ABC | Volume 112, Nº4, April 2019

Original Article Philbois et al Obesity and barorreflex sensitivity Arq Bras Cardiol. 2019; 112(4):424-429 use any medication, and were screened at the outpatient clinic of the Gynecology and Obstetrics Clinic of Clinical Hospital of Ribeirao Preto Medical School (HC-FMRP/USP). Polycystic ovary syndrome diagnostic Transvaginal pelvic ultrasound was performed with the Voluson 730 Expert Machine (GE Medical Systems, ZIPF, Austria) to analysis the cysts presence or absence. The ovarian volume and follicles number/size were evaluated, and to calculate ovarian volume the prolate ellipsoid formula (depth x width x length x 0.5) was used. 13 In addition, laboratory tests for serum total testosterone, androstenedione, sex hormone binding globulin and free androgen, prolactin, 17-hydroxyprogesterone and thyrotropin dosed to diagnose exclusion causes. Blood samples were collected during the follicular phase in women with regular ovulatory cycles and at any time in those with irregular cycles. All the above examinations were performed at the Gynecology Laboratory of HC-FMRP, between 07h00 and 09h00 a.m. after a previous 12-hour fast. Ergospirometric test The peak oxygen uptake (VO 2peak ) was assessed by a submaximal exercise test on a treadmill (Super ATLMillenium®, Inbramed/Inbrasport, Brazil) using the Modificated Bruce protocol. The analysis of exhaled gases (VO 2 and VCO 2 ) was performed using a metabolic device (UltimaTM CardiO 2 , Medical Graphics Corp., USA). Anthropometric parameters Body weight and height were obtained using an analogue scale with an altimeter (Welmy), while the body mass index (BMI) values were obtained using the formula W/H 2 , where W is the weight in kilograms and H is the height of the subject in meters. Body composition was evaluated using the bioelectrical impedancemethod (QuantumBIA 101; Q-RJL Systems, Clinton Township, Michigan, USA). The groups were subdivided by their BMI, where the eutrophic groups had BMI < 25 kg/m² and the obese group had BMI > 30 kg/m². 14 Analysis of the heart rate variability and blood pressure variability The spectral analysis of HRV was recorded between 09h00 and 10h00 a.m. according to the following protocol: after remaining in a supine rest position on orthostatic bed for 20 min, the volunteers were passively placed in an inclined position (75° angle) for an additional 10min. HRV for supine and inclined positions (that is, the tilt test) was recorded using an electrocardiogram (AD Instruments, Sydney, Australia), and a time series of RR interval (RRi) was obtained. TheHRVwasobtainedusingtheRRifromelectrocardiographic record (ECG), through the modified MC5 shunt at a sampling frequency of 1000Hz. The BPV data values were obtained from the systolic arterial pressure (SAP) recorded beat-to-beat by means of digital plethysmography recording equipment, FINOMETER (Finometer Pro, Finapress Medical System, Amsterdam, Netherland). The room temperature was kept at 21ºC, the ambient light and the noise were controlled, to prevent any interference with recording of data. The BPV and HRV analyses were performed using custom computer software (CardioSeries v2.0, http://sites.google.com/ site/cardioseries). The values of the RRi and SAP intervals were redesigned in 3 Hz cubic spline interpolation, to normalize the time interval between the beats. The series of interpolated RRi and SAP follow the Welch Protocol; 15 they have been divided into half-overlapping sets of 256 data points, overlapping 50%. The stationary segment was visually inspected and those with artifacts or transients were excluded. Each RRi and SAP stationary segment were submitted to spectral analysis by Fast Fourier Transform (FFT), after Hanning window. The RRi specters were integrated in low frequency (LF; 0.04 - 0.15 Hz) and high frequency (HF; 0.15 - 0.5 Hz) bands and the results are expressed in absolute (ms²) and normalized units (nu), while the SAP specters were integrated only in low frequency band (LF; 0,04 – 0,15Hz) and the results are expressed in absolute units (mmHg 2 ). The HRV normalized values were obtained by calculating the percentage of LF and HF power related to the total power of spectrum minus the very low-frequency band (VLF; < 0.2 Hz). 16,17 In addition, normalization procedure was performed to minimize variations of total power in the absolute value of LF and HF. 18 To assess the sympathovagal balance, LF/HF ratio of RRi variability was also calculated. 19 Spontaneous baroreflex sensitivity The BRS was assessed in time-domain using the sequence technique, as described by Di Rienzo et al., 20 The computer software CardioSeries v2.4 scanned beat-to-beat time series of RRi and SAP values searching for sequences of at least 3 consecutive beats in which; progressive increases in SAP were followed by progressive increases in RRi (up sequence) and progressive decreases in SAP were followed by progressive decreases in RRi (down sequence), with a correlation coefficient (r) between RRi and SAP values higher than 0.8. The mean slope of the linear regression line between the SAP and RRi values of each sequence found determined spontaneous BRS. Statistical analysis In a comparison between two groups the Student's t-test and in comparison of three groups the one ways variance analysis (ANOVA ONE WAY) were performed. The Shapiro‑Wilk test was used to verify de the dates normality; when the distribution was not normal, non-parametric tests were used, the Mann-Whitney test to compare between two groups, and in comparison of three groups, the Kruskal-Wallis test. When the variables had a normal distribution, they were described as mean (± standard deviation), and which had non-parametric distribution they were described as median (± interquartile range). The differences in p were less than 5% (p < 0.05) were considered statistically significant. All statistical tests were performed with Sigma Stat 3.5 software (Systat Software Inc., San Jose, CA, USA). 425