Use of naltrexone in postmenopausal women with exaggerated insulin secretion: a pilot study.
OBJECTIVE
To determine the effect of naltrexone (an opiate receptor blocker) on insulin metabolism in postmenopausal women with different insulinemic patterns.


METHODS
Randomized placebo-controlled study.


METHODS
Academic research environment.


METHODS
Forty-one healthy normoinsulinemic or hyperinsulinemic postmenopausal women.


METHODS
Oral glucose tolerance test (OGTT) before and after 5 weeks of the opioid antagonist (naltrexone, 50 mg/d orally) or the placebo administration; euglycemic-hyperinsulinemic glucose clamp.


METHODS
Glucose, insulin, and C-peptide plasma levels assessed in fasting condition and during the OGTT. Insulin sensitivity was calculated as total body glucose utilization.


RESULTS
Naltrexone reduced fasting and stimulated insulin response to the glucose load while inducing a significant improvement of the hepatic extraction, only in the hyperinsulinemic patients. No differences were found in the C-peptide pancreatic secretion and in the peripheral insulin sensitivity. No net change in the glycoinsulinemic metabolism was observed in normoinsulinemic patients or in placebo-controlled normoinsulinemic and hyperinsulinemic subjects.


CONCLUSIONS
Similar to that reported in premenopausal women, endogenous opioid peptides are involved in the modulation of glycoinsulinemic metabolism in postmenopause. Through a prevalent action on liver insulin metabolism, without any clear improvement of insulin resistance and pancreatic beta-cell function, the chronic administration of naltrexone appears to reduce the hyperinsulinemia in those women with an exaggerated insulin response to the OGTT.
Cucinelli
Francesco
F
Department of Obstetrics and Gynecology, Catholic University of Sacred Heart, Rome, Italy.
Soranna
Liberato
L
Perri
Concetta
C
Barini
Angela
A
Cento
Rosa Maria
RM
Mancuso
Salvatore
S
Lanzone
Antonio
A
D001786:Blood Glucose / Q000032:analysis; D002096:C-Peptide / Q000097:blood; D005215:Fasting / Q000097:blood; D005260:Female; D005947:Glucose / Q000378:metabolism; D005951:Glucose Tolerance Test; D006801:Humans; D006946:Hyperinsulinism / Q000097:blood / Q000188:drug therapy*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008875:Middle Aged; D009271:Naltrexone / Q000627:therapeutic use*; D009292:Narcotic Antagonists / Q000627:therapeutic use*; D010865:Pilot Projects; D017698:Postmenopause; D016896:Treatment Outcome
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D009292:Narcotic Antagonists; D009271:Naltrexone; D005947:Glucose