Life events trajectories, allostatic load, and the moderating role of age at arrival from Puerto Rico to the US mainland

Abstract

Our aim was to examine the effects of trajectories of stressful life events on allostatic load, measured over a two year time period, and to investigate the roles of language acculturation and age at migration in this association, in a sample of Puerto Rican migrants. We used data from the Boston Puerto Rican Health Study; a population-based prospective cohort of older Puerto Ricans recruited between the ages of 45 and 75 years. The Institutional Review Boards at Tufts Medical Center and Northeastern University approved the study. We used latent growth mixture modeling (LGMM) to identify different classes of two-year trajectories of stressful life events; analysis of variance to examine group differences by stress trajectory; and linear regression to test for the modifying effects of age at arrival on the association of stress trajectory with allostatic load at follow-up. In LGMM analysis, we identified three distinct stress trajectories; low, moderate ascending, and high. Unexpectedly, participants in the low stress group had the highest allostatic load at follow-up (F=4.4, p=0.01) relative to the other two groups. Age at arrival had a statistically significant moderating effect on the association. A reported two year period of moderate but repetitive and increasingly bad life events was associated with increases in allostatic load for participants who arrived to the U.S. mainland after the age of 5 years, and was particularly strong for those arriving between 6–11 years, but not for those arriving earlier or later. Results from this study highlight the complex effects of stress during the life course, and point to certain vulnerable periods for immigrant children that could modify long term effects of stress.

Allostatic load and biological anthropology

“…It is possible allostatic load accumulates too gradually for the stress of teenage alcohol consumption to significantly impact ALI measures during teenage years. However, as previously mentioned, adults do not exhibit positive relationships between allostatic load and alcohol consumption either and, in some samples, the association is negative (Ar evalo et al, 2014;Kusano et al, 2016;McClure et al, 2015;Petrovic et al, 2016).…”

“…In other research, medications were accounted for by adjusting the construction of the reported ALI. For example, some researchers add a point for every biomarker directly affected by a medication to the ALI regardless of the biomarker's current level, although specific adjustments vary by study (Ar evalo, Tucker, & Falc on, 2014;Doamekpor & Dinwiddie, 2015;Gale, Booth, Starr, & Deary, 2015;Hampson et al, 2009;Mattei et al, 2010;Robertson et al, 2014;Robertson & Watts, 2016 Clinically based constructs directly counteract the usefulness of ALIs to determine individuals in a group at greatest underlying risk for future health issues and early mortality. However, within medical settings, applying ALIs using clinical cut-points may be more practical, particularly as sample distributions are not usually available when working with individual patients (Mauss et al, 2016).…”

“…Both language acculturation(Ar evalo et al, 2014) and younger age at arrival in the USA(Ar evalo et al, 2014;Doamekpor & Dinwiddie, 2015;McClure et al, 2015) are associated significantly with allostatic load, lower and higher respectively, in foreign-born individuals. Mediators contributing to allostatic load also may vary by ethnicity.…”

“…Dietary components (e.g., alcohol and vegetable intake) influence allostatic load among Japanese women(Kusano et al, 2016). Of general interest, higher alcohol consumption has been shown to be significantly associated with lower allostatic load across several samples(Ar evalo et al, 2014;Kusano et al, 2016;McClure et al, 2015; Petrovic et al, 2016), similar to reductions in CVD associated with moderate alcohol intake.…”

“…SES influences how individuals interact with their cultures and environments, and such differences are reflected in variable assessments of allostatic load across social settings(McEwen & Seeman, 1999). For example, nonsmokers have lower allostatic load when compared to past and present smokers(Ar evalo et al, 2014;Barboza Solís et al, 2015;Lipowicz et al, 2014), while reports of greater regular physical activity are associated with lower allostatic load(Gay et al, 2015;Lipowicz et al, 2014; Petrovic et al, 2016;Rosenberg et al, 2014;Upchurch, Stein, et al, 2015; but seeRiva et al, 2014). Dietary components (e.g., alcohol and vegetable intake) influence allostatic load among Japanese women(Kusano et al, 2016).…”