Hormonal Profiles of Menstrual Bleeding Patterns During the Luteal-Follicular Transition.

CONTEXT: Menstrual cycle function is determined by a complex endocrine axis that controls the ovaries and endometrium. While the late luteal phase is characterized by declining progesterone and estrogen, how these hormonal profiles relate to menstrual bleeding patterns is not well understood. OBJECTIVE: Characterize associations between luteal phase hormonal profiles and subsequent menstrual bleeding patterns, specifically spotting before bleeding. DESIGN, SETTING, AND PARTICIPANTS: We examined creatinine-adjusted urinary estrone 3-glucuronide (E13G) and pregnanediol 3-glucuronide (Pd3G) levels in relation to spotting in 116 premenopausal women (ages 20-47) who kept daily menstrual diaries and collected first morning urine samples for ≥ 2 consecutive cycles or 1 luteal-follicular transition (n = 283 transitions). We used linear mixed models to estimate associations between luteal phase hormone levels and spotting before bleeding. MAIN OUTCOME MEASURE(S) AND RESULTS: Transitions with ≥ 1 days of spotting before menstrual bleeding (n = 118) had greater luteal phase Pd3G levels vs nonspotting transitions (n = 165). Differences in Pd3G between spotting and nonspotting transitions were largest at menses onset (34.8%, 95% confidence interval, 18.9%, 52.7%). Pd3G levels for spotting transitions dropped to similar levels as nonspotting transitions an average of 1 day later, which aligned with the first day of bleeding for transitions with contiguous spotting. Spotting transitions were preceded by slower rates of Pd3G decline than nonspotting transitions, whereas E13G declines were similar. CONCLUSIONS: Self-reported bleeding patterns may provide insight into luteal phase Pd3G levels. First bleed appears to be the best choice for defining the end of the luteal phase and achieving hormonal consistency across transitions.

Premenstrual Syndrome, Inflammatory Status, and Mood States in Soccer Players.

OBJECTIVE: To evaluate the relationship between the inflammatory profile and mood states in the different phases of the menstrual cycle in soccer players with and without premenstrual syndrome (PMS). METHODS: Data on the menstrual cycle and mood states were collected using the Daily Symptom Report and the Brunel Mood Scale. Cytokine and stress hormone concentrations were measured in urine by flow cytometry before and after a game in the luteal phase and in the follicular phase of one menstrual cycle. RESULTS: In all, 59.6% of the athletes had PMS. The PMS group showed higher concentrations of interleukin (IL)-1ß, IL-6, and IL-8 than the athletes without PMS. After the game, IL-6 decreased in the follicular phase and the luteal phase. The tumor necrosis factor-α levels were higher in the group without PMS during the post-game follicular phase than before the game. In the PMS group, tension was higher in the follicular phase before the game and depression was higher in the pre-game luteal phase than in the group without PMS. The PMS group also presented a negative correlation between depression and IL-10 levels in the pre-game follicular phase. Finally, in the pre-game luteal phase were found positive correlations between growth hormone and IL-10. CONCLUSION: PMS influences the inflammatory condition related to mood states and stress hormones in female soccer players.

Elevation of C-reactive protein during the luteal phase in healthy adolescents.

INTRODUCTION: Variations in inflammatory markers have been reported in adult women during the luteal phase, but whether these findings are observed during adolescence is unknown. We postulate that higher ultrasensitive C-reactive protein (usCRP) and lower 2-hydroxyestrone (2OHE) levels, an estrogen metabolite with cardioprotective actions, are present during the luteal phase in young women. AIM: To evaluate usCRP levels during the menstrual cycle and to determine its association with 2OHE and 16α-hydroxyestrone (16OHE) in adolescents. METHODS: Healthy postmenarcheal adolescents (N = 37) were studied during one menstrual cycle in follicular phase (FP) and luteal phase-like period (LP-L). RESULTS: Elevations in usCRP levels in the LP-L were observed in the entire group and in anovulatory cycles (1.9 ± 1.1 mg/L in FP to 2.5 ± 1.8 mg/L in LP-L; p < 0.0001). Increases in estrone, estradiol, free and bioavailable estradiol, testosterone, usCRP and 2OHE levels were observed in LP-L compared with FP (p < 0.01), with a borderline elevation in IFG-I levels (p = 0.06). CONCLUSIONS: We report an elevation of usCRP and 2OHE levels during the luteal phase in healthy adolescents. Elevations of this inflammatory marker in anovulatory adolescents without an increase in 2OHE may play a role in metabolic risks associated with chronic anovulation.

Urine 3-hydroxykynurenine is higher during the postovulatory phase than in the preovulatory phase indicating a higher vitamin B6 requirement.

The relationship between l-tryptophan to nicotinamide metabolism and the menstrual cycle of Japanese women was investigated. Nine metabolism intermediates from urine samples collected during the preovulatory and postovulatory phases were measured. Only urine 3-hydroxykynurenine was higher in the postovulatory phase than in the preovulatory phase. This increase in 3-hydroxykynurenine suggests a decreased reaction of 3-hydroxykynurenine → 3-hydroxyanthranilic acid catalyzed by kynureninase, a vitamin B6 enzyme.

Characterization of follicle stimulating hormone profiles in normal ovulating women.

OBJECTIVE: To describe FSH profile variants. DESIGN: Observational study. SETTING: Multicenter collaborative study. PATIENT(S): A total of 107 women. INTERVENTION(S): Women collected daily first morning urine and underwent serial ovarian ultrasound. MAIN OUTCOME MEASURE(S) FSH RESULT(S): The individual FSH cyclic profiles demonstrated a significant departure from the currently accepted model. A decline in FSH levels at the end of the follicular phase was observed in only 42% of cycles. The absence of this decline was significantly associated with a shorter luteal phase and higher pregnanediol-3α-glucuronide, FSH, and LH levels at the time of ovulation. In 34% of the cycles, significant FSH variability was observed throughout the follicular phase; this variability was associated with higher body mass index and lower overall FSH and LH levels throughout the cycle. The FSH peak occurs on average 2 hours before ovulation. The FSH peak duration was shorter than the LH peak. CONCLUSION(S): These results suggest that average FSH profiles may not reflect the more complex dynamics of daily hormonal variations in the menstrual cycle. It is possible that discrepancies between the average normal FSH profile and the individual day-to-day variants can be used to detect abnormalities.

An independent positive relationship between the serum total osteocalcin level and fat-free mass in healthy premenopausal women.

CONTEXT: It is widely reported that osteocalcin is negatively associated with fat mass. However, there are few reports describing its correlation with fat-free mass, particularly in women. OBJECTIVES: The objective of the current study was to investigate the possible relationship between osteocalcin and fat-free mass in healthy, nonobese women. DESIGN AND SETTING: This study was performed in a tertiary university teaching hospital. SUBJECTS: A total of 504 healthy women aged 20-75 years were enrolled. MAIN OUTCOME MEASURES: Body composition was measured using a bioelectronics impedance analyzer. The serum concentrations of total osteocalcin, estradiol, leptin, osteoprotegerin, the receptor activator of nuclear factor-κB ligand, IGF-I, fasting plasma glucose, and urinary N-terminal telopeptide of type I collagen were tested. The bone mineral densities (BMDs) at the lumbar spine and proximal femoral neck were measured by dual-energy X-ray absorptiometry. RESULTS: The serum total osteocalcin level had a significant positive association with fat-free mass (r = 0.168, P = .007) after adjusting for age, fat mass, menopausal status, estradiol, fasting glucose, leptin, osteoprotegerin, receptor activator of nuclear factor-κB ligand, IGF-I, N-terminal telopeptide of type I collagen, BMDs, and waist and hip circumference. Analysis in pre- and postmenopausal women demonstrated that this association was only present in premenopausal women (r = 0.190, P = .005). The multiple stepwise regression analysis revealed that hip circumference, femoral neck-BMD, fat mass, leptin, osteocalcin, and age are the contributors to the changes in fat-free mass in premenopausal women (adjusted R(2) = 0.521, P < .001). CONCLUSION: The serum level of total osteocalcin was positively associated with fat-free mass independent of age, fat mass, leptin, and other confounders in premenopausal women.

Circadian variation of sleep during the follicular and luteal phases of the menstrual cycle.

STUDY OBJECTIVES: Women experience insomnia more frequently than men. Menstrual cycle changes in reproductive hormones and circadian rhythms may contribute to sleep disruptions. Our aim, therefore, was to clarify the interaction between menstrual and circadian processes as it affects sleep. DESIGN: Participants entered the laboratory during the mid-follicular (MF) and mid-luteal (ML) phases of their menstrual cycle for an ultra-rapid sleep-wake cycle (URSW) procedure, consisting of 36 cycles of 60-min wake episodes alternating with 60-min nap opportunities. This procedure concluded with an ad libitum nap episode. SETTING: Time-isolation suite. PARTICIPANTS: Eight unmedicated, physically and mentally healthy females with regular ovulatory menstrual cycles. INTERVENTIONS: N/A. MEASUREMENTS: Polysomnographic sleep from nocturnal sleep episodes and 60-min naps; subjective alertness; core body temperature (CBT); salivary melatonin; urinary estradiol; and urinary progesterone. RESULTS: Increased CBT values at night and decreased CBT amplitude were observed during ML compared to MF. Circadian phase of CBT and the circadian melatonin profile were unaffected by menstrual phase. All analyzed sleep parameters showed a circadian variation throughout the URSW procedure, with no menstrual phase differences observed for most, including slow wave sleep (SWS). The circadian variation of REM sleep duration, however, was sensitive to menstrual phase, with reduced REM sleep during ML at circadian phase 0 degrees and 30 degrees. CONCLUSIONS: Moderate but significant changes in REM sleep across the menstrual and circadian cycles were observed. These results support an interaction between circadian and menstrual processes in the regulation of REM sleep.

Effects of menstrual cycle phase on metabolomic profiles in premenopausal women.

BACKGROUND: Characterization of the normal degree of physiological variation in the metabolomic profiles of healthy humans is a necessary step in the development of metabolomics as both a clinical research and diagnostic tool. This study investigated the effects of the menstrual cycle on (1)H nuclear magnetic resonance (NMR) derived metabolomic profiles of urine and plasma from healthy women. METHODS: In this study, 34 healthy women were recruited and a first void urine and fasting blood sample were collected from each woman at four different time points during one menstrual cycle. Serum hormone levels were used in combination with the menstrual calendar to classify the urine and plasma samples into five different phases i.e. menstrual, follicular, periovulatory, luteal and premenstrual. The urine and plasma samples were analysed using (1)H NMR spectroscopy and subsequent data were analysed using principal component analysis (PCA) and partial least squares discriminant analysis. RESULTS: PCA of the urine spectra showed no separation of samples based on the phases of the menstrual cycle. Multivariate analysis of the plasma spectra showed a separation of the menstrual phase and the luteal phase samples (R(2) = 0.61, Q(2) = 0.41). Subsequent analysis revealed a significant decrease in levels of glutamine, glycine, alanine, lysine, serine and creatinine and a significant increase in levels of acetoacetate and very low density lipoprotein (VLDL CH(2)) during the luteal phase. CONCLUSIONS: These results establish a need to control for metabolic changes that occur in plasma due to the menstrual cycle in the design of future metabolomic studies involving premenopausal women.

Nandrolone excretion in sedentary vs physically trained young women.

We investigated the effects of the menstrual cycle, oral contraception and physical training on exhaustive exercise-induced changes in the excretion of nandrolone metabolites [19-norandrosterone (19-NA), and 19-noretiocholanolone (19-NE)] in young women. Twenty-eight women were allocated to an untrained group (n=16) or a trained group (n=12), depending on their physical training background. The untrained group was composed of nine oral contraceptive users (OC+) and seven eumenorrheic women (OC-), while the trained group was entirely composed of OC+ subjects. Three laboratory sessions were conducted in a randomized order: a prolonged exercise test, a short-term exercise test and a control session. Urine specimens were collected before and 30, 60 and 90 min after the exercise test and at the same times of the day during the control session. Urinary concentrations of nandrolone metabolites were determined by gas chromatography coupled to mass spectrometry. Urinary concentrations of 19-NA and 19-NE ranged from undetectable levels to 1.14 and 0.47 ng/mL, respectively. Nandrolone excretion was not affected by the menstrual cycle phase (early follicular vs mid-luteal), prior physical training, oral contraception or acute physical exercise. Therefore, a urinary concentration of 2 ng/mL of 19-NA appears to be fair as the upper acceptable limit in doping control tests for female athletes.

Lifestyle and reproductive factors associated with follicular phase length.

PURPOSE: Variability in menstrual cycle length, largely determined by variation in follicular phase length, is related to several health outcomes, yet the causes of this variability are incompletely understood. We sought to identify characteristics associated with follicular phase length. METHODS: We used the North Carolina Early Pregnancy Study to describe factors correlated with timing of ovulation (follicular phase length). Women collected daily urine specimens and recorded vaginal bleeding. Specimens were assayed for estrone 3-glucuronide and pregnanediol 3-glucuronide, which in turn were used to estimate the day of ovulation. All other variables were assessed through interview. Associations with follicular phase length were evaluated using a multiple regression model. RESULTS: We determined follicular phase length for the first cycles of 201 women. Women with a history of miscarriage tended to have shorter follicular phases (2.2 days). Longer duration of oral contraceptive (OC) use and recent OC use (in the last 90 days) were both correlated with longer follicular phase. Occasional marijuana users (up to three times in the last 3 months) had a longer follicular phase than nonusers (3.5 days); the follicular phase in frequent users (more than three times) was almost 2 days longer than that of nonusers. CONCLUSIONS: The association between marijuana use and longer follicular phase is consistent with prior rhesus monkey research that shows ovulatory delay or inhibition.

Characterisation of the sympathetic nervous system of Asian (Elephas maximus) and African (Loxodonta africana) elephants based on urinary catecholamine analyses.

Assessing the welfare status of captive animals using non-invasive measurements of hormones is of growing interest because this can serve as an effective tool to facilitate the optimization of environmental and husbandry conditions. Both the African elephant (Loxodonta africana) and the Asian elephant (Elephas maximus) exhibit extremely low breeding success in captivity, and because elevated levels of stress may negatively influence reproductive functions, this study sought to establish a method for assessing sympathoadrenal activity in captive female elephants. We found a circadian variation in urinary noradrenaline (norepinephrine, NE), adrenaline (epinephrine, Epi) and dopamine (DA) under short day length. Peak activity of noradrenaline and dopamine was noted at 3 a.m. Adrenaline showed a biphasic pattern with a minor peak recorded at 3 a.m. and a major peak 9 a.m. Under long-day photoperiodic conditions, simultaneous peaks of noradrenaline and adrenaline were again noted at 3 a.m. whereas dopamine does not appear to have a distinct circadian pattern under long-day length. A transfer of two elephant cows resulted in a marked increase in urinary adrenaline and noradrenaline levels, confirming that the transfer represented a stressful event. During the peripartal period, noradrenaline concentrations increased and maximum concentrations were obtained at delivery. Daily measurements of urinary dopamine throughout the follicular phase revealed an increase in dopamine secretion close to ovulation. This increase might indicate a role of dopamine in the ovulatory mechanisms. These results suggest that changes in urinary catecholamine excretion reflect fluctuations in sympathoadrenal activity and may be a useful indicator of stress.

Variability in the phases of the menstrual cycle.

OBJECTIVE: To determine variability in the phases of the menstrual cycle among healthy, regularly cycling women. DESIGN: A prospective descriptive study of a new data set with biological markers to estimate parameters of the menstrual cycles. PARTICIPANTS: One hundred forty one healthy women (mean age 29 years) who monitored 3 to 13 menstrual cycles with an electronic fertility monitor and produced 1,060 usable cycles of data. MEASURES AND OUTCOMES: Variability in the length of the menstrual cycle and of the follicular, fertile, and luteal phases, and menses. The estimated day of ovulation and end of the fertile phase was the peak fertility reading on the monitor (i.e., the urinary luteinizing hormone surge). RESULTS: Mean total length was 28.9 days (SD = 3.4) with 95% of the cycles between 22 and 36 days. Intracycle variability of greater than 7 days was observed in 42.5% of the women. Ninety-five percent of the cycles had all 6 days of fertile phase between days 4 and 23, but only 25% of participants had all days of the fertile phase between days 10 and 17. CONCLUSIONS: Among regularly cycling women, there is considerable normal variability in the phases of the menstrual cycle. The follicular phase contributes most to this variability.

The onset of the initial rise in follicle-stimulating hormone during the human menstrual cycle.

BACKGROUND: The rise in FSH (FSHr) that leads to the recruitment of a cohort of follicles during the menstrual cycle occurs during the luteal-follicular transition, however, it is unclear whether it consistently occurs on one particular day, or is subjected to reproductive ageing. METHODS: We determined the FSHr in 836 complete menstrual cycles from 102 women with regular menses using an algorithm, and additionally compared the relative variation in FSH during the last 14 days of the cycle. Possible effects of reproductive ageing on the onset of FSHr were also investigated. RESULTS: The day of FSHr follows a normal distribution with a median value of -4 (relative to first day of menses), mean -4.1 and SD 2.1. Analysis of the relative changes in FSH during the last 14 days of the cycle revealed the first significant rise on day -4 (P=0.0033), coinciding with the first significant drop in estrogens (P=0.0002). No effect of chronological age, or initial FSH levels, on FSHr was found, however, there was an inverse relationship between total follicular phase length (from day of FSHr to LH peak) and initial FSH levels (P<0.0001). CONCLUSIONS: The initial FSH rise in the cycle occurs consistently 4 days before menses, is related to a drop in estrogen levels, and is not affected by reproductive ageing.

Factors affecting menstrual cycle characteristics.

This 1989-1991 study in California and Utah used daily urinary metabolites of estrogen and progesterone and computer algorithms to assess ovulatory status and day of ovulation. The authors examined the associations of risk factors with menstrual cycle characteristics for 309 working women aged 20-44 years who collected a median of five cycles each of daily urine samples. Linear mixed models were used to assess continuous menstrual outcomes. Compared with women less than age 35 years, women aged 35 years or older had a significantly decreased (-0.94 days, 95% confidence interval: -1.83, -0.05) adjusted mean cycle length. Age modified the effects of smoking, physical activity, ethnicity, and alcohol consumption on mean follicular phase length. Asian women had a significantly longer (1.65 days, 95% confidence interval: 0.54, 2.76) adjusted mean cycle length compared with Caucasian women. Compared with women who did not consume alcoholic drinks, women who did had a significantly shorter (-1.26 days, 95% confidence interval: -2.21, -0.31) adjusted mean cycle length. Mean cycle and phase lengths were significantly associated with length of the prior luteal phase. These results indicate that potentially modifiable risk factors, as well as immutable host factors, are associated with menstrual cycle characteristics that may in turn be related to subsequent disease risk.

Relationship between follicle-stimulating hormone levels at the beginning of the human menstrual cycle, length of the follicular phase and excreted estrogens: the FREEDOM study.

Although reproductive aging has been separately related to elevated FSH and shorter follicular phase (FP), the direct association between both parameters has not been investigated. Also, the exact effects of increased FSH on estrogen production are yet to be established.A large database of daily urinary concentrations of FSH, LH, and estrone 3-glucuronide (E1G) from 37 regularly menstruating women (median 11 cycles per patient) was used. Initial FSH levels (iFSH) were estimated as the mean value of d 1-5. The day of E1G take-off (ETO) was determined by an algorithm, and accordingly, the FP was divided into early (d 1 to ETO) and late (ETO+1 to LH peak). FP maximum and integrated E1G were calculated. Subjects were distributed according to their mean iFSH into three categories (5 to 10, and >10 IU/liter). There was a gradual decrease in FP length with increasing category (15.2 +/- 3.8, 14.1 +/- 3.6, and 13 +/- 2.6 d, respectively; P < 0.0001). A similar effect occurred in early FP (7.5 +/- 4, 6.4 +/- 3.7, and 5.4 +/- 2.7; P < 0.0001); in contrast, late FP was unaffected (7.7 +/- 2.1, 7.7 +/- 2.1, and 7.6 +/- 2.4; P = 0.86). No consistent increase in E1G was found with advancing iFSH category; however, women with mean initial LH higher than 6 IU/liter had significantly elevated maximum (P < 0.0001) and integrated (P = 0.002) E1G.FP length decreases in parallel with increasing iFSH, with a selective effect on the early FP. Increased FSH does not affect E1G; however, elevated initial LH level was related to higher E1G.

Follicle stimulating hormone measured in unextracted urine throughout the menstrual cycle correlates with age and ovarian reserve.

BACKGROUND: A method was previously described to measure FSH reliably in unextracted urine. The aim of the current study was to establish the course of FSH measured in urine throughout the cycle. METHOD: Daily urinary FSH (uFSH) concentrations were determined in 14 regularly menstruating volunteers aged 23-39 years during one complete menstrual cycle. RESULTS: In each subject, mean daily uFSH measured in urine, as gold standard for FSH tone, correlated significantly with FSH in early follicular phase fixed to menstruation on cycle day 3 (r = 0.75, P = 0.002), or fixed to ovulation 9 days before the pre-ovulatory FSH surge (r = 0.87, P = 0.0001), or when selected as being the highest follicular phase value (r = 0.91, P = 0.0001). Age correlated significantly with mean daily uFSH (r = 0.67, P = 0.009), highest follicular phase uFSH (r = 0.60, P = 0.024), uFSH on cycle day 3 (r = 0.80, P = 0.0006), and uFSH 9 days before FSH surge (r = 0.65, P = 0.0016). The uFSH was also measured on cycle day 3 in 104 IVF patients in a cycle prior to pituitary down-regulation. The uFSH correlated significantly with numbers of follicles (P = 0.02) and oocytes (P = 0.024). CONCLUSION: It is concluded that cycle day 3 uFSH is a good reflection of the mean uFSH of the complete cycle, and there is a highly significant correlation between uFSH and age and ovarian reserve. Measurement of FSH in urine on cycle day 3 seems to be a reliable and non-invasive tool for determining ovarian reserve in IVF.

Hypothalamic-pituitary-ovarian dysfunction after prepubertal chemotherapy and cranial irradiation for acute leukaemia.

BACKGROUND: We assessed adult hypothalamic-pituitary-ovarian function following treatment with chemotherapy and cranial irradiation for childhood acute lymphoblastic leukaemia. METHODS: The patients (n = 12) had median age at diagnosis of 4.7 years, and at assessment of 20.8 years. They collected a daily urine sample over two to five consecutive menstrual cycles (total of 41 cycles) for analysis of LH and steroid excretion. Blood sampling and ovarian ultrasound examination was performed in the early follicular phase. Sixteen healthy women with regular menstrual cycles were recruited as controls. RESULTS: Urinary LH excretion was significantly lower in patients throughout the cycle, particularly during the LH surge (P < 0.0001). The length of the luteal phase was significantly shorter in patients than in normal controls (12.2 +/- 0.3 versus 13.6 +/- 0.4 days, P = 0.01) with a high prevalence of short (< or =11 days) luteal phases (15/39 cycles). Luteal phase pregnanediol excretion was slightly but not significantly lower. Follicular and luteal phase excretion of oestrone was lower in patients than in controls (P = 0.01). Early follicular phase plasma oestradiol was also lower in the patient group (P = 0.032) although LH, FSH, inhibin A and B concentrations were similar. CONCLUSIONS: These data indicate that treatment for childhood leukaemia results in subtle ovulatory disorder in some patients, probably related to cranial irradiation. Follow-up of these women is required to detect any effect on reproductive potential.

Reproducibility of plasma and urinary sex hormone levels in premenopausal women over a one-year period.

Although endogenous sex steroid hormones in premenopausal women may be associated with the risk of breast cancer and other illnesses, direct evidence to support this hypothesis is limited in large part by methodological issues in the conduct of relevant studies. One major unresolved issue is whether a single blood sample (such as is available in most epidemiological studies), collected in a specific phase of the menstrual cycle, reflects long-term levels in that phase. To address this issue, two sets of blood and urine samples were obtained from 87 premenopausal women over a 1-year period in both the follicular and luteal phases. Plasma estradiol, estrone, and estrone sulfate were measured in the blood samples obtained in both phases, whereas progesterone and urinary 2- and 16a-hydroxyestrone were measured in luteal-phase samples only. For all of the women combined, intraclass correlation coefficients (ICCs) ranged, with one exception, from 0.52 to 0.71 for the plasma estrogens and the urinary estrogen metabolites. The sole exception was for estradiol in the luteal phase (ICC = 0.19); inclusion of only women who were ovulatory in both cycles and who collected each sample 4-10 days before their next period resulted in a substantially higher ICC for estradiol in the luteal phase (ICC = 0.62; 95% confidence interval, 0.43-0.78). These data indicate that, for several plasma and urinary sex hormones, a single follicular- or luteal-phase measurement in premenopausal women is reasonably representative of hormone levels in that phase for at least a 1-year period.

Effect of head-out water immersion on serum sodium transport inhibitor and urinary nonadrenaline excretion in pre-menopausal women.

The effect of head out water immersion on the excretion of catecholamines and serum sodium transport inhibitor (STI) was studied in healthy young women during the follicular and leuteal phases. Two way ANOVA showed that menstrual cycle had no effect on the excretion of noradrenaline (NA), dopamine (DA) or serum STI. Analysis of pooled data from follicular and leuteal phases showed that immersion caused a significant increase in sodium excretion and serum STI and a significant decrease in urinary NA excretion in healthy young women. After immersion, sodium excretion, DA excretion and serum STI decreased and NA increased.

Quantifying estrogen metabolism: an evaluation of the reproducibility and validity of enzyme immunoassays for 2-hydroxyestrone and 16alpha-hydroxyestrone in urine.

Rapid and simple enzyme immunoassays (EIAs) were recently developed to measure 2-hydroxyestrone and 16alpha-hydroxyestrone in unextracted urine. The balance between these competing estrogen metabolism pathways may serve as a biomarker of breast cancer risk. Before testing these assays in epidemiologic studies, we evaluated their reproducibility, and validity relative to gas chromatography-mass spectroscopy (GC-MS). Overnight 12-hr urine collections from five midfollicular premenopausal women, five midluteal premenopausal women, and five postmenopausal women were aliquoted and stored at -70 degrees C. Two aliquots from each woman were assayed with the EIAs in a random, blinded order, monthly over 4 months and 1 year later. Reproducibility over 4 months was good for both metabolites in premenopausal women (coefficient of variation = 8-14%) and satisfactory in postmenopausal women (approximately 19%). Reproducibility over 12 months remained good in premenopausal women, but was poor in postmenopausal women, with mean readings increasing 50 to 100%. Wide variation in estrogen metabolite levels enabled a single EIA measurement to characterize individual differences among premenopausal women in midfollicular (intraclass correlation coefficient = 98-99%) and midluteal phase (85-91%). A narrower range in metabolite levels among postmenopausal women reduced discrimination (78-82%). The correlation between EIA and GC-MS measurement was excellent for both metabolites (r>0.9), except for 2-hydroxyestrone in postmenopausal women (r=0.6). Analysis of absolute agreement suggested that both EIAs were less sensitive than GC-MS, and each detected nonspecific background. The low concentration of estrogen metabolites in urine from postmenopausal women may explain the problems with reproducibility and validity in this menstrual group. Accordingly, more sensitive EIAs have been developed and are now being evaluated.