Investigation of Responsiveness to Thyrotropin-Releasing Hormone in Growth Hormone-Producing Pituitary Adenomas

Table 1

Baseline characteristics of 41 patients with GH-producing pituitary adenomas according to their response patterns to the TRH suppression test.

	TRH responder	TRH nonresponder	𝑃
Number of patients	32	9
Age at diagnosis	45±11	34±8	0.002*
BMI, kg/m^2	26.3±3.1^a	27.7±3.8^b	0.336
Basal GH, 𝜇g/L	19.4±28.7	49.3±56.6	0.072
Basal IGF-I, 𝜇g/L^a	890±312^c	1012±452^d	0.411
Peak GH during TST, 𝜇g/L	99.1±100.4	74.6±70.1	0.740
ΔGHmax-min during TST, 𝜇g/L	82.0±94.3	33.9±43.1	0.035*
Tumor volume, mm^3	4886±15854	4834±6338	0.429

Data were expressed as mean ± standard deviation. The Mann-Whitney test was used for the statistical comparison between TRH responders and non-responders.
* 𝑃<0.05.
^aData were available in 16 cases.
^bData were available in 10 cases.
^cData were available in 25 cases.
^dData were available in 13 cases.
Abbreviations: TRH: thyrotropin-releasing hormone; BMI: body mass index; GH: growth hormone; IGF-I: insulin-like growth factor-I; TST: TRH stimulation test.