The Aldosterone/Renin Ratio Predicts Cardiometabolic Disorders in Subjects Without Classic Primary Aldosteronism.

BACKGROUND: Aldosterone has been linked with obesity, metabolic syndrome (MetS), pro-inflammatory, and prothrombotic states; however, most studies relate these indicators with primary aldosteronism (PA), excluding non-PA patients. OBJECTIVE: To determine whether aldosterone, renin, or the plasma aldosterone/renin ratio (ARR) are associated with metabolic disorders and inflammatory/vascular biomarkers in a non-PA population. METHODS: We studied 275 patients including adolescents and adults of both genders and measured plasma and urinary aldosterone and determined the plasma renin activity. In all subjects, the presence of MetS was determined according to Adult Treatment Panel III. Renal, vascular, inflammatory, and mineralocorticoid activity biomarkers were evaluated. RESULTS: The ARR correlated with the number of variables of MetS (r = 0.191, P = 0.002), body mass index (BMI; r = 0.136, P = 0.026), systolic blood pressure (r = 0.183, P = 0.002), diastolic blood pressure (r = 0.1917, P = 0.0014), potassium excreted fraction (r = 0.174, P = 0.004), low-density lipoprotein (r = 0.156, P = 0.01), plasminogen activator inhibitor type 1 (r = 0.158, P = 0.009), microalbuminuria (r = 0.136, P = 0.029), and leptin (r = 0.142, P = 0.019). In a linear regression model adjusted by age, BMI, and gender, only the ARR was still significant (r = 0.108, P = 0.05). In a logistic regression analysis, the ARR predicted MetS index (odds ratio (OR) = 1.07 [95% confidence interval (CI) = 1.011-1.131], P= 0.02) even after adjusting for age, BMI, and gender. On the other hand, aldosterone showed no association with MetS or inflammatory markers. CONCLUSION: These results suggest a continuum of cardiometabolic risk beyond the classic PA threshold screening. The ARR could be a more sensitive marker of obesity, MetS, and endothelial damage in non-PA patients than aldosterone or renin alone. Prospective studies are needed to develop future screening cutoff values.

Emerging evidence for the role of neurotransmitters in the modulation of T cell responses to cognate ligands.

Dendritic cells (DCs) are responsible of priming T cells and promoting their differentiation from naïve T cells into appropriate effector cells. Each different phenotype of effector T cells promotes the elimination of a determined kind of pathogen or tumour. Thus, DCs and T cells play critical roles on orchestrating adaptive immune responses against specific threats. Because of their fundamental functions at controlling immunity, DCs and T cells require tight regulatory mechanisms to ensure efficient, but safe, immune responses. Several studies have shown that neurotransmitters, in addition to mediate interactions into the nervous system, can contribute to the modulation of immunity by promoting the communication between nervous and immune systems and in the interaction between different immune cells. Due to the pivotal role that the DC-T cell interaction plays in the development and regulation of adaptive immune responses, it is important to understand how the function of these cells may be regulated by neurotransmitters. Here, we review the emerging role of neurotransmitters as regulators of DC and T cell physiology and also how these molecules, by acting on the DC-T cell interaction, may modulate the fate of T cells and, therefore, the nature of the adaptive immune response. Moreover, we discuss how alterations on the neurotransmitter-mediated immune regulatory mechanisms can contribute to the onset of immune-related disorders. In addition, we discuss potential new targets for the design of strategies for therapies against tumours, autoimmunity and neuro-immune related diseases.