Clinical and metabolic considerations of long-term oral contraceptive use

Management of Polycystic Ovary Syndrome

Polycystic ovary syndrome is a common endocrinological problem in women of reproductive age. Polycystic ovary syndrome is a heterogenous disorder and patients may attend different clinics depending on the main complaint. The exact pathophysiology of polycystic ovary syndrome remains obscure, although there have been insights that have thrown light on this condition. Consensus on the definition of the syndrome has only been recently achieved. The management of polycystic ovary syndrome poses a challenge to the physician as responses to the different treatment regimes have proved to be inconsistent. Diet and lifestyle advice, restoration of menstrual cycle regularity, treatment of hyperandrogenism, treatment of infertility and prevention of long-term consequences form the basis of polycystic ovary syndrome management. This review aims to provide the reader with the latest evidence in the treatment of polycystic ovary syndrome, as well as focus on some of the controversies surrounding its management.

Effect of oral contraceptive use on lipid profile in Korean women aged 35-55 years

BACKGROUND

Although oral contraceptives (OCs) are widely used, their effects on lipid profile need monitoring according to current usage in different populations.

STUDY DESIGN

A cross-sectional study was conducted using data from 1541 participants aged 35-55 years collected by the 2005-2009 Korea National Health and Nutrition Examination Surveys. OC use, demographic characteristics and dietary intake were obtained from the participants by questionnaire, and lipid levels were determined by analysis of blood samples.

RESULTS

Longer duration of OC use was positively associated with increasing levels of high-density lipoprotein cholesterol (HDL-C) and decreasing levels of low-density lipoprotein cholesterol (LDL-C). After adjusting for demographic and dietary factors, the odds ratio (OR) of low HDL-C (<50 mg/dL) was significantly decreased in the longer-term (>12 months) OC users (OR=0.36, 95% confidence interval 0.24-0.52) compared with those who never used OCs. However, use of OCs was not associated with a risk of high total cholesterol (≥ 240 mg/dL), high LDL-C (≥ 130 mg/dL), high triglycerides (≥ 150 mg/dL) or high ratio of triglycerides to HDL-C (>3.8).

CONCLUSIONS

These data suggest that the use of OCs may reduce the risk of dyslipidemia, mainly due to the decreased risk of low HDL-C, in Korean women.

Effect of low-dose oral contraceptives on metabolic risk factors in African-American women

CONTEXT

The effect of oral contraceptive pill (OCP) use on cardiovascular risk in African-American women is unknown.

OBJECTIVE

Our objective was to examine in African-American women the effect of OCP use on insulin resistance, glucose intolerance, and triglycerides (TGs).

DESIGN

This was a cross-sectional study.

SETTING

The study was conducted at the National Institutes of Health Clinical Research Center.

PARTICIPANTS

A total of 104 healthy nondiabetic African-American women [21 OCP users, 83 controls, age mean +/- sd, 34.7 +/- 7.6 yr, body mass index (BMI) 31 +/- 8.4 kg/m(2)] was included in the study.

INTERVENTIONS

Subjects had oral glucose tolerance tests, insulin-modified frequently sampled iv glucose tolerance tests, and fasting lipid profiles. Insulin resistance was determined by the insulin sensitivity index (S(I)).

MAIN OUTCOME MEASURES

Insulin resistance, glucose tolerance status, and TG levels were determined.

RESULTS

Fasting glucose did not differ between OCP users and controls (P = 0.27). In contrast, compared with controls, 2-h glucose (135 +/- 23 vs.120 +/- 25 mg/dl; P = 0.01) and fasting TGs (73 +/- 31 vs.57 +/- 27 mg/dl; P = 0.02) were higher in OCP users. OCP users tended to be more insulin resistant than controls (S(I): 2.51 +/- 2.01 vs. 3.46 +/- 2.09; P = 0.09). Multiple regression analysis revealed that BMI, age, and OCP use were significant determinants of 2-h glucose (adjusted R(2) = 0.37; P < 0.001) and TG levels (adjusted R(2) = 0.21; P < 0.001). As BMI was a determinant of both 2-h glucose and TGs, participants were divided into nonobese and obese groups, and the analyses repeated. Among the nonobese women, the OCP users were more insulin resistant (S(I): 2.91 +/- 1.58 vs. 4.35 +/- 1.88; P = 0.03) and had a higher prevalence of glucose intolerance than controls (odds ratio 5.7; 95% confidence interval 1.4-24; P = 0.01).

CONCLUSION

In African-American women, OCP use is associated with an increase in markers of cardiovascular risk manifested by increased insulin resistance, glucose intolerance, and elevated TGs.

Effect of glucomannan and the dosage form on ethinylestradiol oral absorption in rabbits

To the beneficial properties of dietary fiber in human health, several disadvantages can be added as the possible modification of the bioavailability of other drugs when administered by the oral route. In this study, the influence of glucomannan in the oral bioavailability of ethinyl estradiol (EE), when administered to female rabbits in two different dosage forms (enteric capsules and dispersed in water), was established. To carry out the study, three groups of six animals each were used. All animals received 1 mg kg(-1) oral EE, and rabbits in groups 2 and 3 received 1.5 g glucomannan dispersed in water or in enteric capsules, respectively, immediately before EE. When comparing the results obtained after the administration of EE/glucomannan dispersed in water with those obtained after the administration of this estrogen without fiber, we can see that Cmax is 1.4 times lower, AUC 1.9 times lower and that tmax is identical (10 min). However, after the administration of fiber in enteric capsules, AUC and Cmax are higher (4.1 and 7.8 times, respectively) than when the estrogen was administered alone, and also, there is a delay in tmax (20 min). After the administration of glucomannan in the enteric capsule, the fiber forms, as in the stomach, a highly viscous solution in the gut that would limit EE access to the mucosal surface delaying its absorption. However, this effect could be compensated by a reduction of EE metabolism in the intestinal wall, leading to a higher absorption of the estrogen.

Influence of two dietary fibers in the oral bioavailability and other pharmacokinetic parameters of ethinyloestradiol

Dietary fibers are widely used in hypoglycaemic, hypolipidemic, slimming diets. It is probable that their ingestion coincides with the oral administration of drugs and a modification of their pharmacokinetics can appear. In the present study, the influence of two soluble fibers (guar gum and psyllium) was evaluated on the pharmacokinetics of ethinyloestradiol (EE) when they were administered together to female rabbits via the oral route. Three groups of rabbits were used. All animals received 1 mg/kg of EE; this compound was administered alone in the control group and with 3.5 g of guar gum or psyllium in the other two groups. When guar gum was administered, there was a decrease in the extent of EE absorbed, but no change was observed in the rate of absorption. When psyllium was administered, the extent of EE absorbed increased slightly and the rate of absorption was slower.

Inhibiting effect of ethinylestradiol/levonorgestrel combination on microsomal enzymatic activities in rat liver and kidney

The aim of the study was to evaluate the effects of two therapeutic combinations of ethinylestradiol (EE) and levonorgestrel (LE), which are used in triphasic contraceptives, on the activities of drug-metabolizing enzymes in rat liver and kidney. Sexually mature female Wistar rats were given 0.03 mg EE and 0.05 mg LE, or 0.03 mg EE and 0.125 mg LE for 6 or 18 sexual cycles, i.e. for 30 or 90 days. EE/LE inhibited not only the metabolic capacity of P450, a protein which directly undergoes suicide inhibition, but also the level of rat liver cytochrome b5 (dependent on the heme pool) as well as the activities of NADPH-cytochrome P450 reductase and NADH-cytochrome b5 reductase in the liver and kidney. The majority of these effects were independent of the gestagen dose and of the duration of treatment, suggesting that estrogen is a predominant inhibiting factor in the EE/LE combination. The study has revealed differences in the enzyme activities between the liver and kidney, which may result from the fact that these organs display different sets of P450 isoforms and, therefore, their monooxygenase systems show distinct capacities to metabolize exogenous steroids.

Smoking status and nicotine administration differentially modify hemodynamic stress reactivity in men and women

OBJECTIVES

To investigate the impact of cigarette smoking and oral contraceptive (OC) use on hemodynamic stress responses of women. Also, to examine gender differences in stress reactivity as a function of smoking status and acute nicotine administration.

METHODS

Thirty men and 46 women, differing in smoking status and OC use, were tested for cardiovascular stress responses to a variety of behavioral and physical stressors. Each was tested twice, once under a transdermal nicotine patch condition and once under a placebo patch condition. Impedance cardiography was used to estimate hemodynamic reactivity noninvasively.

RESULTS

In response to behavioral stressors, women smokers, irrespective of OC use or nicotine vs placebo, demonstrated significantly blunted cardiac output and heart rate reactivity to stressors, and showed significantly greater estimated total peripheral resistance (TPR) under stress relative to women nonsmokers. There were no differences in hemodynamic stress reactivity between men smokers and nonsmokers. The only significant effect involving nicotine administration on stress reactivity was seen in men where, regardless of smoking status, nicotine increased heart rate reactivity to all stressors relative to placebo responses.

CONCLUSIONS

Results suggest that cigarette smoking may act differently in men and women to increase risk for cardiovascular disease (CVD). For men, nicotine may exert pathogenic influences via increasing the magnitude of heart rate reactivity to stressors. For women, however, smoking seems to have deleterious effects on hemodynamic stress reactivity patterns, reducing myocardial but increasing TPR contributions to blood pressure responses.

Sex hormone preparations and retinal vein occlusion

Retinal vein occlusion (RVO) is most commonly seen in middle-aged or older patients and is associated with underlying cardiovascular risk factors. It is much less common in younger patients. Use of the oral contraceptive pill (OCP) is known to be a risk factor for cardiovascular and cerebrovascular disease. There have previously been a few isolated case reports of patients sustaining an RVO whilst taking the OCP. The aim of this study was to investigate patients sustaining an RVO whilst taking the OCP or hormone replacement therapy (HRT). From a large series of 588 patients, we found 11 with an RVO associated with sex hormone preparations. Of these, 6 had taken the OCP and 5 were HRT users. From this large group there were only 9 female patients aged under 35 years who sustained an RVO. Of these, 6 were associated with use of the OCP. All patients were investigated for recognised medical risk factors for RVO. None of these factors were identified in the patients who had used the OCP. Of the patients taking HRT, 4 of the 5 had other potential risk factors. From our large series, the prevalence of RVO in female patients under 35 years taking the OCP was 66%. There is a 30% uptake of the OCP in the general population. These data support the view that RVO is a contraindication to the use of the OCP. Additionally, it would appear (albeit from limited data) that patients who sustain RVO may continue with their HRT, as HRT is not a major single risk factor for RVO.

Pharmacokinetics of ethinyloestradiol in rabbits after intravenous administration

The pharmacokinetics of ethinyloestradiol (EE2) after intravenous administration of 30, 50 and 100 micrograms.kg-1 was investigated in rabbits. A high-performance liquid chromatographic (HPLC) method with electrochemical (EC) detection was used to measure EE2 in plasma samples in order to avoid the interferences of natural oestrogens. After compartmental analysis, the disposition of EE2 was well described by a two-compartmental open model with mean values of: alpha = 0.3448 +/- 0.2922, 0.1965 +/- 0.1755, 0.3058 +/- 0.1225 min-1, and beta = 0.0137 +/- 0.0018, 0.0140 +/- 0.0065, 0.0198 +/- 0.0066 min-1, for the three doses studied, respectively. There were no dose-related differences (ANOVA, P < 0.05) in a, b or Vss, but significant differences were detected in clearance (90.9 +/- 18.7; 80.6 +/- 17.6; 116.3 +/- 21.5 ml.min-1.kg-1) between the 100 micrograms.kg-1 group and lower dose groups. The AUC increased significantly with the doses (341.7 +/- 67.1; 645.8 +/- 143.9; 892.2 +/- 211.9 ng.min.ml-1). After non-compartmental analysis there were no significant differences in lambda, MRT or Vss as a function of dose, but these differences were significant when Cl or AUC were compared. There were no significant differences in AUC or Cl values obtained by compartmental and non-compartmental analysis.

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.