Allostatic load and frailty in the women's health and aging studies

Frailty involves decrements in many physiologic systems, is prevalent in older ages, and is characterized by increased vulnerability to disability and mortality. It is yet unclear how this geriatric syndrome relates to a preclinical cumulative marker of multisystem dysregulation. The purpose of this study was to evaluate whether allostatic load (AL) was associated with the geriatric syndrome of frailty in older community-dwelling women.

We examined the cross-sectional relationship between AL and a validated measure of frailty in the baseline examination of two complementary population-based cohort studies, the Women's Health and Aging studies (WHAS) I and II. This sample of 728 women had an age range of 70-79. We used ordinal logistic regression to estimate the relationship between AL and frailty controlling for covariates.

About 10% of women were frail and 46% were prefrail. AL ranged from 0 to 8 with 91% of participants scoring between 0 and 4. Regression models showed that a unit increase in the AL score was associated with increasing levels of frailty (OR = 1.16, 95% CI = 1.04-1.28) controlling for race, age, education, smoking status, and comorbidities.

This study suggests that frailty is associated with AL. The observed relationship provides some support for the hypothesis that accumulation of physiological dysregulation may be related to the loss of reserve characterized by frailty.