Derivation of an allostatic load index in the Chilean GERO study cohort reveals the need for specific clinical thresholds in older populations

Abstract

Background Only few studies of Allostatic Load (AL) have been conducted in Latin/Hispanic populations, and even fewer performed in South American cohorts. Here, we replicated a recently proposed algorithm to derive an AL index in a Chilean cohort of cognitive healthy adults.Methods Using data from the GERO cohort (n = 166, age 76.92 ± 5.07 years, 80.12% females) we generated an AL risk index through a comprehensive algorithm (ALCS). Due to the age and the large disparity between males and females of the sample, modifications to the original algorithm were introduced. An empirical algorithm (ALES), without including clinical thresholds was also derived for model comparison.Results Neither ALCS nor ALES achieved adequate goodness of fit. After age and sex corrections, both algorithms largely improved, but only ALES showed satisfactory model fit. ALCS largely improved when correcting for available age-specific clinical thresholds, although failed to achieve sufficient goodness of fit. A final inclusion of an additional inflammatory biomarker resulted in further improvement of ALES, but not on ALCS.Conclusions Even when satisfactory model fit was not achieved by the comprehensive scoring, it was largely improved when some clinical values were corrected for ages ≥65. The ALES algorithm, which do not include clinical thresholds, achieved satisfactory fit after correcting for sample disparities between sexes. This suggests the need to consider the suitability of clinical thresholds developed in younger populations and the need to develop specific thresholds for assessing older adults.Trial registration Geroscience Center for Brain Health and Metabolism Research Project Nº 1140423, approved in May 2015 by the Scientific Ethics Committee (SEC) of the Western Metropolitan Health Service (WMHS), Santiago (Chile). Trial Number NCT04265482.