Table 3– Results according to sleep apnoea severity
AHI <5 events·h−1AHI 5–14 events·h−1AHI ≥15 events·h−1p-value
Subjects n13614076
NT-proBNP pg·mL−184 (45–184)102 (57–191)135 (69–261)0.062
6-min walking distance m560±81551±84535±870.134
Echocardiography
 Ejection fraction % of respective population59±860±1158±90.268
 Ejection fraction <50%8.86.413.20.249
 IVS mm11.7±1.612.2±1.9*12.4±1.8*0.006
 LVPW mm10.8±1.411.2±1.4*11.3±1.4*0.006
 Left ventricular mass g220±65230±58254±76*,#0.001
 Left ventricular mass index g·m−2113±26119±26125±290.012
 LVEDD mm50±650±552±7*,#0.015
 Left ventricular end-systolic volume mL41±2039±1545±270.166
 Left ventricular end-systolic volume index mL·m−221±920±722±110.366
 Left ventricular end-diastolic volume mL95±3191 ±2599±320.257
 Left ventricular end-diastolic volume index mL·m−249±1347±1149±140.635
 Left atrial volume mL48±1950±1657±210.110
 LAVI mL·m−224±826±828±80.254
 E/A ratio1.0±0.31.0±0.31.0±0.40.418
 EDCT ms240±69257±76253±700.153
 IVRT ms98±17100±1996±190.291
 e′ medial5.9±1.75.6±1.55.6±1.60.151
 e′ lateral8.3±2.67.8±2.27.4±2.1*0.021
 E/e′ mean ratio11.0±3.611.7±3.512.7±5.3*0.011
  • Data are presented as median (interquartile range) or mean±sd, unless otherwise stated. AHI: apnoea/hypopnoea index; NT-proBNP: N-terminal pro-brain natriuretic peptide; IVS: interventricular septum; LVPW: left ventricular posterior wall; LVEDD: left ventricular end-diastolic diameter; LAVI: left atrial volume index; E/A ratio: ratio of early to late pulsed wave Doppler of diastolic ventricular filling; EDCT: E wave deceleration time; IVRT: isovolumetric relaxation time; e′: tissue Doppler of early diastolic ventricular filling; E/e′: ratio of early diastolic pulsed wave Doppler to early diastolic Tissue Doppler (mean of medial and lateral mitral annulus). *: p<0.05 versus AHI <5 events·h−1; #: p<0.05 versus AHI 5–14 events·h−1.