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

OBJECTIVE: 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. METHODS: 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. RESULTS: AL and SPPB were inversely associated, with older adults with high allostatic load scoring lower on SPPB (ß: -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. CONCLUSIONS: 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.

HbA1c and physical performance in older adults from different aging epidemiological contexts: Longitudinal findings of the International Mobility in Aging Study (IMIAS).

OBJECTIVE: This study aimed to assess the longitudinal predictions between glycated hemoglobin A1c (HbA1c) and physical performance scores in different epidemiological contexts of aging. MATERIAL AND METHODS: Longitudinal data of 1,337 older people from three countries (Canada, Brazil and Colombia) of the International Mobility in Aging Study (IMIAS) were used to assess the relationship between HbA1c and Short Physical Performance Battery (SPPB) scores between 2012 and 2016. Linear Mixed Models grouped by sex and adjusted by Age, Study site, Chronic Conditions, Anthropometric Measures, and Inflammatory Level were used to estimate the influence of HbA1c and covariates on SPPB scores. RESULTS: At the IMIAS baseline, Latin American (LA) cities had higher HbA1c averages compared to Canadian cities, with Natal (Brazil) being the city with the highest HbA1c averages in men and women (6.32 ± 1.49; 6,56 ± 1.70 respectively). SPPB scores were significantly lower in LA cities, and older people in Natal had lower SPPB averages in men (9.67 ± 2.38; p-value < 0.05) and women (8.52 ± 2.33; p-value <0.05). In the multivariate mixed linear models of longitudinal analyses, HbA1c was significantly associated with lower SPPB scores in men (ß = -0.25, 95% CI: -0.39 to -0.12, p-value = 0.02) but not in women. CONCLUSION: High HbA1c levels at baseline were longitudinally associated in older adults from different countries, and this association was observed only in men and not in women. This study highlights a possible influence of gender on this relationship.