The Ketone Bridge Between the Heart and the Bladder: How Fast Should We Go?

Metabolic syndrome (MS) is associated with both cardiovascular and bladder dysfunction. Insulin resistance (IR) and central obesity, in particular, are the main risk factors. In these patients, vicious pathological cycles exacerbate abnormal carbohydrate metabolism and sustain an inflammatory state, with serious implications for both the heart and bladder. Ketone bodies serve as an alternative energy source in this context. They are considered a "super-fuel" because they generate adenosine triphosphate with less oxygen consumption per molecule, thus enhancing metabolic efficiency. Ketone bodies have a positive impact on all components of MS. They aid in weight loss and glycemic control, lower blood pressure, improve lipid profiles, and enhance endothelial function. Additionally, they possess direct anti-inflammatory, antioxidant, and vasodilatory properties. A shared key player in dysfunction of both the heart and bladder dysfunction is the formation of the NLRP3 inflammasome, which ketone bodies inhibit. Interventions that elevate ketone body levels-such as fasting, a ketogenic diet, ketone supplements, and sodium-glucose cotransporter 2 inhibitors-have been shown to directly affect cardiovascular outcomes and improve lower urinary tract symptoms derived from MS. This review explores the pathophysiological basis of the benefits of ketone bodies in cardiac and bladder dysfunction.

Detrusor contractility to parasympathetic mediators is differentially altered in the compensated and decompensated states of diabetic bladder dysfunction

Diabetic bladder dysfunction (DBD) affects up to 50% of all patients with diabetes, characterized by symptoms of both overactive and underactive bladder. Although most diabetic bladder dysfunction studies have been performed using models with type 1 diabetes, few have been performed in models of type 2 diabetes, which accounts for ~90% of all diabetic cases. In a type 2 rat model using a high-fat diet (HFD) and two low doses of streptozotocin (STZ), we examined voiding measurements and functional experiments in urothelium-denuded bladder strips to establish a timeline of disease progression. We hypothesized that overactive bladder symptoms (compensated state) would develop and progress into symptoms characterized by underactive bladder (decompensated state). Our results indicated that this model developed the compensated state at 1 wk after STZ and the decompensated state at 4 mo after STZ administration. Diabetic bladders were hypertrophied compared with control bladders. Increased volume per void and detrusor muscle contractility to exogenous addition of carbachol and ATP confirmed the development of the compensated state. This enhanced contractility to carbachol was not due to increased levels of M₃ receptor expression. Decompensation was characterized by increased volume per void, number of voids, and contractility to ATP but not carbachol. Thus, progression from the compensated to decompensated state may involve decreased contractility to muscarinic stimulation. These data suggest that the compensated state of DBD progresses temporally into the decompensated state in the male HFD/STZ model of diabetes; therefore, this male HFD/STZ model can be used to study the progression of DBD.