Enhanced basal and disorderly growth hormone secretion distinguish acromegalic from normal pulsatile growth hormone release

Mark L. Hartman, Steven M. Pincus, Michael L. Johnson, D. Hunter Matthews, Lindsay M. Faunt, Mary Lee Vance, Michael O. Thorner, Johannes D. Veldhuis

Research output: Contribution to journalArticlepeer-review

204 Scopus citations


Pulses of growth hormone (GH) release in acromegaly may arise from hypothalamic regulation or from random events intrinsic to adenomatous tissue. To distinguish between these possibilities, serum GH concentrations were measured at 5-min intervals for 24 h in acromegalic men and women with active (n = 19) and inactive (n = 9) disease and in normal young adults in the fed (n = 20) and fasted (n = 16) states. Daily GH secretion rates, calculated by deconvolution analysis, were greater in patients with active acromegaly than in fed (P < 0.05) but not fasted normal subjects. Significant basal (nonpulsatile) GH secretion was present in virtually all active acromegalics but not those in remission or in fed and fasted normal subjects. A recently introduced scale-and model-independent statistic, approximate entropy (ApEn), was used to test for regularity (orderliness) in the GH data. All but one acromegalic had ApEn values greater than the absolute range in normal subjects, indicating reduced orderliness of GH release; ApEn distinguished acromegalic from normal GH secretion (fed, P < 10-12; fasted, P < 10-7) with high sensitivity (95%) and specificity (100%). Acromegalics in remission had ApEn scores larger than those of normal subjects (P < 0.0001) but smaller than those of active acromegalics (P < 0.001). The coefficient of variation of successive incremental changes in GH concentrations was significantly lower in acromegalics than in normal subjects (P < 0.001). Fourier analysis in acromegalics revealed reduced fractional amplitudes compared to normal subjects (P < 0.05). We conclude that GH secretion in acromegaly is highly irregular with disorderly release accompanying significant basal secretion.

Original languageEnglish (US)
Pages (from-to)1277-1288
Number of pages12
JournalJournal of Clinical Investigation
Issue number3
StatePublished - Sep 1994


  • acromegaly
  • algorithms
  • periodicity
  • pituitary neoplasms
  • somatotropin

ASJC Scopus subject areas

  • Medicine(all)


Dive into the research topics of 'Enhanced basal and disorderly growth hormone secretion distinguish acromegalic from normal pulsatile growth hormone release'. Together they form a unique fingerprint.

Cite this