Table 3.

Adjusted geometric mean levels of sex steroid hormones by average frequency of non-aspirin NSAID use in 1997 and 1999 among 2034 premenopausal women in the Nurses’ Health Study II

	N	Frequency of use (days/week)*				Percent difference†	P-value for trend‡
		0	1	2 to 3	4+
Maximum N		949	567	342	176
Estradiol, pg/mL
Follicular	1422	47	47	46	53	13.2	0.11
Luteal	1553	132	133	133	125	−5.5	0.98
Luteal – ovulatory cycles	1342	136	136	142	130	−4.8	0.77
Free estradiol, pg/mL
Follicular	1386	0.59	0.58	0.58	0.66	13.5**	0.11
Luteal	1537	1.7	1.7	1.7	1.5	−8.2	0.54
Luteal – ovulatory cycles	1325	1.7	1.7	1.8	1.5	−9.6**	0.40
Estrone, pg/mL
Follicular	1442	41	41	41	41	1.1	0.96
Luteal	1601	85	85	87	79	−7.2	0.64
Luteal – ovulatory cycles	1377	85	85	88	78	−8.1**	0.52
Estrone sulfate, pg/mL
Follicular	447	655	663	734	715	9.2	0.24
Luteal	452	1363	1419	1483	1474	8.2	0.28
Luteal – ovulatory cycles	404	1373	1484	1584	1352	−1.6	0.75
DHEA, ng/dL (luteal/random)	479	606	612	685	572	−5.7	0.67
DHEAS, ug/dL (luteal/random)	1254	83	88	84	77	−6.2	0.25
Progesterone, ng/dL (luteal)	1619	1090	1069	1061	960	−12.1	0.20
Progesterone, ng/dL (luteal-ovulatory cycles)	1386	1512	1476	1559	1526	0.9	0.44
Testosterone, ng/dL§	2000	23	23	23	23	−0.5	0.79
Free testosterone, ng/dL§	1939	0.20	0.20	0.19	0.19	−4.3	0.33
Androstenedione, ng/dL§	633	100	98	102	98	−1.9	0.90
Prolactin, ng/mL§	1314	15	14	16	16	2.4	0.24
Ratio of follicular estrone/androstenedione	468	0.44	0.43	0.44	0.39	−12.5	0.36
Ratio of luteal estrone/androstenedione	487	0.76	0.79	0.76	0.65	−15.1	0.29
Ratio of luteal estrone/ androstenedione – ovulatory cycles	435	0.78	0.80	0.77	0.61	−20.9**	0.05
Ratio of follicular estradiol/testosterone	437	2.3	2.2	2.4	2.4	1.7	0.65
Ratio of luteal estradiol/testosterone	1553	5.7	5.6	5.7	5.3	−7.1	0.40
Ratio of luteal estradiol/ testosterone – ovulatory cycles	1334	5.9	5.8	6.2	5.5	−7.5	0.54

NOTE: Adjusted for age at blood draw (continuous), fasting status at blood draw (follicular and luteal phase), date and time of blood draw (follicular and luteal phase), race/ethnicity, parity, age at first birth, BMI (continuous), physical activity, smoking history, duration of oral contraceptive use among past users, alcohol intake, and frequency of use of other analgesics

^*Average of frequency reported in 1997 and 1999

^†Percent difference for highest vs. lowest category of acetaminophen use; calculated using e^β−1

^‡Weighted by the midpoint of each frequency category (0, 1, 2–3, 4–5, or 6+ days of use per week) and calculated using the Wald test

^§Average of follicular and luteal measures, or untimed

^**P<0.05