The Significance of Body Mass Index in Calculating the Cut-Off Points for Low Muscle Mass in the Elderly: Methodological Issues

Table 1

Basic characteristics of body composition of young healthy females included in the study (reference group) and elderly ones (studied group).

Characteristics	Females 20–30 years; (); mean ± SD	Range	Elderly females; (); mean ± SD	Range	P value
Age, (years)	22.29 ± 2.44	20.00–30.00	74.93 ± 8.53	60.00–90.00	<0.001
Weight, (kg)	59.97 ± 9.22	41.60–96.90	65.67 ± 14.59	43.20–102.20	<0.01
Height, (m)	1.66 ± 0.06	1.46–1.86	1.54 ± 0.06	1.38–1.71	<0.001
BMI, (kg/m^2)	21.67 ± 3.00	16.32–36.39	27.67 ± 5.49	18.98–41.30	<0.001
Muscle mass, (kg)^*	23.92 ± 3.00	16.80–39.80	21.01 ± 3.20	15.30–30.20	<0.001
Fat free mass, (kg)^*	43.85 ± 5.05	32.00–70.00	39.37 ± 5.29	29.80–54.80	<0.001
Appendicular lean mass, (kg)	18.18 ± 2.49	11.46–29.55	15.09 ± 2.77	10.02–22.08	<0.001
Fat mass, (kg)^*	16.12 ± 6.03	5.70–47.90	26.30 ± 10.46	10.90–53.10	<0.001
Percent body fat^*, (%)	26.23 ± 6.18	12.10–50.10	38.72 ± 7.72	22.00–52.00	<0.001
Total body water^*, (L)	32.08 ± 3.72	19.10–51.10	28.95 ± 3.91	21.90–40.10	<0.001
ALM index, (kg/m^2)	6.55 ± 0.59	5.10–9.27	6.34 ± 0.89	4.61–8.27	<0.001

BMI: body mass index; ALM: appendicular lean mass; SD: standard deviation; ^*these parameters are from the whole body.