Power spectral analysis of heart rate variability in the two groups of subjects

HRV indices, expressed as mean (SD), in baseline conditions and during and in response to (Δ) provocative tests (active standing, paced breathing). Significant results are shown in bold typeface.astatistical analyses performed on log 10 - transformed variable;bcorrection for multiple testing by means of the Benjamini-Hochberg procedure with a 5% False Discovery Rate (FDR);cadjustment for potential confounders by means of multiple linear regression (see text for details). NC: normal cognition (controls); MCI: mild cognitive impairment; n.u.: normalized units; LFn: low frequency power (normalized); HFn: high frequency power (normalized); LF/HF: LF to HF ratio; Δ standing: standing HRV index - baseline HRV index; Δ paced breathing: paced breathing HRV index - baseline HRV index.