Relationship between stress systems and inflammation in older adults concerned about falling - Findings from the...

Concerns about falling (CaF) in older adults are associated with decreased activity and negative health outcomes. The aim of this study was to examine associations between CaF, stress system activity, and low-grade inflammation in community-dwelling older adults. In the randomized-controlled FEARFALL study, N = 160 older adults (≥70 years) were enrolled (mean age: 79.5; 73.8 % women); data from 102 were analyzed. The Falls Efficacy Scale-International (FES-I), the FES-I Avoidance Behavior (FES-IAB) and Updated Perceived Control over Falling Scale (UP-CoF) were used to assess CaF. Saliva samples were analyzed to determine stress system activity (cortisol, alpha-amylase). Inflammatory markers (C-reactive protein [CRP], interleukin-6 [IL-6]) were determined in blood. A higher UP-CoF score was significantly associated with higher individual cortisol values (β = 0.01, 95 %-CI [0.00, 0.01], p = .047) and was marginally associated with a steeper diurnal cortisol decline (p = .059). No significant associations were found between CaF and alpha-amylase or its parameters (AAR, slope, AUCg). IL-6 was significantly associated with age (β = 0.01, 95 %-CI [0.00, 0.01], p = .019) and BMI (β = 0.27, 95 %-CI [0.00, 0.02], p = .004), while CRP also showed a significant association with BMI (β = 0.01, 95 %-CI [0.00, 0.02], p = .004). There were no significant associations between CaF and inflammatory markers. Perceived control over falls is associated with physiological cortisol dynamics and may play a role in regulating the stress system activity in older adults. These findings show that psychological factors, such as perceived control, may influence stress regulation in older adults.