Table 1.

Hormone levels, sexual orientation, and volumetric data

FCsFtM transsexualsMtF transsexualsMCs
n23232122
E2 (pg/ml)110.86 ± 130.82c,d100.00 ± 70.10c,d28.70 ± 17.69a,b26.62 ± 9.66a,b
T (ng/ml)0.29 ± 0.14c,d0.38 ± 0.18c,d4.94 ± 2.22a,b5.31 ± 1.89a,b
P4 (ng/ml)0.81 (0.41/7.44)1.18 (0.72/9.76)c,d0.59 (0.48/0.80)c0.74 (0.61/0.90)c
Sexual orientation (n)
    Females519416
    Males15156
    Bisexual33120
GMV (ml)630.32 ± 52.37c,d633.86 ± 50.58d671.81 ± 48.55a712.89 ± 48.64a,b
WMV (ml)489.57 ± 42.22c,d497.91 ± 54.83c,d538.65 ± 57.19a,b578.45 ± 42.99a,b
CSF (ml)214.45 ± 16.81c,d212.47 ± 22.05c,d242.56 ± 36.29a,b245.16 ± 34.29a,b
TIV (ml)1334.35 ± 83.45c,d1344.24 ± 104.17c,d1453.02 ± 117.71a,b1536.49 ± 113.57a,b
  • E2 and T plasma levels per group are given in means ± SDs. P4 plasma levels are given as medians and quartiles because of non-normal distribution in all groups except for MC (assessed using Kolmogorov–Smirnov test, p < 0.05). Genetic females had significantly higher E2 and significantly lower T plasma levels compared with genetic males (assessed using ANOVA and post hoc t test, p < 0.05, Bonferroni's corrected). No differences were observed between FCs and FtM transsexuals and between MtF transsexuals and MCs (p > 0.1, uncorrected). P4 plasma levels were significantly higher in FtM transsexuals compared with MtF transsexuals and MCs but similar for other group comparisons (assessed using Kruskal–Wallis test and post hoc pairwise comparisons using Mann–Whitney U test, p < 0.01, Bonferroni's corrected). Sexual orientation is given in numbers of participants attracted toward females or males or having a bisexual orientation. Sexual orientation ratings were assessed using a Likert scale from 1 (females) to 7 (males), where values 1 and 2 are combined as attraction towards females, 3–5 denote a bisexual orientation, and 6 and 7 denote attraction towards males. Volumetric data include GMV, WMV, CSF, and the sum of the three volumes, denoted as TIV. As expected, volumes were significantly larger in genetic males than genetic females (assessed using ANOVA and post hoc t test, p < 0.05, Bonferroni's corrected). Interestingly, except for CSF, volumes exhibited the transition FC < FtM < MtF < MC.

  • aSignificant difference to FCs, p < 0.05, Bonferroni's corrected.

  • bSignificant difference to FtM transsexuals, p < 0.05, Bonferroni's corrected.

  • cSignificant difference to MtF transsexuals, p < 0.05, Bonferroni's corrected.

  • dSignificant difference to MCs, p < 0.05, Bonferroni's corrected.