Hormone Secretion By Pituitary Adenomas Is Characterized By Increased Disorderliness and Spikiness

Presentation Number: SAT-0650
Date of Presentation: June 21st, 2014

Ferdinand Roelfsema*1, Alberto M. Pereira1, Nienke R. Biermasz2 and Johannes D Veldhuis3
1Leiden University Medical Center, Leiden, Netherlands, 2Leiden University Medical Center, Netherlands, 3Mayo Clinic, Rochester, MN


Previous investigations by our group have shown that hormone secretion by hyperfunctioning pituitary tumors is characterized by increased basal (nonpulsatile) secretion, enhanced pulse frequency, amplified pulse mass and increased disorderliness (1-3). Tools for analyzing patterns of hormone secretion have advanced and improved. A recently described tool is spikiness, which quantitates short-lived sudden increases in hormone levels (4, 5). In addition, the algorithm for ApEn was refined and more precise, and re-named JackApEn.  We aimed to explore whether these new tools contribute to new insights in the pathological secretion of hormones. Consequently, we reanalyzed available data files of 24-hour hormone profiles (10-min interval) of 24 patients with active acromegaly, 17 with untreated prolactinoma and 20 patients with active Cushing’s disease, and compared with matched controls. Spikiness was increased in active acromegaly,  Cushing’s disease and  prolactinoma compared with healthy controls : Acromegaly 0.501 ±  0.029 vs 0.394 ± 0.013, P= 0.002; Cushing’s disease ACTH 0.577 ± 0.027 vs 0.512 ± 0.017, P = 0.04, cortisol 0.758 ± 0.045 vs 0.417 ± 0.014, P<0.0001; prolactinoma 0.776 ± 0.052 vs 0.379 ± 0.016, P<0.0001). Likewise, Jack ApEn was increased in the three groups of patients. In acromegaly, Jack ApEn was 1.349 ± 0.066 vs 0.456 ± 0.032, P<0.0001; in prolactinoma patients 1.808 ± 0.084 vs 0.990 ± 0.038, P<0.001. JackApEn for ACTH in Cushing’s disease was 1.563 ± 0.042 vs 0.992 ±0.047, P<0.0001 and for cortisol 1.687 ± 0.061 vs 1.062 ± 0.027. The present data confirm previous reports on disorganized hormone secretion by hyperfunctioning pituitary adenomas. The new finding is increased spikiness in these patient groups, reflecting sudden short-lived serum (plasma) hormone increases. The mechanisms behind increased disorderliness and spikiness are not established yet, but may include diminished feedback signaling and loss of anatomical cell-cell interaction of the endocrine network in the adenoma (6).


Nothing to Disclose: FR, AMP, NRB, JDV