ABC | Volume 110, Nº2, February 2018

Original Article Casali et al Short & very short-term blood pressure variability Arq Bras Cardiol. 2018; 110(2):157-165 Time-rate (24h-ABPM) was correlated with delta_LF/HF (FBPM, 24 hours, and daytime). In DH group, although some correlations were statistically significant, none of them represented large-effect sizes (correlation coefficient of 0.50 or higher). Moderate-effect sizes (correlation coefficient near 0.50) were shown for total BP variability (24h-ABPM), coefficient of variation, and standard deviation (FBPM, 24 hours, and daytime). There was no correlation between short-term (24h-ABPM) and very short-term variability (FBPM) parameters, considering delta indices for DH subjects. Discussion BP and HR variabilities were assessed in healthy and diabetic-hypertensive individuals by two well-known methods—24h-ABPM and FBPM—, seeking potential concordance between results of each method, which was indeed observed. Correlations between indices of BP variability (time rate with LF component BPV, standard deviation with LF component BPV, and coefficient of variation Table 4 – Correlation between very short- (FBPM) and short-term (24h-ABPM) BP variability parameters – DH group. 24-hour Daytime Nighttime Time-rate Coefficient of variation Standard deviation Time-rate Coefficient of variation Standard deviation Time-rate Coefficient of variation Standard deviation AT REST Total BPV R 0.03 0.280 0.240 0.210 0.261 0.286 -0.036 0.026 0.103 (P) 0.486 0.046 0.090 0.152 0.064 0.042 0.807 0.857 0.471 LF component BPV R 0.330 0.356 0.347 0.332 0.185 0.259 0.234 0.278 0.337 (P) 0.022 0.010 0.013 0.021 0.194 0.066 0.110 0.048 0.016 Alpha index R -0.371 -0.250 -0.264 -0.420 -0.171 -0.222 -0.158 -0.151 -0.220 (P) 0.009 0.076 0.062 0.003 0.229 0.117 0.283 0.289 0.122 AFTER SYMPATHETIC ACTIVATION (Standing‑up maneuver) Total BPV R 0.192 0.403 0.413 0.269 0.447 0.486 0.033 0.029 0.176 (P) 0.191 0.003 0.003 0.065 0.001 0.000 0.826 0.841 0.218 LF component BPV R 0.140 0.274 0.283 0.156 0.166 0.245 0.042 0.090 0.134 (P) 0.341 0.052 0.044 0.290 0.244 0.083 0.777 0.532 0.349 Alpha index R -0.359 -0.206 -0.263 -0.405 -0.098 -0.192 -0.172 -0.306 -0.336 (P) 0.012 0.146 0.063 0.004 0.493 0.177 0.243 0.029 0.016 DELTA INDEXES (AT REST/AFTER SYMPATHETIC ACTIVATION) Delta_HRV R 0.054 0.018 -0.011 -0.003 -0.045 -0.058 0.055 0.106 0.059 (P) 0.714 0.901 0.938 0.985 0.754 0.688 0.711 0.460 0.679 Delta_LF/HF R -0.015 -0.152 -0.099 -0.037 -0.215 -0.190 0.088 0.097 0.083 (P) 0.922 0.291 0.492 0.807 0.134 0.186 0.557 0.501 0.568 Delta LF_BPV R -0.162 -0.105 -0.077 -0.210 -0.093 -0.070 -0.069 -0.070 -0.097 (P) 0.271 0.464 0.590 0.152 0.515 0.623 0.643 0.623 0.500 BPV: blood pressure variability, LF: low frequency, LF_BPV: LF component of BPV; DH: Diabetic-Hypertensive. Statistic correlation expressed as correlation coefficient (R) and significance (P), obtained by Spearman’s test with total BPV and alpha index) and indices of HR variability (time rate with delta_LF/HF) were high and significant in controls. On the other hand, few moderate correlations were observed in diabetic-hypertensive patients only after sympathetic activation. As expected, there were differences between 24h-ABPM indices obtained in total, daytime, and nighttime periods because of the well-known circadian variations of BP levels 26,27 which occurred in both healthy and diabetic-hypertensive subjects. This leads us to conclude that data were adequately collected. Moreover, periods division showed differences between groups only when data collection included the day period, in accordance with previous reports. 28,29 Additionally, indices obtained from FBPM had lower HRV, LF component of HRV, and alpha index (at rest and after standing-up maneuver) in DH vs. C group. This finding suggests the presence of autonomic neuropathy in the diabetic population, as expected and previously demonstrated by evaluating similar indices. 30,31 162