Oral contraceptive use and glucose metabolism in a national sample of women in the united states

OBJECTIVE

This study was undertaken to determine whether users of oral contraceptives in a nationally representative population of US women had elevated levels of measures of glucose metabolism.

STUDY DESIGN

Cross-sectional data from the Third National Health and Nutrition Examination Survey (1988-1994) included hemoglobin A(1c) levels and fasting glucose, insulin, and C-peptide levels. Means were compared among those who had never used oral contraceptives, current users of oral contraceptives, and former users of oral contraceptives, with and without adjustment for potential confounders.

RESULTS

The vast majority of current users of oral contraceptives were using low-dose estrogen formulations. The two most common preparations were a triphasic formulation containing 0. 035 mg ethinyl estradiol and 0.5, 0.75, and 1 mg norethindrone (23. 9%) and a monophasic formulation containing 0.035 ethinyl estradiol and 1 mg norethindrone (20.7%). Current users of oral contraceptives did not have elevated values for any of the four measures of glucose metabolism. Hemoglobin A(1c) level and fasting glucose, insulin, and C-peptide levels were not related to duration of current use, age at which use began, or major formulation type. Among women who were former users of oral contraceptives there was no evidence of higher values among those who had recently ceased use.

CONCLUSION

Oral contraceptive formulations currently available in the United States are not associated with an adverse glucose metabolic profile.

Association between poor glucose tolerance and rapid post natal weight gain in seven-year-old children

A number of studies have shown that glucose tolerance falls with decreasing birth weight and that people with low birth weight and high body mass index (BMI) as adults are those at greatest risk of developing Type II (non-insulin-dependent) diabetes mellitus. No such studies have been carried out in African populations. Therefore we investigated the relation between glucose tolerance and birth weight in a group of 7-year-old black South Africans for whom longitudinal anthropometric data were available. Oral glucose tolerance tests (OGTTs) were carried out on 152 subjects and inverse correlations were found between birth weight and the total amount of insulin secreted during the first 30 min (r = -0.19, p = 0.04) and last 90 min (r = -0.19, p = 0.04) of the oral glucose tolerance test and also between birth weight and the 30 min glucose concentrations (r = -0.20, p = 0.02). Children born with low birth weights but who had high weights at 7 years had higher insulin concentrations and indices of obesity compared with those with low birth weights and low weights at 7 years. There were also positive correlations between weight velocity and BMI (r = 0.24, p = 0.02) and weight velocity and insulin resistance (r = 0.18, p = 0.04) as measured using homeostasis model assessment (HOMA). Thus, low birth weight in conjunction with rapid childhood gains in weight especially as subcutaneous fat, produces poor glucose tolerance in 7-year-old children and can make them susceptible to the development of Type II diabetes later in life.

A study of the interactive effects of oral contraceptive use and dietary fat intake on blood pressure, cardiovascular reactivity and glucose tolerance in normotensive women

OBJECTIVE

To investigate the interactive effects of oral contraceptive pill use and dietary fat intake on cardiovascular haemodynamics and metabolic parameters in young normotensive women.

DESIGN

Thirty-two women participated, of whom 16 were taking oral contraceptive pills (ethinyl-oestradiol plus levonorgestrel) and 16 were age-matched and weight-matched controls not taking such pills. Subjects consumed either a high-fat or a low-fat diet for 2 weeks in an open, randomized, crossover study lasting 6 weeks. Investigations were performed at the end of each diet during the luteal phase of the menstrual cycle.

METHODS

Blood pressure was measured by 24 h ambulatory recording; cardiovascular reactivity was determined by examining blood pressure responses to systemic infusions of noradrenaline and angiotensin II and to the cold pressor test; and carbohydrate metabolism was investigated by an intravenous glucose-tolerance test.

RESULTS

Plasma triglyceride levels were significantly higher in women taking oral contraceptive pills compared with non-users on both diets; however, responses of lipoprotein levels to the two diets did not differ between study groups (total and low-density lipoprotein cholesterol levels decreased by 15 and 17% in oral contraceptive pill users and by 14% each in non-users, on the low-fat compared with the high-fat diet). Fasting plasma insulin levels, the insulin-production response to administration of glucose (insulin area under the curve) and resting clinic and night-time systolic blood pressures were all significantly reduced on the low-fat diet, but only in non-users. Blood pressure responses to noradrenaline and maximal heart rate response to cold were significantly attenuated during the low-fat diet in oral contraceptive pill users. During the low-fat diet, resting systolic, 24 h systolic and diastolic blood pressures and insulin area under the curve were all significantly higher for women taking the oral contraceptive pills. Users of these pills also exhibited a greater systolic sensitivity to administration both of noradrenaline and of angiotensin II and had a higher plasma renin activity irrespective of dietary phase.

CONCLUSIONS

These results confirm that oral contraceptive pills have the potential to cause adverse effects on blood pressure, cardiovascular reactivity and the insulin-production response to administration of glucose and suggest that some of the beneficial effects of a low-fat diet on these parameters may be negated in women taking oral contraceptive pills.

Safety evaluation of modern oral contraceptives. Effects on lipoprotein and carbohydrate metabolism

An ideal oral contraceptive should either be neutral as regards metabolic risk markers for arterial disease or should only change them in directions that would be expected to reduce risk. Depending on their formulation, modern low dose oral contraceptives affect systems such as hemostasis, lipoprotein metabolism, and glucose and insulin metabolism. Some of these actions would be expected to decrease the risk of arterial disease and some might be expected to increase risk. Despite these associations there is at present no justification for widespread metabolic screening as a strategy to further improve oral contraceptive safety. Recent developments in atherosclerosis research support the introduction of progestogens such as desogestrel that allow the estrogenic increase in high density lipoprotein levels to persist and that may cause less of an elevation in plasma insulin responses to glucose. The predicted benefit of these formulations in terms of arterial disease is difficult to demonstrate in an epidemiological setting because of the rarity of the disease in young women.

The effect of a desogestrel-containing oral contraceptive on glucose tolerance and leptin concentrations in hyperandrogenic women

Ovarian hyperandrogenism can be associated with insulin resistance, hyperinsulinemia, glucose intolerance, and obesity. High levels of the lipostatic hormone, leptin, have also been reported in this condition. The purpose of the present study was to examine the effect of an oral contraceptive (OC) of low androgenicity containing desogestrel on glucose tolerance in hyperandrogenic women and the impact of changes in androgenic/estrogenic status on leptin concentrations. Sixteen nondiabetic hyperandrogenic women, aged 29 +/- 1 yr with a body mass index (BMI) of 36.8 +/- 1.8 kg/m2, underwent an oral glucose tolerance test before and after 6 months of therapy with the OC. Free testosterone decreased and sex hormone-binding globulin increased after therapy (P < 0.001). Glucose tolerance deteriorated significantly, and two women developed diabetes. Body weight, BMI, and leptin did not change significantly. Leptin correlated with BMI before (r = 0.56; P = 0.02) and after (r = 0.51; P = 0.04) treatment, but not with glucose, insulin, total and free testosterone, or sex hormone-binding globulin before or after treatment. In conclusion, 1) glucose tolerance should be monitored in hyperandrogenic women using OC, even those of low androgenicity; and 2) changes in androgenic/estrogenic status had no effect on the leptin concentration, suggesting that its sexual dimorphism is not related to sex steroids.

Use of Norplant in women with or at-risk for noninsulin-dependent diabetes

This review addresses the use of Norplant in women with or at-risk for noninsulin-dependent diabetes mellitus (NIDDM). Background information on NIDDM is given, including pathogenesis, effect on glucose and lipid metabolism, and management. The effect of exogenous estrogen and progestogens on glucose tolerance is briefly discussed. In reviewing the effects of Norplant on glucose metabolism, studies on women with normal glucose tolerance were reviewed, along with the one study of Norplant use in women with a past history of gestational diabetes. Norplant does have a minor effect on glucose metabolism. Studies are contradictory regarding lipid metabolism but most suggest that Norplant does not have a negative effect on the high density lipoprotein/total cholesterol ratio. Factors influencing contraceptive choice are reviewed. Protocols for management of Norplant in women with or at-risk for NIDDM are then presented, followed by a case study and a brief discussion.

The role of triphasic levonorgestrel in oral contraception: a review of metabolic and hemostatic effects

Epidemiological studies suggesting a possible association between the use of combined oral contraceptives and an increased risk of cardiovascular disease have led to extensive investigations into the effect of oral contraceptives on lipid and carbohydrate metabolism, and on hemostasis. Since this association was originally suggested, the steroid dose in oral contraceptives has been significantly reduced and new progestogens have been developed. Also, triphasic formulations have been introduced which offer a well-balanced estrogen/progestogen ratio, allowing a further reduction in the progestogen dose per cycle, and thus helping to minimize unwanted metabolic and hemostatic effects. The metabolic interactions of triphasic levonorgestrel, the first triphasic formulation to be introduced, have received particular attention. Lipid metabolism appears to be largely unaffected by triphasic levonorgestrel, most studies reporting no significant change in high- (HDL-C) or low-density lipoprotein-cholesterol (LDL-C) levels. Several studies have reported a decrease in the lipoprotein subfraction HDL2-C levels, but in most cases measurements of the LDL-C/HDL-C and apolipoprotein A-1/B ratios reveal no clinically significant effects. Concerning lipids, most studies suggest that triphasic levonorgestrel has less metabolic impact than the monophasic formulation. In common with all currently available oral contraceptives, triphasic levonorgestrel appears to have some effect on carbohydrate metabolism. The study results vary, however; some investigators have found an impairment of glucose tolerance, whereas others have not detected any significant effect. Compared with lipid and carbohydrate metabolism, fewer studies have investigated the effect of triphasic levonorgestrel on hemostasis. In common with all estrogen-containing oral contraceptives, levonorgestrel appears to stimulate some procoagulant activity, elevating the levels of factors VII and X, and fibrinogen. However, the effect of triphasic levonorgestrel appears to be balanced, with most studies reporting a corresponding increase in anti-coagulant-fibrinolytic activity. Although most of the studies reviewed here reported some statistically significant metabolic interactions, many authors comment that the changes are probably not clinically relevant in terms of an altered risk of cardiovascular disease. The true risk of vascular disease associated with modern low-dose oral contraceptives remains to be confirmed when sufficient epidemiological data eventually become available.

Depot medroxyprogesterone acetate contraception. Metabolic parameters and mood changes

This review summarizes the existing literature regarding metabolic parameters and mood changes in women using depot medroxyprogesterone acetate (DMPA). MEDLINE and additional bibliographic sources were searched to identify English-language articles describing clinical trials and cross-sectional studies of DMPA published during the last 20 years. DMPA has little or no effect on glucose tolerance, but insulin levels may increase. An increase in low-density lipoprotein cholesterol and a decrease in high-density lipoprotein cholesterol have been observed in cross-sectional and longitudinal studies; however, there are no data to indicate whether the observed lipid alterations lead to adverse clinical events. There is some evidence suggesting decreased bone density in long-term DMPA users. Longitudinal data regarding bone density changes are needed to assess changes both during and after use. Most cross-sectional and longitudinal studies show increased mean weight or weight gain in DMPA users. Controlled studies of weight change that evaluate subgroups and effects of confounding variables are also needed to provide constructive advice to patients. Data regarding depression or mood changes in DMPA users are scanty and do not support a causal relationship between use of this contraceptive and affective disorders. For all of these parameters, case reports indicating adverse clinical outcomes are nearly absent from the literature despite widespread long-term international use of DMPA.

Comparative pharmacology of newer progestogens

The newer progestogens desogestrel, norgestimate, gestodene, dienogest and nomegestrol share the common property of having weak or no androgenic effects, but there is great variation between agents in their pharmacokinetic properties and hormonal activities. Both desogestrel (acting as 3-keto-desogestrel) and norgestimate (acting mainly through levonorgestrel) are prodrugs. While nomegestrol is derived from 19-norprogesterone, the other compounds are 19-nortestosterone derivatives: desogestrel, norgestimate and gestodene belong to the subgroup of 13-ethyl-gonanes with an ethinyl group at C17 alpha, and dienogest represents an estrane (13-methyl-gonane) with a cyanomethyl group at C17 alpha. Both dienogest and nomegestrol have antiandrogenic properties. In proportion to the dose, the highest serum concentrations are observed after intake of gestodene. When combined with ethinylestradiol, gestodene and 3-keto-desogestrel accumulate in serum during daily treatment because of slowed-down elimination. This is probably caused both by binding to sex hormone-binding globulin (SHBG) and by inhibition of inactivating enzymes. Dienogest does not accumulate in serum, although at a dose of 2 mg very high serum concentrations of dienogest are reached. The most potent progestogens are gestodene and desogestrel, while the effect of dienogest and nomegestrol on endometrium and cervix is less, even though in a similar range. As the ovulation-inhibiting effect is brought about not only by receptor-mediated interactions but also by a direct inhibition of steroid biosynthesis, dienogest and nomegestrol are much less effective than gestodene, desogestrel and norgestimate. Ethinylated progestogens, particularly gestodene, have been demonstrated to inhibit cytochrome P450 enzymes. Both gestodene and desogestrel may moderately reduce SHBG levels and counteract the stimulating effect of ethinylestradiol on hepatic serum proteins, while dienogest and nomegestrol have no influence. Compared with progestogens with androgenic properties which may restrict the stimulatory action of ethinylestradiol on haemostatic parameters, the newer progestogens do not seem to be superior with respect to haemostasis. There are no data on the direct effect of the compounds on the arterial and venous vessel wall. Due to the less pronounced antagonism on ethinylestradiol-induced changes in lipid metabolism, the newer progestogens appear to be beneficial rather than deleterious, although atherosclerosis was probably not promoted by the older formulations because of the direct effect of ethinylestradiol on the arterial wall. There is no evidence for a lesser impact of the newer progestogens on carbohydrate metabolism, which is mostly impaired by the estrogen component in oral contraceptives. Formulations containing the newer progestogens are, however, preferable in patients with hyperandrogenaemia, the symptoms of which may be improved by the suppression of total and free testosterone and an increase in SHBG; an additional beneficial effect of the antiandrogenic properties of dienogest or nomegestrol remains to be proven.

Efficacy of standard glucose-based and reduced-osmolarity maltodextrin-based oral rehydration solutions: effect of sugar malabsorption

Previously we reported that standard oral rehydration salts (ORS) solution is not as effective as a reduced-osmolarity glucose-based ORS for the treatment of children with acute noncholera diarrhoea: with standard ORS the diarrhoea lasts longer, stool output is greater, serum sodium is higher, and there is more need for supplemental intravenous infusion. We studied a reduced-osmolarity maltodextrin (MD)-based ORS to determine whether it had similar benefits, and also the effect of sugar malabsorption on the efficacy of standard and MD-based ORS. A total of 90 boys aged 3-24 months with acute noncholera diarrhoea and moderate dehydration were randomly assigned to either standard ORS (glucose 20 g/l, osmolarity 311 mmol/l) or MD-ORS (MD 50 g/l, osmolarity 227 mmol/l). There were no differences in treatment results. Some 46% of subjects had a high total stool output (> 300 g/kg), which was unrelated to the type of ORS given. High stool output was significantly associated with a longer duration of diarrhoea (33 vs. 15 hours; P < 0.001), a persistently elevated serum sodium (149 vs. 144 mmol/l at 24 h; P < 0.02), the need for intravenous infusion (11/41 vs. 0/48; P < 0.002), and an increase in faecal reducing substances (10.8 vs. 3.4 g/l at 24 h; P < 0.001). We conclude that some children given standard ORS develop osmotic diarrhoea owing to the combined effect of transient sugar malabsorption and slight hypertonicity of the ORS. Earlier studies show that this adverse outcome can largely be avoided when extra water is given in reduced-osmolarity glucose-based ORS. Reduced osmolarity has no benefit, however, when glucose is replaced by maltodextrin, probably because the sugars released by hydrolysis of MD, when malabsorbed, raise the intraluminal osmolarity to equal or exceed that of standard ORS. Thus, reduced-osmolarity glucose-based ORS is superior to both standard ORS and reduced-osmolarity solutions based on maltodextrin and probably other complex carbohydrates. Studies are in progress to define the optimal formulation of reduced-osmolarity glucose-based ORS.

Interaction of oral contraceptive use with the effects of age, exercise habits and other cardiovascular risk modifiers on metabolic risk markers

An analysis was undertaken to determine whether combined oral contraceptive (OC) use interacts with the effects of potential cardiovascular risk modifiers (age, body mass index, cigarette smoking, alcohol intake, exercise habit, family histories of heart disease or diabetes, number of pregnancies and duration of OC use) on blood pressure and lipid, lipoprotein, glucose and insulin risk markers for cardiovascular disease. Relationships between risk modifiers and risk markers were compared between non-users (n = 418) and users of low-estrogen dose OC (n = 925, categorised according to progestin content as monophasic levonorgestrel, triphasic levonorgestrel, norethindrone or desogestrel). OC use diminished the adverse effects of age on glucose tolerance. Aerobic exercise had a particularly beneficial effect on triglyceride levels and OGTT insulin response in OC users. The rise in HDL and HDL2 cholesterol concentrations with alcohol intake seen in non-users was diminished in OC users. Increasing duration of use of a desogestrel combination was associated with increasing HDL cholesterol concentrations. No adverse effects of risk modifiers on metabolic risk markers and blood pressure were augmented by OC use, and some were even diminished.

Gestodene-containing contraceptives

As GSD is the most potent progestogen used in oral contraceptives, the doses of GSD can be lower than those of other progestogen components. The monophasic (30 micrograms EE + 75 micrograms GSD) and the triphasic formulation (30 micrograms EE + 50 micrograms GSD/40 micrograms EE + 70 micrograms GSD/30 micrograms EE + 100 micrograms GSD) suppress gonadotropin release and ovarian function profoundly and inhibit ovulation reliably. The strong anti-estrogenic and progestogenic effectiveness of GSD is based on the high GSD serum concentrations achieved during daily intake. Because of the weak androgenic properties of GSD, both formulations can be characterized as estrogen-dominant with respect to their hepatic effects. Except for the first cycles, both formulations afford good cycle control, and the rate of side effects is similar to that with comparable low-dose oral contraceptives. The levels of total and free androgens and androgen precursors, as well as of peripheral androgen activity, are significantly reduced, resulting in a reduced incidence of acne. The concentrations of SHBG and other serum-binding globulins are elevated considerably, and thyroid function is almost unaffected. The estrogen-dominant effect on hepatic metabolism of both formulations also is reflected by a significant increase in the levels of triglycerides and VLDL, HDL, and some apolipoproteins, while LDL-CH and total CH remain unchanged. Similar to other low-dose oral contraceptives, the GSD-containing preparations cause a slight impairment of glucose tolerance that does not appear to be of clinical relevance. However, a significant increase exists in pro-coagulatory and fibrinolytic activity that leads to a considerable stimulation of fibrin turnover. In predisposed women, this may contribute to an elevated risk of venous and arterial thromboembolic diseases.

Desogestrel

Desogestrel is a new, potent progestogen with very low androgenic properties. When used as a contraceptive, it is a strong antiovulatory compound, even at low doses. The clinical efficacy is as good as that of the old progestogens. It has a low incidence of side effects and complications, similar to other progestogens. It may have a role as an anti-androgen in women with hyperandrogenic symptoms in need of adequate oral contraception.

Relationships between blood pressure, oral contraceptive use and metabolic risk markers for cardiovascular disease

Data from a previous study, designed to compare metabolic risk markers for cardiovascular disease in non-users and oral contraceptive (OC) users, were analysed to evaluate the influence of OC composition on blood pressure. Healthy, female volunteers (1189 women) either not using OC (non-users) or currently using one of six different combined formulations (users) were compared. Combinations studied contained 30-40 micrograms ethinyl estradiol combined with the progestins levonorgestrel, norethindrone (at two and three different doses, respectively) or desogestrel. After statistical standardisation to account for the significantly greater age of the non-users and longer duration of OC use amongst the levonorgestrel combination users, mean blood pressure was higher, compared with non-users, in users of monophasic or triphasic levonorgestrel combinations (systolic: +4.3 mmHg (p < 0.001) and +2.7 mmHg (p < 0.001), respectively; diastolic: +2.6 mmHg (p < 0.001) and +2.3 mmHg (p < 0.05), respectively). Blood pressures in users of monophasic norethindrone and desogestrel combinations were not significantly raised and there was no increase in the proportion of women with abnormal values. Diastolic and systolic blood pressures were positively associated with oral glucose tolerance test insulin response (r = 0.11 (p < 0.01) and r = 0.15 (p < 0.001), respectively) in users but not in non-users. Currently used OC containing norethindrone or desogestrel progestins have little impact on blood pressure. Their correlated reduction in impact on insulin concentrations, though small, suggests common mechanisms through which OC affect blood pressure and insulin.

The effects of nomegestrol acetate subdermal implant (Uniplant) on carbohydrate metabolism, serum lipoproteins and on hepatic function in women

This study was undertaken to assess possible variations in body weight, blood pressure, fasting glucose, HbA1C, insulin, total cholesterol, HDL-C, LDL-C, triglycerides, SGPT, SGOT, GGT and bilirubin in women bearing a single subdermal Silastic implant containing 55 mg (10%) of nomegestrol acetate during two years. A total of eighteen volunteers of reproductive age who desired to avoid conception were enrolled in this study. Subjects were healthy women with no contraindications to hormonal contraception. All women were investigated before starting treatment and were followed up for one year. At the end of one year the capsules were removed and a new capsule was inserted. Fasting blood samples were drawn at 8:00 to 8:30 am twice prior to implant insertion and then at the first, third, sixth and twelfth months and every six months thereafter. Body weight increased from 54.9 +/- 1.5 kg at admission to 55.3 +/- 2.0 kg at 12 months of use (p < 0.05) and to 56.0 +/- 2.7 kg at 24 months of use. A slight increase in both systolic and diastolic blood pressure was recorded at month 12 (p < 0.01). At month 24, blood pressure was not significantly different from admission values. All levels were within the normal range. Insulin, HbA1C, LDL-C and GGT remained unchanged during twenty-four months of Uniplant use. A significant decrease in total cholesterol (p < 0.05) was observed in the third month while a significant decrease in HDL-C (p < 0.01) was observed only in the sixth month of Uniplant use.(ABSTRACT TRUNCATED AT 250 WORDS)

Improved energy intakes using amylase-digested weaning foods in Tanzanian children with acute diarrhea

Amylase from germinating cereal grains enables the preparation of porridge with a higher energy density than conventional weaning foods. This food can be combined with fermentation, which inhibits pathogen growth. These food technologies are inexpensive, can be implemented at the household level, and are therefore particularly appropriate for use in developing countries. In a controlled clinical trial, 75 children aged 6-25 months admitted to hospital with acute diarrhea were rehydrated and then randomly allocated to three corn porridge dietary groups: conventional, amylase-digested (AMD), and fermented and amylase-digested (FAD). The study diets were given ad libitum five times daily, and all intakes except breast milk were weighed. Mean daily energy intakes over 4 days in the conventional AMD, and FAD groups, respectively, were 32.4 (95% CI 28.7-36.6), 46.0 (CI 39.6-53.4), and 37.3 (CI 31.8-43.9) kcal/kg/day. The energy intake in the AMD group was 42% higher than the conventional group (p = 0.003). There were no significant differences between the groups for duration of diarrhea, frequency of stooling, or vomiting. Starch digestion using amylase from germination is an effective way of improving energy intake in children with acute diarrhea.

Effects of a new oral contraceptive containing an antimineralocorticoid progestogen, drospirenone, on the renin-aldosterone system, body weight, blood pressure, glucose tolerance, and lipid metabolism

Combined hormonal oral contraceptives (OCs) may lead to a mild rise in blood pressure and body weight. In rare instances, large increments in blood pressure are measured. We investigated the effect of a combination of ethinyl estradiol (EE) plus a progestogen with antimineralocorticoid, i.e. natriuretic, properties [Drospirenone (DRSP)] on body weight, blood pressure, the renin-aldosterone system, atrial natriuretic factor, plasma lipids, and glucose tolerance. It is anticipated that this will lead to the development of an OC that does not raise body weight or blood pressure. Four groups of 20 women each received 30 micrograms EE plus 3 mg DRSP (group A), 20 micrograms EE plus 3 mg DRSP (group B), 15 micrograms EE plus 3 mg DRSP (group C), and, as a control OC, 30 micrograms EE plus 150 micrograms levonorgestrel (Microgynon, Schering; group D) for 6 months. During the OC-free control cycles before and after treatment and throughout treatment, the target parameters were measured. Between the pretreatment cycle and the sixth treatment cycle, mean body weight fell by 0.8 to 1.7 kg in groups A, B, and C (P < 0.05 vs. D), whereas it rose by 0.7 kg in group D. Systolic and diastolic blood pressures fell by 1-4 mm Hg in groups A, B, and C (significant for A and C vs. D) and increased by 1-2 mm Hg in group D. Renin substrate rose equally in all groups (P < 0.05), whereas PRA and plasma aldosterone rose significantly only in the DRSP groups, presumably due to sodium loss. In the DRSP groups, high density lipoprotein cholesterol rose (P < 0.05), in contrast to group D. Low density lipoprotein cholesterol fell slightly (P > 0.05), whereas triglyceride levels showed a stronger increase in the DRSP groups (P < 0.05) than in group D. All groups attained good cycle control; group A had the best. Side-effects were minimal. To our knowledge, this is the first report on a combined OC that leads to a small decrease in body weight and blood pressure. It may be especially beneficial for women susceptible for a gain in weight and a rise in blood pressure.

The effect of Norplant on glucose metabolism under hyperglycemic hyperinsulinemic conditions

OBJECTIVES

To assess the impact of a levonorgestrel-releasing implant contraceptive (Norplant; Wyeth-Ayerst Laboratories, Philadelphia, PA) on glucose metabolism.

DESIGN

Prospective evaluation of insulin action and secretion in women under hyperglycemic hyperinsulinemic clamp conditions in the midfollicular phase before and 8 weeks after Norplant placement.

SETTING

Yale University Clinical Research Center.

PARTICIPANTS

Seven previously normally cycling, nonobese, nondiabetic women participated in the study.

INTERVENTIONS

Norplant insertion.

MAIN OUTCOME MEASURES

Basal levels of glucose and insulin, as well as glucose-mediated insulin secretion, glucose uptake, and tissue sensitivity to insulin were assessed using the hyperglycemic hyperinsulinemic clamp technique before and after Norplant insertion.

RESULTS

Norplant placement did not alter the fasting glucose or insulin levels. However, it was associated with a significant 37% increase in the first phase insulin response from a control level of 51 +/- 8 to 70 +/- 10 microU/mL (conversion factor to SI unit, 7.175), and a significant 48% increase in the second phase insulin response from 60 +/- 5 to 89 +/- 8 microU/mL. In association with this increase in insulin levels after Norplant insertion, total mean body glucose uptake (M) increased from 8.08 +/- 0.91 to 9.53 +/- 0.95 mg/kg per minute. However, when expressed as the total body glucose uptake per unit of insulin, the M:I ratio (a measure of tissue sensitivity to insulin) decreased significantly from a mean of 0.12 +/- 0.02 to 0.10 +/- 0.01 mg/kg per minute per microU/mL.

CONCLUSION

Although Norplant insertion does not alter basal glucose and insulin levels, tissue sensitivity to insulin under hyperglycemic hyperinsulinemic conditions is decreased after Norplant insertion.

Insulin sensitivity is unaltered by the use of the Norplant subdermal implant contraceptive

Prior evaluations of carbohydrate metabolism in Norplant implant users, using the oral glucose tolerance test, have shown mild but clinically insignificant deterioration of insulin sensitivity. Using the more sensitive insulin tolerance test, the effects of the Norplant implant system on insulin sensitivity was studied in normal women. Insulin tolerance tests were performed before Norplant implant insertion in ten ovulatory female volunteers and repeated after 12 weeks of use. Both fasting glucose and fasting insulin values were similar before and after the use of Norplant implants. There was no significant difference in either the Kitt glucose value or the Kitt insulin value at baseline and at 3 months of use. Furthermore, the insulin-to-glucose ratio did not differ before and after the use of Norplant implants. There was a significant correlation with BMI and Kitt glucose value (r = -0.45, p < .05), as well as between fasting insulin and BMI (r = 0.6, p = 0.006). In the first three months of use, the levonorgestrel-containing implant system, Norplant, does not affect sensitivity to insulin or glucose in normal, nondiabetic women.

RU 486 prevents the acute effects of cortisol on glucose and leucine metabolism

Glucocorticoids have deleterious effects on glucose and protein metabolism. RU 486 is an antiprogestin with antiglucocorticoid activity, which could be used to prevent the undesirable metabolic effects of glucocorticoids. A randomized, controlled, double blind study was performed in eight healthy male volunteers who were tested four times: during the iv infusion of cortisol (2 micrograms/kg.min for 5 h) after the oral ingestion of RU 486 (600 mg) or a placebo, and during the infusion of a normal saline solution with placebo or RU 486 ingestion. During each test, a primed continuous iv infusion of D-[6,6-2H]glucose and [1-13C-]leucine was given for the calculation of hepatic glucose production and plasma leucine appearance rate. 13CO2 enrichment in breath was measured for the calculation of leucine oxidation. Plasma concentrations of cortisol, ACTH, insulin, C-peptide, glucagon, and GH were measured at regular intervals. Compared to saline, cortisol infusion increased plasma glucose 5.5 +/- 0.6 vs. 4.7 +/- 0.4 mmol/L; P < 0.01) and leucine (179 +/- 35 vs. 155 +/- 35 mumol/L; P < 0.01) concentrations as well as the leucine appearance rate (2.24 +/- 0.3 vs. 2.0 +/- 0.28 mumol/kg.min; P < 0.05) and oxidation (0.51 +/- 0.22 vs. 0.39 +/- 0.06 mumol/kg.min; P < 0.01), and there was no change in hepatic glucose production. None of the metabolic changes induced by cortisol were seen when cortisol was administered after the ingestion of RU 486. When RU 486 was given before normal saline infusion, plasma glucose concentrations were transiently lower than those after placebo ingestion, as was the hepatic glucose production. No change in insulin, C-peptide, or glucagon was seen between tests. GH concentrations were higher during cortisol infusion, but not when cortisol was administered after the ingestion of RU 486. The following conclusions were reached. 1) RU 486 can suppress the effects of acute hypercortisolemia on glucose and protein metabolism and GH secretion in man. Long term studies are warranted to explore the potential of antiglucocorticoid molecules as preventive agents of the deleterious effects of chronic glucocorticoid administration. 2) RU 486 is useful molecule for studying the metabolic effects of cortisol in man.

The androgenicity of progestins

All steroid hormones are structurally similar, but relatively minor differences cause profound alterations in biochemical activity. The 21-carbon series (pregnane nucleus) includes the corticoids and the true progestins (e.g., medroxyprogesterone acetate). The 19-carbon series (androstane nucleus) includes all the androgens, among them the progestins used in most oral and parenteral contraceptives. The removal of carbon 19 from testosterone changes the major hormonal effect from androgenic to progestogenic, but these "19-nor" steroids retain varying degrees of androgenic activity. (They can also have limited estrogenic activity, but this is insignificant at the low doses used for contraception.) Some of the 19-nortestosterone progestins are metabolized to other compounds (e.g., norethynodrel, ethynodiol diacetate, and lynestrenol to norethindrone), and some (levonorgestrel, desogestrel) are active unchanged. The lingering androgenic effects of 19-nor progestins are dose-related, opposed by estrogen, and are manifested metabolically (e.g., glucose tolerance, lipoprotein synthesis) and symptomatically (e.g., acne, weight gain). The effect of 19-nortestosterones on lipoproteins prompted the development of less androgenic compounds, but the obvious benefit of the new progestins (desogestrel, gestodene, norgestimate) is a reduction in the symptoms associated with the androgenicity of the older compounds. Mitigation of androgenic effects on lipoprotein and carbohydrate metabolism could have long-term benefits, especially for women who are at risk of arteriosclerotic vascular disease; however, these effects remain to be epidemiologically demonstrated.

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.

Sex differences in the adaptation of glucose metabolism to short-term fasting: effects of oral contraceptives

The adaptation to long-term starvation is different in men and women. To evaluate whether there are also sex differences during short-term fasting (< 24 hours), we studied glucose metabolism after 16 and again after 22 hours of starvation in healthy subjects: six men, six women in both the follicular and luteal phases of their menstrual cycle, and six women on oral contraceptives ([OCC] day 12 of cycle). Glucose oxidation was measured by indirect calorimetry, and hepatic glucose output by infusion of 3-3H-glucose. There were no differences in hepatic glucose output between men and women during short-term fasting. The basal (16 hours) plasma glucose concentration was lower in women on OCC than in men (P < .05). Prolongation of the postabsorptive state induced a similar decline in plasma glucose concentrations in all groups. Basal (16 hours) glucose oxidation was lower in women on OCC than in men (P < .05). Prolongation of the postabsorptive state by 6 hours caused a significant decrease in glucose oxidation only in men. After 22 hours of fasting, glucose oxidation was lower in women on OCC than in women with normal menstrual cycles. In conclusion, the metabolic adaptation to the postabsorptive state (< 24 hours of fasting) is regulated differently in women on OCC as compared with women with normal menstrual cycles and men. These differences preclude inclusion of women on OCC in studies of glucose metabolism in the postabsorptive state.

Low amniotic fluid glucose levels are a specific but not a sensitive marker for subclinical intrauterine infections in patients in preterm labor with intact membranes

OBJECTIVE

The purpose of this study was to evaluate the ability of a low amniotic fluid glucose level, as defined by previously published thresholds, to identify a subclinical intrauterine infection in women in preterm labor with intact membranes.

STUDY DESIGN

Amniotic fluid glucose levels, amniotic fluid cultures, and placental histologic characteristics were determined in women with preterm labor (n = 55) and in preterm controls (n = 58). These amniotic fluid glucose levels were compared between women with and without intrauterine infection using the Mann-Whitney U test. The sensitivity, specificity, and positive and negative predictive values for the identification of an intrauterine infection were determined with four different previously published amniotic fluid glucose threshold levels and the threshold from receiver-operator characteristic curve analysis of the study data.

RESULTS

The median amniotic fluid glucose level was significantly lower in patients with positive amniotic fluid cultures (intraamniotic infection group) but was not lower in the group of patients with only histologic chorioamnionitis (extra-amniotic infection group), compared with noninfected controls. The sensitivity of a low amniotic fluid glucose level to detect both types of intrauterine infection ranged from 41% to 55%, depending on the threshold used. The specificity of a low amniotic fluid glucose level to detect an intrauterine infection ranged from 94% to 100%, the positive predictive value ranged from 86% to 100%, and the negative predictive value ranged from 70% to 80% with the same thresholds.

CONCLUSION

Low amniotic fluid glucose levels are a specific but not a sensitive marker for either intraamniotic or extra-amniotic intrauterine infections in patients with preterm labor.

Update on the metabolic effects of steroidal contraceptives and their relationship to cardiovascular disease risk

Evaluation of metabolic disturbances has had an important role in the modification of oral contraceptive formulations toward estrogen-progestin combinations with reduced adverse metabolic impact. An increasing number of interrelationships between metabolic risk factors for cardiovascular disease are being recognized, and a metabolic syndrome of disturbances has been identified with insulin resistance as a potential underlying factor. The insulin resistance syndrome includes hyperinsulinemia and impaired glucose tolerance, hypertriglyceridemia, reduced high-density lipoprotein concentrations, and hypertension. Increased concentration of a small, dense, low-density lipoprotein subtype may also be important. Depending on steroid type and dose, combined oral contraceptives may induce all the features of the insulin resistance syndrome. Reduction in estrogen dose and modification of progestin content have resulted in formulations with no adverse effect on high-density lipoprotein and blood pressure, but insulin resistance and hypertriglyceridemia remain. These are caused primarily by the estrogen component. Therefore modification of the estrogen content of oral contraceptives might result in "metabolically transparent" formulations that could conceivably afford a degree of cardiovascular protection.

Clinical and metabolic features of desogestrel: a new oral contraceptive preparation

Desogestrel is a highly selective gonane progestin. A monophasic formulation containing 150 micrograms of desogestrel and 30 micrograms of ethinyl estradiol has recently been approved as an oral contraceptive (OC) in the United States. Although desogestrel-containing formulations are new to the United States, they have been the most widely prescribed OCs in Europe for almost 10 years. An extensive literature demonstrates that desogestrel-containing preparations are safe, effective, and well tolerated by most women. In light of desogestrel's high selectivity, low affinity for androgen receptors, and lack of interference with the increase in sex hormone-binding globulin, desogestrel-containing OCs may be particularly appropriate for women with androgen-induced skin disorders because of their high selectivity. Several European studies have found significant improvement or almost complete resolution of previously existing acne. Desogestrel provides excellent cycle control, no major impact on weight, minimal or no adverse effects on blood pressure, statistically significant increases in high-density lipoprotein cholesterol with low-density lipoprotein cholesterol usually unchanged or reduced, and little effect on glucose tolerance or insulin resistance.

Efficacy and safety of a monophasic and a triphasic oral contraceptive containing norgestimate

Both monophasic and triphasic formulations of ethinyl estradiol plus norgestimate, a progestin with marked progesterone-receptor affinity and minimal androgen-receptor affinity, have been evaluated in numerous clinical studies designed to determine if norgestimate's receptor-binding profile provides enhanced safety without a reduction in efficacy. To date clinical trials have shown that both formulations of ethinyl estradiol/norgestimate offer contraceptive efficacy equivalent to that of other oral contraceptives. Monophasic ethinyl estradiol/norgestimate was associated with an incidence of breakthrough bleeding and spotting similar to that of monophasic ethinyl estradiol/norgestrel and an incidence of amenorrhea less than that of ethinyl estradiol/norgestrel. Cycle control with triphasic ethinyl estradiol/norgestimate was similar to that with monophasic ethinyl estradiol/norgestimate. Weight gain and elevated blood pressure were insignificant in clinical trials with both fixed-dose and phasic ethinyl estradiol/norgestimate formulations. Perhaps of greatest importance, both monophasic and triphasic ethinyl estradiol/norgestimate formulations consistently showed favorable impact on metabolic parameters, including elevations in serum high-density lipoprotein cholesterol, and reductions in the low-density lipoprotein/high-density lipoprotein ratio, the parameter considered most sensitive for atherosclerotic risk. Both monophasic and triphasic ethinyl estradiol/norgestimate formulations were associated with minimal and clinically neutral effects on carbohydrate metabolism.

Carbohydrate metabolism studies after one year of using an oral contraceptive containing gestodene and ethinyl estradiol

The objective of the study is to evaluate the effects of a gestodene-containing oral contraceptive on carbohydrate metabolism. The design of the study is prospective. The setting is at University of South Florida Outpatient Unit. The patients consisted of twenty-three normal women desiring contraception. Serum glucose and insulin levels were measured during a three-hour glucose tolerance test at control time and after one year of drug use.

RESULTS

All of the one-year glucose values were significantly elevated as well as the fasting and three-hour insulin values. These changes were mostly confined to women over 26 years of age and not in the younger 18 to 23 year olds. An oral contraceptive containing 75 micrograms of gestodene and 30 micrograms of ethinylestradiol can significantly alter carbohydrate metabolism in older women.

Prospective evaluation of insulin resistance and lipid metabolism in women receiving oral contraceptives

OBJECTIVES

It has been suggested that normal women receiving oral contraceptives (OC) may develop a series of metabolic side-effects which relate to the risk of cardiovascular disease. These metabolic disturbances include changes in glucose and insulin metabolism, raised serum lipid and lipoprotein concentrations and elevated blood pressure. All these changes indicate that OC might cause insulin resistance. We have prospectively examined the effect of OC on insulin resistance and lipid metabolism including Lp(a) values.

PATIENTS

The study group comprised 13 normally menstruating Chinese women.

DESIGN

The study subjects were given a combined triphasic oral contraceptive which was administered on a 21-day on, 7-day off medication cyclic regimen, the first pill being administered on day 5 from the beginning of menses. The metabolic investigations were carried out during luteal phase before OC and again the third week of the third month of OC administration.

MEASUREMENTS

Metabolic evaluation including insulin secretion and insulin-mediated glucose uptake were evaluated by oral glucose tolerance test and the modification of insulin suppression test. Fasting triglyceride, cholesterol, HDL-cholesterol and Lp(a) concentrations were also measured.

RESULTS

The plasma glucose and insulin responses during a 75-g oral glucose challenge increased significantly (P < 0.05 and P < 0.03, respectively). The steady-state plasma glucose (SSPG) concentrations achieved during constant infusion of glucose, insulin and somatostatin increased significantly after 3 cycles of OC administration (glucose 7.5 +/- 0.8 vs 12.4 +/- 0.7 mmol/l, P < 0.001) while the steady-state plasma insulin (SSPI) concentrations were relatively similar (410 +/- 14 vs 391 +/- 7 pmol/l, NS). Plasma triglyceride levels increased significantly (0.81 +/- 0.12 vs 1.09 +/- 0.19 mmol/l, P < 0.03) following OC administration. Fasting plasma cholesterol, HDL cholesterol and calculated LDL cholesterol concentrations did not change as compared with baseline values, nor did the ratio of total cholesterol to HDL cholesterol. The Lp(a) concentrations did not change during the administration of OC (81 +/- 25 vs 71 +/- 21 mg/l, NS).

CONCLUSIONS

These data indicated that intake of OC for 3 cycles induced glucose intolerance, hyperinsulinaemia and insulin resistance in normal menstruating Chinese women. These changes occurred in association with elevated plasma triglyceride concentrations and no alteration in Lp(a) or other lipid values.

New progestogens in oral contraception

The major developments in combined oral contraceptives (COCs) have been a reduction in the total dose of both the oestrogen and progestogen administered per cycle and the introduction of new progestogens which are claimed to be more 'selective' than the older ones. This review examines in detail the clinical efficacy of the new COCs, where possible in comparison with those containing levonorgestrel or norethisterone, and their pharmacological effect on carbohydrate and lipid metabolism, haematological factors, pituitary-ovarian function and serum protein and androgen concentrations. Based mainly on the pharmacological evidence, the newer COCs are an improvement over the older low-dose formulations and are clearly preferable to the high-dose ones. However, the older low-dose COCs, despite many years of use, have not resulted in a high incidence of adverse effects. The increasing use of the new COCs, as evidenced by their increasing market share throughout Europe, does indicate that they have been well accepted in clinical practice.

Insulin sensitivity is decreased in normal women by doses of ethinyl estradiol used in oral contraceptives

OBJECTIVE

We determined the independent effects of various doses of ethinyl estradiol used in oral contraceptives or norethindrone acetate, as well as their combination, on insulin sensitivity in normal women.

STUDY DESIGN

Thirty-three normal ovulatory female volunteers were recruited for this study. Insulin tolerance tests were performed after carbohydrate loading to determine the kinetic disappearance of glucose and insulin. After initial testing the women were randomized into four groups: ethinyl estradiol 20 micrograms, 35 micrograms, and 50 micrograms and norethindrone 1 mg. Insulin tolerance tests were repeated after 1 month of treatment and again after a second month, when all ethinyl estradiol groups received the addition of norethindrone 1 mg to their doses of ethinyl estradiol. Plasma glucose and insulin were measured, and insulin sensitivity (K(itt) glucose) and the disappearance of insulin (K(itt) insulin) were calculated.

RESULTS

All groups were comparable at baseline, and no significant changes in fasting glucose and insulin were evident with treatment. After ingestion of 50 micrograms ethinyl estradiol the K(itt) glucose value decreased significantly (p < 0.03) and ingestion of 20 micrograms and 35 micrograms showed individual changes, but as groups the changes were not statistically significant. All ethinyl estradiol groups combined had a significant decrease in K(itt) glucose (p < 0.01). Norethindrone 1 mg alone did not change K(itt) glucose values, and after the addition of norethindrone to ethinyl estradiol, K(itt) glucose values normalized. K(itt) insulin values were also lower with treatment but were lower with ethinyl estradiol plus norethindrone compared with ethinyl estradiol alone (p < 0.04), suggesting an attenuation of insulin clearance with the progestin.

CONCLUSION

Ethinyl estradiol alone decreases insulin sensitivity, and this may occur at lower doses, but norethindrone 1 mg does not appear to do so. However, progestins may alter insulin clearance.

Progestogens: a look at the "other" hormone

Health care providers need a general understanding of progestogens to use them safely and effectively in practice. These hormone formulations are used extensively in combination oral contraceptives and in hormonal replacement therapy with estrogen or alone. Although considered relatively safe for most women, it is important to look closely at the actions of the various progestogens and associated impacts. Major concerns regarding the use of these preparations center on potential untoward lipoprotein changes, carbohydrate metabolism alterations, and breast cancer. Other concerns relate to coagulation effects, prostacyclin changes, sex hormone-binding globulin capacity, psychological disturbances, blood pressure alterations, breakthrough bleeding, headaches, and other side effects. Over the years progestogen preparations have evolved into safer formulations with fewer apparent risks.

Effects of a low-estrogen, desogestrel-containing oral contraceptive on lipid and carbohydrate metabolism

Fasting serum lipids, lipoproteins and apolipoproteins, and fasting plasma glucose, insulin and C-peptide were measured in 107 non-users and 83 users of an oral contraceptive containing the progestin desogestrel, combined with 20 micrograms ethinyl estradiol. Plasma glucose, insulin and C-peptide concentrations during an oral glucose tolerance test (OGTT) were measured in a subgroup of 69 non-users and 39 users. Compared with non-users, users had higher concentrations of total, high density lipoprotein (HDL), HDL subfraction 3 and very low density lipoprotein (VLDL) cholesterol, total triglycerides, VLDL triglycerides, apolipoproteins AI and AII and fasting plasma insulin. There were no differences in HDL subfraction 2, low density lipoprotein cholesterol and apolipoprotein B. OGTT glucose was 60% higher in the users and OGTT insulin response 19% higher. The OGTT C-peptide response did not differ. The effects of 20 micrograms ethinyl estradiol combined with 150 micrograms desogestrel on lipid, lipoprotein, glucose and insulin metabolism are similar to those described previously with a 30 micrograms ethinyl estradiol combination containing the same dose of desogestrel. The relatively favourable metabolic profile associated with the higher estrogen dose desogestrel combination is maintained at the lower dose.

Effects of a 1-year treatment with a low-dose combined oral contraceptive containing ethinyl estradiol and cyproterone acetate on glucose and insulin metabolism

OBJECTIVE

To study the effects of the slightly estrogen-dominant monophasic low-dose oral contraceptive (OC) Diane-35 (Schering AG, Berlin, Germany) (35 micrograms ethinyl estradiol [EE2] + 2 mg cyproterone acetate, a 17 alpha-hydroxyprogesterone derivative [17-OHP]) on glucose and insulin metabolism.

DESIGN

Seven healthy young women were investigated by using the euglycemic hyperinsulinemic glucose clamp technique (insulin delivery rate = 100 mU/kg per hour for 120 minutes). This test was performed, after an overnight fast, during the last 7 days of a spontaneous cycle and within the last 5 days of pill intake during the sixth and twelfth cycle of a continuous treatment with Diane-35 in each subject.

RESULTS

The three indexes measuring the insulin-induced glucose disposal during the clamp (glucose infusion rate, glucose metabolic clearance rate, and glucose infusion rate divided by plasma insulin plateau levels) were not significantly affected by Diane-35. In contrast, the metabolic clearance rate of the exogenous insulin infused during the clamp tended to be slightly increased with Diane-35 (significant after 6 but not after 12 cycles).

CONCLUSION

These results suggest that a 1-year treatment with the OC Diane-35, which contains EE2 + a 17-OHP rather than a 19-nortestosterone derivative as the progestogen compound, does not significantly alter peripheral (presumably muscular) insulin sensitivity but slightly increases insulin (presumably hepatic) clearance.

The effects on hemostasis of oral contraceptives containing desogestrel

Epidemiologic research has shown that current low-dose estrogen oral contraceptives are associated with a low risk of vascular events (e.g., myocardial infarction, stroke, and venous thrombosis or thromboembolism). Yet questions still persist about the effects of low-dose oral contraceptives on the cardiovascular system. Changes in the coagulation system have been linked primarily to the estrogen component; however, it has been proposed that the progestin may have an influence on the fibrinolytic system. Desogestrel, a new gonane progestin, has been commercially available in Europe since 1981. It has been widely shown to produce minimal changes of the coagulation and fibrinolytic systems, and it has not been associated with an increased risk of thromboembolic disorders.

Effects of desogestrel on carbohydrate metabolism

Associated with progesterone and the synthetic progestins used in oral contraceptives is a dose-dependent impairment of carbohydrate metabolism. It is well known that in the general population hyperinsulinemia and alterations in glucose metabolism are significant risk factors for the development of cardiovascular disease. Studies that use curve analysis of glucose tolerance tests have demonstrated insulin resistance, rises in plasma insulin, and relative glucose intolerance in women using oral contraceptives. Desogestrel, a new progestin, has been demonstrated to have generally less pronounced effects on these parameters of carbohydrate metabolism.

The effect of a biphasic desogestrel-containing oral contraceptive on carbohydrate metabolism and various hormonal parameters

During 6 cycles of treatment of 19 women, the effect of a low-dose biphasic oral contraceptive containing 40 micrograms ethinylestradiol + 25 micrograms desogestrel (7 tablets) and 30 micrograms ethinylestradiol + 125 micrograms desogestrel (15 tablets) on various hormonal parameters and glucose metabolism was compared with the values of the pre- and post-treatment cycle. There was a profound reduction in gonadotropin secretion and ovarian steroid synthesis. The serum levels of testosterone were reduced by 35%, free testosterone by 55%, and DHEA-S by 30%. Cortisol increased by 100%, SHBG by 250%, and TBG by 60%, while FT3 and FT4 were only marginally influenced. Fasting levels of glucose and insulin did not change significantly, but the glucose load revealed a slight impairment of glucose tolerance. Three weeks after termination of pill intake, the various parameters returned to pretreatment levels, except for SHBG and TBG which were still elevated by 20 to 30%. The results demonstrate a marked preponderance of the effect of the estrogen component, a reliable inhibition of ovulation and very good cycle control during treatment with the biphasic formulation.

Combined oral contraceptives: acceptability and effective use

With over 60 million users of 'the pill' worldwide, safety and efficacy remain the two most relevant issues to both the consumer and the research scientist. Safety of combined oral contraception (COC) has advanced appreciably. Lessons learned from cohort and case-control studies have been applied to the practical management of oral contraception use, based on screening, selection and regular monitoring of users. Most health risks of COCs appear to be dependent on the dose and potency (or biological impact) of the constituent steroids. While many of the non-contraceptive benefits of COCs are maintained when modern low dose preparations are used, most, if not all, of the adverse effects have been reduced progressively. Moreover the range of modern hormonal contraceptives has widened with the introduction of a new generation of 'selective' progestogens (Desogestrel, Norgestimate and Gestodene), which have minimal androgenicity. User failure of COCs is still high in many countries. The cause is a combination of poor compliance and anxiety about perceived adverse effects. Compliance can be enhanced by improving the quality of instruction in pill use. Fears of adverse effects of COCs may be allayed through education of users and providers, and sympathetic management of side effects.

Clinical experience and pharmacological effects of an oral contraceptive containing 20 micrograms oestrogen

The performance of a new low-dose oral contraceptive (Mercilon) containing only 20 micrograms ethinyloestradiol combined with 150 micrograms desogestrel is reviewed. Eight multicentre clinical trials have been completed and provide information on 10,672 women studied over 73,477 cycles. The high efficacy of Mercilon was indicated by the finding that only 10 pregnancies were reported; nine of these occurred in women who omitted to take Mercilon on a number of days and only one in a woman who took all the tablets according to instructions. Cycle control was good; as with all oral contraceptives, the incidence of breakthrough bleeding and spotting was highest in the first treatment cycle and by the sixth treatment cycle the values were usually < 5% and < 7%. More than 80% of women had regular cycles. Side effects were few, the most common being headache, nausea and breast tenderness with incidences in the sixth treatment cycle of less than 2%, 6% and 6%, respectively. There were no significant changes in body weight or blood pressure. Pharmacodynamic investigations showed no adverse effects. Only 1 of 5 studies found an increased response to a glucose tolerance test compared to the pretreatment test. In 8 of 10 studies, serum HDL-C concentrations increased on treatment and this was associated with increases in apoproteins A1 and A2. Serum triglyceride levels also increased but no change occurred in serum cholesterol or LDL-C levels. Haematological factors were assessed in 8 studies and only minor changes were observed. Serum binding protein (SHBG, CBG, caeruloplasmin) concentrations increased and serum androgen levels decreased. Measurements of blood FSH, LH, oestradiol and progesterone indicated adequate inhibition of ovulation. Mercilon is the only oral contraceptive containing 20 micrograms ethinyloestradiol to have high efficacy, to have no adverse pharmacodynamic effects and, importantly, to produce an acceptable bleeding pattern not significantly different from that of oral contraceptives with a higher content of ethinyloestradiol.