Inflammatory Markers Change with Age, but do not Fall Beyond Reported Normal Ranges

Abstract

We examined the serum levels of IL-6, IL-8, TNF, IL-6R, TNF-R1, and CRP and the dynamics of changes in these levels according to age. The study included healthy individuals of 20–90 years of age. Participants were divided into subgroups based on their decade of life, and into subgroups of ≥65 or <65 years. Serum cytokine levels were assayed by ELISA, and CRP using an immunoturbidimetric method. Serum CRP levels were within the normal range for all subgroups. The 60- to 70-year age group showed higher CRP than the 20- to 30- (p = 0.003), 30- to 40- (p = 0.009), and 40- to 50- (p = 0.030) year age groups. Serum cytokine levels were low. It was greater in the 60- to 70-year age group than in the 20- to 30- (p = 0.008) and 30- to 40- (p = 0.040) year groups, and was greater in the 70- to 90-year group than the 20- to 30-year group (p = 0.043). Serum TNF-R1 level in the 70- to 90-year group was greater than in all other age groups (p = 0.000 for all comparisons). Other measured parameters did not differ between groups. Serum levels of IL-6, CRP, and TNF-R1 were greater in participants ≥65 than <65 years of age. Healthy older people showed low serum levels of CRP and pro-inflammatory cytokines, but higher than in younger population. Therefore, the adjustment of normal ranges in the elderly should be considered. Serum levels of pro-inflammatory cytokines elevated beyond normal ranges indicate particular diseases.

Trajectories of inflammatory biomarkers over the eighth decade and their associations with immune cell counts and epigenetic ageing

“…Finally, the mean age of the cohort at Wave 1 was 70 years and it is possible participants had already undergone a transition to an increased inflammatory profile and this is why we did not capture a rise in CRP over time. This is in line with findings from a previous study which reported an increased serum level of CRP between a 20-30-year-old age group and 60-70-year-olds, but no significant difference in levels between 60-70-year-olds and the 70-90-year-olds (36).…”

Systemic inflammation in dogs with advanced-stage heart failure

“…Moreover, no associations between CRP and age, body weight or breed were found in canine cardiac patients [ 18 ]. In humans, CRP concentration increased with age; however, it remained within the normal range [ 53 ]. We cannot totally exclude possible effect of age and breed on hematological variables [ 54 ].…”

Review of biomarkers to assess the effects of switching from cigarettes to modified risk tobacco products

“…Thus, it may be concluded that TNF-a, although mechanistically involved in the pathogenesis of inflammation-related diseases such as COPD, CVD and cancer, demonstrates no convincing evidence that it will be a suitable cytokine for measuring effects of smoking cessation or switching to a potentially less harmful product. Serum concentrations of TNF-a do not appear to change with increasing age (Kim et al 2011, Kleiner et al 2013, Wyczalkowska-Tomasik et al 2016) except in subjects with type 2 diabetes where increases are seen over time, especially in females above the age of 41 years (Fatima et al 2017). TNF-a levels are also not affected by gender (Lee et al 1993, Arican et al 2005 except in Chinese subjects in which levels are higher in females than males in the age range 20-45 years (Yuan et al 2015).…”