Caffeine: cardiorespiratory effects and tissue protection in animal models

The aim of this review is to analyze the cardiorespiratory and tissue-protective effects of caffeine in animal models. Peer-reviewed literature published between 1975 and 2021 was retrieved from CAB Abstracts, PubMed, ISI Web of Knowledge, and Scopus. Extracted data were analyzed to address the mechanism of action of caffeine on cardiorespiratory parameters (heart rate and rhythm), vasopressor effects, and some indices of respiratory function; we close this review by discussing the current debate on the research carried out on the effects of caffeine on tissue protection. Adenosine acts through specific receptors and is a negative inotropic and chronotropic agent. Blockage of its cardiac receptors can cause tachycardia (with arrhythmogenic potential) due to the intense activity of β1 receptors. In terms of tissue protection, caffeine inhibits hyperoxia-induced pulmonary inflammation by decreasing proinflammatory cytokine expression in animal models. The protection that caffeine provides to tissues is not limited to the CNS, as studies have demonstrated that it generates attenuation of inflammatory effects in pulmonary tissue. It inhibits the effects of some pro-inflammatory cytokines and prevents functional and structural changes.

Beware Energy Drinks: A Case of a Toxic Triad Syndrome in a Diabetic Patient With Nonalcoholic Fatty Liver Disease

Energy drinks are widely used and very popular. They are touted as "harmless" energy boosters for use in professional, recreational and domestic settings. They are typically high in monosaccharides, and caffeine with other assorted products like ginseng. Careful study of the potential risks of their use is nonexistent while rigorous documentation of their touted energy boosting capacity is also meagre. We present the cautionary case of a 46-year-old Caucasian man with well-controlled type 2 diabetes and nonalcoholic fatty liver disease who developed a toxic triad syndrome of gastritis, hepatitis and pancreatitis within 4 months of commencing daily consumption of 2-3 160z cans of the energy drink Monster Energy. His clinical symptoms and biochemical derangements promptly resolved with stopping the beverage. We discuss the potential risks inherent in unsupervised liberal consumption of energy drinks and the need for both caution and vigilance among clinicians and patients.