IJCS | Volume 33, Nº3, May / June 2020

212 Figure 1 - Median and Interval quartiles of Plasma Renin from the studied groups. Plasma Renin No Combined Oral Contraceptive Group Combined Oral Contraceptive Group thus reducing BP. In the study by Suthipongse and Taneepanichskul, 8 120 women were randomized with drospirenone and ethinyl estradiol or levonorgestrel and ethinyl estradiol. The group using drospirenone showed a mean decrease in SBP of 4 mmHg and mean BP lower than the levonorgestrel group. An integrative literature review conducted on articles published between 2012 and 2016, found the same result. 9 In our study, we found that renin values ​are threefold higher in the COC group. However, because of the sample size, it was not possible to compare the effect of progestin type on plasma renin values. Increased plasma renin levels increase RAAS activity, which culminates in increased BP. In addition, plasma renin increase is not only associated with increased BP. According to the Framingham study, high plasma renin levels, in addition to increasing RAAS activity, directly contribute to vascular dysfunction, raising the all-cause mortality rate in the general population. 11 Increased RAAS activity activates other cellular processes, inducing the generation of reactive oxygen species and vascular inflammation that contribute not only to the genesis of hypertension, but also to accelerate damage in the so-called target organs (heart, brain and kidneys). 12 Studies on inflammation and SAH show a close relationship between infiltration of inflammatory cells and oxidative stress in vascular tissues. RAAS triggers oxidative stress because it stimulates the production of reactive oxygen species such as oxygen superoxide (O2-) and hydrogen peroxide (H2O2). Some studies have contributed to clarifying how RAAS causes elevation in ROS production. Both angiotensin II and aldosterone are capable of inducing the expression of the nicotinamide adenine dinucleotide phosphate oxidase enzyme (NADPHoxidase), amajor producer of superoxide anion in vascular tissues. 15 Nitric oxide, responsible for vasodilation, may have its action altered by the presence of ROS, resulting in increased BP and cellular injury phenomena. This impairment affects the mechanisms of tissue repair and stimulate hyperplasia, hypertrophy and apoptosis, as well as the development of arterial vascular fibrosis. 17 The findings of our study hypothesized that increased renin production in women taking COC promotes increased inflammation and consequently oxidative stress. This Oliveira et al. Plasma renin and use of oral contraceptives Int J Cardiovasc Sci. 2020; 33(3):208-214 Original Article