ABC | Volume 112, Nº4, April 2019

Original Article Philbois et al Obesity and barorreflex sensitivity Arq Bras Cardiol. 2019; 112(4):424-429 Table 2 – Parameters of the spectral analysis of the heart rate variability analysis calculated from the time series RR intervals and systolic arterial pressure variability calculated by the pulse beat-to-heart rate interval obtained between women without and with polycystic ovaries syndrome (PCOS) divided according to the body mass index eutrophic < 25 kg/m 2 and obese > 30 kg/m 2 Rest Control PCOS eutrophic PCOS obese p Ι p ΙΙ HR variability RRi, ms 872 ± 31 879 ± 20.6 812 ± 18.5 † 0.961 0.049 Variance, ms 2 2389 ± 310 2654 ± 341 1851 ± 405 *† 0.971 0.010 LF, ms 2 697 ± 105 720 ± 93 413 ± 80 *† 0.855 0.002 LF, un 40.3 ± 3.8 45.5 ± 3.5 46.4 ± 2.9 0.350 0.850 HF, ms 2 1134 ± 188 1180 ± 229 968 ± 204 *† 0.502 0.014 HF, un 59.6 ± 3.8 54.4 ± 3.5 53.4 ± 2.9 0.350 0.850 LF/HF Ratio 0.79 ± 0.1 0.92 ± 0.1 0.94 ± 0.1 0.474 0.99 BP variability Variance, mmHg 2 22.9 ± 4.3 24.9 ± 2.2 21 ± 2 0.168 0.052 LF, mmHg 2 6.7 ± 1.4 7.6 ± 0.8 5.7 ± 0.7 0.196 0.054 Values expressed as means ± SD: standard deviation; HR: heart rate; RRi: interval between R waves on the electrocardiogram; nu: normalized units; ms²: milliseconds squared; LF: low frequency band; HF: high frequency band; BP: blood pressure; significant difference p < 0.05; (*) vs rest control, (†) vs. rest eutrophic PCOS; P Ι : eutrophic control group vs PCOS eutrophic group; P ΙΙ : PCOS eutrophic group vs. PCOS obese group. Finally, in relation to BPV similarity were found between the studied groups, there are few information since there are no studies in the literature about the behaviour of BPV in PCOS women, the studies found are associated with cardiovascular diseases, unrelated to PCOS. 29-31 Although, PCOS women have a greater predisposition to develop cardiovascular diseases, the present study population were healthy and did not use medication, suggesting that PCOS does not alter the BPV. In addition, the obese PCOS group also did not present differences in relation to eutrophic groups. The studies found on BPV and obesity are contradictory, some suggest an increase 24,32 while others point out a reduction of BPV. 33 However, both suggest that the baroreflex could justify these changes. Meanwhile, in our Table 3 – Parameters of the baroreflex analysis by the calculated sequence series of RR intervals obtained between women with and without polycystic ovary syndrome (PCOS) divided according to the body mass index eutrophic < 25 kg/m 2 and obese > 30 kg/m 2 Rest Control PCOS eutrophic PCOS obese p Ι p ΙΙ Baroreflex Sensitivity Ramp numbers 85 ± 40.7 84.3 ± 39.8 93.7 ± 42.4 0.853 0.379 BEI 0.74 ± 0.13 0.63 ± 0.12* 0.58 ± 0.15* 0.005 0.225 UP, ms/mmHg 15.1 ± 6 18 ± 11 11.7 ± 6.7 *† 0.738 0.008 DOWN, ms/mmHg 16.5 ± 5.6 18.3 ± 8.8 12.7 ± 7.5 *† 0.738 0.004 GAIN, ms/mmHg 16.1 ± 5.5 18.3 ± 9.3 12.3 ± 7.2 *† 0.687 0.003 Values expressed as means ± SD: standard deviation; BEI: baroreflex efficacy index; GAIN: total gain; DOWN: hypotensive responses associated with tachycardia responses; UP: hypertensive responses associated with bradycardic responses; significant difference p < 0.05; (*) vs rest Control, (†) vs rest eutrophic PCOS; P Ι : eutrophic control group vs PCOS eutrophic group; P ΙΙ : PCOS eutrophic group vs. PCOS obese group. study, although the obese PCOS group presented a decrease in BRS, the BPV, apparently, was not affected. In this way, we need more studies to elucidate these findings. Study limitations The present study had some limitations, as insulin, glucose and inflammatory markers dosages absence, which could contribute to results discussion; another limitation was HRV and BPV measure only in supine position. It is possible that during an autonomic provocation test, as in tilt test, we could find different responses in autonomic modulation between the studied groups. However, it is important to note that the study limitations do not invalidate the main findings in supine position and its clinical implications. 427