Raised cortisol:DHEAS ratios in the elderly after injury: potential impact upon neutrophil function and immunity

Summary The detrimental effect of stress on the immune response increases with age, though the mechanisms responsible are not fully understood. The physiological response to stress is regulated in part by the adrenocortical system. Adrenal hormones dehydroepiandrosterone sulphate (DHEAS) and cortisol have opposing effects on the innate immune system, DHEAS enhances while cortisol suppresses immunity and the molar ratio of cortisol to DHEAS increases with age. We found that elderly hip fracture patients produced a robust neutrophilia after injury, but circulating neutrophils showed an impaired antibacterial response. We therefore proposed that adrenocortical hormones mediate the heightened immunosuppression seen in the elderly after injury. We examined neutrophil function and adrenocortical hormone levels in elderly (> 65 years) hip fracture patients and age‐matched healthy controls. Thirteen out of 35 elderly patients acquired infections following hip fracture. Neutrophil superoxide production was lower in elderly hip fracture patients compared with controls (P