scholarly journals Soy Isoflavones Exert Modest Hormonal Effects in Premenopausal Women1

1999 ◽  
Vol 84 (1) ◽  
pp. 192-197 ◽  
Author(s):  
Alison M. Duncan ◽  
Barbara E. Merz ◽  
Xia Xu ◽  
Theodore C. Nagel ◽  
William R. Phipps ◽  
...  

Soy isoflavones are hypothesized to be responsible for changes in hormone action associated with reduced breast cancer risk. To test this hypothesis, we studied the effects of isoflavone consumption in 14 premenopausal women. Isoflavones were consumed in soy protein powders and provided relative to body weight (control diet, 10 ± 1.1; low isoflavone diet, 64 ± 9.2; high isoflavone diet, 128 ± 16 mg/day) for three menstrual cycles plus 9 days in a randomized cross-over design. During the last 6 weeks of each diet period, plasma was collected every other day for analysis of estrogens, progesterone, LH, and FSH. Diet effects were assessed during each of four distinctly defined menstrual cycle phases. Plasma from the early follicular phase was analyzed for androgens, cortisol, thyroid hormones, insulin, PRL, and sex hormone-binding globulin. The low isoflavone diet decreased LH (P = 0.009) and FSH (P = 0.04) levels during the periovulatory phase. The high isoflavone diet decreased free T3 (P = 0.02) and dehydroepiandrosterone sulfate (P = 0.02) levels during the early follicular phase and estrone levels during the midfollicular phase (P = 0.02). No other significant changes were observed in hormone concentrations or in the length of the menstrual cycle, follicular phase, or luteal phase. Endometrial biopsies performed in the luteal phase of cycle 3 of each diet period revealed no effect of isoflavone consumption on histological dating. These data suggest that effects on plasma hormones and the menstrual cycle are not likely to be the primary mechanisms by which isoflavones may prevent cancer in premenopausal women.

2004 ◽  
Vol 34 (1) ◽  
pp. 93-102 ◽  
Author(s):  
C. S. SYMONDS ◽  
P. GALLAGHER ◽  
J. M. THOMPSON ◽  
A. H. YOUNG

Background. Neurocognitive functioning may be impaired in the luteal phase of the menstrual cycle due to associated changes in hypothalamic–pituitary–adrenal (HPA) axis function. This study examines the relationship between changes in neurocognition and HPA axis function in different phases of the menstrual cycle.Method. Fifteen female volunteers, free from psychiatric history and hormonal medication were tested twice, during mid-follicular and late-luteal phases in a randomized, crossover design. Mood, neurocognitive function, and basal cortisol and dehydroepiandrosterone (DHEA) were profiled.Results. Relative to the follicular phase, verbal fluency was impaired in the luteal phase and reaction times speeded on a continuous performance task, without affecting overall accuracy. ‘Hedonic’ scores on the UWIST-MACL scale were decreased in the luteal phase. There was also evidence of changes in the function of the HPA axis, with 24 h urinary cortisol concentrations and salivary DHEA levels being significantly lower during the luteal phase.Conclusions. These data suggest that luteal phase HPA axis function is lower than in the follicular phase in premenopausal healthy women. This putative biological difference may be important for our understanding of the aetiopathogenesis of menstrually related mood change and neurocognitive disturbance.


2002 ◽  
Vol 13 (2) ◽  
pp. 446-452
Author(s):  
Mala Chidambaram ◽  
John A. Duncan ◽  
Vesta S. Lai ◽  
Daniel C. Cattran ◽  
John S. Floras ◽  
...  

ABSTRACT. It has been demonstrated elsewhere that circulating renin angiotensin system (RAS) components peak when plasma estrogen levels are highest, during the luteal phase of the normal menstrual cycle. This phenomenon has been attributed to “activation” of the RAS. The end-organ vasoconstrictive response to this phenomenon has not been well established. In two related experiments, the RAS was studied in healthy, premenopausal women during predefined phases of the normal menstrual cycle. In the first experiment, the circulating components of the RAS and the systemic hemodynamic response to incremental lower body negative pressure (LBNP) during the follicular and luteal phases of the menstrual cycle were examined. Response variables included mean arterial pressure (MAP), renin, plasma renin activity (PRA), angiotensin II (AngII), and aldosterone. Baseline levels of renin, PRA, and aldosterone were significantly higher in the luteal phase. In response to LBNP, there were significant increases in all variables in both phases; however, the humoral response to this stimulus was significantly augmented in the luteal phase compared with the follicular phase. Despite these elevations in circulating components of the RAS during the luteal phase, subjects were unable to maintain MAP in response to LBNP, exhibiting a dramatic depressor response that did not occur during the follicular phase. In the second experiment, renal and peripheral hemodynamic function at baseline, and in response to AngII blockade with losartan, were examined in women during these high and low estrogen phases of the menstrual cycle. The renal and peripheral hemodynamic responses were similar in the luteal phase and the follicular phase. These results demonstrate that, despite an increase in circulating RAS components during the luteal phase of the menstrual cycle, the system is blunted rather than “activated,” at least at a tissue level. Further studies are needed to clarify this mechanism.


1999 ◽  
Vol 84 (10) ◽  
pp. 3479-3484 ◽  
Author(s):  
Alison M. Duncan ◽  
Kerry E.W. Underhill ◽  
Xia Xu ◽  
June LaValleur ◽  
William R. Phipps ◽  
...  

Abstract Soy isoflavones have been hypothesized to exert hormonal effects in postmenopausal women. To test this hypothesis, we studied the effects of three soy powders containing different levels of isoflavones in 18 postmenopausal women. Isoflavones were consumed relative to body weight[ control: 0.11 ± 0.01; low isoflavone (low-iso): 1.00 ± 0.01; high isoflavone (high-iso): 2.00 ± 0.02 mg/kg/day] for 93 days each in a randomized crossover design. Blood was collected on day 1 of the study (baseline) and days 36–38, 64–66, and 92–94 of each diet period, for analysis of estrogens, androgens, gonadotropins, sex hormone binding globulin (SHBG), prolactin, insulin, cortisol, and thyroid hormones. Vaginal cytology specimens were obtained at baseline and at the end of each diet period, and endometrial biopsies were performed at baseline and at the end of the high-iso diet period, to provide additional measures of estrogen action. Overall, compared with the control diet, the effects of the low-iso and high-iso diets were modest in degree. The high-iso diet resulted in a small but significant decrease in estrone-sulfate (E1-S), a trend toward lower estradiol (E2) and estrone (E1), and a small but significant increase in SHBG. For the other hormones, the few significant changes noted were also small and probably not of physiological importance. There were no significant effects of the low-iso or high-iso diets on vaginal cytology or endometrial biopsy results. These data suggest that effects of isoflavones on plasma hormones per se are not significant mechanisms by which soy consumption may exert estrogen-like effects in postmenopausal women. These data also show that neither isoflavones nor soy exert clinically important estrogenic effects on vaginal epithelium or endometrium.


1975 ◽  
Vol 79 (4) ◽  
pp. 625-634 ◽  
Author(s):  
Elwyn M. Grimes ◽  
Irwin E. Thompson ◽  
Melvin L. Taymor

ABSTRACT Thirty-one ovulatory women between 20 and 33 years of age were given 150 μg of synthetic LH-RH during different phases of the menstrual cycle. Five patients were studied during the early follicular phase (days 4–7); 10 patients during the late follicular phase (days 9–12); 6 patients during the "LH Surge"; 5 patients during the early luteal phase (days 14–16); 3 patients during mid-luteal phase (days 17–21); and 2 patients during late luteal phase (days 22–27). Oestrogen, progesterone, FSH and LH levels were determined from 30 min prior to LH-RH administration to 90 min thereafter in all cases. LH response to LH-RH increased progressively during the follicular phase. Enhanced pituitary responsiveness to LH-RH occurred at mid-cycle for both LH and FSH and maximum LH responses occurred during the "LH Surge" and early luteal phase. LH responses during the mid and late luteal phases were similar to late follicular phase responses. There were no significant differences between FSH responses during the early follicular, late follicular, mid-luteal and late luteal phases. Maximum pituitary responsiveness appears to occur in a gonadal steroid milieu of high oestrogen levels in association with rising but low progesterone levels. Progesterone or a crucial oestrogen: progesterone ratio may in fact potentiate pituitary release of LH during the early stages of corpus luteum formation. Pituitary responsiveness to LH-RH correlates positively with basal LH and oestrogen levels during the menstrual cycle and with the oestrogen:progesterone ratio during the luteal phase.


2020 ◽  
pp. 028418512095840
Author(s):  
Konstantinos Angelopoulos ◽  
Magnus Palmér ◽  
Berit Gull ◽  
Niklas Lundqvist ◽  
Linda Kopelia ◽  
...  

Background There are different types of computed tomography (CT) contrast enhancement patterns of the uterus. It is not known whether these are hormonally dependent. Purpose To assess the relationship between these patterns and the menstrual cycle in non-users of hormonal contraception, and the possible impact of hormonal contraception. Material and Methods Prospective observational study of abdominal CT scans of 53 premenopausal women of whom 28 were non-users and 25 users of hormonal contraception. The non-users were divided according to menstrual cycle phase: follicular (n = 12); ovulatory (n = 1); and luteal (n = 12). The pattern and intensity of contrast enhancement of the uterine myometrium were assessed. Results The dominant pattern of contrast enhancement of the myometrium was the diffuse homogeneous type in both non-users and users. The intensity of the enhancement measured in Hounsfield units (HU) was higher in the follicular phase (median 102, range 73–130) compared to the luteal phase in non-users (median 92, range 57–130); however this was not statistically significant ( P = 0.2). The HU values observed in users (median 95, range 45–160) were at the same levels compared to those of the luteal phase in non-users. Conclusion The dominant pattern of contrast enhancement in the portal venous phase of the myometrium in fertile ages is the diffuse homogeneous type and is independent of menstrual cycle phase or the use of hormonal contraception. However, these factors seem to play a role in the intensity of contrast enhancement, with a tendency of higher HU values in the follicular phase of non-users.


1982 ◽  
Vol 100 (3) ◽  
pp. 427-433 ◽  
Author(s):  
N. Kruyt ◽  
R. Rolland

Abstract. The release of cortisol, 17α-OH-progesterone, androstenedione and testosterone during a standardized ACTH-stimulation test was investigated in three different stages of the normal menstrual cycle, to conclude if there is any stage dependency on the release of these hormones. No statistically significant differences were observed between the three stages concerning cortisol and testosterone increase. The increase of androstenedione in the pre-ovulatory stage was significantly higher than that seen during the early follicular phase of the cycle. The increase of 17α-OH-progesterone in the luteal phase was significantly less than that of both the early and late follicular stages of the cycle. Progesterone levels showed a small, but significant increase after ACTH-stimulation, in both the early and late stage of the follicular phase. However, the levels remained within the normal range of the follicular phase. In the luteal phase no increase was seen after ACTH-stimulation. Oestradtiol-17β levels did not change at all after ACTH-stimulation. The stage dependency of androstenedione and 17α-OH-progesterone is discussed. The described stage-dependency different increase of 17α-OH-progesterone release can be of importance when the results of ACTH-tests are evaluated to detect carriers of congenital adrenal hyperplasia.


1978 ◽  
Vol 89 (1) ◽  
pp. 48-59 ◽  
Author(s):  
M. Ferin ◽  
J. Bogumil ◽  
J. Drewes ◽  
I. Dyrenfurth ◽  
R. Jewelewicz ◽  
...  

ABSTRACT The effects of prolonged gonadotrophin-releasing hormone (GnRH) infusions on LH, FSH, oestrogens and progesterone secretion were studied in female rhesus monkeys at various times of the menstrual cycle and after castration. GnRH was infused at the rate of 15 μg/h for 48 h. This resulted in mean peripheral GnRH levels of 398 ± 31.5 pg/ml (± se) as measured by radioimmunoassay. As expected the pattern of gonadotrophin responses to GnRH varied considerably with the phase of the menstrual cycle. The largest LH increase was seen during the late follicular phase (6-fold over baseline), with a 3-fold increase during the luteal phase and a 2-fold one during the early follicular phase and in the period following the LH surge. Significant FSH increases (4-fold) were seen only during the follicular phase. Oestrogens increased about 2-fold within 4 h of the start of the infusion during the early follicular phase. In the late follicular phase and during the LH surge, they declined within 24 and 1 h, respectively. Large progesterone increases were seen only during the luteal phase. Of special interest is the fact that the increase in gonadotrophin secretion could not be maintained for the entire duration of the experiment even though GnRH continued to be infused at rates sufficient to elicit initial increases of several fold over baseline. Gonadotrophin release declined 4–28 h after the initial stimulation. A further decrease below pre-infusion control levels was particularly evident during the midcycle surge and, for FSH, after ovariectomy. These results indicate that a continuous mode of administration may rapidly induce a desensitization phenomenon at the level of the gonadotroph.


1982 ◽  
Vol 99 (4) ◽  
pp. 481-486 ◽  
Author(s):  
S. Baumgarten ◽  
A. Römmler ◽  
K.G. Post ◽  
J. Hammerstein

Abstract. The objective of this study was to re-investigate the capacity of pituitary prolactin (Prl) and thyrotrophin (TSH) secretion throughout the normal menstrual cycle to respond to repeated thyrotrophin releasing hormone (TRH) stimulation analogous to the double luteinizing hormone-releasing hormone (LRH) stimulation test. This test has been shown to be a sensitive parameter for oestrogenic effects on the gonadotrophs. In addition, the volunteers were selected carefully on the basis of ovulatory cycles and otherwise normal endocrine function. In 9 women a combined LRH/TRH double stimulation test was performed during the early follicular, periovulatory and mid-luteal phases. TRH (200 μg) and LRH (25 μg) each were given iv twice, 2 h apart. Basal and LRH stimulated luteinizing hormone (LH) and follicle stimulating hormone (FSH) were found to follow characteristic cyclic response patterns. The LH responses after both LRH stimulations were greatest in the periovulatory phase; Δ1 and Δ2 were higher in the mid-luteal phase than in the follicular phase. Maximum FSH response to LRH was found during the periovulatory phase, but the FSH response in the early follicular phase was greater than that found in the mid-luteal phase. In contrast, basal and TRH stimulated serum concentrations of TSH and Prl remained constant throughout the cycle. The gonadotrophin ratios Δ2:Δ1 were generally greater than 1. They increased from 1.4 in the early follicular phase to 3.0 in the late follicular phase, concomitant with the rise in oestrogens. The Δ2: Δ1 ratios for TSH and Prl were less than 1, ranging from 0.66 to 0.98 for TSH and from 0.26 to 0.99 for Prl. They did not show any cyclic changes. Thus, this study shows that after LRH/TRH double stimulation, the gonadotrophin but not the Prl and TSH responses vary with the physiological changes in oestrogens during the menstrual cycle. The supposed mechanism of oestrogen effects on pituitary hormone secretion and their possible clinical significance are discussed.


Circulation ◽  
2014 ◽  
Vol 129 (suppl_1) ◽  
Author(s):  
Lindsey M Duca ◽  
Rachel M Sippl ◽  
Janet K Snell-Bergeon

Women with type 1 diabetes (T1D) lose the premenopausal protection from cardiovascular disease (CVD) that non-diabetic (non-DM) women have compared to men, and are also more insulin resistant than non-DM women. Standard CVD risk factors have not been found to adequately predict CVD in the T1D population, but insulin resistance is emerging as a potentially important risk factor. The aim of this study was to determine whether sex hormone levels such as estradiol (E2), total testosterone (TT), and sex-hormone binding globulin (SHBG) explained any of the decreased insulin sensitivity in women with T1D, which could be important in CVD prevention. This study included 25 premenopausal women 18-45 years of age with a mean ± SD age of 33 ± 8 years who completed a three stage (4, 8 and 40 mU/m2/min) hyperinsulinemic-euglycemic clamp during the luteal phase of the menstrual cycle (T1D n=12 and non-DM n=13). A steady state was achieved during the last 30 minutes of the high insulin infusion stage and mean glucose infusion rate (GIR [mg/kg/FFM/min]) during this time was used as an estimate of the skeletal muscle glucose disposal rate. Sex hormones were compared using unpaired Student t tests between T1D and non-DM participants during each phase of the menstrual cycle and during the morning of the clamp.. Significant differences were explored in multivariable linear regression in which stepwise model selection was used to determine the final model adjusting for age and diabetes status. In age-adjusted analysis, women with T1D were less than half as insulin sensitive as non-DM women (least squares mean ± SE: 7.5±2.2 vs. 19.0±2.1, respectively, p=0.0014). SHBG was significantly higher in the T1D than the non-DM subjects the morning of the clamp (p<0.0001) and during each phase of the menstrual cycle (p = 0.01). TT was significantly higher in T1D women during the early follicular phase of the menstrual cycle (p=0.02) and was negatively correlated with GIR (r = -0.54, p = 0.04). E2 during the early follicular phase was positively correlated with GIR (r = 0.83, p = 0.01). In multivariable analysis, the difference in the GIR was attenuated by 58%(1-(5.1/12.14)) (least squares mean ± SE: 10.9 ± 1.7 in T1D vs. 16.0 ± 1.5 in non-DM, p = 0.07) after adjusting for age, diabetes status, minutes of vigorous activity, average waist circumference, free estradiol index and testosterone during the early follicular phase of the menstrual cycle In conclusion, the decreased insulin sensitivity observed in premenopausal T1D women with regular menstrual cycles can be mostly explained by lower levels of physical activity, greater central adiposity and differences in sex hormone levels. Most of these factors are modifiable, and so could be important targets in the reduction of CVD.


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