Participation of the hypothalamus-hypophysis axis in the sympathetic activation of human obesity

Guido Grassi, Gino Seravalle, Raffaella Dell'Oro, Carlo Turri, Lucia Pasqualinotto, Manuela Colombo, Giuseppe Mancia

Research output: Contribution to journalArticle


Previous studies have shown that hypothalamic and hypophyseal factors are involved in the acute sympathoexcitation induced by a variety of laboratory stimuli. Whether a chronic condition of sympathetic activation, such as that characterizing human obesity, is also dependent on these factors has never been investigated. In 40 normotensive obese subjects ([mean±SEM] age, 39.1±0.8 years) we measured blood pressure (Finapres), heart rate (ECG), and postganglionic muscle sympathetic nerve activity (MSNA) (microneurography). In 20 subjects measurements were repeated, according to a double-blind randomized sequence, after a midnight oral dose of dexamethasone (1 mg) (n=10) or placebo (n=10), while in the remaining subjects they were performed again after 1 week of a daily evening oral administration of 1 mg of dexamethasone (n=10) or placebo (n=10). The same protocol was performed in 16 age-matched lean normotensives. In both groups acute dexamethasone administration markedly reduced plasma cortisol (radioimmunoassay), without affecting hemodynamic and neural variables. In contrast to the acute administration, in obese subjects prolonged dexamethasone administration, although not affecting blood pressure and heart rate, significantly reduced both plasma cortisol (from 16.0±1.3 to 0.7±0.1 μg/dL; P

Original languageEnglish
Pages (from-to)1316-1320
Number of pages5
Issue number6
Publication statusPublished - 2001



  • Hormones
  • Hypothalamus
  • Obesity
  • Sympathetic nervous system

ASJC Scopus subject areas

  • Internal Medicine

Cite this

Grassi, G., Seravalle, G., Dell'Oro, R., Turri, C., Pasqualinotto, L., Colombo, M., & Mancia, G. (2001). Participation of the hypothalamus-hypophysis axis in the sympathetic activation of human obesity. Hypertension, 38(6), 1316-1320.