Some studies on Femara

JohnnyB

Community Veteran
Here's one study

The role of sex steroids in the regulation of insulin sensitivity and serum lipid concentrations during male puberty: a prospective study with a P450-aromatase inhibitor.

Wickman S, Saukkonen T, Dunkel L.

Hospital for Children and Adolescents, University of Helsinki, PL281, FIN-00029 HUS, Helsinki, Finland. sanna.wickman@helsinki.fi

OBJECTIVE: Our purpose was to study the sex steroid-mediated changes in serum insulin and lipid concentrations in boys during puberty.

DESIGN AND METHODS: We treated boys with constitutional delay of puberty either with testosterone plus placebo or with testosterone plus an aromatase inhibitor, letrozole, which inhibits the conversion of androgens to oestrogens. We demonstrated previously that during treatment with testosterone plus letrozole the increase in testosterone concentration was more than 5-fold higher than during treatment with testosterone plus placebo. The concentrations of 17beta-oestradiol, IGF-I and IGF-binding protein-3 increased during testosterone-plus-placebo treatment, but during testosterone-plus-letrozole treatment the concentrations remained unchanged. These divergent changes in the two groups enabled us to study the effects of sex steroids and GH on insulin sensitivity and lipid concentrations.

RESULTS: The insulin concentration in the testosterone-plus-placebo-treated group did not change. In contrast, in the testosterone-plus-letrozole-treated group, the concentration decreased during letrozole treatment, indicating improved insulin sensitivity. Changes in insulin and IGF-I concentrations within 12 and 18 months were correlated. In the testosterone-plus-placebo-treated group, the high-density lipoprotein cholesterol concentration did not change but in the testosterone-plus-letrozole-treated group the concentration decreased. The concentrations of low-density lipoprotein cholesterol (LDL-cholesterol) and triglycerides did not change in either of the groups.

CONCLUSIONS: The findings indicate that androgens do not directly alter insulin sensitivity in boys during puberty. In contrast, the observations suggest tight regulation of glucose--insulin homeostasis by GH in boys at this stage. Furthermore, our findings indicate that sex steroids do not significantly participate in the regulation of serum concentrations of LDL-cholesterol or triglycerides in boys during early and mid-puberty.

JohnnyB
 
Here's one comparing Clomind and Femara

A randomized double-blind comparison of the effects of clomiphene citrate and the aromatase inhibitor letrozole on ovulatory function in normal women.

Fisher SA, Reid RL, Van Vugt DA, Casper RF.

Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Queen's University, Kingston General Hospital, Ontario, Canada.

OBJECTIVE: To evaluate the ovarian follicular dynamics of cycle modification with the aromatase inhibitor letrozole compared with clomiphene citrate in normal ovulatory women.

DESIGN: Randomized double-blind controlled trial.

SETTING: Tertiary care hospital.

PATIENT(S): Nineteen ovulatory female volunteers, ages 18-35 years.

INTERVENTION(S): Subjects were monitored in one control cycle. Subjects then received either letrozole 2.5 mg daily or clomiphene citrate 50 mg daily on days 5-9 after menses.
MAIN OUTCOME MEASURE(S): Number of mature follicles, endometrial thickness and endometrial pattern at ovulation, and follicular profiles of LH, FSH, and E(2).

RESULT(S): The number of mature follicles at the LH surge in natural cycles was 1.0 with an exaggerated response seen for treatment both with clomiphene and letrozole. There was no difference in the endometrial thickness at midcycle during either the natural cycles or the medicated cycles. LH surges and spontaneous ovulation were documented in all natural and medicated cycles. When measured daily, follicular profiles of LH and FSH are similar between the groups in both the natural and medicated cycles. In the medicated cycles, clomiphene results in a significant increase in E(2) levels, while E(2) levels in letrozole-stimulated cycles appeared lower than in natural cycles.

CONCLUSION(S): Transient inhibition of aromatase activity in the early follicular phase with the aromatase inhibitor letrozole results in stimulation of ovarian folliculogenesis similar to that seen with clomiphene citrate with no apparent adverse effect on endometrial thickness or pattern at midcycle.

JohnnyB
 
SWeet post Johnny B! I saved that one on to my computer. I can always count on JB to bring some nice post to the table

FC
 
Femara raising test

Aromatase inhibitors in men

The effect of aromatase inhibition on male gonadotrophin and sex steroid concentrations is illustrated in the paper by Trunet et al. (1993): 2.5 mg letrozole suppressed plasma oestradiol concentrations to less than 50% of pretreatment after 2 days, with recovery to approximately pretreatment values after 6 days. These decreases were accompanied by increased gonadotrophin concentrations, with resultant increases of approximately 50% in plasma testosterone. These results, and those previously published (Bhatnagar et al. 1992) on the effects of fadrozole in men, indicate that the aromatization pathway is of major importance in the regulation of gonodotrophin secretion by aromatically androgens.

Full text of this article can be downloaded in PDF format.
http://journals.endocrinology.org/erc/006/0181/0060181.pdf

JohnnyB
 
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