Effects of posture on heart rate variability in non-frail and prefrail individuals: a cross-sectional study

BMC Geriatrics

Table 2 Differences of HRV parameters across postures in non-frail and prefrail individuals

	Non-frail (n = 33)						Prefrail (n = 10)			Comparative difference in HRV of each posture between two groups (p value)
	Statistics			Pairwise comparison^a (P value)			Statistics
	Median (IQR)	χ ²	P value	sd-ly	sd-st	ly-st	Median (IQR)	χ ²	P value
SDNN		8.42	0.015	0.147	0.014	> 0.999		3.80	0.150	-
Standing	24.02 (12.67)						21.82 (26.41)			0.832^c
Sitting	28.37 (12.41)						34.13 (48.91)			0.166^b
Lying	25.05 (11.93)						27.40 (33.27)			0.561^c
RMSSD		12.18	0.002	0.003	0.029	> 0.999		0.60	0.741	-
Standing	21.99 (13.59)						27.25 (25.75)			0.226^c
Sitting	26.90 (15.25)						38.42 (56.82)			0.237^c
Lying	29.54 (16.87)						30.24 (37.53)			0.620^c
LF		7.34	0.025	> 0.999	0.223	0.024		0.80	0.670	-
Standing	189.26 (401.47)						172.69 (342.98)			0.899^c
Sitting	248.40 (291.63)						151.70 (921.76)			0.832^c
Lying	136.29 (217.69)						150.30 (309.98)			0.921^c
HF		13.78	0.001	0.001	0.127	0.290		1.40	0.497	-
Standing	96.34 (221.86)						188.75 (391.81)			0.125^c
Sitting	195.66 (178.32)						330.21 (656.83)			0.286^c
Lying	210.34 (247.38)						241.83 (746.89)			0.435^c
LF/HF		16.78	< 0.001	< 0.001	0.886	0.011		1.40	0.497	-
Standing	2.02 (3.72)						1.21 (1.22)			0.093^c
Sitting	1.26 (2.41)						0.57 (2.38)			0.141^c
Lying	0.77 (1.15)						0.39 (1.30)			0.204^c

SD Standing, ST Sitting, LY Lying, SDNN Standard deviation of all NN intervals, RMSSD Root mean square of the successive differences, LF Low frequency, HF High frequency
^aPairwise comparison across postures in the non-frail group;
^b results by independent t-test;
^c results by Mann–Whitney U test

ISSN: 1471-2318