IJCS | Volume 33, Nº3, May / June 2020

210 performed with the subjects barefoot and buttocks and shoulders supported in vertical abutment. Total body mass wasmeasuredwith Filizola digital scales, maximum capacity of 150 kg, measured by INMETRO, with its own certificate specifying a margin of error of ± 100 g. To measure waist circumference, flexible metallic Starrett tape was used, with measurement definition of 0.1 cm. Abdominal circumference was taken from the lowest curvature located between the ribs and the iliac crest without compressing the tissues. When the slightest curvature could be identified, measurement was taken two centimeters above the umbilical scar. The cut-off points adopted for abdominal circumference were stipulated according to the degree of risk for cardiovascular diseases, namely ≥ 80 cm for women and ≥ 94 cm for men. 12 BMI was calculated with mass and height measurements, according to the following equation: BMI = mass (kg)/height 2 (cm). The BMI cutoff points adopted were those recommended by the 4 th Brazilian Guideline on Dyslipidemia and Prevention of Atherosclerosis, from the Department of Atherosclerosis of the Brazilian Society of Cardiology, 13 that is, lowweight (BMI < 18.5); eutrophy (BMI 18.5 – 24.9); overweight (BMI 25 – 29.9) and obesity (BMI ≥ 30). Five mL of fasting blood sample were collected for the measurement of CRP, total cholesterol and fractions, triglycerides, glycemia and glutamic pyruvic transaminase. The samples were collected by trained professionals in a laboratory environment appropriate for this type of procedure. PCR was measured by the nephelometry method with plasma serum and precision of 0.1 mg/L. Glycemia, triglycerides, total cholesterol andhigh-density lipoprotein were obtained by the enzymatic colorimetric method of Trinder. Low-density and very low-density lipoprotein valueswere obtained by the Friedewald equation. Pyruvic glutamic transaminase was measured by the Reitman- Frankel colorimetric method. Renin was measured by EDTA plasma kinetic radioimmunoassay method. All volunteers were instructed not to change their diet during the week of collection and to avoid any physical exertion other than usual, as well as not to drink alcohol in the 24 hours prior to the test. NCOCG collectionwas performed between the fifth and tenth day of the menstrual cycle, considering the lowest hormonal fluctuations, and/or on the 28 th day without medication (inactive phase) as recommended by Casazza et al. 14 Sample size calculation Sample adequacy calculation was performed with reference to the plasma renin values. A pilot study with six women, three of each group, in which the mean and standard deviation of plasma renin were, respectively, 1.2 ± 0.5 for the NCOCG and 2.6 ± 2.1 for the COCG. With these data, sample calculation was made in the program GraphPad StatMate 2.0 for Windows, with alpha of 0.05 and beta of 0.8, considering as significant a difference of 0.2 between the groups. The calculation resulted in 21 women in each group. After data collection, a calculationwas carried out to determine sample power, which resulted in 0.98. Statistical analysis Initially, to determine data distribution, symmetry and kurtosis tests and the Shapiro-Wilk test were conducted. Plasma renin levels ​did not show normal behavior and were described in median and interquartile range. The other study variables presented normal behavior and were detailed in mean and standard deviation. Abnormal behavior variables were analyzed using the Mann-Whitney test for independent samples. For the variables of usual behavior, unpaired bidirectional Student’s t test was used. Correlation analyses using Spearman’s test were conducted between plasma renin and fasting lipid profile variables and plasma renin with PCR. All analyses were performed in the statistical package SPSS (Statistical Package for the Social Sciences) version 13.0, adopting a level of significance of 5%. Results Clinical and anthropometric conditions of the sample, 1,970 by 44 women, 22 in each group. Note the homogeneity between the groups, which stands out in the systemic arterial pressure (SBP) (p = 0.02), which is higher in the COCG. A higher level of CRP was also observed in the COCG (< 0.01) (Table 1). Of the COCs used by the volunteers, 100% contained ethinyl estradiol associated with drospirenone 41% (9), gestodene 27% (6), levonorgestrel 14% (3), chlormadinone acetate 9% (2) and desogrestrel 9% (2). Comparing the fasting lipid variables (Table 2), it can be seen that COCG has a higher triglyceride value (p < 0.01) and total cholesterol (p = 0.02) than NCOCG. Oliveira et al. Plasma renin and use of oral contraceptives Int J Cardiovasc Sci. 2020; 33(3):208-214 Original Article