1.
The conundrum of human immune system "senescence".
Pawelec, G, Bronikowski, A, Cunnane, SC, Ferrucci, L, Franceschi, C, Fülöp, T, Gaudreau, P, Gladyshev, VN, Gonos, ES, Gorbunova, V, et al
Mechanisms of ageing and development. 2020;:111357
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Abstract
There is a great deal of debate on the question of whether or not we know what ageing is (Ref. Cohen et al., 2020). Here, we consider what we believe to be the especially confused and confusing case of the ageing of the human immune system, commonly referred to as "immunosenescence". But what exactly is meant by this term? It has been used loosely in the literature, resulting in a certain degree of confusion as to its definition and implications. Here, we argue that only those differences in immune parameters between younger and older adults that are associated in some definitive manner with detrimental health outcomes and/or impaired survival prospects should be classed as indicators of immunosenescence in the strictest sense of the word, and that in humans we know remarkably little about their identity. Such biomarkers of immunosenescence may nonetheless indicate beneficial effects in other contexts, consistent with the notion of antagonistic pleiotropy. Identifying what could be true immunosenescence in this respect requires examining: (1) what appears to correlate with age, though generality across human populations is not yet confirmed; (2) what clearly is part of a suite of canonical changes in the immune system that happen with age; (3) which subset of those changes accelerates rather than slows aging; and (4) all changes, potentially population-specific, that accelerate agig. This remains an immense challenge. These questions acquire an added urgency in the current SARS-CoV-2 pandemic, given the clearly greater susceptibility of older adults to COVID-19.
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Effect of CPAP treatment for obstructive sleep apnea hypopnea syndrome on lipid profile: a meta-regression analysis.
Nadeem, R, Singh, M, Nida, M, Kwon, S, Sajid, H, Witkowski, J, Pahomov, E, Shah, K, Park, W, Champeau, D
Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine. 2014;(12):1295-302
Abstract
STUDY OBJECTIVE Patients with obstructive sleep apnea (OSA) frequently exhibit higher rates of dyslipidemia, a risk factor for cardiovascular and cerebrovascular disorders. Treatment for OSA by CPAP may improve cholesterol metabolism. This meta-regression analysis (MA) estimates the effect of CPAP treatment on dyslipidemia. METHODS PubMed and Cochrane libraries were searched by utilizing different combinations of keywords: CPAP, obstructive sleep apnea, serum lipids, dyslipidemia, cholesterol, total cholesterol (TC), low density lipoprotein, LDL, high density lipoprotein, HDL, triglyceride, and TG. Inclusion criteria were: (1) English articles and (2) studies with an adult population with the diagnosis of OSA who were treated with CPAP. The OSA group must have cholesterol profile including TC, LDLc, HDLc, and TG, without and with CPAP treatment. Fifty-four studies were reviewed, while 29 studies pooled for MA. RESULTS Thirty-four datasets from 29 studies with 1,958 subjects pooled. Treatment duration range was from 2 days to 1 year. TC standardized mean differences (SMD) ranged from -41.5 to -0.077, pooled mean difference (PMD) was -5.660 (LL -6.715 to UL -4.606, p < 0.001). SMD in LDL ranged from -3.7 to 0; PMD was -0.488 (LL -0.715 to UL -0.261, p < 0.001). HDL SMD ranged from -0.498 to 1.94. The PMD was 0.207 (LL 0.05 to UL 0.364, p < 0.01). TG SMD ranged from -9.327 to 1.98; PMD was -0.054 (LL -0.124 to UL 0.016, p < 0.129). CONCLUSIONS CPAP treatment for OSA seems to improve dyslipidemia (decrease in total cholesterol and LDL, and increase in HDL). It does not appear to affect TG levels.