Diet-induced prediabetes: Effects on the systemic and renal renin-angiotensin-aldosterone system

The activity of the renin-angiotensin-aldosterone system (RAAS) in type2 diabetes (T2D) has been characterized. However, the effects of high-fat high carbohydrate diet-induced prediabetes on the RAAS has not been elucidated. Hence, male Sprague Dawley rats were randomly assigned to a normal diet (NPD) group and (HFHC) group (n=6) for 20 weeks to allow for the induction of prediabetes. Blood glucose concentration, mean arterial pressure (MAP), kidney renin, angiotensinogen, angiotensin-converting enzyme (ACE), angiotensin II type 1a receptor (Agtr1a) in addition to kidney and plasma angiotensin II (Ang II), aldosterone were analyzed at week 20 to investigate the RAAS activity. In addition to kidney injury marker (Kim1) and urinary protein, concentrations were analyzed at week 20. The results demonstrated an increase in blood glucose, MAP, relative expression of kidney RAAS components in the HFHC group by comparison to the NPD. Furthermore, an increase in plasma Ang II and aldosterone was accompanied by elevated Kim-1 and albumin excretion in the HFHC diet group by comparison to the NPD group. Thus, we suggest that the RAAS is activated in diet-induced prediabetes and may induce early kidney damage.