Altered reflex control of cutaneous circulation by female sex steroids is independent of prostaglandins.
We tested the hypothesis that the shift in the cutaneous vasodilator response to hyperthermia seen with elevated female reproductive hormones is a prostaglandin-dependent resetting of thermoregulation to higher internal temperatures, similar to that seen in the febrile response to bacterial infection. Using water-perfused suits to control body temperature, we conducted heat stress experiments in resting women under conditions of low and high progesterone and estrogen and repeated these experiments after an acute dose of ibuprofen (800 mg). In six women the hormones were exogenous (oral contraceptives); three women had regular menstrual cycles and were tested in the early follicular and midluteal phases. Resting oral temperature (Tor) was significantly elevated with high hormone status (P < 0.05); this was not affected by ibuprofen treatment (P > 0.2). The Tor threshold for cutaneous vasodilation was significantly increased by high hormone status (+0.27 +/- 0.07 degrees C, P < 0. 02); the shift was not affected by ibuprofen treatment (with ibuprofen: +0.29 +/- 0.08 degrees C, P > 0.2 vs. control experiments). The Tor threshold for sweating was similarly increased by high hormone status (+0.22 +/- 0.05 degrees C, P < 0.05); this shift was not influenced by ibuprofen (with ibuprofen: +0.35 +/- 0. 05, P > 0.1 vs. control experiments). Thus the shift in thermoregulatory control of skin blood flow and sweating mediated by female reproductive steroids is not sensitive to ibuprofen; it therefore appears that this shift is independent of prostaglandins. (+info)
Recurrent use of newer oral contraceptives and the risk of venous thromboembolism.
The epidemiological studies that assessed the risk of venous thromboembolism (VTE) associated with newer oral contraceptives (OC) did not distinguish between patterns of OC use, namely first-time users, repeaters and switchers. Data from a Transnational case-control study were used to assess the risk of VTE for the latter patterns of use, while accounting for duration of use. Over the period 1993-1996, 551 cases of VTE were identified in Germany and the UK along with 2066 controls. Totals of 128 cases and 650 controls were analysed for repeat use and 135 cases and 622 controls for switching patterns. The adjusted rate ratio of VTE for repeat users of third generation OC was 0.6 (95% CI:0.3-1.2) relative to repeat users of second generation pills, whereas it was 1.3 (95% CI:0.7-2.4) for switchers from second to third generation pills relative to switchers from third to second generation pills. We conclude that second and third generation agents are associated with equivalent risks of VTE when the same agent is used repeatedly after interruption periods or when users are switched between the two generations of pills. These analyses suggest that the higher risk observed for the newer OC in other studies may be the result of inadequate comparisons of pill users with different patterns of pill use. (+info)
Effect of oral contraceptive agents on nutrients: I. Minerals.
The epidemiological aspects of oral contraceptive agents on nutrient metabolism were studied in a large population of women. Incidence of clinical abnormalities, related to malnutrition, were more frequently observed in the lower (B) as compared to the higher (A) socioeconomic groups. In the A groups some clinical signs were more common in the nonsupplemented groups of subjects. In general, the intake of oral contraceptive agent subjects for calories, protein, calcium, magnesium, iron, copper and zinc did not differ from the controls. The intake of the above nutrients in group A subjects were higher than those of group B except for calories. The subjects who took supplements had higher intakes of calcium, iron, magnesium and copper. No effect of oral contraceptive agents was seen on hemoglobin, hematocrit and erythrocyte count. Serum iron was increased due to "Norinyl." Total iron binding capacity was increased as a result of oral contraceptive agent administration. Total iron binding capacity values were higher in group B as compared to group A and in the nonsupplemented as compared to the supplemented groups. Plasma copper was increased and plasma zinc was decreased as a result of oral contraceptive agent administration. An increase in erythrocyte zinc was observed due to "Norinyl." No effect of oral contraceptive agents on plasma calcium, magnesium and erythrocyte magnesium was observed. Although no effect of oral contraceptive agents on plasma total protein was found, serum albumin was decreased. (+info)
Effect of oral contraceptive agents on vitamin nutrition status.
Effects of low estrogen combination type oral contraceptives on some of the biochemical parameters used for assessing vitamin nutritional status were investigated in a group of women who had used the pill for 6 to 12 months. Another group of women was examined initially and then at one or more points of time within the first 6 months of treatment. Following changes were observed in women treated with oral contraceptives: 1) increased excretion of kynurenic acid and xanthurenic acid following tryptophan load; 2) increased EGOT activity and also an increase in vitro stimulation of EGOT with added PALP; 3) increased plasma vitamin A levels; 4) fall in erythrocyte folate levels; 5) fall in erythrocyte transketolase activity with no change in vitro stimulation with TPP; and 6) fall in erythrocyte riboflavin concentration associated with a decrease in erythrocyte glutathione reductase activity and increase in vitro stimulation with FAD. Most of these changes were observed during the first few cycles of oral contraceptive treatment. (+info)
Effect of oral contraceptive agents on nutrients: II. Vitamins.
Clinical, biochemical and nutritional data were collected from a large population of women using oral contraceptive agents. Higher incidence of abnormal clinical signs related to malnutrition were observed in the lower (B) as compared to the higher (A) socioeconomic groups, and also in the nonsupplemented groups as compared to the supplemented groups in the B subjects. As a rule the intake of oral contraceptive agent subjects of vitamin A, C, B6 and folic acid did not differ from that of the controls As expected, subjects from the supplemented groups had higher intake of vitamin A, C, B6, thiamin, riboflavin and folic acid, and A groups had higher intake of vitamin C, B6, riboflavin and folic acid. Increased plasma vitamin A and decreased carotene levels were observed in oral contraceptive agent users. In general oral contraceptive agents had little or no effect on plasma ascorbic acid. Urinary excretion of both thiamin and riboflavin in subjects using oral contraceptive agents were lower in A groups. Erythrocyte folate and plasma pyridoxal phosphate was decreased in A groups due to oral contraceptive agents. Subjects who took supplements had higher levels of plasma vitamin A, ascorbic acid and folate. But urinary thiamin and riboflavin were higher only in group A subjects who took supplements. (+info)
The effects of estrogen administration on bone mineral density in adolescents with anorexia nervosa.
OBJECTIVE: Profound osteopenia is a serious complication of anorexia nervosa (AN). The aim of this work was to study the effect of prolonged AN on lumbar spine bone mineral density (BMD) and to determine whether oral estrogen administration prevents bone loss in women with this disorder. SUBJECTS AND METHODS: Thirty-eight amenorrheic women with AN (mean age: 17.3 years) were treated with estrogen (50 microg of ethinyl estradiol) and gestagen (0.5 mg of norgestrel) during 1 year. Clinical variations, biochemical indices and BMD were studied at three different time points, including after a period of amenorrhea of at least 12 months (n=38), after the administration of estrogens for 1 year (n=22), and after a 1-year follow-up period (n=12). RESULTS: Initial mean BMD was significantly lower than normal (-2.1+/-0.8 s.d.) and less than -2.5 s.d. below normal in 38% of the women with AN. The estrogen-treated group had no significant change in BMD even after the follow-up period and partial recovery of weight. Estradiol and total IGF-I levels were significantly lower throughout the study. All subjects had normal thyroxine (T(4)) and TSH levels and calcium metabolism. However, total tri-iodothyronine (T(3)) was decreased in all anorexic subjects in the first and second study points and were within normal limits after the follow-up period. CONCLUSIONS: (1) Estrogen replacement alone cannot prevent progressive osteopenia in young women with AN. (2) Other factors, such as the loss of weight, the duration of the amenorrhea and the low levels of total insulin-like growth factor-I (IGF-I) could contribute to the loss of bone mass in women with this disorder. (+info)
Insulin sensitivity in non-obese women with polycystic ovary syndrome during treatment with oral contraceptives containing low-androgenic progestin.
BACKGROUND: Combined oral contraceptives (COC) effectively suppress hyperandrogenism in women with polycystic ovary syndrome (PCOS), though deterioration of insulin sensitivity during treatment is assumed. The study aim was to investigate insulin action and androgen production during treatment with COC containing low-androgenic progestin. METHODS: A total of 13 PCOS women and nine controls was enrolled into the study. Only non-obese women with a body mass index (BMI) +info)
Current status of fertility control methods in India.
Approximately 48.2% of couples of 15 to 49 years of age practice family planning methods in India. Female sterilization accounts for 34.2%, with male sterilization declining from 3.4% in 1992-93 to 1.9% in 1998-99. Use of the condom increased to 3.1% from 2.4%. There is an urgent need for research to develop new contraceptive modalities especially for men and also for women and to make existing methods more safe, affordable and acceptable. Current efforts in India to develop a male contraceptive are mainly directed towards (i) development of antispermatogenic agents to suppress sperm production, (ii) prevention of sperm maturation, (iii) prevention of sperm transport through vas deferens or rendering these sperm infertile and (iv) prevention of sperm deposition. Research work in the field of prevention of sperm transport through vas deferens has made significant advances. Styrene maleic anhydride (SMA) disturbed the electrical charge of spermatozoa leading to acrosome rupture and consequent loss in fertilizing ability of sperm. A multicentre phase-III clinical trial using SMA is continuing and it is hoped that the SMA approach would be available in the near future as an indigenously developed injectable intra-vasal male contraceptive. The safety and efficacy of available oral contraceptives were evaluated. An indigenously developed oral contraceptive 'Centchorman', which is a nonsteroidal, weakly estrogenic but potently antiestrogenic, was found to be safe and effective and is now being marketed in India since 1991 as a 'once a week' pill. Cyclofem and Mesigyna have been recommended as injectable contraceptives with proper counselling and service delivery by Indian studies. It has been recommended that these injectable contraceptives be added to the existing range of contraceptive methods available in the National Family Planning Programme. Based on the Indian studies CuT 200 was also recommended. Studies have indicated the advantage of intrauterine devices (IUD); they are long acting, relatively easily removed and fertility returns rapidly after their removal. Recent studies have recommended CuT 200 for use up to 5 years. The combination of some plant products i.e. Embelia ribes, Borax and Piper longum has been found to be safe and effective as a female contraceptive and the results of phase-I clinical trials are encouraging. Research work is going on in the country in various areas with special reference to hormonal contraceptive - a three monthly injectable contraceptive, immuno-contraceptives, antiprogestins, etc. (+info)