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Biomedical subjects

R T Burkman

Publications and source records attributed to R T Burkman.

At least 19 recordsLinked to original sources
PubMed1997

The estrogen component of OCs: cardiovascular benefits and risks.

The relationship of oral contraceptive (OC) use to risk of venous thrombolism, stroke, and myocardial infarction continues to be evaluated. The estrogen component of combination OCs, which is primarily responsible for maintaining the endometrium and minimizing breakthrough bleeding (BTB) and spotting, was the initial focus of clinical and epidemiologic interest following early reports of an increased risk of vascular events with high-estrogen-dose formulations. OC estrogen continues to hold attention; current areas or interest include the relationship of estrogen to laboratory changes in hemostatic, lipid/lipoprotein, and carbohydrate variables, and, more important, to their possible clinical consequences. The historical view that OC-induced lipoprotein changes are responsible for observed increases in vascular risk in OC users is being debated, but the preponderance of evidence suggests that CO-related vascular disease is most likely due to thrombosis rather than atherosclerosis. This issue is made somewhat moot, however, by cumulative epidemiologic data indicating that although some combination OCs containing < or = 35 micrograms estrogen appear to produce a slight increase in the risk of venous thromboembolism, they have no adverse effect on the risk of myocardial infarction and minimal, if any, effect on the risk of stroke. The risks that may be associated with cigarette smoking and concomitant OC use have recently emerged as a somewhat contested issue relative to estrogen dose. Critical examination of the available information suggests that women over 35 years of age who smoke should be advised to use non-estrogen contraceptive methods and that smokers under age 35 may use any OC containing < 50 micrograms estrogen.

Adult↗
PubMed1995

Oral contraceptives: an update.

Despite continual improvement in oral contraceptive formulations, many women still have unwarranted concerns about their safety and remain ignorant of their nonreproductive health benefits. The need for a reliable method of contraception is the greatest among adolescents and women older than 35 years--the two groups in the United States with the highest abortion rates.

Adolescent↗
PubMed1995

The role of oral contraceptives in the treatment of hyperandrogenic disorders.

The clinical manifestations associated with hyperandrogenism, such as hirsutism and acne, are disturbing to most patients. In addition to correcting androgen-related problems, concerns such as contraception or other metabolic problems (for example, lipid/lipoprotein abnormalities, diabetes, hypertension) associated with these disorders and the effects of unopposed estrogen on the endometrium also need to be considered. Oral contraceptives are a therapeutic modality that may address these multiple problems. The potential mechanisms of action by which oral contraceptives correct excess androgen states include gonadotropin suppression, reduction of circulating androgens, increased androgen binding, suppression of adrenal androgen secretion and inhibition of 5 alpha-reductase, and androgen receptor binding. In normal women, there is good evidence that these actions occur with the use of oral contraceptives. Among women with anovulatory hyperandrogenic states, such as polycystic ovary syndrome, the response to oral contraceptives in each of these areas is somewhat more variable. However, oral contraceptive preparations that are more estrogen dominant appear to produce many of the desired effects. From a clinical standpoint, 60-100% of women with hirsutism improve on oral contraceptives; acne shows improvement in a high percentage of women as well. The use of oral contraceptives also reduces the risk of endometrial hyperplasia that may be associated with anovulatory states. Finally, current low-dose preparations containing the newer progestins (for example, norgestimate and desogestrel) appear to be either neutral, or perhaps beneficial, with respect to their metabolic impact.

Adrenal Glands↗
PubMed1994

Noncontraceptive effects of hormonal contraceptives: bone mass, sexually transmitted disease and pelvic inflammatory disease, cardiovascular disease, menstrual function, and future fertility.

Noncontraceptive actions of oral contraceptives (OCs) include hormonal effects on bone mass, sexually transmitted disease, pelvic inflammatory disease, the cardiovascular system, menstrual function, and future fertility. Information about the effects of OCs on bone mass is limited and contradictory. Two recent studies failed to show a positive effect of OC use on bone mass or density compared with the three cross-sectional studies and one longitudinal study that showed favorable effects. A recently completed study of 156 healthy females indicated a significant correlation between OC use and the rate of change in total body bone-mineral content. One study involving depot medroxyprogesterone acetate suggests bone density decreases with long-term use of the drug. The use of OCs does not reduce the risk of gonococcal or chlamydial infection of the lower tract and in fact may enhance spread of lower tract infection. However, OCs may exert a protective effect against some types of pelvic inflammatory disease. Regarding transmission of human immunodeficiency virus, the results of recent studies are conflicting. Research related to newer OC formulations containing 35 micrograms or less of ethinyl estradiol suggests that the risk of a negative cardiovascular effect is substantially reduced. All forms of hormonal contraception alter menstrual function to some degree, but most patterns improve with duration of use. No evidence exists that hormonal contraception permanently affects fertility, although fertility restoration may be delayed with some agents.

Bone Density↗
PubMed1994

A continuous quality improvement project to improve the quality of cervical Papanicolaou smears.

OBJECTIVE: To improve the quality of cervical Papanicolaou smears by continuous quality improvement techniques. METHODS: The study used a Papanicolaou smear data base of over 200,000 specimens collected between June 1988 and December 1992. A team approach employing techniques such as process flow-charting, cause and effect diagrams, run charts, and a randomized trial of collection methods was used to evaluate potential causes of Papanicolaou smear reports with the notation "inadequate" or "less than optimal" due to too few or absent endocervical cells. Once a key process variable (method of collection) was identified, the proportion of Papanicolaou smears with inadequate or absent endocervical cells was determined before and after employment of a collection technique using a spatula and Cytobrush. We measured the rate of less than optimal Papanicolaou smears due to too few or absent endocervical cells. RESULTS: Before implementing the new collection technique fully by June 1990, the overall rate of less than optimal cervical Papanicolaou smears ranged from 20-25%; by December 1993, it had stabilized at about 10%. CONCLUSION: Continuous quality improvement can be used successfully to study a clinical process and implement change that will lead to improvement.

Databases, Factual↗
PubMed1993

Lipid metabolism effects with desogestrel-containing oral contraceptives.

Desogestrel is a gonane progestogen that in early studies had an improved ratio between desired progestational effects and undesired androgenic effects. A review of more than 50 clinical studies suggests that desogestrel differs from progestins currently used in oral contraception in that it does not interfere with the estrogen effects on lipoprotein metabolism. This profile is attributable to the high selectivity of desogestrel.

Animals↗
PubMed1993

A randomized trial of three oral contraceptives: comparison of bleeding patterns by contraceptive types and steroid levels.

OBJECTIVE: Our purpose was to determine the relationship between bioavailability of contraceptive steroids and bleeding patterns. STUDY DESIGN: A randomized clinical trial evaluated 192 women on 50 micrograms of ethinyl estradiol and 1.0 mg of norethindrone (OC1), 35 micrograms ethinyl estradiol and 1.0 mg of norethindrone (OC2), and 35 micrograms ethinyl estradiol and 0.5 mg norethindrone (OC3) over nine cycles. RESULTS: Intermenstrual bleeding rates were higher for OC3 when compared with OC1 (p = 0.01). The number of intermenstrual bleeding days was highest for OC3 (p = 0.001) and higher for OC2 when compared with OC1 (p < 0.006). The onset of withdrawal bleeding occurred faster in OC3 patients (p < 0.02). Bioavailability of both contraceptive steroids as measured by baseline values and 1-hour slopes did not correlate with bleeding patterns at 3, 6, and 9 months of use. CONCLUSION: These data suggest that differences in biologic responses associated with pill use cannot be explained solely on the basis of these particular hormone measurements.

Biological Availability↗
PubMed1993

Contraception and dyslipidemia.

The risks of cardiovascular disease associated with dyslipidemia differ in women and men, being more strongly associated with triglyceride/high-density lipoprotein in middle-aged women than in men. Although the incidence of heart disease is lower in women because they live longer, over a lifetime, cardiovascular disease in women is equal to that in men, with the greatest incidence after age 65 years. Major coronary events are rare among reproductive-age women who use oral contraceptives and are related to the concomitant effects of age, smoking, diabetes, hypertension, and obesity. Low estrogen-progestin dose oral contraceptives appear not to promote cardiovascular disease and can be used in women with controlled cholesterol elevations. Alternative contraceptive measures should be considered for patients with severe uncontrolled hypercholesterolemia or a lipid disorder that carries a high risk of coronary heart disease. In these conditions, thrombotic propensity associated with supraphysiologic doses of estrogen in oral contraceptives might accelerate coronary thrombosis should an arteriosclerotic plaque rupture. Treatment of hypercholesterolemia should follow the guidelines of the National Cholesterol Education Program and emphasize hygienic measures. Contraceptive selection in hyperlipidemic patients should reflect a balance between the risks--and their management--of developing cardiovascular disease versus the risks of pregnancy.

Cardiovascular Diseases↗
PubMed1993

Puerperium and breast-feeding.

This review focuses on several aspects of breast-feeding, including mothers' skills and attitudes, risk of HIV transmission in breast milk, lactational amenorrhea and its contraceptive effects, and the effects of anesthesia and analgesia on lactation. Also discussed is postpartum contraception and sources of referral for low-income women desiring assistance in nutrition.

Amenorrhea↗
PubMed1992

The metabolic impact of oral contraceptives.

The hormonal components of oral contraceptives exert major effects on plasma lipoprotein metabolism. Estrogens may increase production of plasma triglycerides, leading to increased levels of very low-density lipoproteins, but they may also reduce levels of cholesterol-enriched and potentially atherogenic intermediate- and low-density lipoproteins. Furthermore, estrogens increase levels of high-density lipoproteins (HDLs), particularly the HDL2 subspecies, an effect linked to reduced mortality rates from cardiovascular disease in postmenopausal women receiving hormone replacement therapy. All combination oral contraceptives in use in the United States tend to raise levels of plasma triglycerides, low-density lipoprotein, and HDL3 to varying degrees. In contrast, changes in HDL and HDL2 reflect the combined effects of estrogen dose and relative androgenicity of the progestin component. Although in general, the lipoprotein changes are greater in magnitude with higher dose oral contraceptive preparations, they can be significant in lower dose preparations as well. Oral contraceptives also affect carbohydrate metabolism, primarily through the activity of progestin. Studies have demonstrated insulin resistance, rises in plasma insulin, and relative glucose intolerance by means of curve analysis of glucose tolerance tests. These effects are far less pronounced with lower dose preparations and with formulations using the newer progestins.

Blood Vessels↗
PubMed1992

Existence of multiple peaks in plasma ethinyl estradiol and norethindrone after oral administration of a contraceptive pill.

Previous measurements of plasma ethinyl estradiol (EE2) and norethindrone (NE) over 24 h after oral administration of a contraceptive pill have demonstrated a single steroid peak occurring 1-2 h after pill ingestion, with a gradual decline over the next 22 h. In the present study plasma concentrations of EE2 and NE were measured 0, 0.5, 0.75, 1, 2, 4, 12, and 24 h after oral ingestion of a contraceptive pill containing 35 micrograms EE2 and 1 mg NE at 0, 3, 6, and 9 months of use in 58 normal healthy women. Contrary to previous reports, analysis of the 464 steroid curves (58 subjects x 4 time periods x 2 steroids) revealed the presence of multiple hormone peaks. Two peaks of EE2 were identified in 44.8% of women during the first pill cycle and in 75.9%, 55.2%, and 67.2% of women after 3, 6, and 9 months of pill use. Two hormone peaks of NE were observed in 29.3% of women during the first cycle and in 36.2%, 50%, and 44.8% at 3, 6, and 9 months, respectively. Existence of these multiple peaks at the frequency observed has not previously been reported. Further quantification of the frequency and magnitude of these peaks could be helpful in explaining differences in biological responses associated with pill use.

Adult↗
PubMed1992

Lipid and carbohydrate effects of a new triphasic oral contraceptive containing norgestimate.

Data are reported from the combined results of two studies assessing the lipid and carbohydrate effects of a triphasic preparation of norgestimate and ethinyl estradiol (Ortho TriCyclen, Tri-Cilest) over a 2-year period in 1,783 healthy women. Mean values for serum levels of high-density lipoprotein cholesterol (HDL-C) were increased significantly, with a percent change at 24 months of 13.2. Values for the ratio of low-density lipoprotein cholesterol to HDL-C were reduced throughout the study period (mean change of -6.4% at cycle 24). There were no clinically significant changes in fasting blood glucose levels or insulin levels or in values for glycosylated hemoglobin. These results are consistent with those of previous studies and indicate that the triphasic preparation of norgestimate and etinyl estradiol is a selective and minimally androgenic oral contraceptive agent. Long-term therapeutic benefit may accrue from the favorable influences on the lipid profile.

Adolescent↗
PubMed1991

The effect of tetracycline on levels of oral contraceptives.

Despite the widespread use of tetracycline for treatment of dermatologic disorders and sexually transmitted diseases, the pharmacodynamics of oral contraceptive use in the presence of tetracycline has not been studied. Seven normal women ingested an oral contraceptive containing ethinyl estradiol 35 micrograms and norethindrone 1 mg in the follicular phase of the menstrual cycle. On day 0 baseline ethinyl estradiol and norethindrone levels were obtained at 0, 1/2, 3/4, 1, 2, 4, 12, and 24 hours after oral contraceptive administration. On day 1 tetracycline 500 mg was given orally every 6 hours while the oral contraceptive was continued. Tetracycline, ethinyl estradiol, and norethindrone levels were determined at the same time intervals as on day 0. Oral contraceptive and tetracycline were continued for up to 10 days, and additional concentrations of ethinyl estradiol, norethindrone, and tetracycline were determined between days 5 and 10. Four additional normal women ingested tetracycline for 5 to 10 days. Tetracycline levels were determined at the time intervals noted above on day 1 and days 5 to 10. No significant decrease in plasma ethinyl estradiol or norethindrone concentration was seen with either short-term (24 hours) or long-term (5 to 10 days) ingestion of tetracycline. Similarly, levels of tetracycline do not significantly decrease with ingestion of a low-dose oral contraceptive.

Adolescent↗
PubMed1991

Oral contraceptives and antithrombin III: variations by dosage and ABO blood group.

A randomized clinical trial of oral contraceptives evaluated 67 women on a regimen of 50 micrograms ethinyl estradiol and 1.0 mg norethindrone, 61 women on a regimen of 35 micrograms ethinyl estradiol and 1.0 mg norethindrone, and 64 women on a regimen of 35 micrograms ethinyl estradiol and 0.5 mg norethindrone. ABO blood group type was determined in all women. At baseline and at 3, 6, and 9 months, plasma antithrombin III levels, by both an immunologic and an activity method, and selected plasma levels of the contraceptive steroids were measured. Antithrombin III levels for all oral contraceptive groups combined decreased from baseline by 19.7% and 28.8% for the immunologic and activity methods, respectively. Analysis of interrelationships among antithrombin III by activity method, oral contraceptive type, and ABO blood group showed larger declines in antithrombin III for type O women using the highest estrogen dose preparation (31.6%) and for non-type O women using the lowest progestin dose preparation (38.9%). Plasma levels of contraceptive steroids also were related to changes in the most extreme levels of antithrombin III.

ABO Blood-Group System↗