Cyclic Variation in Micronutrient Concentrations and Plasma Volume
Cyclic Variation in Micronutrient Concentrations and Plasma Volume
The overall goal of this study is to examine the influence of the menstrual cycle on
 micronutrient concentrations and plasma volume in healthy, reproductive-age women with
 regular cycles. The investigators aim to quantify changes in micronutrient biomarker
 concentrations (zinc, copper, iron, and vitamin A) and plasma volume across the menstrual
 cycle in healthy women.
This is a longitudinal prospective study wherein all subjects will be examined at three time
 points within a single menstrual cycle: the early follicular phase (~day 2), periovulation
 (~day 12), and the luteal phase (~day 21)-based on an approximate 28-day cycle length. The
 actual days of visits will be adjusted for the length of the woman's menstrual cycle. At
 least 35 non-pregnant women ages 18 to 44 years will be recruited as a convenience sample of
 eligible women in the State College area and surrounding towns within Centre County,
 Pennsylvania, USA. If a woman responds to the recruitment, she will be asked a set of
 pre-screening questions to determine eligibility. If a woman is thought to be eligible, she
 will complete a verbal consent for the screening (and the actual screening will occur at the
 first visit). Then she will be invited to the Clinical Research Center (CRC), a service unit
 in Penn State's Clinical and Translational Science Institute, for full screening and
 participation. Before scheduling the visit, the woman will be asked for the expected date of
 the first day of her next menstrual period. The woman will then be tentatively scheduled for
 her first visit at the CRC approximately 1 day after this date (avoiding weekend days).

 As part of the preparation for study visits, the woman will be asked to fast the night before
 her visit. Women will also be asked to avoid alcohol intake for 12 hours preceding their
 scheduled visits to the CRC, and to drink plenty of water. On the morning of the visit, the
 woman will arrive at the CRC, go through complete screening (including height, weight, blood
 pressure, and pregnancy test). If eligible for the main study, the woman will then go through
 the consent process for the main study. If the woman gives consent to participate, the
 investigators will then proceed with study measurements (including a questionnaire and body
 composition measurement).

 Following these measurements, the study nurse or doctor will insert an IV into the vein of
 one arm and an initial baseline blood draw will be taken (~15-20 ml, in several tubes). This
 blood will be used for biomarker assessment (hemoglobin, hematocrit, vitamins, minerals, etc)
 and as a blank sample before the dye injection. Next, indocyanine green (ICG) will be used to
 measure plasma volume. A solution will be prepared using 25 mg of ICG lyophilized powder
 dissolved in 10 ml of sterile water. The investigators will draw enough solution to inject
 0.25 mg/kg body weight into a syringe. The syringe will be weighed to measure the exact
 amount. Then the solution will be injected via the IV and flushed with saline. After 2
 minutes, five ~3 ml blood samples will be drawn at intervals of 45 seconds over the next 3
 minutes. Expected total volume of blood drawn at the visit will be <35 mL.

 At the end of this first visit the participant will be given a home-based fertility monitor
 to take home to track her cycle. She will be instructed on how to use the monitor at home but
 the research team will maintain contact with her on a regular basis to ensure that she is
 using the monitor correctly. She will conduct a daily urine test with the monitor, which uses
 urine hormone concentrations to track the stage of the menstrual cycle for the participants
 by displaying low, high, or peak fertility. The second and third visits will be scheduled
 using an algorithm that takes into consideration the woman's menstrual cycle length and
 results from a home-based urine fertility monitor.

 At the third visit, the participant will return the monitor to the CRC and the urine test
 results, which are stored in the monitor, will be retrieved. At the end of the third visit
 her study participation is complete but the investigators will keep in contact with her to
 record the first date of her next cycle (to calculate actual cycle length).
Inclusion Criteria:

 -  Female

 -  18 to 44 years of age

 -  General good health (does not have a known, ongoing health condition/medical issue
 that requires regular monitoring by a doctor or regular visits to the hospital)

 -  BMI 18.5-24.9 kg/m2

 -  Regular menstrual cycle (26-35 days)

 -  Non-smoker

 -  Non-pregnant

 -  If pregnant before, ≥12 months since last pregnancy

 Exclusion Criteria:

 -  Known allergy to shellfish or iodine

 -  Blood pressure on the day of measurements is low or high (systolic blood pressure
 (SBP) <90 or ≥130 mmHg and/or diastolic blood pressure (DBP) <60 or ≥80 mmHg)

 -  Currently has low or high blood pressure (SBP <90 or ≥130 mmHg and/or DBP <60 or ≥80
 mmHg), self-reported

 -  Current hypertension or previous hypertensive disorder in pregnancy (gestational
 hypertension or preeclampsia)

 -  Taking regular medication(s) (physician's prescribed medications for a health
 condition)

 -  Currently trying to conceive

 -  Currently breastfeeding

 -  Currently using hormonal birth control or used within last 3 months

 -  Used depot medroxyprogesterone acetate (DMPA) in the past 12 months

 -  Diagnosis of polycystic ovary syndrome