatic Load (AL) and physical performance scores in older adults from four cities in North and South America. In this cross-sectional study, data from 1101 volunteers from three countries (Canada, Brazil, and Colombia) from the International Mobility in Aging Study (IMIAS) were used to evaluate the association between AL index and Short Physical Performance Battery (SPPB) scores. Three multiple linear regression models adjusted by age, Socioeconomic Status (SES), chronic conditions, depression symptoms, and Leganés Cognitive Test (LCT) were developed to estimate the independent association between SPPB and AL. Mediation analysis with 2012 LA data and covariates was performed to access the total, direct, and indirect effects of mediation on SPPB scores from 2016. AL and SPPB were inversely associated, with older adults with high allostatic load scoring lower on SPPB (β: -0.234, Std: 0.033, p-value: <0.001). Indirect effects were evidenced between age, SES and chronic conditions with AL and SPPB scores. Chronic conditions also had a total effect on SPPB scores and were also mediated by AL. However, indirect effects of depressive symptoms and LCT on SPPB scores mediated by AL were not observed. Findings from this study support that increased AL index determines worse physical performance states after full adjustments. AL has a mediator role between the number of chronic diseases, depressive symptoms, cognitive status and physical performance. Socioeconomic status also influenced physical scores mediated by the AL index. [ABSTRACT FROM AUTHOR]