Table 2.

Baseline characteristics according to total antioxidant capacity in participants by quartile and menopausal status

Characteristic	Premenopause (n 568)					Postmenopause (n 291)
	Q1	Q2	Q3	Q4	P value	Q1	Q2	Q3	Q4	P value
	n 142	n 142	n 142	n 142		n 73	n 73	n 73	n 72
Median score	5·62	9·26	12·03	19·66	<0·001	6·47	9·73	12·68	19·16	<0·001
Age (years)	37·09	41·19	41·24	41·30	<0·001	52·95	53·56	56·34	56·80	0·07
BMI (kg/m2)	26·81	27·30	28·80	28·69	0·02	29·46	28·74	29·37	30·52	0·07
Physical activity (MET h/weak)	24·99	20·00	23·15	26·93	0·26	22·34	21·96	19·55	29·75	0·33
Age at menarche (years)	13·21	13·23	13·07	12·98	0·71	13·02	12·87	13·05	13·30	0·78
Educational level, n%
Un university	77·5	80·3	83·8	84·5	0·38	90·4	82·2	91·8	88·9	0·28
University	22·5	19·7	16·2	15·5		9·6	17·8	8·2	11·1
Married (%)	85·21	85·21	85·21	85·92	0·54	82·19	84·93	76·71	77·78	0·89
Family history of breast cancer (yes) (%)	5·63	3·52	6·34	5·63	0·73	9·59	6·85	5·48	4·17	0·58
Oral contraceptive use (yes) (%)	54·47	58·21	61·36	58·27	0·63	47·89	54·93	59·15	60·61	0·43
Postmenopausal hormone use (%)	0·70	0	1·41	0	0·29	2·74	0	5·48	2·78	0·25
Current smoking (%)	5·63	0·70	0	4·93	0·005	2·74	1·37	6·85	16·67	0·006
Alcohol intake (%)	6·34	4·23	2·13	4·93	0·37	2·74	4·11	1·37	6·94	0·33
Fertility treatment (%)	4·93	3·52	5·63	5·63	0·82	8·22	2·74	5·48	8·33	0·44
Nulligravid (%)	19·72	17·61	14·79	14·08	0·55	4·11	6·85	13·70	9·72	0·19
Parity
Nulliparous/missing	40·85	44·37	42·25	37·32	0·04	34·25	42·47	50·68	54·17	0·11
1	18·31	8·45	10·56	9·15		5·48	5·48	1·37	4·17
2–3	37·32	34·51	36·62	42·25		23·29	30·14	16·44	22·22
≥4	3·52	12·68	10·56	11·27		36·99	21·92	31·51	19·44

Values are mean (sd) or percentages.

χ ² Test for ordinal qualitative variables and ANOVA for continuous variables.