Peripheral biomarker composite associated with smaller hippocampal volume

Abstract

Animal and human studies demonstrate an association between smaller hippocampal volume and stress. A composite index of peripheral biomarkers used to objectively quantify human psychosocial stress has demonstrated utility, but has not yet been linked to hippocampal volume in putative 'high stress' groups. Structural magnetic resonance imaging exams and a composite of biomarkers representing cardiovascular, atherosclerosis, hypothylamic-pituitary-adrenal axis, glucose metabolism, and sympathetic nervous system activity were assessed in 30 healthy women with histories of stress precipitated by their child's diagnosis of a life-threatening illness. Hippocampal volume was significantly predicted by age, time since stressor onset, and the composite. An objective biomarker index may improve temporal tracking of brain changes in relation to stress-related psychological symptoms, with implications for basic and clinical research.

Stress Biomarkers as Outcomes for HIV+ Prevention: Participation, Feasibility and Findings Among HIV+ Latina and African American Mothers

“…Replicating previous studies among healthy women (Glover and Stuber 2006; Glover et al 2008), the present data show that the biomarker composite is associated with clinically relevant outcomes among HIV+ samples. Greater self-reported medication adherence was associated with a higher composite and lower CD4 counts, suggesting a potential role for the composite in understanding the impact of worsening illness symptoms on medication adherence.…”

“…655). Studies among primarily healthy (and HIV negative) groups have shown success in using stress-influenced biomarkers to predict later physical and cognitive decline (Seeman et al 2008), reflect the presence and severity of mental health symptoms (Glover and Stuber 2006) and estimate the size of the hippocampus, a brain structure highly influenced by acute and chronic stress (Glover et al 2008). …”

“…In a study of illness-precipitated PSS among mothers of children with cancer, the index has been shown to discriminate between groups in a “dose-response” manner (highest to lowest: PSS-symptomatic cancer mothers, non-symptomatic but chronically stressed cancer mothers, control mothers of healthy children), even when individual biomarkers do not (Glover and Stuber 2006). Recently, a high biomarker composite index was linked to smaller hippocampal volume in mothers of seriously ill children (Glover et al 2008). …”

“…Second, the biomarkers represent multiple biological systems that can be analyzed individually, collectively, or in subsets to understand interrelationships across systems. Third, the approach uses relative risk composite scores that may be better predictors of poor health outcomes than levels of individual biomarkers that fall into a “clinical” range for pathology (Glover and Stuber 2006; Glover et al 2008; Kopinsky et al 2004). Composites inherently select “extreme” scorers, thereby supporting comparisons of individuals at greatest risk and those displaying the greatest “resilience” to HIV+ stress.…”

Using novel methods to examine stress among HIV-positive African American men who have sex with men and women

“…These peripherally measured primary and secondary biological mediators combined into a composite appear to reflect central neurobiological processes that include structural changes in the brain. In support, BC levels were examined in relation to hippocampal volume measured via brain imaging among healthy, mostly White, chronically stressed mothers of seriously ill children (Glover et al, 2008). After controlling for mother’s age and time since the child’s medical diagnosis, higher BCs were associated with lower hippocampal volume.…”