Urinary reproductive hormone level differences between African American and Caucasian women of reproductive age

OBJECTIVE: To compare urinary levels of reproductive hormones in African American and Caucasian women. DESIGN: Cross-sectional study. SETTING: Ten United States Air Force (USAF) bases. PATIENT(S): African American (n = 33) and Caucasian (n = 65) women of reproductive age from a larger study of USAF women (n = 170). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Urinary endocrine end points: follicular luteinizing hormone (LH), preovulatory LH, level of LH surge peak, early follicular follicle stimulating hormone (FSH), follicular LH:FSH ratio, midluteal FSH, FSH rise before menses, early follicular estrone 3-glucuronide (E(1)3G), midfollicular E(1)3G, periovulatory E(1)3G peak, midluteal E(1)3G, early follicular pregnanediol 3-glucuronide (Pd3G), follicular Pd3G, rate of periovulatory Pd3G increase, E(1)3G:Pd3G on the day of luteal transition, slope of E(1)3G:Pd3G, and midluteal Pd3G. RESULT(S): Relative to Caucasians, African American women had significantly lower follicular phase LH:FSH ratios (mean +/- SD: 0.7 +/- 0.4 vs. 1.0 +/- 0.6), lower follicular phase Pd3G levels (1.0 +/- 0.5 vs. 1.2 +/- 0.8 microg/mg creatinine), and lower rates of periovulatory Pd3G increase (0.5 +/- 0.7 vs. 1.0 +/- 1.2 microg/mg creatinine). CONCLUSION(S): Findings of this analysis should be considered preliminary evidence of racial differences in hormone levels. Future studies are needed to determine whether these differences have clinical significance.