Insulin sensitivity during postmenopausal hormone replacement with transdermal estradiol and intrauterine levonorgestrel.
BACKGROUND
The study was devised to measure the effect of intrauterinely delivered levonorgestrel and transdermal estradiol on insulin sensitivity in postmenopausal women and compare this effect with that induced by transdermal estradiol alone.


METHODS
An open, prospective, comparative study of healthy postmenopausal women without earlier use of hormone replacement therapy. The estrogen therapy group consisted of eight hysterectomized women, who used a transdermal patch delivering a daily dose of 50 microg of estradiol continuously for 6 months. The estrogen-progestin therapy group consisted of 13 women with an intact uterus, who received a simultaneous combination of a transdermal patch and a levonorgestrel (20 microg/day) intrauterine system for the same length of time. Fasting plasma concentrations of glucose, insulin and C-peptide and an insulin tolerance test were used to measure glucose metabolism and insulin sensitivity.


RESULTS
Neither therapy changed the fasting plasma levels of glucose, insulin or C-peptide. Transdermal estrogen improved insulin sensitivity by 22%, as measured by an insulin tolerance test, while a small increase of 3.6% was observed using the combination therapy.


CONCLUSIONS
Transdermal estradiol improves insulin sensitivity in healthy postmenopausal women. Combining intrauterine levonorgestrel to transdermal estradiol reverses this effect. This combination does not, however, seem to induce insulin resistance.
Raudaskoski
T
T
Department of Obstetrics and Gynecology, University of Oulu, Finland.
Tomás
C
C
Laatikainen
T
T
D000279:Administration, Cutaneous; D001786:Blood Glucose / Q000032:analysis; D002096:C-Peptide / Q000097:blood; D004958:Estradiol / Q000008:administration & dosage* / Q000097:blood; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D007044:Hysterectomy; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D016912:Levonorgestrel / Q000008:administration & dosage*; D008875:Middle Aged; D017698:Postmenopause; D045167:Progesterone Congeners / Q000008:administration & dosage*
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D045167:Progesterone Congeners; D004958:Estradiol; D016912:Levonorgestrel