Chronic intermittent hypoxia (CIH) is the dominant pathological feature of human obstructive sleep apnoea (OSA), which is highly prevalent and associated with cardiovascular and renal diseases. CIH causes hypertension, centred on sympathetic nervous overactivity, which persists following removal of the CIH stimulus. Molecular mechanisms contributing to CIH‐induced hypertension have been carefully delineated. However, there is a dearth of knowledge on the efficacy of interventions to ameliorate high blood pressure in established disease. CIH causes endothelial dysfunction, aberrant structural remodelling of vessels and accelerates atherosclerotic processes. Pro‐inflammatory and pro‐oxidant pathways converge on disrupted nitric oxide signalling driving vascular dysfunction. In addition, CIH has adverse effects on the myocardium, manifesting atrial fibrillation, and cardiac remodelling progressing to contractile dysfunction. Sympatho‐vagal imbalance, oxidative stress, inflammation, dysregulated HIF‐1α transcriptional responses and resultant pro‐apoptotic ER stress, calcium dysregulation, and mitochondrial dysfunction conspire to drive myocardial injury and failure. CIH elaborates direct and indirect effects in the kidney that initially contribute to the development of hypertension and later to chronic kidney disease. CIH‐induced morphological damage of the kidney is dependent on TLR4/NF‐κB/NLRP3/caspase‐1 inflammasome activation and associated pyroptosis. Emerging potential therapies related to the gut–kidney axis and blockade of aryl hydrocarbon receptors (AhR) are promising. Cardiorenal outcomes in response to intermittent hypoxia present along a continuum from adaptation to maladaptation and are dependent on the intensity and duration of exposure to intermittent hypoxia. This heterogeneity of OSA is relevant to therapeutic treatment options and we argue the need for better stratification of OSA phenotypes. image
Oxalate is a metabolic end-product whose systemic concentrations are highly variable among individuals. Genetic (primary hyperoxaluria) and non-genetic (e.g., diet, microbiota, renal and metabolic disease) reasons underlie elevated plasma concentrations and tissue accumulation of oxalate, which is toxic to the body. A classic example is the triad of primary hyperoxaluria, nephrolithiasis, and kidney injury. Lessons learned from this example suggest further investigation of other putative factors associated with oxalate dysmetabolism, namely the identification of precursors (glyoxylate, aromatic amino acids, glyoxal and vitamin C), the regulation of the endogenous pathways that produce oxalate, or the microbiota’s contribution to oxalate systemic availability. The association between secondary nephrolithiasis and cardiovascular and metabolic diseases (hypertension, type 2 diabetes, and obesity) inspired the authors to perform this comprehensive review about oxalate dysmetabolism and its relation to cardiometabolic toxicity. This perspective may offer something substantial that helps advance understanding of effective management and draws attention to the novel class of treatments available in clinical practice.
22 January 2025 in Toxicology and Applied Pharmacology
Millions of individuals make illicit use of anabolic-androgenic steroids (AAS), remaining a public health issue. It often leads to detrimental effects, including cardiovascular and renal diseases, besides hormonal and metabolic imbalances. The objective of this review is to emphasize the contribution of oxidative stress and inflammation to these effects and connect the findings of experimental animal studies with the alterations found in clinical contexts, in AAS users. The study's results showed that AAS promotes a redox disruption and a pro-inflammatory state on organs that are involved in important physiologic processes. These drugs increase inflammatory high-sensitivity C-reactive protein (hs-CRP) and cytokines that contribute to the progression of atherosclerosis, cardiovascular disease risk or endpoints, including stroke, myocardial infarction and death. In the kidney, the AAS increase proteinuria and structural damage. Studies have linked AAS abuse with high BP, low HDL-C levels, high triglyceride levels and impaired fasting blood glucose that characterize Metabolic syndrome. Overall, the studies indicate that oxidative stress, apoptosis, and AAS-mediated inflammation play a significant role in tissue damage, regardless of the dose and duration of exposure, and we point it as a putative independent risk factor to Cardiovascular, Kidney and Metabolic syndrome.