PubMed Health⌕ Search

Biomedical subjects

Herbert Kuhl

Publications and source records attributed to Herbert Kuhl.

16 recordsLinked to original sources
PubMed2006

Fertility after discontinuation of treatment with an oral contraceptive containing 30 microg of ethinyl estradiol and 2 mg of dienogest.

OBJECTIVE: To examine the conception rate after cessation of a combination of 30 microg ethinyl E2 and 2 mg dienogest (EE/DNG). DESIGN: Prospective observational study. SETTING: Population-based cohort in Germany. PATIENT(S): Women who wished to become pregnant after cessation of an oral contraceptive (EE/DNG). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Cumulative conception rate within 1 year after termination of EE/DNG and time to pregnancy. RESULT(S): After 1 year of follow-up, the cumulative pregnancy rate was 86.6% (full analysis set; n = 706). When all participants with complete data were analyzed (n = 652), the cumulative pregnancy rate was 94.0%. More than 15% of the patients conceived in each of the first three cycles after termination of EE/DNG; the mean time to pregnancy was 3.5 cycles. The preceding duration of treatment with EE/DNG did not influence the conception rate. Except in the youngest age group (16-18 years), a certain delay was observed in the other age groups. CONCLUSION(S): The present prospective study revealed only a slight delay in regaining fertility during the first three cycles after cessation of EE/DNG. Thereafter, the cumulative rate of conception did not differ from that observed in fertile women who attempted to become pregnant without prior contraception.

Adult↗
PubMed2006

The effect of medroxyprogesterone acetate on estrogen-dependent risks and benefits--an attempt to interpret the Women's Health Initiative results.

The results of the two arms of the Women's Health Initiative (WHI) study allow a comparative assessment of the contribution of the progestogen component to the changes in risk of cardiovascular disease and cancer during treatment of postmenopausal women with conjugated equine estrogens and medroxyprogesterone acetate (CEE/MPA). However, the high proportion of older and overweight or obese women compromises any conclusions, since we estimate that 50% of the women would have the metabolic syndrome. In overweight postmenopausal women with hyperinsulinemia, the risk of breast cancer is elevated and cannot be increased further by hormone replacement therapy (HRT). Therefore, the non-significant, but consistent reduction in breast cancer risk during treatment with CEE alone might be based on an improvement of hyperinsulinemia. The 24% increase in breast cancer risk in the CEE/MPA group can be regarded as an artifact due to very low numbers of breast cancer diagnoses in the placebo group of women who had received HRT prior to the WHI study. The elevated risk of venous thromboembolism and the transient increase in the risk of coronary heart disease (CHD) during treatment with CEE/MPA but not CEE alone suggests a direct effect of MPA on the vessel wall. MPA has been demonstrated to upregulate the thrombin receptor, the thrombin-induced production of tissue factor and procoagulatory activity in the vessel wall owing to its glucocorticoid activity. In contrast, CEE alone reduced non-significantly the risk of CHD in women aged 50-59 years, suggesting that primary prevention is possible if estrogen replacement therapy is initiated early. As clinical studies on the effect of different progestogens combined with estrogens are scarce, a possible superiority of progestogens other than MPA remains to be proven.

Aged↗
PubMed2006

Metabolic and clinical effects of progestogens.

Synthetic progestogens differ not only in their hormonal potency, but also in their spectrum of hormonal activities. Beside their progestogenic and anti-oestrogenic effects, they may exert oestrogenic, androgenic, antiandrogenic, glucocorticoid and/or anti-mineralocorticoid activities. Consequently, progestogens may influence various metabolic parameters and modulate oestrogen-induced alterations in lipid metabolism, haemostasis, and various other factors. Progestogens with androgenic properties may counteract ethinyloestradiol (EE)-induced changes in lipoprotein metabolism, but do not cause atherosclerosis in the presence of EE. Oral contraceptives (OCs) containing androgenic progestogens which attenuate the EE-dependent changes in haemostasis, may be associated with a lower risk of venous thromboembolic disease than OCs whose progestogens have a less androgenic profile. Progestogens with androgenic activity may also antagonize oestrogen-induced alterations in various other hepatic proteins and modulate the effect of EE on growth factors. Progestogens with antiandrogenic activity may enhance the beneficial effect of EE in women with hyperandrogenic manifestations. Progestogens with glucocorticoid effects may increase procoagulatory activity in the vessel wall, while progestogens with anti-mineralocorticoid activity may reduce the aldosterone-induced water-retention in some women. For most women the differences in the hormonal pattern of progestogens used in OCs are without clinical relevance, but may be useful for women predisposed for the development of certain disorders.

Contraceptives, Oral, Synthetic↗
PubMed2005

Breast cancer risk in the WHI study: the problem of obesity.

In the climacteric, about 40% of the women have occult breast tumors the growth of which may be stimulated by hormones. Many genetic, reproductive and lifestyle factors may influence the incidence of breast cancer. Epidemiological data suggest that the increase in the relative risk (RR) of breast cancer induced by hormone replacement therapy (HRT) is comparable with that associated with early menarche, late menopause, late first birth, alcohol consumption, etc. One of the most important risk factors is obesity which exceeds the effect of HRT by far, and in overweight postmenopausal women the elevated risk of breast cancer is not further increased by HRT. As in the WHI study the majority of women was overweight or obese, this trial was unsuitable for the investigation of breast cancer risk. In the women treated with an estrogen/progestin combination, the RR of breast cancer rose only in those women who have been treated with hormones prior to the study, suggesting a selection bias. In the women not pretreated with hormones, it was not elevated. In the estrogen-only arm of the WHI study, there was no increase but a steady decrease in the RR of breast cancer during 6.8 years of estrogen therapy. This result was unexpected, as estrogens are known to facilitate the development and growth of breast tumors, and the effect is enhanced by the addition of progestins. Obese women are at high risk to develop a metabolic syndrome including insulin resistance and hyperinsulinemia. In postmenopausal women, elevated insulin levels are not only associated with an increased risk for cardiovascular disease, but also for breast cancer. This might explain the effects observed in both arms of the WHI study: HRT with relative low doses of estrogens may improve insulin resistance and, hence, reduce the elevated breast cancer risk in obese patients, whereas this beneficial estrogen effect may be antagonized by progestins. The principal options for the reduction of breast cancer risk in postmenopausal women are the prevention of overweight and obesity to avoid the development of hyperinsulinemia, the medical treatment of insulin resistance, the use of low doses of estrogens and the reduction of exposure to progestins. The latter might include long-cycles with the sequential use of appropriate progestins every 3 months for 14 days. There are large inter-individual variations in the proliferative response to estrogens of the endometrium. Control by vaginalsonography and progestin challenge tests may help to identify those women who may be candidates for low-dose estrogen-only therapy.

Body Weight↗
PubMed2004

Mechanisms of sex steroids. Future developments.

The discussion on the risks of hormone therapy supports the search for alternative drugs such as selective estrogen receptor modulators (SERMs). These compounds are suitable for special preventive goals, but cannot be expected to replace the use of estrogens in patients with estrogen deficiency. The development of selective progesterone receptor modulators (SPRMs) which has to resolve various problems, might be a promising approach. Hormone replacement therapy (HRT) with natural estrogens remains the measure of choice for treatment of symptoms caused by estrogen deficiency. Recent findings suggest that the additional progestogen which is used for the protection of the endometrium, plays a crucial role with regard to the risk of breast cancer and cardiovascular disease. As surrogate parameters cannot predict the extent of risks, suitable tools for the selection of progestogens with the least potential for causing adverse effects, are urgently needed. Experimental, clinical and epidemiological data suggest that the elevation in breast cancer risk is due to the proliferative effect of estrogens on breast tissue which is largely enhanced by progestogens. A short-term in vivo-test might be helpful for the evaluation of proliferative effects of estrogen-progestogen preparations. Similarly, a strictly standardized in vivo-test for the assessment of the atherogenic potential of estrogen-progestogen preparations might help to select the preparations with the lowest risk for ischemic diseases. The available data suggest that it is probably not the androgenic but the glucocorticoid activity of a progestogen which plays a role in the development of cardiovascular disease. Progestogens with glucocorticoid effects may up-regulate the thrombin receptor in the vessel wall which is involved in the development of atherosclerosis and stimulation of extrinsic coagulation.

Estrogen Replacement Therapy↗
PubMed2004

Progestogen therapies: differences in clinical effects?

A large number of estrogen/progestogen preparations are available for the treatment of estrogen-deficiency symptoms. These preparations differ in the route of administration, the type and dose of both the estrogen and progestogen. The only indication for the addition of a progestogen is endometrial protection, but, depending on its chemical structure, a progestogen can either enhance (e.g. hot flushes, gonadotropin release, breast-epithelial proliferation and bone mineral density) or antagonize (e.g. endometrium, arterial wall, lipid metabolism, hepatic protein synthesis and mood) the effects of the estrogen component. Available progestogens differ largely in their hormonal pattern and, in addition to their progestogenic and antiestrogenic action on the endometrium, they can exert androgenic, antiandrogenic, glucocorticoid and/or antimineralocorticoid effects. There are no comprehensive trials comparing directly the modulating effects of the various progestogens, and clinical and epidemiological data do not allow a definite conclusion on the clinical relevance of differences between progestogens.

Affect↗
PubMed2004

Long-cycle treatment with oral contraceptives.

The conventional regimen of oral contraceptive (OC) use mimics the natural cycles by causing regular withdrawal bleeding, which can be avoided by omission of the hormone-free interval of 7 days. Consequently, long-cycle regimens with continuous administration of OCs for 3 or 6 months followed by a hormone-free interval of 7 days may reduce the frequency of menstruations and cycle-dependent complaints. Surveys have revealed that, despite a higher rate of irregular bleeding, the majority of women prefer the long-cycle regimen to the conventional OC regimen with regular bleeds every 4 weeks because it may improve quality of life. As this regimen increases the contraceptive efficacy to a large degree, continuous treatment with OCs may prevent unintended pregnancies in women who miss a pill or are concomitantly treated with drugs that are able to impair the efficacy of OCs. Postponement of withdrawal bleeding may also reduce or prevent menses-associated disorders such as hypermenorrhoea and dysmenorrhoea, and have beneficial effects in patients with haemorrhagic diathesis, endometriosis, uterine leiomyoma and polycystic ovary syndrome. Continuous use of OCs prevents the cyclic fluctuations of serum levels of ethinylestradiol and progestogen and, hence, the cyclic variations of metabolic serum parameters. Although the long-cycle regimen is initially associated with an elevated rate of irregular bleeding, the total number of bleeding days that require sanitary product protection is lower than during conventional OC treatment. Many physicians tend to prescribe extended OC cycles for postponement of menstruation or reduction of frequency of regular bleeding. This review summarises and examines the available data on OC long-cycle regimens. The data suggest that the rate of treatment-related side effects with OCs according to the long-cycle regimen is similar to that of conventional OC regimens. However, clinical trials are necessary to assess the impact of long-term OC long cycles on safety, particularly the risk of cancer and cardiovascular disease, and fertility after discontinuation of treatment.

Adolescent↗
PubMed2002

Modulation of tamoxifen-induced apoptosis by peripheral benzodiazepine receptor ligands in breast cancer cells.

The peripheral benzodiazepine receptor (PBR), an integral protein of the mitochondrial membrane, is involved in the formation of mitochondrial permeability transition (MPT) pores. The opening of the MPT-leading to the dissipation of the inner-mitochondrial transmembrane potential (deltapsi(m))-is considered to be an early apoptotic event. Therefore, we investigated the effect of the high-affinity PBR ligands Ro5-4684 and PK 11195 on tamoxifen (TAM)-induced apoptosis in MCF-7 and BT-20 breast cancer cell lines. Application of 100 nM TAM led to induction of apoptosis in both cell lines. Estrogene receptor (ER)-positive MCF-7 cells arrested in G(2/M) by TAM treatment showed no general dissipation of deltapsi(m), but reduction of deltapsi(m) was observed in a population of cells with high deltapsi(m). In ER-negative BT-20 cells TAM treatment induced no arrest of the cell cycle but dissipation of deltapsi(m). In both cell lines, nanomolar concentrations of the PBR ligands, which showed minor pro-apoptotic action themselves, reduced TAM-induced decrease of deltapsi(m) and apoptosis. In MCF-7 cells, a reduction of bcl-2 protein expression by TAM treatment was abolished by a combination of TAM with PBR ligands. Bax protein expression in BT-20 cells showed a significant increase in TAM-treated cells after 24hr but was not increased when treated with TAM and PBR ligands. From these findings, we concluded that binding of PBR ligands in nanomolar concentrations protects cells against apoptosis.

Antineoplastic Agents, Hormonal↗
PubMed2002

Effect of tibolone compared with sequential hormone replacement therapy on carbohydrate metabolism in postmenopausal women.

OBJECTIVE: To investigate the effects of tibolone on carbohydrate metabolism, and to compare these effects with those of a sequential regimen of conjugated equine estrogens and medrogestone. METHODS: This was an open-label, multicentre, comparative study. Seventy-two postmenopausal women were randomized to receive either tibolone 2.5 mg/day or conjugated equine estrogens 0.6 mg plus sequential medrogestone 5 mg (CEE/M) for six 28-day cycles. Carbohydrate metabolism was evaluated at baseline and after three and six cycles of treatment by an oral glucose tolerance test (OGTT). A blood sample was taken at 30, 60, 90 and 120 mm after glucose 75 mg dosing for determination of plasma glucose, insulin and connecting peptide (C-peptide) levels. RESULTS: The changes from baseline of glucose, insulin and C-peptide area-under-the-curve (AUC) values were not statistically significant after 3 and 6 months of tibolone or CEE/M treatment. There was a small transitory decrease in HbA(1C) after three cycles of treatment with tibolone. CONCLUSION: The effects of tibolone and CEE/M on carbohydrate metabolism were considered to have no clinical significance.

Blood Glucose↗
PubMed2002

Managing cutaneous manifestations of hyperandrogenic disorders: the role of oral contraceptives.

Cutaneous manifestations of hyperandrogenic disorders (acne, seborrhea, hirsutism and androgenetic alopecia) can be caused by elevated levels of free testosterone or androgen precursors. In women with normal serum levels of testosterone or androgen precursors, enhanced local conversion to testosterone, or to the more potent androgen dihydrotestosterone, may lead to increased androgen activity in the pilosebaceous unit. Large individual variations in the response to normal or elevated androgens suggests considerable differences in local androgen metabolism and androgen receptor-mediated activities, which may partly be related to genetic disposition. Androgens cause opposite effects on hair follicles in the scalp compared with the face and body, and there are large differences in the length of anagen phase. Androgens enhance sebum production and keratinization, prolong the growth phase of face and body hair, stimulate the transformation of vellus to terminal hair, and shorten the anagen phase of scalp hair. Estrogens may antagonize the androgen-induced actions on sebaceous glands and hair follicles. Treatment with oral contraceptives (OCs) reduces the production of androgens and androgen precursors and increases sex hormone-binding globulin, resulting in a decrease of free testosterone levels. According to type and dose, the estrogen and progestogen components of OCs may directly reduce the effect of androgens within sebaceous glands and hair follicles. Therefore, OCs with a predominant estrogen effect may improve mild to moderate forms of acne and seborrhea, hirsutism and androgenetic alopecia, in a time-dependent manner. In women who do not respond satisfactorily, treatment with OCs containing a progestogen with antiandrogenic activity is recommended. In many women with severe acne or hirsutism, a considerable increase in the local concentration of the antiandrogenic progestogen is required to reduce the androgenic interaction with the androgen receptor. For this therapy, an OC containing cyproterone acetate can be used. If necessary, the dose of cyproterone acetate can be increased in a stepwise manner. While androgenetic alopecia is best treated with a low-dose OC containing cyproterone acetate (optimal effect occurs after at least 12 months of therapy), severe acne and hirsutism are significantly improved after 6-12 months of regimens containing high doses of cyproterone acetate (25-100 mg/day). After termination of treatment the disorders may reappear, therefore treatment with suitable low-dose formulations is recommended to maintain the therapeutic effect.

Contraceptives, Oral↗
PubMedDate not supplied

Formation of 7 alpha-methyl-ethinyl estradiol during treatment with tibolone.

OBJECTIVE: To investigate whether tibolone, which is orally used for hormone replacement therapy, is transformed to a derivative of ethinyl estradiol (EE). DESIGN: In 10 young women who received 2.5 mg orally administered tibolone daily between cycle day 19 and 25, blood was obtained before and 0.5, 1, 1.5, 2, 3, 4, 6, 8, and 24 h after the last tablet intake. The concentration of 7 alpha-methyl-EE was determined by the gas chromatography with mass spectrometry method. RESULTS: The results demonstrate that, during daily treatment of women with 2.5 mg tibolone, a small proportion of tibolone is transformed to 7 alpha-methyl-EE. The maximal serum concentrations of 125 +/- 40 pg/mL were in the range of the levels of EE observed during treatment with oral contraceptives containing 30 microg EE. CONCLUSIONS: Caution is advisable when considering treatment with tibolone of postmenopausal women with contraindications for estrogens.

Adult↗