The Kidney-Heart Connection in Obesity.

There is a strong relationship between the kidney and the heart, where if one of these organs fails, so does the other, in the so-called cardiorenal syndrome (CRS). Besides, there are also interactions with the rest of the body leading to a metabolic state that establishes a feedback loop that is perpetuated. The CRS is characterized by hemodynamic changes, activation of neuro-humoral systems, natriuretic peptides, and changes in mineral metabolism. In this scenario, the kidney and heart, connected by a dysfunctional endothelium, inevitably fail. In obesity, this syndrome is exacerbated due to the complications of adipose tissue dysfunction, in the so-called cardiorenal metabolic syndrome (CRMetS). Obesity promotes adipose tissue dysfunction because it exceeds lipid storage capacity and leads to a lipotoxic state, characterized by inflammation, hypertension, insulin resistance and dyslipidemia, oxidative stress, and hyperuricemia, among others, that affect different organs other than the adipose tissue. In addition, the pro-inflammatory gut microbiota present in obese patients releases uremic toxins, contributing to oxidative stress and inflammation, perpetuating and accelerating the progression of this pathology. In this article, we describe the contribution of obesity, the factors and mechanisms implicated in the development of the CRMetS. Despite the great knowledge about the CRS, more research is needed to characterize the CRMetS given the global obesity epidemic.