Skip to main content

Table 1 Characteristics of the Norwegian EBBA-I study population overall and by CYP19A1 single-nucleotide polymorphisms rs7172156 and rs749292

From: Gene variations in oestrogen pathways, CYP19A1, daily 17β-estradiol and mammographic density phenotypes in premenopausal women

Study characteristics

Overall means (SD)

rs7172156

rs749292

Major genotype, AA

Heterozygous genotype, Aa

Minor genotype, aa

P -value b

Major genotype, AA

Heterozygous genotype, Aa

Minor genotype, aa

P -value b

  

( n  = 82) a

( n  = 91) a

( n  = 31) a

 

( n  = 62 ) a

( n  = 93) a

( n  = 48) a

 

Age (yr)

30.7 (3.07)

30.2 (3.09)

31.1 (3.12)

30.7 (2.79)

0.149

30.5 (2.99)

31.0 (3.17)

30.4 (3.00)

0.425

Education (total yr)

16.1 (3.01)

15.9 (2.65)

16.2 (3.41)

16.3 (2.73)

0.701

15.8 (3.02)

16.3 (3.15)

16.2 (2.70)

0.603

Reproductive factorsc

         

 Age at menarche (yr)

13.1 (1.36)

13.1 (1.40)

13.2 (1.43)

13.1 (1.04)

0.793

13.0 (1.14)

13.2 (1.52)

13.2 (1.20)

0.536

 Menstrual cycle length (days)

28.3 (3.42)

28.7 (3.01)

28.2 (3.66)

27.8 (3.69)

0.463

28.0 (3.48)

28.3 (3.50)

28.8 (3.22)

0.503

 Number of children

0.91 (1.13)

0.85 (1.17)

0.98 (1.11)

0.84 (1.10)

0.721

0.73 (1.01)

0.99 (1.12)

0.98 (1.28)

0.320

 Weight at birth (g)

3,389 (561)

3,428 (554)

3,369 (585)

3,343 (519)

0.701

3,274 (574)

3,507 (530)

3,328 (556)

0.024

Clinical parameters

         

 BMI (kg/m2)d

24.4 (3.77)

24.4 (3.74)

24.2 (3.73)

25.0 (4.00)

0.606

24.8 (4.66)

24.1 (3.19)

24.3 (3.33)

0.467

 Total tissue fat (%) (DXA)e

34.2 (7.62)

33.9 (7.69)

33.7 (7.92

36.0 (6.41)

0.328

35.1 (8.10)

33.5 (7.51)

33.9 (7.08)

0.455

Serum samplesf

         

 Total cholesterol (mmol/L)

4.45 (0.78)

4.55 (0.84)

4.36 (0.75)

4.40 (0.71)

0.268

4.45 (0.77)

4.33 (0.79)

4.68 (0.76)

0.044

 HDL-C (mmol/L)

1.54 (0.33)

1.55 (0.30)

1.54 (0.36)

1.51 (0.34)

0.833

1.53 (0.32)

1.54 (0.36)

1.55 (0.31)

0.940

Serum hormonesf

         

 Estradiol (nmol/L)

0.15 (0.06)

0.15 (0.06)

0.15 (0.07)

0.14 (0.06)

0.644

0.14 (0.06)

0.15 (0.07)

0.14 (0.06)

0.646

 SHBG (nmol/L)

51.9 (19.5)

51.7 (18.1)

52.7 (22.0)

50.2 (15.3)

0.828

51.6 (17.0)

53.3 (22.8)

50.0 (15.5)

0.626

Salivary hormones g

         

 Midmenstrual estradiol (pmol/L)

18.2 (8.98)

19.4 (9.52)

19.0 (8.81)

12.6 (5.39)

0.001

16.3 (7.67)

18.4 (9.59)

19.8 (9.03)

0.095

Lifestyle factors c

         

 Current smokers (%)

22.3

19.3

22.8

28.1

0.586

13.8

23.2

10.8

0.768

 Alcohol (U/wk)

2.89 (3.38)

3.03 (3.41)

2.84 (3.38)

2.67 (3.38)

0.865

2.52 (3.07)

3.07 (3.41)

3.08 (3.74)

0.561

 Energy intake (kJ/day)

8,093 (1,900)

8,371 (1,837)

8,085 (1,754)

7,381 (2,314)

0.046

7,749 (1,975)

8,087 (2,005)

8,495 (1,480)

0.123

 Previous use of OC (%)

83.4

81.9

85.7

81.2

0.747

81.0

83.9

85.7

0.788

 Leisure time MET (hr/wk)

57.6 (88.6)

68.2 (133)

48.4 (32.0)

56.7 (42.9)

0.337

51.9 (39.4)

63.4 (125)

53.6 (36.8)

0.685

Mammographic density e

         

 Total area (cm2)

137 (62.5)

131 (64.9)

137 (59.6)

155 (62.8)

0.209

149 (69.5)

132 (61.1)

129 (52.6)

0.161

 Absolute density (cm2)

34.7 (23.4)

34.7 (22.4)

32.8 (23.8)

40.7 (24.4)

0.283

39.1 (26.2)

33.5 (23.8)

32.3 (17.4)

0.238

 Percent density (%)

29.8 (19.0)

31.5 (19.0)

28.6 (20.4)

28.8 (14.5)

0.594

30.1 (18.1)

29.8 (20.2)

29.9 (17.9)

0.995

  1. Numbers in parentheses are standard deviations (SDs). BMI, body mass index; E2, 17β-estradiol; DXA, Dual-energy X-ray absorptiometry; HDL-C, High-density lipoprotein-cholesterol; LDL-C, Low-density lipoprotein-cholesterol; MET, Metabolic equivalent; OC, Oral contraceptives; SHBG, Sex hormone-binding globulin. aNumbers may vary due to missing information. bOneWay ANOVA or χ2 test, significance level P < 0.05. cQuestionnaires. dMeasurements at days 1 to 5 after onset of menstrual cycle. eMeasurements at days 7 to 12 after onset of menstrual cycle. fSerum samples in early follicular phase: days 1 to 5 after onset of menstrual cycle. gDaily salivary samples throughout one entire menstrual cycle.