In-utero exposure to polybrominated biphenyl (PBB) and menstrual cycle function in adulthood.

BACKGROUND: There is evidence that in-utero exposure to PBBs, and similar chemicals, are associated with several adverse reproductive health outcomes including altered pubertal timing. However, less is known about the effects of in-utero exposure to PBBs on menstrual cycle function and reproductive hormone levels in adulthood. METHODS: For this menstrual cycle study, we recruited reproductive-aged women in the Michigan PBB Registry who were not pregnant, lactating, or taking hormonal medications (2004-2014). A total of 41 women who were born after the PBB contamination incident (1973-1974) and were prenatally exposed to PBBs, were included in this analysis. We estimated in-utero PBB exposure using maternal serum PBB measurements taken after exposure and extrapolated to time of pregnancy using a PBB elimination model. Women were followed for up to 6 months during which they provided daily urine samples and completed daily diaries. The urine samples were assayed for estrone 3-glucuronide (E13G), pregnanediol 3-glucuronide (Pd3G), and follicle stimulating hormone (FSH). RESULTS: Women in our study were, on average, 27.5 (SD:5.3) years old and contributed 4.9 (SD:1.9) menstrual cycles of follow-up. Compared to women with low in-utero PBB exposure (≤1 ppb), women with medium (>1.0-3.0 ppb) and high (>3.0 ppb) exposure had higher maximum 3-day mean Pd3G levels during the luteal phase. Specifically, the age- and creatinine-adjusted maximum 3-day mean luteal phase Pd3G levels (95% CI) in increasing categories of in-utero PBB exposure were 9.2 (4.6,13.9), 14.8 (11.6,18.0), and 16.1 (12.9,19.3) µg/mg creatinine. There were no meaningful differences in average cycle length, follicular or luteal phase cycle length, bleed length, or creatinine-adjusted E13G or FSH levels by category of in-utero PBB exposure. CONCLUSION: Higher exposure to PBB in-utero was associated with increased progesterone levels across the luteal phase, however, most other menstrual cycle characteristics were largely unassociated with in-utero PBB exposure. Given our modest sample size, our results require cautious interpretation.

Urinary and salivary endocrine measurements to complement Tanner staging in studies of pubertal development.

BACKGROUND: Many studies investigating pubertal development use Tanner staging to assess maturation. Endocrine markers in urine and saliva may provide an objective, sensitive, and non-invasive method for assessing development. OBJECTIVE: Our objective was to examine whether changes in endocrine levels can indicate the onset of pubertal development prior to changes in self-rated Tanner stage. METHODS: Thirty-five girls and 42 boys aged 7 to 15 years were enrolled in the Growth and Puberty (GAP) study, a longitudinal pilot study conducted from 2007-2009 involving children of women enrolled in the Agricultural Health Study (AHS) in Iowa. We collected saliva and urine samples and assessed pubertal development by self-rated Tanner staging (pubic hair, breast development (girls), genital development (boys)) at three visits over six months. We measured dehydroepiandrosterone (DHEA) in saliva and creatinine-adjusted luteinizing hormone (LH), testosterone, follicle stimulating hormone (FSH), estrone 3-glucuronide (E13G) and pregnanediol 3-glucuronide (Pd3G) concentrations in first morning urine. We evaluated the relationships over time between Tanner stage and each biomarker using repeated measures analysis. RESULTS: Among girls still reporting Tanner breast stage 1 at the final visit, FSH levels increased over the 6-month follow-up period and were no longer lower than higher stage girls at the end of follow-up. We observed a similar pattern for testosterone in boys. By visit 3, boys still reporting Tanner genital stage 1 or pubic hair stage 1 had attained DHEA levels that were comparable to those among boys reporting Tanner stages 2 or 3. CONCLUSIONS: Increasing concentrations of FSH in girls and DHEA and testosterone in boys over a 6-month period revealed the start of the pubertal process prior to changes in self-rated Tanner stage. Repeated, non-invasive endocrine measures may complement the more subjective assessment of physical markers in studies determining pubertal onset.

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.

Polybrominated Biphenyl Exposure and Menstrual Cycle Function.

BACKGROUND: Brominated flame retardants, including polybrominated biphenyls (PBB), are persistent compounds reported to affect sex hormones in animals; less is known about potential effects in humans. An industrial accident in 1973-1974 exposed Michigan residents to PBB through contaminated food. We examined whether this exposure to PBB had long-term effects on menstrual cycle function. METHODS: In 2004-2006, we recruited reproductive-aged women in the Michigan PBB Registry who were not pregnant, lactating, or taking hormonal medications. Participants kept daily diaries and provided daily urine samples for up to 6 months. We assayed the urine samples for estrone 3-glucuronide (E13G), pregnanediol 3-glucuronide (Pd3G), and follicle stimulating hormone (FSH). We fit linear mixed models among women aged 35-42 years to describe the relation between serum PBB levels and log-transformed, creatinine-adjusted daily endocrine levels among women who were premenarchal during the exposure incident in 1973-1974 (n = 70). RESULTS: We observed that high (>3.0 parts per billion [ppb]) and medium (>1.0-3.0 ppb) PBB exposure were associated with lower E13G levels across the menstrual cycle and lower FSH levels during the follicular phase, compared with low PBB exposure (≤1.0 ppb). High PBB exposure was also associated with lower Pd3G levels across the cycle compared with low PBB exposure, whereas Pd3G levels were similar in women with medium and low PBB exposure. CONCLUSION: Our results are consistent with a hypothesized effect of exposure to an exogenous estrogen agonist but the modest sample size of the study requires cautious interpretation.

Thyroid hormones and menstrual cycle function in a longitudinal cohort of premenopausal women.

BACKGROUND: Previous studies have reported that hyperthyroid and hypothyroid women experience menstrual irregularities more often compared with euthyroid women, but reasons for this are not well-understood and studies on thyroid hormones among euthyroid women are lacking. In a prospective cohort study of euthyroid women, this study characterised the relationship between thyroid hormone concentrations and prospectively collected menstrual function outcomes. METHODS: Between 2004-2014, 86 euthyroid premenopausal women not lactating or taking hormonal medications participated in a study measuring menstrual function. Serum thyroid hormones were measured before the menstrual function study began. Women then collected first morning urine voids and completed daily bleeding diaries every day for three cycles. Urinary oestrogen and progesterone metabolites (estrone 3-glucuronide (E1 3G) and pregnanediol 3-glucuronide (Pd3G)) and follicle-stimulating hormone were measured and adjusted for creatinine (Cr). RESULTS: Total thyroxine (T4 ) concentrations were positively associated with Pd3G and E1 3G. Women with higher (vs lower) T4 had greater luteal phase maximum Pd3G (Pd3G = 11.7 µg/mg Cr for women with high T4 vs Pd3G = 9.5 and 8.1 µg/mg Cr for women with medium and low T4 , respectively) and greater follicular phase maximum E1 3G (E1 3G = 41.7 ng/mg Cr for women with high T4 vs E1 3G = 34.3 and 33.7 ng/mg Cr for women with medium and low T4 , respectively). CONCLUSIONS: Circulating thyroid hormone concentrations were associated with subtle differences in menstrual cycle function outcomes, particularly sex steroid hormone levels in healthy women. Results contribute to the understanding of the relationship between thyroid function and the menstrual cycle, and may have implications for fertility and chronic disease.

Association Between Biomarkers of Ovarian Reserve and Infertility Among Older Women of Reproductive Age.

Importance: Despite lack of evidence of their utility, biomarkers of ovarian reserve are being promoted as potential markers of reproductive potential. Objective: To determine the associations between biomarkers of ovarian reserve and reproductive potential among women of late reproductive age. Design, Setting, and Participants: Prospective time-to-pregnancy cohort study (2008 to date of last follow-up in March 2016) of women (N = 981) aged 30 to 44 years without a history of infertility who had been trying to conceive for 3 months or less, recruited from the community in the Raleigh-Durham, North Carolina, area. Exposures: Early-follicular-phase serum level of antimüllerian hormone (AMH), follicle-stimulating hormone (FSH), and inhibin B and urinary level of FSH. Main Outcomes and Measures: The primary outcomes were the cumulative probability of conception by 6 and 12 cycles of attempt and relative fecundability (probability of conception in a given menstrual cycle). Conception was defined as a positive pregnancy test result. Results: A total of 750 women (mean age, 33.3 [SD, 3.2] years; 77% white; 36% overweight or obese) provided a blood and urine sample and were included in the analysis. After adjusting for age, body mass index, race, current smoking status, and recent hormonal contraceptive use, women with low AMH values (<0.7 ng/mL [n = 84]) did not have a significantly different predicted probability of conceiving by 6 cycles of attempt (65%; 95% CI, 50%-75%) compared with women (n = 579) with normal values (62%; 95% CI, 57%-66%) or by 12 cycles of attempt (84% [95% CI, 70%-91%] vs 75% [95% CI, 70%-79%], respectively). Women with high serum FSH values (>10 mIU/mL [n = 83]) did not have a significantly different predicted probability of conceiving after 6 cycles of attempt (63%; 95% CI, 50%-73%) compared with women (n = 654) with normal values (62%; 95% CI, 57%-66%) or after 12 cycles of attempt (82% [95% CI, 70%-89%] vs 75% [95% CI, 70%-78%], respectively). Women with high urinary FSH values (>11.5 mIU/mg creatinine [n = 69]) did not have a significantly different predicted probability of conceiving after 6 cycles of attempt (61%; 95% CI, 46%-74%) compared with women (n = 660) with normal values (62%; 95% CI, 58%-66%) or after 12 cycles of attempt (70% [95% CI, 54%-80%] vs 76% [95% CI, 72%-80%], respectively). Inhibin B levels (n = 737) were not associated with the probability of conceiving in a given cycle (hazard ratio per 1-pg/mL increase, 0.999; 95% CI, 0.997-1.001). Conclusions and Relevance: Among women aged 30 to 44 years without a history of infertility who had been trying to conceive for 3 months or less, biomarkers indicating diminished ovarian reserve compared with normal ovarian reserve were not associated with reduced fertility. These findings do not support the use of urinary or blood follicle-stimulating hormone tests or antimüllerian hormone levels to assess natural fertility for women with these characteristics.

Associations between urinary biomarkers of polycyclic aromatic hydrocarbon exposure and reproductive function during menstrual cycles in women.

Essentially all women are exposed to polycyclic aromatic hydrocarbons (PAHs), formed during incomplete combustion of organic materials, including fossil fuels, wood, foods, and tobacco. PAHs are ovarian toxicants in rodents, and cigarette smoking is associated with reproductive abnormalities in women. Biomonitoring of hydroxylated PAH (OH-PAH) metabolites in urine provides an integrated measure of exposure to PAHs via multiple routes and has been used to characterize exposure to PAHs in humans. We hypothesized that concentrations of OH-PAHs in urine are associated with reproductive function in women. We recruited women 18-44years old, living in Orange County, California to conduct daily measurement of urinary luteinizing hormone (LH) and estrone 3-glucuronide (E13G) using a microelectronic fertility monitor for multiple menstrual cycles; these data were used to calculate endocrine endpoints. Participants also collected urine samples on cycle day 10 for measurement of nine OH-PAHs. Models were constructed for eight endpoints using a Bayesian mixed modeling approach with subject-specific random effects allowing each participant to act as a baseline for her set of measurements. We observed associations between individual OH-PAH concentrations and follicular phase length, follicular phase LH and E13G concentrations, preovulatory LH surge concentrations, and periovulatory E13G slope and concentration. We have demonstrated the feasibility of using urinary reproductive hormone data obtained via fertility monitors to calculate endocrine endpoints for epidemiological studies of ovarian function during multiple menstrual cycles. The results show that environmental exposure to PAHs is associated with changes in endocrine markers of ovarian function in women in a PAH-specific manner.

Menstrual cycle perturbation by organohalogens and elements in the Cree of James Bay, Canada.

Persistent organohalogens (POHs) and metals have been linked to alterations in menstrual cycle function and fertility in humans. The Cree First Nations people living near James Bay in Ontario and Quebec, Canada, have elevated levels of POHs, mercury and lead compared to other Canadians. The present study examines the interrelationships between selected POHs and elements on menstrual cycle function in these Cree women. Menstrual cycle characteristics were derived from structured daily diaries and endocrine measurements from daily urine samples collected during one cycle for 42 women age 19-42. We measured 31 POHs in blood plasma and 18 elements in whole blood, for 31 of the participants. POHs and elements detected in ≥ 70% of the participants were transformed by principal component (PC) analysis to reduce the contaminant exposure data to fewer, uncorrelated PCA variables. Multiple regression analysis revealed that, after adjusting for confounders, PC-3 values showed significant negative association with cycle length, after adjusting for confounders (p = 0.002). PC-3 accounted for 9.2% of the variance and shows positive loadings for cadmium, selenium, and PBDE congeners 47 and 153, and a negative loading for copper. Sensitivity analysis of the model to quantify likely effect sizes showed a range of menstrual cycle length from 25.3 to 28.3 days using the lower and upper 95% confidence limits of mean measured contaminant concentrations to predict cycle length. Our observations support the hypothesis that the menstrual cycle function of these women may be altered by exposure to POHs and elements from their environment.

Time-related increase in urinary testosterone levels and stable semen analysis parameters after bariatric surgery in men.

The aim of this prospective cohort study was to determine the time-course in androgen and semen parameters in men after weight loss associated with bariatric surgery. Six men aged 18-40 years, meeting National Institutes of Health bariatric surgery guidelines, were followed between 2005 and 2008. Study visits took place at baseline, then 1, 3, 6 and 12 months after surgery. All men underwent Roux-en-y gastric bypass (RYGB). At each visit, biometric, questionnaire, serum, and urinary specimens and seman analysis were collected. Urinary integrated total testosterone levels increased significantly (P < 0.0001) by 3 months after surgery, and remained elevated throughout the study. Circulating testosterone levels were also higher at 1 and 6 months after surgery, compared with baseline. Serum sex hormone-binding globulin levels were significantly elevated at all time points after surgery (P < 0.01 to P = 0.02). After RYGB surgery, no significant changes occurred in urinary oestrogen metabolites (oestrone 3-glucuronide), serum oestradiol levels, serial semen parameters or male sexual function by questionnaire. A threshold of weight loss is necessary to improve male reproductive function by reversing male hypogonadism, manifested as increased testosterone levels. Further serial semen analyses showed normal ranges for most parameters despite massive weight loss.

Effects of gestational and lactational exposure to heptachlor epoxide on age at puberty and reproductive function in men and women.

BACKGROUND: For 15 months in 1981-1982, the commercial milk supply on the Hawaiian island of Oahu was contaminated with heptachlor epoxide, a metabolite of the insecticide heptachlor, resulting in gestational and/or lactational exposure to offspring of women who drank cow milk during that period. OBJECTIVE: To determine whether gestational and lactational exposure to heptachlor epoxide alters reproductive function and age at puberty in men or women. METHODS: 457 participants were recruited from a prior high school enrollment sampling frame of 20,000 adults born during 1981-1982 who lived on Oahu since at least first grade. Number of glasses of cow milk consumed weekly by the mother during the participant's gestation was used as a surrogate measure of heptachlor epoxide exposure. Reproductive function measures included semen analyses; reproductive hormones or their metabolites in daily urine specimens for one menstrual cycle; serum reproductive hormone levels in both sexes; and reported ages of onset for pubertal milestones. RESULTS: We observed no strong associations of heptachlor epoxide exposure during gestation and lactation with reproductive endpoints. In females, heptachlor epoxide exposure was associated with longer luteal phase length and slower drop in the ratio of estradiol to progesterone metabolites after ovulation. In males, heptachlor epoxide exposure was weakly associated with higher serum follicle stimulating hormone and luteinizing hormone concentrations, but no dose-response relationship was apparent. CONCLUSIONS: The results provide limited evidence that gestational and lactational exposure to heptachlor epoxide, due to milk contamination on Oahu in 1981-1982, resulted in clinically significant disturbances of reproductive function in men or women.

Urinary follicle-stimulating hormone as a measure of natural fertility in a community cohort.

High serum follicle-stimulating hormone (FSH) levels have been associated with diminished ovarian reserve; however, the association between high urinary FSH and reduced natural fertility has yet to be established. We sought to characterize the relationship between a single or multiple measurements of early follicular phase urinary FSH and fertility. Women (n = 209), 30 to 44 years old with no history of infertility, who had been trying to conceive for less than 3 months, provided early follicular phase urine. Participants subsequently kept a diary to record bleeding and intercourse and conducted standardized pregnancy testing for up to 6 months. A subset of women (N = 95) collected urine on cycle day 3 for up to 6 cycles. Urine was analyzed for FSH and creatinine (cr) corrected. Proportional hazard models were used to calculate fecundability ratios (FRs). Urinary FSH levels across cycles from the same woman were highly correlated (adjusted intraclass correlation = .77); within-woman variance was 3-fold lower than variance among women. Women with an initial urinary FSH level <7 mIU/mg cr exhibited a nonsignificant reduction in the probability of pregnancy (adjusted FR 0.71, 95% confidence interval [CI]: 0.45-1.13), as did women with elevated urinary FSH (≥12 mIU/mg cr; adjusted FR 0.78, 95% CI: 0.46-1.32). Using the most recent or maximum urinary FSH value did not strengthen the association. In the general population, urinary FSH levels appear to be nonlinearly associated with fertility; however, broad CIs indicate a lack of statistical significance. Repetitive testing appears to be of little benefit.

Effects of gastric bypass surgery on female reproductive function.

CONTEXT: Reproductive function may improve after bariatric surgery, although the mechanisms and time-related changes are unclear. OBJECTIVE: The objective of the study was to determine whether ovulation frequency/quality as well as associated reproductive parameters improve after Roux en Y gastric bypass surgery. DESIGN: This was a prospective cohort study that enrolled female subjects from 2005 to 2008 with study visits at baseline and then 1, 3, 6, 12, and up to 24 months after surgery. SETTING: The study was conducted at an academic health center. PATIENTS: Twenty-nine obese, reproductive-aged women not using confounding medications participated in the study. MAIN OUTCOME MEASURES: The primary outcome was integrated levels of urinary progestin (pregnanediol 3-glururonide) from daily urinary collections at 12 months postoperatively. Secondary outcomes were changes in vaginal bleeding, other biometric, hormonal, ultrasound, dual-energy x-ray absorptiometry measures, and Female Sexual Function Index. RESULTS: Ninety percent of patients with morbid obesity had ovulatory cycles at baseline, and the ovulatory frequency and luteal phase quality (based on integrated pregnanediol 3-glururonide levels) were not modified by bariatric surgery. The follicular phase was shorter postoperatively [6.5 d shorter at 3 months and 7.9-8.9 d shorter at 6-24 months (P < 0.01)]. Biochemical hyperandrogenism improved, largely due to an immediate postoperative increase in serum SHBG levels (P < 0.01), with no change in clinical hyperandrogenism (sebum production, acne, hirsutism). Bone density was preserved, contrasting with a significant loss of lean muscle mass and fat (P < 0.001), reflecting preferential abdominal fat loss (P < 0.001). Female sexual function improved 28% (P = 0.02) by 12 months. CONCLUSIONS: Ovulation persists despite morbid obesity and the changes from bypass surgery. Reproductive function after surgery is characterized by a shortened follicular phase and improved female sexual function.

Evaluation and comparison of urinary metabolic biomarkers of exposure for the jet fuel JP-8.

A study of workers exposed to jet fuel propellant 8 (JP-8) was conducted at U.S. Air Force bases and included the evaluation of three biomarkers of exposure: S-benzylmercapturic acid (BMA), S-phenylmercapturic acid (PMA), and (2-methoxyethoxy)acetic acid (MEAA). Postshift urine specimens were collected from various personnel categorized as high (n = 98), moderate (n = 38) and low (n = 61) JP-8 exposure based on work activities. BMA and PMA urinary levels were determined by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and MEAA urinary levels were determined by gas chromatography-mass spectrometry (GC-MS). The numbers of samples determined as positive for the presence of the BMA biomarker (above the test method's limit of detection [LOD = 0.5 ng/ml]) were 96 (98.0%), 37 (97.4%), and 58 (95.1%) for the high, moderate, and low (control) exposure workgroup categories, respectively. The numbers of samples determined as positive for the presence of the PMA biomarker (LOD = 0.5 ng/ml) were 33 (33.7%), 9 (23.7%), and 12 (19.7%) for the high, moderate, and low exposure categories. The numbers of samples determined as positive for the presence of the MEAA biomarker (LOD = 0.1 µ g/ml) were 92 (93.4%), 13 (34.2%), and 2 (3.3%) for the high, moderate, and low exposure categories. Statistical analysis of the mean levels of the analytes demonstrated MEAA to be the most accurate or appropriate biomarker for JP-8 exposure using urinary concentrations either adjusted or not adjusted for creatinine; mean levels of BMA and PMA were not statistically significant between workgroup categories after adjusting for creatinine.

Reproductive hormones and interleukin-6 in serious leisure male athletes.

Lifestyles associated with different types and intensities of exercise result in improved health including positive changes in chronic low-grade inflammatory biomarkers. Alternatively, some forms of exercise adversely affect reproductive health of men, including changes in circulating reproductive hormones. To explore the associations between exercise intensity and circulating levels of reproductive hormones, and inflammatory analytes in serious leisure athletes (triathletes and cyclists) and recreational athletes. Male athletes 18-60 years old, 16 triathletes, 46 cyclists and 45 recreational athletes, were recruited to provide plasma for the measurement of total testosterone, estradiol, follicular stimulating hormone, luteinizing hormone (LH), sex hormone-binding globulin (SHBG), cortisol, interleukin-6 (IL-6), and interleukin-1ß (IL-1ß) levels, and calculation of free androgen index (FAI) and the estradiol:SHBG ratio (ESR). Plasma estradiol concentrations were more than two times higher in cyclists than in triathletes and recreational athletes (p < 0.01). Testosterone levels were also higher in cyclists than recreational athletes (p < 0.01), but not significantly different from triathletes. SHBG levels were higher in triathletes and cyclists than in recreational athletes (p < 0.01). LH levels were lower in cyclists than in recreational athletes (p < 0.05). IL-6 and IL-1ß levels were each two times lower in triathletes than in cyclists (p < 0.05) and IL-6 levels were lower in cyclists than in recreational athletes (p < 0.01). IL-1ß levels were two times lower in triathletes than in cyclists (p < 0.05). Circulating estradiol and testosterone levels were elevated in serious leisure male cyclists. This effect is discussed in light in the absence of a substantial concomitant change in gonadotropin levels and other variables.

(2-methoxyethoxy)acetic acid: a urinary biomarker of exposure for jet fuel JP-8.

PURPOSE: To demonstrate the utility of the urinary metabolite (2-methoxyethoxy)acetic acid (MEAA) as a biomarker of exposure. 2-(2-methoxyethoxy)ethanol [diethylene glycol monomethyl ether] is an anti-icing agent used in the formulation of JP-8, and it is added at a known uniform 0.1% (v/v) concentration to each batch lot. JP-8 is a kerosene-based fuel containing different compounds that vary in the content of every batch/lot of fuel; thus, MEAA has the potential to be a more specific and a consistent quantitative biomarker for JP-8 exposure. METHODS: MEAA was used to measure exposure of jet propulsion fuel 8 (JP-8) in United States Air Force (USAF) personnel working at six airbases within the United States. Post-shift urine specimens from various personnel including high (n = 98), moderate (n = 38), and low (n = 61) exposure workgroup categories were collected and analyzed by a gas chromatographic-mass spectrometric test method. The three exposure groups were evaluated for the number per group positive for MEAA, and a statistical analysis consisted of pair-wise t-tests for unequal variances was used to test for the differences in mean MEAA concentrations between the exposure groups. RESULTS: The number of samples detected as positive for MEAA exposure, that is, those above the test method's limit of detection (LOD = 0.1 µg/ml), were 92 (93.9%), 13 (34.2%), and 2 (3.3%) for the high, moderate, and low exposure workgroup categories, respectively. The mean urinary MEAA level was significantly greater in the high exposure category (6.8 µg/ml), compared to the moderate (0.42 µg/ml) and the low (0.07 µg/ml) exposure categories. The maximum concentration of urinary MEAA was 110 µg/ml for the high exposure category, while 4.8 µg/ml and 0.2 µg/ml maximum levels were found in the moderate and low exposure categories, respectively. CONCLUSION: This study demonstrated that urinary MEAA can be used as an accurate biomarker of exposure for JP-8 workers and clearly distinguished the differences in JP-8 exposure by workgroup category.

Menstrual cycle characteristics and reproductive hormone levels in women exposed to atrazine in drinking water.

Atrazine is the most commonly used herbicide in the U.S. and a wide-spread groundwater contaminant. Epidemiologic and laboratory evidence exists that atrazine disrupts reproductive health and hormone secretion. We examined the relationship between exposure to atrazine in drinking water and menstrual cycle function including reproductive hormone levels. Women 18-40 years old residing in agricultural communities where atrazine is used extensively (Illinois) and sparingly (Vermont) answered a questionnaire (n=102), maintained menstrual cycle diaries (n=67), and provided daily urine samples for analyses of luteinizing hormone (LH), and estradiol and progesterone metabolites (n=35). Markers of exposures included state of residence, atrazine and chlorotriazine concentrations in tap water, municipal water and urine, and estimated dose from water consumption. Women who lived in Illinois were more likely to report menstrual cycle length irregularity (odds ratio (OR)=4.69; 95% confidence interval (CI): 1.58-13.95) and more than 6 weeks between periods (OR=6.16; 95% CI: 1.29-29.38) than those who lived in Vermont. Consumption of >2 cups of unfiltered Illinois water daily was associated with increased risk of irregular periods (OR=5.73; 95% CI: 1.58-20.77). Estimated "dose" of atrazine and chlorotriazine from tap water was inversely related to mean mid-luteal estradiol metabolite. Atrazine "dose" from municipal concentrations was directly related to follicular phase length and inversely related to mean mid-luteal progesterone metabolite levels. We present preliminary evidence that atrazine exposure, at levels below the US EPA MCL, is associated with increased menstrual cycle irregularity, longer follicular phases, and decreased levels of menstrual cycle endocrine biomarkers of infertile ovulatory cycles.

Pubertal delay in male nonhuman primates (Macaca mulatta) treated with methylphenidate.

Juvenile male rhesus monkeys treated with methylphenidate hydrochloride (MPH) to evaluate genetic and behavioral toxicity were observed after 14 mo of treatment to have delayed pubertal progression with impaired testicular descent and reduced testicular volume. Further evaluation of animals dosed orally twice a day with (i) 0.5 mL/kg of vehicle (n = 10), (ii) 0.15 mg/kg of MPH increased to 2.5 mg/kg (low dose, n = 10), or (iii) 1.5 mg/kg of MPH increased to 12.5 mg/kg (high dose, n = 10) for a total of 40 mo revealed that testicular volume was significantly reduced (P < 0.05) at months 15 to 19 and month 27. Testicular descent was significantly delayed (P < 0.05) in the high-dose group. Significantly lower serum testosterone levels were detected in both the low- (P = 0.0017) and high-dose (P = 0.0011) animals through month 33 of treatment. Although serum inhibin B levels were increased overall in low-dose animals (P = 0.0328), differences between groups disappeared by the end of the study. Our findings indicate that MPH administration, beginning before puberty, and which produced clinically relevant blood levels of the drug, impaired pubertal testicular development until ∼5 y of age. It was not possible to resolve whether MPH delayed the initiation of the onset of puberty or reduced the early tempo of the developmental process. Regardless, deficits in testicular volume and hormone secretion disappeared over the 40-mo observation period, suggesting that the impact of MPH on puberty is not permanent.

Antimüllerian hormone as a predictor of natural fecundability in women aged 30-42 years.

OBJECTIVE: To generate estimates of the association between markers of ovarian aging and natural fertility in a community sample at risk for ovarian aging. METHODS: Women aged 30-44 years with no history of infertility who had been trying to conceive for less than 3 months provided early-follicular phase serum and urine (N=100). Subsequently, these women kept a diary to record menstrual bleeding and intercourse and conducted standardized pregnancy testing for up to 6 months. Serum was analyzed for estradiol, follicle-stimulating hormone (FSH), antimüllerian hormone, and inhibin B. Urine was analyzed for FSH and estrone 3-glucuronide. Diary data on menstrual cycle day and patterns of intercourse were used to calculate day-specific fecundability ratios. RESULTS: Sixty-three percent of participants conceived within 6 months. After adjusting for age, 18 women (18%) with serum antimüllerian hormone levels of 0.7 ng/mL or less had significantly reduced fecundability given intercourse on a fertile day compared with women with higher antimüllerian hormone levels (fecundability ratio 0.38; 95% confidence interval [CI] 0.08-0.91). The day-specific fecundability for women with early-follicular phase serum FSH values greater than 10 milli-international units/mL compared with women with lower FSH levels was also reduced, although nonsignificantly (11% of women affected; fecundability ratio 0.44; 95% CI 0.08-1.10). The association with urinary FSH was weaker (27% women affected; fecundability ratio 0.61; 95% CI 0.26-1.26), and the associations for the other markers were weaker still. CONCLUSION: Early-follicular phase antimüllerian hormone appears to be associated with natural fertility in the general population. LEVEL OF EVIDENCE: II.

Mother's menopausal age is associated with her daughter's early follicular phase urinary follicle-stimulating hormone level.

OBJECTIVE: Early follicular phase follicle-stimulating hormone (FSH), a marker of ovarian reserve, has been used to predict time to menopause. A mother's age at menopause is related to her daughter's age at menopause, possibly because of genetic factors. In this study we sought to determine the relationship between maternal age at menopause and early follicular phase FSH of premenopausal daughters. DESIGN: The Uterine Fibroid Study enrolled women randomly selected from a prepaid health plan, collected questionnaire data, and obtained early follicular phase urine samples for a subset of participants. For this secondary analysis, premenopausal women between the ages of 35 and 46 years, who provided a urine sample on cycle day 2, 3, 4, or 5 and their mother's age at natural menopause (n = 182) were selected from the original cohort. Initially bivariate analysis and subsequently regression modeling were performed to assess the independent relationship between maternal age at menopause and urinary creatinine-corrected FSH. RESULTS: Unadjusted analyses and those adjusting for age (mean +/- SD, 40.5 +/- 3.2 y), smoking status (16% current smokers), and body mass index (26.8 +/- 6.9 kg/m) showed a significant association between maternal age at menopause and daughter's urinary FSH level (P < 0.04). Women whose mothers experienced earlier menopause had higher urinary FSH levels. CONCLUSIONS: The significantly increased FSH values among women whose mothers experienced early menopause is consistent with previously reported associations between mother's and daughter's age of menopause. FSH, a marker of ovarian reserve, is influenced by both genetic and environmental factors. Future epidemiologic studies on FSH should include collection of information on maternal age at menopause.

Marital status and variability in cortisol excretion in postmenopausal women.

Based on the premise that acute and chronic stresses stimulate and suppress cortisol secretion, respectively, and the hypothesis that marriage provides a buffer to stress, we tested whether extreme values of serum cortisol concentrations would be less likely in married women than in unmarried women. Three hundred women were recruited from two central Connecticut communities. Cortisol was measured in overnight urine samples using liquid chromatography-tandem mass spectrometry. Information on each subject's demographic characteristics, such as income and education level was collected. Mean log urinary cortisol was virtually identical in married and unmarried women, however, as predicted, the variance was significantly larger in the unmarried group (p=0.01). After adjustment for potential confounders, multivariate logistic regression still revealed that absolute deviation of log(10) cortisol from the mean was smaller for married versus unmarried women (p<0.01); deviation from the mean cortisol was also higher for non-working than working women. These results support the idea that marriage and employment reduce the extreme levels of cortisol secretion, and by extension, this may reflect differences in levels of stress in married and in working women compared to unmarried and non-working women.