title: Effect of octreotide, a somatostatin analog, on sleep apnea in patients with acromegaly.
abstract: OBJECTIVE
  To determine the effects of octreotide, a somatostatin analog, on the severity of sleep apnea and on growth hormone levels in patients with acromegaly.
  
  
  METHODS
  Open-label, prospective study.
  
  
  METHODS
  Tertiary referral hospital.
  
  
  METHODS
  19 patients with active acromegaly.
  
  
  METHODS
  Octreotide in a 6-month, stepwise incremental dosage.
  
  
  METHODS
  Sleep studies and indices of hormonal activity (levels of insulin-like growth factor 1 [IGF-1] and growth hormone).
  
  
  RESULTS
  A 50% decrease occurred in the respiratory disturbance index (baseline compared with 6 months, 39 events/h compared with 19 events/h; P = 0.0002), and a 40% decrease occurred in total apnea time (27.6% of total sleep time compared with 15.1%; P = 0.001). Indices of oxygen desaturation, sleep quality, and subjective sleepiness improved after 6 months of octreotide. A parallel decrease was noted in mean levels of growth hormone (40.0 micrograms/L compared with 9.1 micrograms/L; P = 0.003) and IGF-1 (107 nmol/L compared with 47 nmol/L; P = 0.0001). However, no correlation was noted between the decrease in the total amount of sleep time spent in apnea and the decrease in growth hormone levels (rho = -0.35; P > 0.2). The residual respiratory disturbance index after 6 months of treatment was similar in patients who improved, regardless of whether or not biochemical remission (IGF-1 < 35 nmol/L) occurred.
  
  
  CONCLUSIONS
  Improvement in indices of sleep apnea severity occurs in association with octreotide treatment in patients with sleep apnea and acromegaly. However, sleep apnea may either persist despite normalization of growth hormone levels or may improve markedly even if there is only partial biochemical remission.
authors.affiliation: University of Sydney, Australia.
authors.forename: R R
authors.initials: RR
authors.lastname: Grunstein
authors.forename: K K
authors.initials: KK
authors.lastname: Ho
authors.forename: C E
authors.initials: CE
authors.lastname: Sullivan
mesh_terms: D000172:Acromegaly / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D000328:Adult; D000368:Aged; D005260:Female; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000627:therapeutic use*; D010100:Oxygen / Q000502:physiology; D011446:Prospective Studies; D012119:Respiration / Q000187:drug effects; D012891:Sleep Apnea Syndromes / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology
chemical_list: D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D015282:Octreotide; D010100:Oxygen