The potential of classic and specific bioelectrical impedance vector analysis for the assessment of sarcopenia and sarcopenic obesity

Figures & data

Table 1 Descriptive and comparative statistics: sarcopenic versus nonsarcopenic individuals

	Men					Women
	Sarcopenic (n = 18)		Nonsarcopenic (n = 54)			Sarcopenic (n = 5)		Nonsarcopenic (n = 123)
	Mean	SD	Mean	SD	p	Mean	SD	Mean	SD	p
Age	81.5	7.0	73.8	5.9	0.000	70.4	2.6	70.8	4.1	0.835
Anthropometric and body composition variables
Height (cm)	169.2	7.9	170.3	6.0	0.552	155.4	7.5	156.2	5.6	0.746
Weight (kg)	65.8	7.3	79.2	9.9	0.000	51.8	10.7	66.0	7.9	0.000
Upper arm crf (cm)	26.6	3.9	30.8	3.2	0.000	27.7	2.8	30.2	2.5	0.030
Waist crf (cm)	88.2	9.4	98.0	9.4	0.000	78.6	5.2	95.0	13.1	0.006
Calf crf (cm)	33.7	2.5	36.9	2.8	0.000	32.1	3.4	35.8	2.7	0.004
BMI (kg/m^2)	23.0	2.1	27.3	2.8	0.000	21.2	2.2	27.1	3.2	0.000
FM (kg)	14.8	4.5	19.5	5.6	0.002	16.7	6.1	24.2	5.1	0.002
FFM (kg)	49.5	4.6	58.0	5.8	0.000	34.6	4.3	40.6	3.9	0.001
FM%	21.9	5.3	23.9	4.7	0.135	30.7	5.4	36.0	4.4	0.011
SMI (kg/m^2)	6.8	0.4	8.3	0.7	0.000	5.2	0.4	6.7	0.6	0.000
Bioelectrical variables
R/H (Ohm/m)	331.0	31.5	272.1	28.4	0.000	426.4	53.1	356.5	31.1	0.000
Xc/H (Ohm/m)	28.6	5.5	29.0	4.9	0.780	39.0	6.6	38.0	5.4	0.664
Z/H (Ohm/m)	332.2	31.5	273.7	28.3	0.000	428.2	53.4	358.6	31.2	0.000
R sp (Ohm • cm)	387.4	70.8	393.5	52.6	0.698	440.5	65.4	490.2	64.4	0.094
Xc sp (Ohm • cm)	33.7	8.8	42.4	10.3	0.002	40.2	7.3	52.5	10.6	0.012
Z sp (Ohm • cm)	388.9	71.1	395.9	53.0	0.662	442.4	65.7	493.0	64.9	0.090
Phase (degrees)	5.0	1.0	6.1	1.1	0.000	5.2	0.5	6.1	0.8	0.015

Abbreviations: BMI, body mass index; crf, circumference; FFM, fat-free mass; FM, fat mass; H, height; R, resistance; SD, standard deviation; SMI, skeletal muscle mass index; sp, specific; Xc, reactance; Z, impedance.

Figure 1 Mean impedance vectors and confidence ellipses from groups with and without sarcopenia.

Abbreviations: D, Mahalanobis distance; H, height; R, resistance; Xc, reactance.

Table 2 Descriptive and comparative statistics: sarcopenic versus sarcopenic obese men

	Sarcopenic (FM% ≤ 23.8; n = 10)		Sarcopenic-obese (FM% > 23.8; n = 8)
	Mean	SD	Mean	SD	p
Age	81.1	6.8	82.0	7.7	0.795
Anthropometric and body composition variables
Height (cm)	171.6	8.9	166.3	5.8	0.165
Weight (kg)	63.8	8.3	68.3	5.3	0.200
Upper arm crf (cm)	25.3	2.8	28.3	4.7	0.110
Waist crf (cm)	83.2	7.6	94.4	7.9	0.007
Calf crf (cm)	33.2	2.6	34.3	2.4	0.394
BMI (kg/m^2)	21.6	1.6	24.7	1.2	0.000
FM (kg)	11.6	3.1	18.9	2.1	0.000
FFM (kg)	50.2	5.4	48.5	3.4	0.438
SMI	6.5	0.3	7.0	0.2	0.002
Bioelectrical variables
R/H (Ohm/m)	327.0	37.3	335.9	23.7	0.567
Xc/H (Ohm/m)	26.8	4.8	30.8	5.7	0.122
Z/H (Ohm/m)	328.1	37.3	337.3	23.8	0.554
R sp (Ohm • cm)	348.7	49.0	435.9	65.2	0.005
Xc sp (Ohm • cm)	28.9	7.3	39.7	6.9	0.006
Z sp (Ohm • cm)	349.9	49.2	437.7	65.2	0.005
Phase (degrees)	4.7	1.0	5.3	0.9	0.269

Abbreviations: BMI, body mass index; crf, circumference; FFM, fat-free mass; FM, fat mass; H, height; R, resistance; SD, standard deviation; SMI, skeletal muscle mass index; sp, specific; Xc, reactance; Z, impedance.

Figure 2 Mean impedance vectors and confidence ellipses from sarcopenic men with FM% higher or lower than the median value of the sex-specific whole sample. (A) Classic BIVA; (B) specific BIVA.

Abbreviations: D, Mahalanobis distance; FM, fat mass; H, height; R, resistance; sp, specific; Xc, reactance.

Figure 3 The individual specific vectors of sarcopenic men plotted on the sex-specific bivariate tolerance ellipse.

Notes: White dots indicate sarcopenic nonobese men; black dots indicate sarcopenic obese men.
Abbreviations: R, resistance; sp, specific; Xc, reactance.