Table 2.

Comparison of body fat mass (FM) and lean body mass obtained by dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (in-body BIA) in Tibetan adults

	DXA		BIA		Difference *	95 % CI	Percentage of difference (%) †	Spearman r ‡	Lin ρ	Kappa §
	Median	IQR	Median	IQR
1. Total (n 855)
A. Body FM, kg
Total FM	25·31	19·62, 30·83	25·50	18·30, 31·80	–0·15	–8·05, 7·75	–0·58	0·91	0·91	0·68
Truncal FM	12·62	9·32, 16·09	13·70	9·60, 17·00	–0·66	–5·11, 3·79	–5·11	0·91	0·89	0·66
Leg FM	7·73	6·19, 9·70	7·00	5·20, 8·60	1·02	–2·49, 4·53	12·56	0·78	0·74	0·48
Arm FM	3·24	2·40, 4·19	3·50	2·30, 5·00	–0·48	–2·97, 2·01	–14·11	0·88	0·76	0·61
Percentage body fat, %	37·27	31·95, 43·25	36·70	29·50, 43·60	0·91	–9·52, 11·34	2·46	0·85	0·82	0·58
B. Lean body mass, kg
Total lean mass	41·53	35·60, 48·36	42·90	36·80, 50·20	–1·49	–8·74, 5·76	–3·51	0·91	0·89	0·68
Truncal lean mass	20·99	18·16, 24·32	20·80	17·80, 23·90	0·33	–3·84, 4·50	1·55	0·87	0·87	0·58
Leg lean mass	12·52	10·37, 14·93	12·68	10·65, 15·35	–0·24	–3·00, 2·52	–1·88	0·9	0·88	0·70
Arm lean mass	4·56	3·65, 5·63	4·85	3·92, 5·86	–0·28	–1·34, 0·78	–6·04	0·91	0·88	0·68
Percentage lean mass, %	62·05	56·23, 67·02	63·28	56·34, 70·50	–1·74	–12·95, 9·47	–2·80	0·84	0·78	0·57
2. Men (n 391)
A. Body FM, kg
Total FM	23·09	17·24, 28·95	23·60	16·20, 30·30	–0·28	–8·47, 7·91	–1·19	0·90	0·90	0·67
Truncal FM	12·24	8·76, 15·82	13·00	8·50, 16·50	–0·18	–4·65, 4·29	–1·46	0·90	0·91	0·64
Leg FM	6·61	5·27, 8·04	6·30	4·70, 7·80	0·29	–2·67, 3·25	4·30	0·80	0·77	0·50
Arm FM	2·82	2·02, 3·60	3·00	1·80, 4·30	–0·41	–2·84, 2·02	–14·08	0·87	0·72	0·58
Percentage body fat, %	32·18	27·60, 35·77	31·50	24·80, 37·10	0·60	–10·00, 11·20	1·90	0·77	0·74	0·47
B. Lean body mass, kg
Total lean mass	48·64	44·60, 53·01	50·50	46·10, 55·50	–1·65	–9·49, 6·19	–3·37	0·83	0·82	0·51
Truncal lean mass	24·13	21·78, 26·67	24·00	21·90, 26·60	0·22	–4·33, 4·77	0·90	0·79	0·80	0·43
Leg lean mass	15·02	13·69, 16·49	15·47	13·98, 16·89	–0·24	–3·10, 2·62	–1·58	0·80	0·80	0·60
Arm lean mass	5·67	5·19, 6·30	5·90	5·19, 6·74	–0·20	–1·40, 1·00	–3·52	0·85	0·82	0·55
Percentage lean mass, %	66·87	63·65, 71·05	68·52	62·92, 75·22	–1·71	–13·80, 10·38	–2·53	0·75	0·66	0·46
3. Women (n 464)
A. Body FM, kg
Total FM	26·93	21·42, 32·32	27·30	20·15, 33·55	–0·04	–7·68, 7·60	–0·15	0·92	0·92	0·69
Truncal FM	12·94	9·82, 16·18	14·35	10·40, 17·40	–1·05	–5·32, 3·22	–8·03	0·91	0·87	0·69
Leg FM	9·04	7·22, 10·80	7·40	5·80, 9·20	1·64	–1·83, 5·11	17·61	0·78	0·68	0·42
Arm FM	3·67	2·80, 4·59	4·00	2·70, 5·50	–0·54	–3·07. 1·99	–14·13	0·88	0·75	0·62
Percentage body fat, %	42·27	38·29, 45·80	41·55	35·30, 46·85	1·17	–9·10, 11·44	2·81	0·82	0·73	0·54
B. Lean body mass, kg
Total lean mass	36·27	33·40, 40·11	37·50	34·80, 41·50	–1·36	–8·08, 5·36	–3·68	0·81	0·77	0·62
Truncal lean mass	18·58	16·88, 20·79	18·35	16·80, 20·40	0·43	–3·37, 4·23	2·26	0·76	0·74	0·51
Leg lean mass	10·57	9·66, 11·81	10·90	9·89, 12·18	–0·24	–2·93, 2·45	–2·23	0·79	0·73	0·58
Arm lean mass	3·70	3·35, 4·25	4·11	3·61, 4·74	–0·35	–1·27, 0·57	–9·23	0·79	0·66	0·57
Percentage lean mass, %	57·17	53·50, 61·38	58·45	53·19, 64·67	–1·77	–12·2, 8·66	–3·06	0·81	0·72	0·52

Data are presented as median (IQR).

^*Difference was calculated by [DXA value-in-body BIA value].

^†Percentage of difference (%) was calculated by [ ].

^‡ P < 0·001.

^§ Kappa coefficient was calculated by variable values categorised into trisection.