Frailty has a stronger association with inflammation than age in older veterans

BACKGROUND

Upregulation of pro-inflammatory cytokines has not only been associated with increased morbidity and mortality in older adults but also has been linked to frailty. In the current study we aimed to compare the relative relationship of age and frailty on inflammation and thrombosis in older veterans.

RESULTS

We analyzed 117 subjects (age range 62-95 years; median 81) divided into 3 cohorts: non-frail, pre-frail and frail based on the Fried phenotype of frailty. Serum inflammatory markers were determined using commercially available ELISA kits. Frail and pre-frail (PF) subjects had higher levels than non-frail (NF) subjects of IL-6 (NF vs. PF: p = 0.002; NF vs. F: p < 0.001), TNFR1 (NF vs. F: p = 0.012), TNFRII (NF vs. F: 0.002; NF vs. PF: p = 0.005) and inflammatory index: = 0.333*log(IL-6) + 0.666*log(sTNFR1) (NF vs. F: p = 0.009; NF vs. PF: p < 0.001). Frailty status explained a greater percent of variability in markers of inflammation than age: IL-6 (12 % vs. 0.3 %), TNFR1 (5 % vs. 4 %), TNFR2 (11 % vs. 6 %), inflammatory index (16 % vs. 8 %). Aging was significantly associated with higher fibrinogen (p = 0.04) and D-dimer levels (p = 0.01) but only among NF subjects.

CONCLUSION

In conclusion, these data suggest that among older veterans, frailty status has a stronger association with inflammation and the inflammatory index than age does. Larger studies, in more diverse populations are needed to confirm these findings.

Effects of prolonged ACTH-stimulation on adrenocortical accumulation of lipofuscin granules in aged rats

Subcellular deposition of lipofuscin granules is a marker of aging. Human and rodent adrenal cortices accumulate lipofuscin granules with age, but the mechanism that leads to the accumulation is not known. The ultrastructural appearance of lipofuscin granules resembles that of secondary lysosomes. Since adrenocortical subcellular events are predominantly influenced by ACTH action, we therefore studied the effect of prolonged ACTH-stimulation on adrenocortical accumulation of secondary lysosome-like granules, designated herein as lipofuscin granules. Using aged Fischer 344 male rats as a model, we found that a 7 day ACTH stimulation exerts a reducing effect on adrenocortical lipofuscin accumulation. Thus, adrenocortical accumulation of lipofuscin granules with age in vivo may not be an irreversible process.

Clinical epidemiology of endocrine disorders in the elderly

Many epidemiologic studies have examined age-related processes in humans. Some of the difficulties with these studies are noted. Endocrinologic changes of aging often are compensated for by feedback mechanisms and do not cause dysfunction. Common aging changes are reviewed.

Apolipoprotein E is increased in aged rat kidney

There is growing evidence to indicate that apolipoprotein (apo) E may be associated with age-related disorders and altered longevity in humans. Using rats as a model, we measured apoE in plasma, brain, heart, kidney, liver and spleen in aged (24-25 mo) and younger rats (6-8 mo). The results disclosed that: (a) the plasma concentrations of immunoreactive apoE in aged rats were higher than those in young animals by 70% (P < 0.01); (b) there was no age-related difference of apoE in the brain, heart, liver or spleen; (c) in contrast, the concentrations of apoE in the kidney of aged rats were markedly higher than those of young animals by 490% (P < 0.01). Our data suggest that, in the rat, age-related change in the organ concentrations of apoE is heterogeneous, and the selective increase in the kidney may have physiologic importance which merits further study.