Effect of oral contraceptives on sebum excretion rate

Neuroendocrinology and neurobiology of sebaceous glands

The nervous system communicates with peripheral tissues through nerve fibres and the systemic release of hypothalamic and pituitary neurohormones. Communication between the nervous system and the largest human organ, skin, has traditionally received little attention. In particular, the neuro-regulation of sebaceous glands (SGs), a major skin appendage, is rarely considered. Yet, it is clear that the SG is under stringent pituitary control, and forms a fascinating, clinically relevant peripheral target organ in which to study the neuroendocrine and neural regulation of epithelia. Sebum, the major secretory product of the SG, is composed of a complex mixture of lipids resulting from the holocrine secretion of specialised epithelial cells (sebocytes). It is indicative of a role of the neuroendocrine system in SG function that excess circulating levels of growth hormone, thyroxine or prolactin result in increased sebum production (seborrhoea). Conversely, growth hormone deficiency, hypothyroidism, and adrenal insufficiency result in reduced sebum production and dry skin. Furthermore, the androgen sensitivity of SGs appears to be under neuroendocrine control, as hypophysectomy (removal of the pituitary) renders SGs largely insensitive to stimulation by testosterone, which is crucial for maintaining SG homeostasis. However, several neurohormones, such as adrenocorticotropic hormone and α-melanocyte-stimulating hormone, can stimulate sebum production independently of either the testes or the adrenal glands, further underscoring the importance of neuroendocrine control in SG biology. Moreover, sebocytes synthesise several neurohormones and express their receptors, suggestive of the presence of neuro-autocrine mechanisms of sebocyte modulation. Aside from the neuroendocrine system, it is conceivable that secretion of neuropeptides and neurotransmitters from cutaneous nerve endings may also act on sebocytes or their progenitors, given that the skin is richly innervated. However, to date, the neural controls of SG development and function remain poorly investigated and incompletely understood. Botulinum toxin-mediated or facial paresis-associated reduction of human sebum secretion suggests that cutaneous nerve-derived substances modulate lipid and inflammatory cytokine synthesis by sebocytes, possibly implicating the nervous system in acne pathogenesis. Additionally, evidence suggests that cutaneous denervation in mice alters the expression of key regulators of SG homeostasis. In this review, we examine the current evidence regarding neuroendocrine and neurobiological regulation of human SG function in physiology and pathology. We further call attention to this line of research as an instructive model for probing and therapeutically manipulating the mechanistic links between the nervous system and mammalian skin.

The role of combined oral contraceptives in the management of acne and seborrhea

Acne and seborrhea (or facial oiliness) are related androgenic skin disorders which affect a high proportion of women after menarche. They can have a negative effect on psychological well-being and social life. Androgens play an important role in the pathogenesis of acne through the stimulation of sebum secretion, increasing sebaceous gland size and possibly through follicular hyperkeratinization. Conversely, estrogens decrease sebum production by suppressing gonadotropin release and androgen production and increasing sex hormone binding globulin production. One of the treatment options for these conditions is hormonal therapy, especially for women who require contraception. The effect of combined oral contraceptives in androgenic skin disorders depends on their estrogen:progestogen balance and on the antiestrogenic activity of the progestogen component. Improved understanding of what women value about oral contraceptives suggests that the choice of product should be tailored as much as possible to the individual. Several combined oral contraceptives containing new-generation progestogens (e.g. desogestrel, gestodene) or progestational antiandrogens (e.g. cyproterone acetate, chlormadinone acetate) have demonstrated efficacy in the treatment of women with acne, although comparisons between trials are difficult because of differing endpoints. Seborrhea has been less well studied, but the few studies that are available show an improvement in women with this condition using combined oral contraceptives.

Newer progestogens

OBJECTIVE

To review the literature on the most recent progestogens to be developed, to provide clinical comparisons with older progestogens and to look at the potential of products not yet marketed.

DATA SOURCES

Searches of Medline and Popline together with requests for bibliographies from the Population Council, Wyeth-Ayerst Research and Schering Health Care.

STUDY SELECTION

Information from technical papers was used to ascertain the metabolic characteristics and receptor binding affinities of the compounds. Previous reviews were scrutinised in order to make comparisons with older compounds. Any available trials were examined to ascertain efficacy, bleeding patterns and tolerability, more weight being given to comparative trials.

DISCUSSION

Five progestogens have been developed in the last decade. They are all devoid of androgenic activity; some have antiandrogenic activity. Combined oral contraceptive (COC) pills containing dienogest and drospirenone are already marketed. Nomegestrol and nestorone have been extensively studied as subdermal implants.

CONCLUSIONS

Newer progestogens used in combination with oestrogen behave very similarly to existing products. Progestogen-only products using new progestogens have potential for significantly better tolerability due to their lack of androgenic activity.

Update on androgenicity

The development of a new generation of progestins deemed less androgenic than their earlier counterparts has led to a number of misconceptions regarding their possible benefits in combination oral contraceptives. All combination oral contraceptives are beneficial for treating such androgenic conditions as acne and hirsutism. The only expressed androgenic effect of some first- and second-generation combined oral contraceptives are changes in plasma lipid and lipoprotein levels. However, the overall effect of today's low-dose oral contraceptives is largely lipid neutral, and human and monkey studies have shown that oral contraceptive use is associated with reduced, not increased, atherosclerosis rates. Myocardial infarction rates are not increased among oral contraceptive users, except among those who are heavy smokers.

Twelve years of clinical experience with an oral contraceptive containing 30 micrograms ethinyloestradiol and 150 micrograms desogestrel

The clinical experience with a combined oral contraceptive (COC) containing 150 micrograms desogestrel and 30 micrograms ethinylestradiol is reviewed. Fourteen clinical trials have been reported involving over 44,000 women for more than 190,000 cycles. None of the 17 pregnancies which occurred (overall Pearl Index 0.12) were due to method failure. The incidences of breakthrough bleeding and spotting after 6 treatment cycles varied from 0.1-6.0% and 2.8-11% of subjects, respectively, and at this time they were not significantly different from pretreatment in most trials. About 90% of subjects maintained regular cycles. The incidence of subjective side effects (approximately 5% for headache, 4% for breast tenderness, 2% for nausea) was low. No significant changes occurred in body weight or blood pressure. In all trials, the COC was well accepted and the rates of discontinuation were similar to those in other COC trials. Pharmacodynamic effects have been widely investigated. There were no significant changes in glucose metabolism or in haematological factors except for possibly minor increases in factors VII and X, fibrinogen and plasminogen. Over thirty studies of the effect of the COC on lipid metabolism have been published; significant increases occur in serum triglycerides, HDL-C and apoprotein A1. SHBG concentrations increase 2-3 fold with a consequent decrease in the levels of free testosterone. This effect can be particularly important therapeutically in women with hyperandrogenic skin disorders and 14 trials in women with these disorders have demonstrated significant clinical improvement with the COC. The findings from the various trials show the COC to be effective and acceptable with no adverse metabolic effects.

Unwanted pregnancies: understanding contraceptive use and benefits in adolescents and older women

The highest percentages of unintended pregnancies and the largest increases in births reported in the United States in recent years were in adolescents and in women more than 35 years of age. Increasing numbers of these women will require contraception to avoid unintended pregnancy. In adolescents the combined oral contraceptive agents protect fertility indirectly and exert favorable actions on menstrual dysfunction and certain hormone-related disorders such as acne and hirsutism. To avoid sexually transmitted disease, barrier protection should be used along with oral contraceptives until mutually monogamous, stable relationships are established. Healthy older women who are nonsmokers may also safely use currently available contraceptives. These agents have little impact on metabolic parameters linked to the development of cardiovascular disease. In addition to providing reliable contraception, oral contraceptives offer noncontraceptive benefits to older reproductive-age women, including control of abnormal bleeding and a reduction in the incidence of ovarian and endometrial cancers and other gynecologic pathology. Intrauterine devices and progestin implants are safe, effective, and underused in the United States. Progestin implants may have an additional role in patients for whom estrogen preparations are contraindicated. Counseling is very important before insertion because of the high rate of nuisance side effects. The contraception selection process must consider the efficacy and acceptability of the specific method to avoid the probability of unintended pregnancy and the risk of sexually transmitted diseases.

Evolution of a strategy for the treatment of acne

The management of skin disease may differ in different parts of the world, but in most countries, acne should be a most treatable disease. Acne therapy has not evolved in the most logical fashion, but this article reviews our demonstration of risk factors in the treatment of acne. Young patients, male patients, truncal acne, a marked seborrhea, and a low dose (500 mg/day or less) of tetracycline are factors associated with a poorer response and, when oral therapy is stopped, a greater relapse rate. One gram a day of tetracycline, given for 6 months, is the minimum course of oral therapy and should be given along with topical therapy. One of the most widely used topical treatments is benzoyl peroxide, and this presentation was given in honor of Dr. William Pace, who was possibly the first dermatologist to be aware of the benefit of benzoyl peroxide--a fact not adequately recorded in dermatologic history. A small number of patients do not respond well to conventional therapy, but alternative treatments should bring about a successful outcome. Alternative treatments include hormonal therapy (i.e., 2 mg cyproterone acetate plus 50 micrograms ethinyl estradiol; spironolactone, 100 mg twice daily; or isotretinoin, 1 mg/kg). The success of all these treatments bears some relationship to their effect in modulating the etiologic factors of acne: an enhanced sebum production, increased ductal cornification, abnormal bacterial colonization, and the production of inflammation. Isotretinoin is the most beneficial of all drug regimens, and this fact no doubt relates to its favorable effect on all etiologic factors.

Anti-androgen treatment in women with acne: a controlled trial

Ninety female patients with acne were allocated randomly to one of three groups and treated either with Diane, a high dose cyproterone acetate (CPA) regime with ethinyloestradiol, or Minovlar. The same dose of oestrogen was common to all three treatment groups. Patients were assessed every 2 months for 6 months, by grading for severity of the acne, lesion counts and photography, and subjectively using a visual analogue scale. In addition, bacteriological sampling and sebum excretion rate (SER) measurements were performed. The results showed a clinical improvement in all three treatment groups, but a more rapid and complete response was seen in those groups who received CPA. There was also a consistent trend suggesting a more favourable response in those in the high dose CPA group. Although there was a marked reduction in SER in the groups treated with CPA, there was no correlation between reduction in SER and clinical improvement in individuals, nor could a reduction in the surface bacterial population be shown to be a primary event in the success of anti-androgen therapy. We have shown that the addition of CPA to oestrogen adds significantly to the therapeutic effect in acne and that anti-androgen and oestrogen combinations are more effective than standard oestrogen and progestagen contraceptive pills.

Acne: double blind clinical and laboratory trial of tetracycline, oestrogen-cyproterone acetate, and combined treatment

Since the recent introduction of a drug regimen containing 2 mg of the antiandrogen cyproterone acetate and 50 micrograms ethinyl-oestradiol (Diane; oestrogen-cyproterone acetate) several uncontrolled reports have extolled the benefits of this drug. Double blind studies, however, are lacking. Sixty two patients with moderate or moderately severe acne were therefore included in a double blind trial of treatment for six months comparing tetracycline alone, oestrogen-cyproterone acetate alone, and a combination of these agents. Sebum excretion rates and bacterial counts were measured before, during, and after treatment, at the same time as a clinical assessment was made. At six months the acne (as assessed by overall grade) had improved by 68% in the antibiotic treated group and by 74% in the oestrogen-cyproterone treated group. The group given a combination of both agents improved by 82%, which was significantly better (p less than 0.025) than the improvement in the tetracycline treated patients. No significant difference was found between the groups given oestrogen-cyproterone alone and the combined treatment. The sebum excretion rate was suppressed by 25% in the patients in both groups receiving oestrogen-cyproterone but not in the group given antibiotics alone. Oestrogen-cyproterone acetate is as effective as antibiotics in treating acne in women, and adding antibiotics offers no advantage over using oestrogen-cyproterone on its own, although in this study the combination was more effective than tetracycline alone at six months.

Binding of progestagens to receptor proteins in MCF-7 cells

With the aim of finding an explanation for the biological properties of progestagens currently used for contraceptive purposes, we have assessed their specificity for progesterone, androgen and oestrogen receptors in MCF-7 cells. The specificity of progestagens for the progesterone receptors in the cytosol fraction of MCF-7 cells was similar to that for progesterone receptors in human and rabbit myometrial cytosol but different from that for the progesterone receptor in rat myometrial cytosol. At 37 degrees C the relative affinity of 3-keto-desogestrel, the major metabolite of desogestrel, for the progesterone receptor in intact MCF-7 cells was twice that of levonorgestrel and Org 2058, three times that of medroxy-progesterone acetate (MPA), 4.5 times that of norethisterone and 5 times that of progesterone and cyproterone acetate whereas at 4 degrees C in the cytosol fraction of MCF-7 cells exposed to molybdate (nontransformed receptor complexes) 3-keto-desogestrel and Org 2058 displayed similar affinity. The stronger binding of 3-keto-desogestrel in intact cells was due to the higher stability of its complex with the progesterone receptor. At 37 degrees C the relative affinity of 3-keto-desogestrel for the androgen receptor in intact MCF-7 cells was half that of levonorgestrel, similar to that of norethisterone and medroxyprogesterone acetate (MPA) and at least three times higher than that of progestagens with anti-androgenic activity whereas at 4 degrees C in the cytosol fraction exposed to molybdate there was no clear difference between the relative affinities of progestagens with androgenic and anti-androgenic properties. Of the progestagens tested in this study, only norethinodrel displayed measurable but very low relative affinity for the oestrogen receptor in MCF-7 cells. We conclude that the present results of binding studies with intact MCF-7 cells correlate better with the known hormonal properties of progestagens than those obtained with the cytosol fraction exposed to molybdate at 4 degrees C.

Low dose prednisolone or oestrogen in the treatment of women with late onset or persistent acne vulgaris

Women with persistent or late onset acne vulgaris were divided into two treatment groups. The first received continuous low dose prednisolone to suppress ACTH-dependent androgen secretion and the second was treated with cyclical oestrogens with medroxyprogesterone to elevate sex hormone binding globulin (SHBG). In both groups there was a significant improvement in the severity of the acne after 4 months' treatment. Although pre-existing hormonal abnormalities were corrected, the improvement in the acne did not correlate with the baseline hormone levels. However, suitable oestrogen-progesterone combinations or low dose prednisolone may be given, alone or in combination, to suppress free circulating androgens in these patients with a high probability of improving their acne.

Sebaceous gland suppression in female acne patients by combined glucocorticoid-oestrogen therapy

Women with severe acne were treated with a combination of oestrogen and a low dose of glucocorticoid daily in order to suppress their androgen production. This combination therapy reduced their sebum production by 50%, with a concomitant improvement in their acne.