[Oral or trandsdermanl hormone replacement therapy reduces interleukine-6 levels]

To compare the effect of oral and transdermal estrogen replacement therapy (ET) on circulating interleukin-6 (IL-6) in post-menopausal women.

Prospective open trial study in 55 healthy hysterectomized postmenopausal women with a mean age of 52 years. Twenty-seven women received oral conjugated equine estrogens (0.625 mg daily) and the remaining 28 received transdermal estrogen replacement therapy (50 microg/day) during 6 months. At baseline both groups were similar as to age, body weight, and body mass index as well as serum levels of LH, FSH, 17-beta estradiol (E2) and IL-6.

Baseline elevated IL-6 levels decreased significantly (p<0.05) after both oral and transdermal estrogen replacement therapy; this decrement showed no difference between the two groups. After the follow-up there were no differences in body weight and body mass index between groups; however, in the oral group there was a trend to increment this parameters. Serum levels of E2 and IL-6 were negatively correlated in the two groups and IL-6 was positively correlated with body mass index in untreated women and this correlation was the same in women with estrogen replacement therapy.

The decrement of IL-6 after estrogen replacement therapy was similar for both routes of administration; in addition IL-6 had a negative correlation with E2 and a positive correlation with body mass index.