Table 4.

Muscle thickness and echogenicity in adults stratified for sex and age

	Abdomen
	Women						Men
Quartile	Age quartile	n	MT (mm)	EG (%)	MT/SAT	Age		n	MT (mm)	EG (%)	MT/SAT
I	18–25 years	126	16.06 ± 2.47a	55.15 ± 10.42a	1.48 ± 1.10a	18–23 years		273	17.60 ± 2.99a	54.49 ± 11.91a	2.24 ± 1.51a
II	26–38 years	125	14.75 ± 2.89b	57.44 ± 9.25a	0.99 ± 0.68b	24–31 years		284	18.63 ± 3.48b	55.01 ± 11.00a	1.63 ± 1.00b
III	39–49 years	124	13.33 ± 2.72c	66.90 ± 9.74b	0.65 ± 0.54c	32–45 years		266	16.83 ± 2.70c	59.10 ± 12.04b	1.20 ± 0.79c
IV	50–89 years	138	11.71 ± 2.94d	71.37 ± 12.86c	0.47 ± 0.28c	46–84 years		294	15.47 ± 3.46d	63.59 ± 12.47c	1.00 ± 0.92c
	p		< 0.001	< 0.001	< 0.001	p			< 0.001	< 0.001	< 0.001
	Thigh
	Women					Men
I	18–27 years	270	38.31 ± 7.40a	39.14 ± 14.37a	3.06 ± 1.56a	18–22 years		239	40.95 ± 8.19a	37.94 ± 14.59a	6.76 ± 3.34a
II	28–40 years	257	33.05 ± 8.36b	46.74 ± 15.77b	2.26 ± 0.87b	23–30 years		300	42.00 ± 9.46a	43.08 ± 13.66b	6.68 ± 3.10a
III	41–50 years	282	30.99 ± 7.06c	53.91 ± 15.25c	1.93 ± 0.79c	31–45 years		293	40.27 ± 7.69a	43.77 ± 14.07b	3.63 ± 3.66a
IV	51–89 years	276	27.90 ± 7.33d	55.69 ± 17.94c	1.72 ± 0.80c	46–84 years		280	32.32 ± 7.07b	52.35 ± 15.51c	5.19 ± 2.14b
	p		< 0.001	< 0.001	< 0.001	p			< 0.001	< 0.001	< 0.001
Hip						Chest
I	18–33 years	177	22.15 ± 4.75a	61.85 ± 11.84a	2.18 ± 1.36a	18–24 years		202	27.59 ± 6.20a	51.22 ± 11.88a	7.09 ± 3.81a
II	34–43 years	155	20.73 ± 4.26b	64.91 ± 10.90a	2.19 ± 1.46a	25–31 years		202	29.39 ± 7.17a	53.55 ± 12.05a	6.03 ± 3.47b
III	44–51 years	189	21.28 ± 4.26a, b	70.28 ± 12.38b	1.47 ± 0.84b	32–46 years		250	28.57 ± 7.12a	56.87 ± 13.52b	5.06 ± 3.59c
IV	52–74 years	200	20.09 ± 4.33b	72.89 ± 11.65b	1.46 ± 0.86b	47–74 years		236	24.74 ± 7.81b	66.06 ± 13.10c	4.37 ± 3.15c
	p		< 0.001	< 0.001	< 0.001	p			< 0.001	< 0.001	< 0.001
Triceps
I	18–33 years	204	32.17 ± 7.01a	42.55 ± 14.86a	2.40 ± 1.01a
II	34–44 years	208	32.59 ± 6.93a	43.03 ± 14.87a, b	2.13 ± 0.73b
III	45–53 years	210	32.65 ± 5.84a	46.57 ± 14.11b, c	1.88 ± 0.56c
IV	54–89 years	210	31.16 ± 6.03a	49.84 ± 15.68c	1.89 ± 0.59c
	p		0.069	< 0.001	< 0.001

Data are expressed as mean ± SD. Difference between groups were compared by one-way ANOVA, followed by Bonferroni test as post-hoc test. Letters refer to the differences between groups (a = quartile I vs. quartile II, quartile III, and quartile IV; b = quartile II vs. quartile I, quartile III, and quartile IV; c = quartile III vs. quartile I, quartile II, and quartile IV; d = quartile IV vs. quartile I, quartile II, and quartile III). A p value in bold type denotes a significant difference (p < 0.05)

Abbreviations: subcutaneous adipose tissue, SAT; muscle thickness, MT; echogenicity, EG; standard deviation, SD