The Makowiec Generalised Asymmetry Index for assessing asymmetry in heart rate and blood pressure variability in obstructive sleep apnea and healthy men

Abstract The Makowiec Generalised Asymmetry Index, denoted by $${{\,\textrm{MI}\,}}(q)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mrow> <mml:mspace/> <mml:mtext>MI</mml:mtext> <mml:mspace/> </mml:mrow> <mml:mo>(</mml:mo> <mml:mi>q</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> , is a q -parameterised family of directional asymmetry measures for time series, computed from short-term recordings to quantify the imbalance between opposite changes (increases vs. decreases) across fluctuation magnitudes. In this study, we apply the Makowiec Generalised Asymmetry Index to daytime recordings of heart rate variability (HRV) and blood pressure variability (BPV) collected during wakefulness, and we evaluate its usefulness for the characterization of healthy men and obstructive sleep apnea (OSA) patients. Our findings suggest that asymmetry quantified by the Makowiec Generalised Asymmetry Index in daytime for blood pressure signals during wakefulness may serve as a noninvasive marker supporting OSA screening and risk stratification, motivating further validation in larger prospective cohorts.