Limits...
Pituitary-hormone secretion by thyrotropinomas.

Roelfsema F, Kok S, Kok P, Pereira AM, Biermasz NR, Smit JW, Frolich M, Keenan DM, Veldhuis JD, Romijn JA - Pituitary (2009)

Bottom Line: PRL secretion was increased in one patient, but all patients had a significant cross-correlation with TSH and showed decreased PRL regularity.Cross-ApEn synchrony between TSH and GH did not differ between patients and controls, but TSH and PRL synchrony was reduced in patients.In addition, abnormalities in GH and PRL secretion exist ranging from decreased (joint) regularity to overt hypersecretion, although not always clinically obvious, suggesting tumoral transformation of thyrotrope lineage cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Albinusdreef 2 NL2333ZA, Leiden, The Netherlands. f.roelfsema@lumc.nl

ABSTRACT
Hormone secretion by somatotropinomas, corticotropinomas and prolactinomas exhibits increased pulse frequency, basal and pulsatile secretion, accompanied by greater disorderliness. Increased concentrations of growth hormone (GH) or prolactin (PRL) are observed in about 30% of thyrotropinomas leading to acromegaly or disturbed sexual functions beyond thyrotropin (TSH)-induced hyperthyroidism. Regulation of non-TSH pituitary hormones in this context is not well understood. We there therefore evaluated TSH, GH and PRL secretion in 6 patients with up-to-date analytical and mathematical tools by 24-h blood sampling at 10-min intervals in a clinical research laboratory. The profiles were analyzed with a new deconvolution method, approximate entropy, cross-approximate entropy, cross-correlation and cosinor regression. TSH burst frequency and basal and pulsatile secretion were increased in patients compared with controls. TSH secretion patterns in patients were more irregular, but the diurnal rhythm was preserved at a higher mean with a 2.5 h phase delay. Although only one patient had clinical acromegaly, GH secretion and IGF-I levels were increased in two other patients and all three had a significant cross-correlation between the GH and TSH. PRL secretion was increased in one patient, but all patients had a significant cross-correlation with TSH and showed decreased PRL regularity. Cross-ApEn synchrony between TSH and GH did not differ between patients and controls, but TSH and PRL synchrony was reduced in patients. We conclude that TSH secretion by thyrotropinomas shares many characteristics of other pituitary hormone-secreting adenomas. In addition, abnormalities in GH and PRL secretion exist ranging from decreased (joint) regularity to overt hypersecretion, although not always clinically obvious, suggesting tumoral transformation of thyrotrope lineage cells.

Show MeSH

Related in: MedlinePlus

Serum GH concentration profiles of 5 patients with a thyrotropinoma and 2 healthy representative controls (left upper panel, continuous line male subject, dashed line female subject). Note the difference in scales of the abscissa. The GH secretion patterns of patients #1–3 are clearly abnormal, while that of patient #6 only shows an increased basal (interpulse) level
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2712623&req=5

Fig4: Serum GH concentration profiles of 5 patients with a thyrotropinoma and 2 healthy representative controls (left upper panel, continuous line male subject, dashed line female subject). Note the difference in scales of the abscissa. The GH secretion patterns of patients #1–3 are clearly abnormal, while that of patient #6 only shows an increased basal (interpulse) level

Mentions: With the exception of one patient, GH secretion as also analyzed. The results are summarized in Table 2 and the GH concentration profiles are displayed in Fig. 4. Serum IGF-I concentrations and standard deviation scores were increased in patients 1–3, of whom only patient 2 had clinically active disease. However, patients 1 and 3 had (slightly) increased GH secretion, with respect to age and both had a definitely abnormal GH secretion profile, compared with the other two patients and examples of healthy controls (Fig. 4). Approximate entropy for GH secretion was only increased in the patient with active acromegaly.Table 2


Pituitary-hormone secretion by thyrotropinomas.

Roelfsema F, Kok S, Kok P, Pereira AM, Biermasz NR, Smit JW, Frolich M, Keenan DM, Veldhuis JD, Romijn JA - Pituitary (2009)

Serum GH concentration profiles of 5 patients with a thyrotropinoma and 2 healthy representative controls (left upper panel, continuous line male subject, dashed line female subject). Note the difference in scales of the abscissa. The GH secretion patterns of patients #1–3 are clearly abnormal, while that of patient #6 only shows an increased basal (interpulse) level
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2712623&req=5

Fig4: Serum GH concentration profiles of 5 patients with a thyrotropinoma and 2 healthy representative controls (left upper panel, continuous line male subject, dashed line female subject). Note the difference in scales of the abscissa. The GH secretion patterns of patients #1–3 are clearly abnormal, while that of patient #6 only shows an increased basal (interpulse) level
Mentions: With the exception of one patient, GH secretion as also analyzed. The results are summarized in Table 2 and the GH concentration profiles are displayed in Fig. 4. Serum IGF-I concentrations and standard deviation scores were increased in patients 1–3, of whom only patient 2 had clinically active disease. However, patients 1 and 3 had (slightly) increased GH secretion, with respect to age and both had a definitely abnormal GH secretion profile, compared with the other two patients and examples of healthy controls (Fig. 4). Approximate entropy for GH secretion was only increased in the patient with active acromegaly.Table 2

Bottom Line: PRL secretion was increased in one patient, but all patients had a significant cross-correlation with TSH and showed decreased PRL regularity.Cross-ApEn synchrony between TSH and GH did not differ between patients and controls, but TSH and PRL synchrony was reduced in patients.In addition, abnormalities in GH and PRL secretion exist ranging from decreased (joint) regularity to overt hypersecretion, although not always clinically obvious, suggesting tumoral transformation of thyrotrope lineage cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Endocrinology and Metabolic Diseases, Leiden University Medical Center, Albinusdreef 2 NL2333ZA, Leiden, The Netherlands. f.roelfsema@lumc.nl

ABSTRACT
Hormone secretion by somatotropinomas, corticotropinomas and prolactinomas exhibits increased pulse frequency, basal and pulsatile secretion, accompanied by greater disorderliness. Increased concentrations of growth hormone (GH) or prolactin (PRL) are observed in about 30% of thyrotropinomas leading to acromegaly or disturbed sexual functions beyond thyrotropin (TSH)-induced hyperthyroidism. Regulation of non-TSH pituitary hormones in this context is not well understood. We there therefore evaluated TSH, GH and PRL secretion in 6 patients with up-to-date analytical and mathematical tools by 24-h blood sampling at 10-min intervals in a clinical research laboratory. The profiles were analyzed with a new deconvolution method, approximate entropy, cross-approximate entropy, cross-correlation and cosinor regression. TSH burst frequency and basal and pulsatile secretion were increased in patients compared with controls. TSH secretion patterns in patients were more irregular, but the diurnal rhythm was preserved at a higher mean with a 2.5 h phase delay. Although only one patient had clinical acromegaly, GH secretion and IGF-I levels were increased in two other patients and all three had a significant cross-correlation between the GH and TSH. PRL secretion was increased in one patient, but all patients had a significant cross-correlation with TSH and showed decreased PRL regularity. Cross-ApEn synchrony between TSH and GH did not differ between patients and controls, but TSH and PRL synchrony was reduced in patients. We conclude that TSH secretion by thyrotropinomas shares many characteristics of other pituitary hormone-secreting adenomas. In addition, abnormalities in GH and PRL secretion exist ranging from decreased (joint) regularity to overt hypersecretion, although not always clinically obvious, suggesting tumoral transformation of thyrotrope lineage cells.

Show MeSH
Related in: MedlinePlus