Plasma insulin and glucagon concentrations and biochemical variables in regularly menstruating females with ovulatory and anovulatory menstrual cycles.

Ovarian hormones are known to affect endocrine pancreas function. However, data concerning the effects of anovulatory menstrual cycles in regularly menstruating women on endocrine pancreas and blood metabolites are lacking. We examined plasma insulin, glucagon, glucose, lactate, urea and glycerol concentrations in reproductive-age, regularly menstruating females classified as ovulating or non-ovulating on the basis of basal body temperature measurements and plasma 17beta-estradiol and progesterone determinations. All measurements were performed twice--in the follicular and again in the luteal phases of the menstrual cycle. There were no differences in plasma lactate and glycerol concentrations between the two groups of subjects. Plasma insulin concentrations tended to be lower in non-ovulating than in ovulating women. In addition, plasma glucagon did not differ in the follicular (33.2 pmol/l) or luteal phase of the menstrual cycle in females with disturbed ovarian hormone secretion (34.1 pmol/l). In contrast, plasma glucagon concentrations in the luteal phase (32.8 pmol/l) were significantly higher than in the follicular phase (24.9 pmol/l) of the menstrual cycle in ovulating women. Plasma glucose concentrations in the follicular phase of the menstrual cycle in non-ovulating women (4.1 mmol/l) were slightly but significantly lower than in their ovulating counterparts (5.3 mmol/l). Furthermore, no correlations were noted between plasma glucose and insulin-to-glucagon molar ratio in non-ovulating subjects. Plasma urea concentrations in non-ovulating women were markedly lower than in ovulating women in both follicular and luteal phases of the menstrual cycle (4.1 and 3.9 mmol/l vs. 5.3 and 5.4 mmol/l in non-ovulating and ovulating women, respectively). In ovulating women, plasma urea levels in both cycle phases were significantly correlated with plasma glucagon concentrations, but no such correlation was found in non-ovulating women. In conclusion, anovulatory menstrual cycles in premenopausal females slightly altered pancreatic hormone plasma levels but markedly impaired their action on plasma glucose and urea concentrations.     

Growth hormone secretion after baclofen administration in different phases of the menstrual cycle in healthy women

AIM: The aim of this study was to investigate the effect of baclofen administration on growth hormone (GH) secretion during different phases of the menstrual cycle. METHODS: Twelve healthy women (33.6 +/- (SD) 2.8 years; range 23-40 years) with regular menstrual cycles were enrolled. The phases of the menstrual cycle were determined using transvaginal ultrasonography (TV-US) and detecting hormonal serum levels. Plasma GH levels were evaluated during the early follicular, periovulatory and luteal phases of the cycle before and after the baclofen challenge test. RESULTS: After acute baclofen administration, GH levels increased significantly (p < 0.001) compared to basal values during the periovulatory and luteal phases, while no significant variation was detected during the early follicular phase. In addition, plasma GH levels resulted significantly (p < 0.001) higher during the luteal phase than during the periovulatory phase. CONCLUSION: Acute baclofen administration induces a significant increase in plasma GH levels in healthy females during the periovulatory and luteal phases, but not during the early follicular phase. These data suggest a modulator role of plasma sex steroids levels on GH release induced by baclofen.     

Menstrual cycle variation in spatial ability: relation to salivary cortisol levels

This study examined whether menstrual cycle phase was associated with performance on the Primary Mental Abilities Test of Spatial Relations, a test of mental rotation, in undergraduate students (N = 82). As cortisol levels also vary across the menstrual cycle under conditions of stress and influence cognitive performance, saliva samples were obtained before and after the test session to examine whether cortisol levels were related to between- and within-group differences in spatial performance. Men scored higher on the spatial test than all the groups of women, although the difference between men and women in the menstrual phase was not significant. Women in the luteal phase scored lower than the menstrual, follicular, and oral contraceptive user groups of women. There were no sex or menstrual cycle differences in cortisol levels, and no association between cortisol levels and spatial performance. The poorer performance of women in the luteal phase was not related to differences in ratings of perceived stress, perceived success on the test, or mood. Although menstrual cycle phase accounted for a significant proportion of the variance (15%) in performance on the spatial test, this does not explain why men outperformed women regardless of the phase of the cycle. Thus, there are clearly several other variables, sociocultural and physiological, involved in mediating individual differences in spatial performance.     

Plasma gonadotrophin and ovarian steroid concentrations in women with menstrual cycles with a short luteal phase

Daily plasma concentrations of FSH, LH, oestradiol-17 beta and progesterone were compared for 12 cycles with a short luteal phase and 19 cycles with a luteal phase of normal length (i.e. cycles in which the luteal phase lasted 12 or more days). FSH and LH concentrations were suppressed in short luteal-phase cycles in the early follicular phase and the length of the follicular phase was prolonged (median duration, 14.5 days, range 13-21 days: compared with 12 days, range 9-17, in control cycles; P less than 0.025). Preovulatory oestradiol-17 beta values and the mid-cycle concentrations of FSH and LH were similar in both groups. Plasma progesterone values in the luteal phase were similar in both groups over the 2nd to 5th days inclusive after the midcycle LH peak but declined in the short luteal phases thereafter. In short luteal-phase cycles, menstruation occurred in the presence of higher levels of oestradiol-17 beta and progesterone than in cycles of normal length and the rise of gonadotrophin in the late luteal phase of the cycle was delayed. These findings suggest that in cycles with a short luteal phase there is a lack of synchrony between the ovarian and menstrual events.     

Effects of the menstrual cycle on muscle recruitment and oxidative fuel selection during cold exposure

Differences in core temperature and body heat content, generally observed between the luteal and follicular phase of the menstrual cycle, have been reported to modulate the thermogenic activity of cold-exposed women. However, it is unclear how this change in whole body shivering activity will influence fuel selection. The goal of this study was to quantify the effects of the menstrual cycle on muscle recruitment and oxidative fuel selection during low-intensity shivering. Electromyographic activity of eight large muscles was monitored while carbohydrate, lipid, and protein utilization was simultaneously quantified in the follicular and luteal phases of the menstrual cycle in nonacclimatized women shivering at a low intensity. The onset (～25 min), intensity (～15% of maximal voluntary contraction), and pattern (～6 shivering bursts/min) of the shivering response did not differ between menstrual cycle phases, regardless of differences in core temperature and hormone levels. This resulted in lipids remaining the predominant substrate, contributing 75% of total heat production, independent of menstrual phase. We conclude that hormone fluctuations inherent in the menstrual cycle do not affect mechanisms of substrate utilization in the cold. Whether the large contribution of lipids to total heat production in fuel selection confers a survival advantage remains to be established.     

Seasonal effects on ovarian folliculogenesis in rhesus monkeys

Reproductive performance is reportedly reduced in some rhesus monkeys during the summer months, even when environmental conditions are controlled. The mechanism(s) underlying this phenomenon remain unknown. We noted that the pattern of folliculogenesis appeared to be altered in rhesus monkeys that continued to exhibit ovulatory menstrual cycles during the "nonbreeding" season. This study was designed to investigate the effect of season on development of the dominant follicle (DF) and upon levels of serum gonadotropins and sex steroids in animals maintained in a controlled environment. Forty-four menstrual cycles were evaluated from October, 1982 to October, 1983. Animals were housed individually in controlled light (12L:12D) and temperature (22-25 degrees C). A DF was identified by laparoscopy on Day 6 of the cycle in only 45% of cycles during the months of May through September, compared with 87.5% the remainder of the year. No effect of season was detected on either the length of the menstrual cycle or luteal phase, mean follicular diameter, or the percentage of ovulatory cycles. During the follicular phase, amounts of follicle-stimulating hormone (FSH) in peripheral sera were depressed, whereas those of luteinizing hormone (LH) were consistently elevated. Amounts of circulating estradiol were similar between groups. However, serum concentrations of progesterone were markedly reduced in the summer. Development of the DF appeared to be delayed in the early follicular phase during the summer months in those rhesus monkeys that had ovulatory menstrual cycles. This delay was accompanied by an alteration in the FSH to LH ratio. Although most cycles were ovulatory, altered follicular development resulted in deficient luteal function.     

Effect of sex hormones on neuromuscular control patterns during landing.

The purpose of the study was to investigate the effects of sex hormones across menstrual cycle phases on lower extremity neuromuscular control patterns during the landing phase of a drop jump. A repeated-measures design was utilized to examine sex hormone effects in 26 recreationally active eumenorrheic women. Varus/valgus knee angle and EMG activity from six lower extremity muscles were recorded during three drop jumps from a 50 cm platform in each phase of the menstrual cycle. Blood assays verified sex hormone levels and cycle phase. The semitendinosus muscle exhibited onset delays (p0.006) relative to ground contact during the luteal phase, and demonstrated a significant (p0.05) difference between early and late follicular phases. Muscle timing differences between the gluteus maximus and semitendinosus were decreased (p0.05) in the luteal compared to early follicular phases. These results suggest a different co-contractive behavior between the gluteus maximus and semitendinosus, signifying a shift in neuromuscular control patterns. It appears that female recreational athletes utilize a different neuromuscular control pattern for performing a drop jump sequence when estrogen levels are high (luteal phase) compared to when they are low (early follicular phase).     

Subnormal follicular-phase serum progesterone levels and elevated follicular-phase serum estradiol levels in young women with insulin-dependent diabetes

In a search for possible hormonal reasons for the loss of protection from myocardial infarction seen in diabetic women, serum levels of estradiol, progesterone, and luteinizing hormone were compared throughout a menstrual cycle (17 points) in eight healthy nonsmoking women and five otherwise healthy nonsmoking insulin-dependent diabetic women. The total length of the menstrual cycle and the lengths of the follicular and luteal phases did not differ between the groups. During the periovulatory and luteal phases, there was no significant intergroup difference with respect to any of the three hormones. During the follicular phase, in both groups, there was a plateau in serum progesterone concentration, with the level approximately 42% lower in the diabetic group (12.0 +/- 6.6 ng/dl versus 20.7 +/- 5.7; P less than 0.0001). Follicular-phase serum estradiol showed a rising curve in both groups; day-by-day comparison (days -10 to -3 before the luteinizing hormone peak) showed consistently higher levels in the diabetic group (mean, 108 pg/ml versus 95 pg/ml; P less than 0.001). The follicular-phase serum estradiol to progesterone ratio was nearly twice as high in the diabetic group as in the normal group (8.9 versus 4.6), a difference that was highly significant. The finding of elevated serum estradiol and subnormal serum progesterone concentrations during the follicular phase is so far unique to women with insulin-dependent diabetes mellitus. The possibility that this pronounced abnormality in diabetic women may be related to coronary disease merits testing in suitable in vivo and in vitro models of atherogenesis.     

Menstrual Cycle Effects on Attitudes toward Romantic Kissing

Hormonal changes associated with the human menstrual cycle have been previously found to affect female mate preference, whereby women in the late follicular phase of their cycle (i.e., at higher risk of conception) prefer males displaying putative signals of underlying genetic fitness. Past research also suggests that romantic kissing is utilized in human mating contexts to assess potential mating partners. The current study examined whether women in their late follicular cycle phase place greater value on kissing at times when it might help serve mate assessment functions. Using an international online questionnaire, results showed that women in the follicular phase of their menstrual cycle felt that kissing was more important at initial stages of a relationship than women in the luteal phase of their cycle. Furthermore, it was found that estimated progesterone levels were a significant negative predictor for these ratings.     

Physiological variability of fluid-regulation hormones in young women.

We tested the physiological reliability of plasma renin activity (PRA) and plasma concentrations of arginine vasopressin (P[AVP]), aldosterone (P[ALD]), and atrial natriuretic peptide (P[ANP]) in the early follicular phase and midluteal phases over the course of two menstrual cycles (n = 9 women, ages 25 +/- 1 yr). The reliability (Cronbach's alpha >/=0.80) of these hormones within a given phase of the cycle was tested 1) at rest, 2) after 2.5 h of dehydrating exercise, and 3) during a rehydration period. The mean hormone concentrations were similar within both the early follicular and midluteal phase tests; and the mean concentrations of P[ALD] and PRA for the three test conditions were significantly greater during the midluteal compared with the early follicular phase. Although Cronbach's alpha for resting and recovery P[ANP] were high (0.80 and 0.87, respectively), the resting and rehydration values for P[AVP], P[ALD], and PRA were variable between trials for the follicular (alpha from 0.49 to 0.55) and the luteal phase (alpha from 0.25 to 0. 66). Physiological reliability was better after dehydration for P[AVP] and PRA but remained low for P[ALD]. Although resting and recovery P[AVP], P[ALD], and PRA were not consistent within a given menstrual phase, the differences in the concentrations of these hormones between the different menstrual phases far exceeded the variability within the phases, indicating that the low within-phase reliability does not prevent the detection of menstrual phase-related differences in these hormonal variables.     

Changes in mood, cognitive performance and appetite in the late luteal and follicular phases of the menstrual cycle in women with and without PMDD (premenstrual dysphoric disorder)

Although it's been reported that women with premenstrual dysphoric disorder (PMDD) have increased negative mood, appetite (food cravings and food intake), alcohol intake and cognitive deficits premenstrually, few studies have examined these changes concurrently within the same group of women or compared to women without PMDD. Thus, to date, there is not a clear understanding of the full range of PMDD symptoms. The present study concurrently assessed mood and performance tasks in 29 normally cycling women (14 women who met DSM-IV criteria for PMDD and 15 women without PMDD). Women had a total of ten sessions: two practice sessions, 4 sessions during the follicular phase and 4 sessions during the late luteal phase of the menstrual cycle. Each session, participants completed mood and food-related questionnaires, a motor coordination task, performed various cognitive tasks and ate lunch. There was a significant increase in dysphoric mood during the luteal phase in women with PMDD compared to their follicular phase and compared to Control women. Further, during the luteal phase, women with PMDD showed impaired performance on the Immediate and Delayed Word Recall Task, the Immediate and Delayed Digit Recall Task and the Digit Symbol Substitution Test compared to Control women. Women with PMDD, but not Control women, also showed increased desire for food items high in fat during the luteal phase compared to the follicular phase and correspondingly, women with PMDD consumed more calories during the luteal phase (mostly derived from fat) compared to the follicular phase. In summary, women with PMDD experience dysphoric mood, a greater desire and actual intake of certain foods and show impaired cognitive performance during the luteal phase. An altered serotonergic system in women with PMDD may be the underlying mechanism for the observed symptoms; correspondingly, treatment with specific serotonin reuptake inhibitors (SSRIs) remains the preferred treatment at this time.     

Food cravings, mood, and the menstrual cycle

The primary objective of the present investigation was to document positive changes in food cravings, food consumption, and mood changes over the menstrual cycle and to explore the relation between these factors and dieting habits. A total of 32 female undergraduates completed daily self-reports of food cravings, foods eaten, and mood, for 5 or more weeks. Comparisons of these measures in the 10 days preceding (luteal phase) and 10 days following menstruation onset (follicular phase) revealed that both food cravings and amount eaten were greater in the luteal phase than in the follicular phase. Although women also experienced less positive affect in the luteal phase, there was no correlation between mood and either cravings or amount eaten. Women rated as chronic dieters craved less than those rated an nondieters. The findings on mood and eating confirm previous research, whereas those on cravings extend such research by suggesting that carbohydrate cravings may be augmented by the luteal phase in healthy women.     

Features of cardiovascular functioning during different phases of the menstrual cycle

The purpose of the present study was to determine whether there is a menstrual cycle effect on heart rate, blood pressure and heart rate variability. 10 healthy regularly cycling females (age 19-23 years) were studied during the follicular phase and luteal phase over two month. We found significant changes in heart rate, AMo and stress index during the menstrual cycle with a minimum in the follicular phase and maximum in the luteal phase. The HF and LF components decreased more during the luteal phase than during the follicular phase (p < 0.05), whereas a tendency for increase LF/HF was observed in the luteal phase. In the follicular phase SDNN, pNN50, Mo, MxDMn were significantly higher than in the luteal phase. Furthermore, the VIK was higher in the luteal phase compared to the follicular phase (p = 0.003). Blood pressure did not show any significant change during both these phases of the menstrual cycle. These findings indicate that sympathetic nervous activity in the luteal phase is greater than in the follicular phase, whereas parasympathetic nervous activity is predominant in the follicular phase. A difference of the balance of ovarian hormones may be responsible for these changes of autonomic functions during the menstrual cycle.     

Acute pre-learning stress and declarative memory: impact of sex,cortisol response and menstrual cycle phase

This study explores the influence of pre-learning stress on performance on declarative memory tasks in healthy young adults in relation to sex and menstrual cycle phase. The sample was composed of 119 students (32 men and 87 women) from 18 to 25 years of age. The women were tested in different hormonal stages (30 in follicular phase, 34 in luteal phase, and 23 using oral contraceptives). The participants were exposed to the Trier Social Stress Test (TSST) or a control condition. Afterwards, their memory performance was measured using a standardized memory test (Rey's Auditory Verbal Learning Test). In the control condition, all groups of women recalled more words than men, but these differences disappeared in the group exposed to TSST because men's performance on the memory test improved, but only to the level of women. In addition, our data suggest that in women the relationship between cortisol and memory can be modulated by sex hormone levels, since in luteal women a negative relationship was found between memory performance and peak cortisol level. These results confirm that sex differences need to be considered in the relationship between pre-learning stress and memory performance.     

Sex hormones correlated with sex skin swelling and rectal temperature during the menstrual cycle of the pigtail macaque (Macaca nemestrina).

Daily measurement of serum luteinizing hormone, estradiol-17beta, and progesterone were made during the menstrual cycle in nine pigtail macaques (Macaca nemestrina). All data were normalized to the day of the luteinizing hormone peak. Serum estradiol-17beta increased from approximately 100 pg/ml during the early follicular phase to 442 +/- 156 pg/ml during the maximum midcycle concomitant with the luteinizing hormone peak, and a small increase in serum estradiol-17beta was observed during the luteal phase coincident with the progesterone peak. Serum progesterone values increased slightly at the time of the luteinizing hormone peak and increased from 0.2-0.3 ng/ml during the midfollicular phase to peak levels of 8.3 +/- 1.75 ng/ml 9 days after the luteinizing hormone surge. Serum luteinizing hormone remained low and relatively constant throughout the early and midcycle, then sharply increased approximately four-fold to peak values of 6.25 +/- 0.9 ng/ml. Sex skin swelling increased slowly during the follicular phase and declined slowly throughout the early luteal phase. Rectal temperature did not change significantly throughout the menstrual cycle. The similarity of plasma sex hormone changes during the menstrual cycle between women and the pigtail macaque suggested that this nonhuman primate should be a useful animal model for studying human reproduction.     

Prostaglandins and premenstrual syndrome.

We examined plasma PGF2 alpha, PGE, PGE2, TXB2 and 6-keto-PGF1 alpha at intervals throughout 3 menstrual cycles in 20 patients with PMS. Similar measurements throughout 1 menstrual cycle were made in 12 age-matched control women. The plasma concentration of PGF2 alpha in the late luteal phase was significantly lower in patients with PMS compared with that in the control subjects. The plasma concentrations of PGE in the middle follicular phase and middle luteal phase, PGE2 alpha in the middle follicular phase and TXB2 in the middle and late luteal phase were significantly higher in 20 patients compared with the values in the controls. A disturbance of PG metabolism may contribute to the etiology of PMS.     

Evaluation of brain-derived neurotrophic factor in menstrual blood and its identification in human endometrium

The presence of high-affinity brain-derived neurotrophic factor receptor Trk B in mouse and in human fetal oocytes, together with the presence of neurotrophins in human follicular fluid suggests a paracrine role for brain-derived neurotrophic factor (BDNF) in female biology. This study aims to evaluate if BDNF is present and quantitatively determined in human menstrual blood and endometrium. Twenty-one women were studied and subdivided in two groups: A, 11 fertile women (27 ± 2 days cycle length) and B, 10 anovulatory women and/or women with inadequate luteal phase (36 ± 2 days cycle length). In fertile women menstrual BDNF levels was higher than plasma (679.3 ± 92.2 vs 301.9 ± 46.7 pg/ml p <0.001). Similarly, in Group B, BDNF in menstrual blood was higher than plasma (386.1 ± 85.2 vs 166.8 ± 24.1 pg/ml p < 0.001). Moreover, both menstrual and plasma BDNF concentrations in Group A were significantly higher respect to Group B (679.3 ± 92.2 vs 386.1 ± 85.2 pg/ml p < 0.001; 301.9 ± 46.7 vs 166.8 ± 24.1 pg/ml p < 0.001). Immunohistochemistry evidence of BDNF in endometrium, during follicular and luteal phase, was also shown. The detection of BDNF in the human menstrual blood and endometrium further supports the role of this neurotrophin in female reproductive function.     

Variation in sociosexuality across natural menstrual cycles: Associations with ovarian hormones and cycle phase

The psychological construct of sociosexuality—one's sexual openness or propensity to engage in uncommitted sexual relationships—has been broadly examined within numerous cultures and mating contexts. Although there is some evidence suggesting that components of sociosexuality, namely behavior, desire and attitude, change within-person, relatively little research has investigated potential sources of such variation. The aim of our study was to explore if the individual components of sociosexuality change across the menstrual cycle, either as a function of cycle phase or ovarian hormones. One hundred and two naturally cycling women, both single and in a committed relationships, completed questions from the the SOI-R (Sociosexuality Revised) questionnaire three times during a menstrual cycle, scheduled to coincide with their early follicular, peri-ovulatory, and luteal phases. Women provided saliva samples and performed luteinizing hormone tests to distinguish between ovulatory and anovulatory cycles. Women reported slightly more openness to uncommitted sexual relationships during the peri-ovulatory session, but significant differences were restricted only to women who exhibited the luteinizing hormone surge. Ovarian hormone concentrations within cycles significantly predicted SOI Attitude and Desire scores, with estradiol positively related, and progesterone negatively related to openness to uncommitted sexuality. These effects were generally modest in size. The results of this study suggest that sociosexuality can vary within short periods of time, such as a single menstrual cycle.     

Pathogen disgust,but not moral disgust,changes across the menstrual cycle

The Compensatory Prophylaxis Hypothesis (CPH) proposes that during periods of increased susceptibility to infections, e.g., during the luteal phase of the menstrual cycle when progesterone suppresses immune function, women should feel more disgust toward pathogen cues and behave prophylactically. We investigate differences in disgust sensitivity and contamination sensitivity during different phases of the menstrual cycle in regularly cycling, healthy 93 rural and urban Polish women using the within-subject design. Disgust sensitivity was measured during two different phases of a menstrual cycle: 1) the follicular phase (the 5th or 6th day of the cycle) and 2) the luteal phase (on the 5th day after a positive ovulatory test or on 20th day of a cycle if the result of the ovulatory test was not positive). In the luteal phase, women scored higher on the Pathogen Disgust of the Three-Domain Disgust Scale, the Contamination Obsessions and Washing Compulsions Subscale of Padua Inventory, and on ratings of photographs showing sources of potential infections than in the follicular phase. Moral Disgust of the Three-Domain Disgust Scale did not differ between cycle phases. Hence, results suggest that women feel more disgusted toward cues to pathogens during the luteal phase, when susceptibility to infection is greater. We suggest that it is necessary to incorporate ovulatory testing as well as to conduct repeated measurements of disgust sensitivity in future tests of the CPH. Moreover, we believe that understanding how the feeling of pathogen disgust varies across the menstrual cycle and in relation to progesterone levels could be useful in designing effective infectious diseases prevention strategies for women.     

Exogenous androgens decrease the length of the luteal phase and increase the length of the follicular phase

This study investigated the effects of exogenous androgens on the menstrual cycle of eight transsexual females. It was found that the luteal phase decreased from 13.7 +/- 0.8 to 11.6 +/- 0.8 days, whereas the follicular phase increased in length from 13.5 +/- 0.6 to 15.3 +/- 0.6 days. With the testosterone levels attained in venous blood (+/- 4.5 nmol/l) ovulation continued, judged by the rise of basal body temperature and the increase of oestrogen and progesterone blood levels. These results relate hyperandrogenism to luteal insufficiency.