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Summary: Recent studies have found associations between obstructive sleep apnea and cognitive decline. The underlying mechanisms are still unclear. Here, we investigate the associations between changes in micro‐architecture, specifically sleep spindles, and cognitive function in community‐dwelling middle‐aged and older adults, some with obstructive sleep apnea, with a focus on sex differences. A total of 125 voluntary participants (mean age 66.0 ± 6.4 years, 64 females) from a larger cohort (participants of the Brain in Motion Studies I and II) underwent 1 night of in‐home polysomnography and a neuropsychological battery (sleep and cognitive testing were conducted within 2 weeks of each other). A semi‐automatic computerized algorithm was used to score polysomnography data and detect spindle characteristics in non‐rapid eye movement Stages 2 and 3 in both frontal and central electrodes. Based on their apnea–hypopnea index, participants were divided into those with no obstructive sleep apnea (apnea–hypopnea index < 5 per hr, n = 21), mild obstructive sleep apnea (5 ≥ apnea–hypopnea index < 15, n = 47), moderate obstructive sleep apnea (15 ≥ apnea–hypopnea index < 30, n = 34) and severe obstructive sleep apnea (apnea–hypopnea index ≥ 30, n = 23). There were no significant differences in spindle characteristics between the four obstructive sleep apnea severity groups. Spindle density and percentage of fast spindles were positively associated with some verbal fluency measures on the cognitive testing. Sex might be linked with these associations. Biological sex could play a role in the associations between spindle characteristics and some verbal fluency measures. Obstructive sleep apnea severity was not found to be a contributing factor in this non‐clinical community‐dwelling cohort. [ABSTRACT FROM AUTHOR]

Metformin is an orally effective anti-hyperglycemic drug that despite being introduced over 60 years ago is still utilized by an estimated 120 to 150 million people worldwide for the treatment of type 2 diabetes (T2D). Metformin is used off-label for the treatment of polycystic ovary syndrome (PCOS) and for pre-diabetes and weight loss. Metformin is a safe, inexpensive drug with side effects mostly limited to gastrointestinal issues. Prospective clinical data from the United Kingdom Prospective Diabetes Study (UKPDS), completed in 1998, demonstrated that metformin not only has excellent therapeutic efficacy as an anti-diabetes drug but also that good glycemic control reduced the risk of micro- and macro-vascular complications, especially in obese patients and thereby reduced the risk of diabetes-associated cardiovascular disease (CVD). Based on a long history of clinical use and an excellent safety record metformin has been investigated to be repurposed for numerous other diseases including as an anti-aging agent, Alzheimer's disease and other dementias, cancer, COVID-19 and also atrial fibrillation (AF). AF is the most frequently diagnosed cardiac arrhythmia and its prevalence is increasing globally as the population ages. The argument for repurposing metformin for AF is based on a combination of retrospective clinical data and in vivo and in vitro pre-clinical laboratory studies. In this review, we critically evaluate the evidence that metformin has cardioprotective actions and assess whether the clinical and pre-clinical evidence support the use of metformin to reduce the risk and treat AF. [ABSTRACT FROM AUTHOR]

Over the past 66 years, our knowledge of the role of the endothelium in the regulation of cardiovascular function and dysfunction has advanced from the assumption that it is a single layer of cells that serves as a barrier between the blood stream and vascular smooth muscle to an understanding of its role as an essential endocrine-like organ. In terms of historical contributions, we pay particular credit to (1) the Canadian scientist Dr. Rudolf Altschul who, based on pathological changes in the appearance of the endothelium, advanced the argument in 1954 that 'one is only as old as one's endothelium' and (2) the American scientist Dr. Robert Furchgott, a 1998 Nobel Prize winner in Physiology or Medicine, who identified the importance of the endothelium in the regulation of blood flow. This review provides a brief history of how our knowledge of endothelial function has advanced and now recognize that the endothelium produces a plethora of signaling molecules possessing paracrine, autocrine, and, arguably, systemic hormone functions. In addition, the endothelium is a therapeutic target for the anti-diabetic drugs metformin, glucagon-like peptide I (GLP-1) receptor agonists, and inhibitors of the sodium-glucose cotransporter 2 (SGLT2) that offset the vascular disease associated with diabetes. Key words: endothelium, endothelial dysfunction, diabetes, hyperglycaemia, metformin, GLP-1 agonists, SGLT2 inhibitors. Au cours des 66 dernieres annees, notre connaissance du role de l'endothelium sur la regulation du fonctionnement et des dysfonctionnements du systeme cardiovasculaire a fait des progres a partir de la presomption qu'il s'agirait d'une couche monocellulaire servant de barriere entre la circulation sanguine et le muscle lisse vasculaire, pour parvenir a la comprehension de son role s'apparentant a celui d'un organe endocrinien essentiel. Nous rendons hommage aux personnes suivantes pour leurs contributions historiques : (1) le docteur Rudolf Altschul, scientifique canadien qui s'est base sur des variations pathologiques dans l'apparence de l'endothelium pour avancer en 1954 l'argument selon lequel on n'a guere plus que l'age de son endothelium (<< one is only as old as one's endothelium >>) et (2) le docteur Robert Furchgott, scientifique americain laureat du prix Nobel de physiologie ou de medecine de 1998, qui a etabli l'importance de l'endothelium dans la regulation de la circulation sanguine. Cet article de synthese comporte un bref historique sur la maniere dont notre connaissance du fonctionnement de l'endothelium s'est accrue et reconnait maintenant que l'endothelium produit une plethore de molecules de signalisation avec des fonctions hormonales paracrines, autocrines et sans doute generales. De plus, l'endothelium est une cible therapeutique pour des medicaments antidiabetiques comme la metformine, les agonistes des recepteurs du peptide 1 de type glucagon (GLP-1) et les inhibiteurs du co-transporteur 2 sodium-glucose (SGLT2), qui permettent d'eloigner les patients de la maladie vasculaire associee au diabete. Mots-des : endothelium, dysfonctionnement endothelial, diabete, hyperglycemie, metformine, agonistes des recepteurs du GLP-1, inhibiteur du SGLT2., Introduction: why the endothelium? When asking the question 'why the endothelium?', one immediately thinks of the landmark paper published in Nature in 1980 by Furchgott and Zawadzki that first described [...]