Mini–ReviewInflammatory mediators in the elderly
Section snippets
The ageing immune system
The term immunosenescence usually refers to the notion that there is an age-related dysfunction of the immune system. The number of studies in this area is large and, unfortunately, the results are often contradictory. Many investigators compare donors of different ages in cross-sectional studies and these populations differ in their genetic background, nutritional and environmental influences, co-morbidity, selection criteria, and in the techniques applied to measure immune parameters across
Ageing is associated with increased levels of circulating cytokines
Levels of circulating inflammatory mediators and their clinical importance have not been explored in population-based samples of elderly people until recently. Most studies have focused on interleukin (IL)-6, which has been called a cytokine for gerontologists (Ershler, 1993) and most studies report increased plasma/serum levels of this cytokine with advancing age (Wei et al., 1992, Ershler et al., 1993, Bruunsgaard et al., 1999a, Hager et al., 1994) although some studies have found no changes (
Cytokine production in vitro versus in vivo in elderly humans
A wide range of different factors is likely to contribute to increased low-grade inflammatory activity in elderly populations including decreased production of sex steroids, smoking, subclinical disorders such as atherosclerosis and asymptomatic bacteriuria, and a higher relative/absolute amount of fat tissue, which has been demonstrated to produce cytokines such as TNF-α and IL-6. Furthermore, increased levels of circulating inflammatory mediators may result from a constant, low-grade
Effects of inflammatory mediators in age-associated chronic diseases
The strong association between low-grade elevations in levels of circulating inflammatory mediators and high mortality risk independently of pre-existing morbidity, suggests that cytokines trigger/exaggerate pathological processes or act as very sensitive markers of subclinical disorders in elderly populations.
The longitudinal study of Danish centenarians has demonstrated that the extreme lifespan is accompanied by a high prevalence of CVD (>70%) and dementia (>50%) (Andersen-Ranberg et al.,
Concluding remarks
Ageing is associated with low-grade elevations in levels of circulating inflammatory mediators, which act as predictors of mortality independent of pre-existing morbidity. Moreover, there is strong evidence that the development of age-related multi-factorial conditions such as atherosclerosis, cognitive decline and the syndrome of frailty are associated to these elevations. The nature of these associations remains controversial, as it is unclear whether inflammatory mediators have primarily
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