The effect of circulating estradiol concentrations on gonadotropin secretion in young and old castrated male-to-female transsexuals

Figures & data

Table I.  Parameters at baseline, comparing the age group.

	Young	Old	p
Age (years)	37.6 ± 6.2	68.1 ± 7.0	0.000
BMI (kg/m^2)	25.7 ± 4.8	26.8 ± 5.1	0.595
Time of castration (years)	5.5 ± 4.0	17.7 ± 9.4	0.001
E2 (pmol/l)	483 ± 496	334 ± 318	0.419
T (nmol/l)	0.70 ± 0.45	0.48 ± 0.34	0.222
SHBG (nmol/l)	66.6 ± 44.0	71.3 ± 40.2	0.801
LH (IU/l)	18.6 ± 15.9	9.2 ± 7.2	0.089
FSH (IU/l)	34.1 ± 33.2	15.7 ± 13.6	0.108

Table II.  Parameters at baseline, comparing estradiol use.

	Oral estradiol intake	Transdermal estradiol application	p
Age (years)	49.5 ± 16.7	61.7 ± 15.2	0.121
BMI (kg/m^2)	25.0 ± 4.7	28.7 ± 4.5	0.100
Time of castration (years)	10.8 ± 7.6	13.0 ± 12.7	0.678
E2 (pmol/l)	477 ± 473	259 ± 188	0.259
T (nmol/l)	0.65 ± 0.45	0.47 ± 0.28	0.370
SHBG (nmol/l)	73.0 ± 45.0	61.3 ± 33.5	0.553
LH (IU/l)	16.8 ± 14.0	7.4 ± 7.0	0.114
FSH (IU/l)	30.7 ± 29.4	11.8 ± 10.3	0.118

Table III.  Hormone and SHBG levels in studied subjects (mean ± SD), grouped by study week and age group.

Age group	E2 100 μg patch/week 1		E2 50 μg patch/week 2		E2 25 μg patch/week 3		No patch/week 4
	Young	Old	Young	Old	Young	Old	Young	Old
E2 (pmol/l)	184 ± 64	149 ± 84	137 ± 52	74 ± 47	90 ± 32	38 ± 31	20 ± 13	19 ± 24
Bioavailable E2 (pmol/l)	114 ± 43	94 ± 74	89 ± 41	47 ± 36	61 ± 27	25 ± 25	14 ± 11	13 ± 19
SHBG (nmol/l)	58 ± 28	69 ± 36	52 ± 24	66 ± 29	44 ± 15	68 ± 29	44 ± 17	66 ± 32
LH (IU/l)	12 ± 11	8.8 ± 8.0	11 ± 8.7	10 ± 9.4	17 ± 7.0	12 ± 12	27 ± 9.6	14 ± 12
FSH (IU/l)	25 ± 22	15 ± 13	29 ± 17	18 ± 16	41 ± 20	23 ± 19	68 ± 31	30 ± 20

Figure 1.  Box plot of bioavailable estradiol in young (black) and old (grey) castrated men per study week.

Figure 2.  Box plot of LH levels in young (black) and old (grey) castrated men per study week. Significant difference between the age groups only in the week when no patch was applied (p = 0.02).

Figure 3.  Box plot of FSH levels in young (black) and old (grey) castrated men per study week. Significant difference between the age groups only in the week when no patch was applied (p = 0.004).

Figure 4.  The suppressive effect of estradiol on LH (left) and FSH (right) levels. The levels of LH and FSH from the no patch week were used as reference for 100% amount.