Intrauterine or oral administration of levonorgestrel in combination with estradiol to perimenopausal women--effects on lipid metabolism during 12 months of treatment.

Objective: Limited data concerning serum lipids and lipoproteins are available on the effect of HRT in perimenopausal women, who commonly have marked bleeding disturbances and may have severe climacteric symptoms. Almost all previously published data have utilized a simplified form of lipoprotein analysis, which includes an estimation and not a determination of LDL cholesterol. To delineate the role of locally administered progestogen, perimenopausal women were studied for a year.

Patients and methods: 40 perimenopausal women with climacteric complaints. The continuous release of low-dose levonorgestrel from an intrauterine device was used as progestogen co-medication to estradiol in a new type of continuous combined hormone replacement therapy. Women were randomized to either cyclical treatment with 2 mg of oral estradiol valerate in combination with 250 micrograms of levonorgestrel for the last ten days (Cyclo Progynova) or continuously with 2 mg estradiol valerate orally in combination with a 20 micrograms per 24 hour levonorgestrel releasing intrauterine device.

Results: Reduced HDL cholesterol was initially recorded in both treatment arms and disappeared after 1 year of treatment. Triglycerides were reduced in the orally treated group, but not in the device group. No changes in LDL cholesterol were noted.

Conclusions: The findings suggest that continuous combined HRT with intrauterine release of 20 micrograms levonorgestrel per 24 hours in perimenopausal women is neutral as far as lipid metabolism is concerned, since no alterations compared with pretreatment values could be noted after 12 months of treatment. Less marked lipid changes were obtained in perimenopausal women as compared with data on postmenopausal women. Differences in methodology may partly account for this.