Adiponectin and Sarcopenia: A Systematic Review With Meta-Analysis

Background: Sarcopenia is a progressive loss of skeletal muscle mass whose pathophysiology has been proposed to possibly involve mechanisms of altered inflammatory status and endocrine function. Adiponectin has been shown to modulate inflammatory status and muscle metabolism. However, the possible association between adiponectin levels and sarcopenia is poorly understood. In order to fill this gap, in the present manuscript we aimed to summarize the current evidence with a systematic review and a meta-analysis of studies reporting serum adiponectin levels in patients with sarcopenia compared to non-sarcopenic controls. Methods: An electronic search through Medline/PubMed, Cochrane Library, and Science Direct was performed till March 1, 2020. From the included papers, meta-analysis of cross-sectional studies comparing serum levels of adiponectin between patients with sarcopenia and controls was performed. Results: Out of 1,370 initial studies, seven studies were meta-analyzed. Sarcopenic participants had significantly higher levels of adiponectin Hedges’ g with 95% confidence interval (CI): 1.20 (0.19–2.22), p = 0.02 than controls. Subgroup analysis, performed in Asian population and focused on identification of the condition based on AWGS criteria, reported higher adiponectin levels in sarcopenic population (2.1 (0.17–4.03), p = 0.03 and I2 = 98.98%. Meta-regression analysis revealed female gender to significantly influence the results as demonstrated by beta = 0.14 (95% CI (0.010–0.280), p = 0.040). Conclusions: Our meta-analysis found evidence that sarcopenia is associated with higher adiponectin levels. However, caution is warranted on the interpretation of these findings, and future longitudinal research is required to disentangle and better understand the topic

COVID-19 and the elderly: insights into pathogenesis and clinical decision-making

The elderly may represent a specific cluster of high-risk patients for developing COVID-19 with rapidly progressive clinical deterioration. Indeed, in older individuals, immunosenescence and comorbid disorders are more likely to promote viral-induced cytokine storm resulting in life-threatening respiratory failure and multisystemic involvement. Early diagnosis and individualized therapeutic management should be developed for elderly subjects based on personal medical history and polypharmacotherapy. Our review examines the pathogenesis and clinical implications of ageing in COVID-19 patients; finally, we discuss the evidence and controversies in the management in the long-stay residential care homes and aspects of end-of-life care for elderly patients with COVID-19

β-adrenergic receptors and G protein-coupled receptor kinase-2 in Alzheimer's disease: a new paradigm for prognosis and therapy?

Alzheimer's disease (AD) is a devastating form of dementia that imposes a severe burden on health systems and society. Although several aspects of AD pathogenesis have been elucidated over the last few decades, many questions still need to be addressed. In fact, currently available medications only provide symptomatic improvement in patients with AD without affecting disease progression. The β-adrenergic receptor (β-AR) system can be considered a possible target that deserves further exploration in AD. The central noradrenergic system undergoes substantial changes in the course of AD and β-ARs have been implicated not only in amyloid formation in AD brain but also in amyloid-induced neurotoxicity. Moreover, clinical evidence suggests a protective role of β-AR blockers on AD onset. In addition to that, post-receptor components of β-AR signaling seem to have a role in AD pathogenesis. In particular, the G protein coupled receptor kinase 2, responsible for β-AR desensitization and downregulation, mediates amyloid-induced β-AR dysfunction in neurons, and its levels in circulating lymphocytes of AD patients are increased and inversely correlated with patient's cognitive status. Therefore, there is an urgent need to gain further insight on the role of the adrenergic system components in AD pathogenesis in order to translate preclinical and clinical knowledge to more efficacious prognostic and therapeutic strategies

Imaging and molecular mechanisms of Alzheimer's fisease: a review

Alzheimer’s disease is the most common form of dementia and is a significant burden for affected patients, carers, and health systems. Great advances have been made in understanding its pathophysiology, to a point that we are moving from a purely clinical diagnosis to a biological one based on the use of biomarkers. Among those, imaging biomarkers are invaluable in Alzheimer’s, as they provide an in vivo window to the pathological processes occurring in Alzheimer’s brain. While some imaging techniques are still under evaluation in the research setting, some have reached widespread clinical use. In this review, we provide an overview of the most commonly used imaging biomarkers in Alzheimer’s disease, from molecular PET imaging to structural MRI, emphasising the concept that multimodal imaging would likely prove to be the optimal tool in the future of Alzheimer’s research and clinical practice

Antidiabetic Drugs in Alzheimer's Disease: Mechanisms of Action and Future Perspectives

Diabetes mellitus (DM) and Alzheimer’s disease (AD) are two highly prevalent conditions in the elderly population and major public health burden. In the past decades, a pathophysiological link between DM and AD has emerged and central nervous system insulin resistance might play a significant role as a common mechanism; however, other factors such as inflammation and oxidative stress seem to contribute to the shared pathophysiological link. Both preclinical and clinical studies have evaluated the possible neuroprotective mechanisms of different classes of antidiabetic medications in AD, with some promising results. Here, we review the evidence on the mechanisms of action of antidiabetic drugs and their potential use in AD