| Sex, age, and stress may affect inflammatory markers, such as albumin, C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-a). This research explored whether sex, age, and cortisol are associated with inflammatory markers in western lowland gorillas. Biomarkers were assayed from banked gorilla serum (n=63, aged 6-52 years) from three North American zoos. Relationships between inflammatory markers and sex were tested using t-tests, and relationships with age and cortisol were tested using linear regressions (α=0.05). Males had higher albumin than females (p=0.001). Albumin was negatively associated with age (p=0.000, R2=0.195) and cortisol (p=0.024, R2=0.073). Females had higher CRP than males (p=0.000). CRP showed no relationship with age (p=0.874), but a positive association with cortisol (p=0.000, R2=0.236). IL-6 showed no significant difference between males and females (p=0.956). In addition, IL-6 was positively associated with age (p=0.001, R2=0.195), but was not associated with cortisol (p=0.729). When outliers were excluded, females had significantly higher TNF-α than males (p=0.037), although this relationship was absent when outliers were retained (p=0.145). TNF-α was not significantly associated with age (p=0.440), but was positively associated with cortisol (p=0.000, R2=0.432). As persistent elevations in inflammatory markers are associated with chronic degenerative conditions (e.g., cardiovascular disease, arthritis) and many zoo-housed great apes develop such conditions, understanding how sex, age, and stress affect their serum concentrations may aid in improving primate health and welfare. |
