. Author manuscript; available in PMC: 2014 Dec 1.

Published in final edited form as: Cancer Epidemiol Biomarkers Prev. 2014 Mar 19;23(6):976–985. doi: 10.1158/1055-9965.EPI-13-1210-T

Table 2.

Adjusted geometric mean IGF-I concentrations (nmol/l) and 95% CI in 735 controls.

	n	Geometric mean and 95% CI^a			p_difference^b	p_trend^c
All controls	735	17.1	16.8	17.5	–	–
Sex
Male	164	17.5	16.7	18.3
Female	571	17.0	16.6	17.4	0.33	–
Age at blood collection (years)
< 48	253	19.3	18.6	20.0
48–55	253	16.8	16.2	17.4
≥ 56	229	15.3	14.7	15.9	< 0.0001	< 0.0001
Height (cm)
<160	253	17.2	16.5	17.9
160–164	182	17.5	16.7	18.3
165–169	134	17.6	16.8	18.4
≥170	166	16.3	15.4	17.3	0.27	0.62
Weight (kg)
< 60	187	17.8	17.1	18.6
60–69	247	17.2	16.6	17.9
70–79	162	17.1	16.4	17.9
≥ 80	139	16.1	15.3	16.9	0.04	0.01
BMI (kg/m²)
<22.3	147	17.5	16.7	18.3
22.3–24.4	146	18.1	17.3	19.0
24.4–26.3	147	17.4	16.7	18.3
26.3–28.6	148	16.8	16.0	17.6
> 28.6	147	15.9	15.2	16.6	0.001	0.0003
Waist to hip ratio^d
< 0.76	163	17.6	16.7	18.5
0.76–0.80	160	17.5	16.7	18.4
0.81–0.88	195	17.3	16.6	18.0
≥ 0.89	177	16.5	15.5	17.6	0.58	0.27
Alcohol (g/d)
0	109	16.5	15.6	17.4
> 0–9	381	17.2	16.8	17.7
10–19	133	17.0	16.2	17.9
≥ 20	112	17.5	16.6	18.5	0.42	0.26
Smoking^d
Never	392	17.2	16.7	17.7
Former	184	17.4	16.6	18.1
Current	150	16.7	16.0	17.5	0.51	0.50
Physical activity^d
Inactive	195	16.8	16.1	17.5
Moderately inactive	279	17.1	16.6	17.7
Moderately active or active	241	17.5	16.9	18.1	0.37	0.16
Education^d
Less than secondary	276	16.8	16.2	17.4
Secondary school	275	17.6	17.0	18.2
University degree	176	17.1	16.4	17.8	0.16	0.42
Menopausal status^e
Premenopausal	212	17.2	16.3	18.2
Perimenopausal or unknown	101	16.5	15.6	17.5
Postmenopausal	258	17.2	16.4	18.0	0.44	–
Hormone replacement therapy at blood collection^d,e
No	462	17.1	16.7	17.6
Yes	95	17.2	16.2	18.2	0.94	–
Hours since last meal at blood collection ^d
< 3	310	17.0	16.5	17.6
3–6	117	16.9	16.1	17.8
> 6	277	17.5	17.0	18.1	0.35	0.21

Adjusted for age at blood collection (as a continuous variable), BMI (in fifths based on the distribution in controls), and sex, where the adjustment variable was not the variable of interest. Analysis of weight was not adjusted for BMI.

P values refer to tests of difference between the logarithm of IGF-I concentration in the separate categories (excluding unknowns) calculated by analysis of variance.

P values refer to tests of linear trend calculated by scoring categories with consecutive whole numbers (excluding unknowns).

Unknown for some participants.

In women only.