Classical and alternative pathways of the renin-angiotensin-aldosterone system in regulating blood pressure in hypertension and obese adolescent

Primary hypertension (PH) is the leading form of arterial hypertension (AH) in adolescents. Hypertension is most common in obese patients, where 20 to 40% of the population has elevated blood pressure. One of the most effective mechanisms for regulating blood pressure is the renin–angiotensin–aldosterone system (RAAS). The new approach to the RAAS talks about two opposing pathways between which a state of equilibrium develops. One of them is a classical pathway, which is responsible for increasing blood pressure and is represented mainly by the angiotensin II (Ang II) peptide and, to a lesser extent, by angiotensin IV (Ang IV). The alternative pathway is responsible for the decrease in blood pressure and is mainly represented by angiotensin 1–7 (Ang 1–7) and angiotensin 1–9 (Ang 1–9). Our research study aimed to assess changes in angiotensin II, angiotensin IV, angiotensin 1–7, and angiotensin 1–9 concentrations in the plasma of adolescents with hypertension, with hypertension and obesity, and obesity patients. The Ang IV concentration was lower in hypertension + obesity versus control and obesity versus control, respectively p = 0.01 and p = 0.028. The Ang 1–9 concentration was lower in the obesity group compared to the control group (p = 0.036). There were no differences in Ang II and Ang 1–7 peptide concentrations in the hypertension, hypertension and obesity, obesity, and control groups. However, differences were observed in the secondary peptides, Ang IV and Ang 1–9. In both cases, the differences were related to obesity.