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Biomedical subjects

S Malmusi

Publications and source records attributed to S Malmusi.

6 recordsLinked to original sources

Effect of exogenous melatonin on vascular reactivity and nitric oxide in postmenopausal women: role of hormone replacement therapy.

OBJECTIVE: Several effects of melatonin are modulated by gonadal steroids and are reduced in ageing women. Administration of melatonin reduces internal carotid artery pulsatility index (PI), and blood pressure in young individuals. Whether these effects are conserved in postmenopausal women and are influenced by hormone replacement therapy (HRT), was herein investigated. DESIGN: Randomised, double-blind placebo controlled study. PATIENTS: Twenty-three postmenopausal women of which 11 were unreplaced with HRT and 12 on the oestrogenic phase of continuous transdermal estradiol (50 microg/day) plus cyclic medroxyprogesterone acetate (5 mg/day x 12 days every 28 days). MEASUREMENTS: Internal carotid PI, by colour Doppler, and supine blood pressure were evaluated 90, 180 and 240 minutes following the oral administration of melatonin (1 mg) or placebo. Levels of nitrites/nitrates (NOx), the stable derivatives of nitric oxide, were also evaluated in samples collected 90 minutes following the administration of placebo or melatonin. RESULTS: In women not on replacement therapy melatonin was ineffective. In HRT-treated women, melatonin reduced internal carotid artery PI (P = 0.005). The effect was maximal within 90 minutes, and maintained for at least 240 minutes, with melatonin levels in the nocturnal physiological range. Systolic and diastolic blood pressures were reduced of 8 mmHg (P = 0.038) and 4 mmHg (P = 0.045), respectively, while NOx levels were significantly increased (P = 0.024). CONCLUSIONS: The circulatory response to melatonin is conserved in postmenopausal women with but not without hormone replacement therapy. Maintenance of the cardiovascular response to melatonin, may be implicated in the reduced cardiovascular risk of postmenopausal women with hormone replacement therapy.

Analysis of Variance↗

Effect of prolonged administration of transdermal estradiol on flow-mediated endothelium-dependent and endothelium-independent vasodilation in healthy postmenopausal women.

In 15 postmenopausal women with no cardiovascular risk factors, hormone replacement with transdermal estradiol (50 microg/day for 2 months) did not enhance flow-mediated endothelium-dependent vasodilation, reduce endothelium-independent vasodilation, and did not modify the pulsatility index and blood flow of the brachial artery. The present data do not support a positive effect of replacement with transdermal estradiol on vessel vasodilation in healthy, postmenopausal women.

Administration, Cutaneous↗

Physiological doses of estradiol decrease nocturnal blood pressure in normotensive postmenopausal women.

The effect of a 2-mo treatment with transdermal estradiol (50 microgram/day) versus placebo on 24 h of blood pressure rhythm was investigated in 18 normotensive healthy postmenopausal women. Whereas daytime blood pressure was not modified, nighttime blood pressure was reduced by estradiol. Estradiol magnified the nocturnal decrement of systolic (14.3 +/- 7.2 vs. 9.8 +/- 6.7 mmHg, P = 0. 0033), diastolic (11.6 +/- 5.0 vs. 7.5 +/- 7.3 mmHg, P = 0.028), and mean (10.8 +/- 5.6 vs. 7.2 +/- 4.5 mmHg, P = 0.011) blood pressure. As a consequence, the 24-h rhythm of mean blood pressure was restored in 50% of the subjects (P = 0.045) in whom it was absent and was amplified in the remaining 50% of the subjects. Body mass index was an independent determinant of blood pressure values being directly related to the amplitude of the 24-h mean blood pressure rhythm (r2 = 0.38; P = 0.0067). In normotensive postmenopausal women, physiological doses of estradiol amplify the nocturnal decline of blood pressure.

Blood Pressure↗

Oral contraceptives and bone metabolism.

In women, the bone metabolism is markedly influenced by gonadal steroids and by their fluctuations. Indeed, estrogens influence bone metabolism by influencing endocrine and paracrine functions involved in bone remodelling. In normally cycling women, the administration of oral contraceptives does not increase bone mineral density and does not induce deleterious effects on bone. In women with ovulatory disturbances, bone turnover is increased and bone mineral density is lower than in normally cycling women. In these cases, administration of oral contraceptives is capable of blocking increased bone loss and of restoring a normal bone mineral density. Similarly, in women treated with gonadotropin releasing hormone (GnRH) analogs, the concomitant administration of oral contraceptives completely antagonizes GnRH analog-induced bone loss. The progestogenic component of oral contraceptives seems to contribute to the protective effect of estrogens on bone. Oral contraceptives are safe for bone maintenance in normal adult women, and are indeed indicated to prevent postmenopausal osteoporosis in women with ovulatory disturbances.

Adolescent↗

Continuous combined hormone replacement therapy with oral 17beta-estradiol and norethisterone acetate improves homocysteine metabolism in postmenopausal women.

OBJECTIVE: To evaluate the effect of a continuous combined oral hormone replacement therapy (HRT) on basal and post-methionine load homocysteine levels in postmenopausal women. DESIGN: Twenty-two postmenopausal women (PMW) were randomly allocated to receive either continuous combined oral HRT (2 mg of estradiol plus 1 mg of norethisterone acetate; n = 11) or no treatment (controls, n = 11) for 6 months. A methionine oral load (0.1 g/kg body weight) was performed in each subject at time 0 and after 6 months. Serum homocysteine levels were measured by high-performance liquid chromatography in samples collected at time 0 and at 4, 8, and 24 h after the methionine load, while levels of vitamin B6 (by high-performance liquid chromatography) and B12 and folate (both by ELISA) were assayed in samples collected at time 0. RESULTS: Serum levels of glucose and body mass index increased in treated PMW, whereas folate decreased in controls. In treated PMW, basal homocysteine tended to decrease (10.6 +/- 3.3 micromol/L vs. 9.62 +/- 2.8 micromol/L, p = 0.062), whereas in controls it significantly increased (10.7 +/- 2.65 micromol/L vs. 12.17 +/- 3.89 micromol/L, p < 0.05). This increase was not significant after correction for vitamin status (p = 0.072). Homocysteine values 4 h (31.9 +/- 13.53 micromol/L vs. 39.83 +/- 22.53 micromol/L, p < 0.05) and 8 h (35.1 +/- 13.13 vs. 43.34 +/- 22.15 micromol/L) after methionine, and integrated homocysteine response to methionine (392.5 +/- 133.8 micromol/24 h vs. 458.8 +/- 104.8 micromol/24 h; p < 0.05), were significantly reduced in HRT-treated, but not in untreated, PMW. CONCLUSIONS: Continuous combined oral HRT with17beta-estradiol plus norethisterone acetate reduces homocysteine levels, mainly after a methionine load. This effect seems to be independent of vitamin status and may have positive implications for the prevention of cardiovascular diseases in PMW.

Administration, Oral↗