Peripheral Inflammatory Parameters in Late-Life Depression: A Systematic Review

Abstract

Depressive disorders appear relatively frequently in older patients, and therefore represent an important disease burden worldwide. Given the high levels of inflammatory parameters found in depressed elderly patients, the “inflammaging” hypothesis is gaining strength. In this systematic review, we summarize current evidence regarding the relationship between inflammatory parameters and late-life depression, with a unique focus on longitudinal studies to guarantee temporality. According to the data summarized in this review, the levels of some proinflammatory parameters—especially interleukin (IL)-8, IL-6, and tumor necrosis factor (TNF)-α—could serve as biomarkers for the future development of depressive symptoms in elderly patients. Proinflammatory cytokines seem to be associated with the future development of clinically significant depression, irrespective of baseline scores, thus indicating that inflammation temporally precedes and increases depression risk. As insufficient research has been conducted in this field, further prospective studies are clearly warranted.

Increased levels of ascorbic acid in the cerebrospinal fluid of cognitively intact elderly patients with major depression: a preliminary study

“…It is well known that peripheral inflammatory substances (e.g., C-reactive protein, interleukin (IL)-8, IL-6, tumor necrosis factor (TNF)-α) are higher in patients with late-life depression 35, 36 . Furthermore, immunological biomarkers, such as vascular endothelial growth factor (VEGF), the chemokine eotaxin, TNF-α, interferon-γ, and macropharge inflammatory protein-1α, are associated with brain structure in late-life depression 36 .…”

Handgrip strength and depression among 34,129 adults aged 50 years and older in six low- and middle-income countries

“…Thus, it may be that weak handgrip strength, which was particularly high in this sample (47.4%), is an indicator of frailty in our sample and this identifies those at risk of depression. Research also suggests that skeletal muscle releases several cytokines and peptides (myokines) into the circulation in response to muscle contractions and that the anti-inflammatory and anti-atherogenic properties of these myokines protect against the risk for depression (Köhler et al, 2017;Martínez-Cengotitabengoa et al, 2016). In addition, it is established that both frailty (Soysal et al, 2016) and…”

Drug repurposing may generate novel approaches to treating depression

“…[18] For instance, increased levels of pro-inflammatory cytokines, such as interleukin-6 and tumour necrosis factor alpha, and high sensitivity C-reactive protein were reported in depressed patients. [28,29] In agreement with this, anti-inflammatory drugs with different mechanisms of action have showed antidepressant effects or improved responses to the first-line antidepressant drugs as add-on therapy. [30] People with advanced age are likely to be diagnosed with late-onset or vascular depression, [10,31] which could probably be a consequence of ongoing neurodegenerative processes such as Alzheimer's and Parkinson's diseases.…”

“…Advances in diagnostic methods have indicated that inflammation could contribute to the pathogenesis of depression . For instance, increased levels of pro‐inflammatory cytokines, such as interleukin‐6 and tumour necrosis factor alpha, and high sensitivity C‐reactive protein were reported in depressed patients . In agreement with this, anti‐inflammatory drugs with different mechanisms of action have showed antidepressant effects or improved responses to the first‐line antidepressant drugs as add‐on therapy .…”