TY - JOUR
T1 - Serum caffeine and paraxanthine concentrations and menstrual cycle function
T2 - Correlations with beverage intakes and associations with race, reproductive hormones, and anovulation in the BioCycle Study
AU - Schliep, Karen C.
AU - Schisterman, Enrique F.
AU - Wactawski-Wende, Jean
AU - Perkins, Neil J.
AU - Radin, Rose G.
AU - Zarek, Shvetha M.
AU - Mitchell, Emily M.
AU - Sjaarda, Lindsey A.
AU - Mumford, Sunni L.
N1 - Funding Information:
Supported by the Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH (contracts HHSN275200403394C and HHSN275201100002I and Task 1 HHSN27500001) and the State University of New York at Buffalo. The NIH Office of Dietary Supplements (OD-00-113) provided support for the caffeine-biomarker assessment.
Publisher Copyright:
© 2016 American Society for Nutrition.
PY - 2016/7/1
Y1 - 2016/7/1
N2 - Background: Clinicians often recommend limiting caffeine intake while attempting to conceive; however, few studies have evaluated the associations between caffeine exposure and menstrual cycle function, and we are aware of no previous studies assessing biological dose via well-timed serum measurements. Objectives: We assessed the relation between caffeine and its metabolites and reproductive hormones in a healthy premenopausal cohort and evaluated potential effect modification by race. Design: Participants (n = 259) were followed for ≤2 menstrual cycles and provided fasting blood specimens ≤8 times/cycle. Linear mixed models were used to estimate associations between serum caffeine biomarkers and geometric mean reproductive hormones, whereas Poisson regression was used to assess risk of sporadic anovulation. Results: The highest compared with the lowest serum caffeine tertile was associated with lower total testosterone [27.9 ng/dL (95% CI: 26.7, 29.0 ng/dL) compared with 29.1 ng/dL (95% CI: 27.9, 30.3 ng/dL), respectively] and free testosterone [0.178 ng/mL (95% CI: 0.171, 0.185 ng/dL) compared with 0.186 ng/mL (95% CI: 0.179, 0.194 ng/dL), respectively] after adjustment for age, race, percentage of body fat, daily vigorous exercise, perceived stress, depression, dietary factors, and alcohol intake. The highest tertiles compared with the lowest tertiles of caffeine and paraxanthine were also associated with reduced risk of anovulation [adjusted RRs (aRRs): 0.39 (95% CI: 0.18, 0.87) and 0.40 (95% CI: 0.18, 0.87), respectively]. Additional adjustment for self-reported coffee intake did not alter the reproductive hormone findings and only slightly attenuated the results for serum caffeine and paraxanthine and anovulation. Although reductions in the concentrations of total testosterone and free testosterone and decreased risk of anovulation were greatest in Asian women, there was no indication of effect modification by race. Conclusion: Caffeine intake, irrespective of the beverage source, may be associated with reduced testosterone and improved menstrual cycle function in healthy premenopausal women.
AB - Background: Clinicians often recommend limiting caffeine intake while attempting to conceive; however, few studies have evaluated the associations between caffeine exposure and menstrual cycle function, and we are aware of no previous studies assessing biological dose via well-timed serum measurements. Objectives: We assessed the relation between caffeine and its metabolites and reproductive hormones in a healthy premenopausal cohort and evaluated potential effect modification by race. Design: Participants (n = 259) were followed for ≤2 menstrual cycles and provided fasting blood specimens ≤8 times/cycle. Linear mixed models were used to estimate associations between serum caffeine biomarkers and geometric mean reproductive hormones, whereas Poisson regression was used to assess risk of sporadic anovulation. Results: The highest compared with the lowest serum caffeine tertile was associated with lower total testosterone [27.9 ng/dL (95% CI: 26.7, 29.0 ng/dL) compared with 29.1 ng/dL (95% CI: 27.9, 30.3 ng/dL), respectively] and free testosterone [0.178 ng/mL (95% CI: 0.171, 0.185 ng/dL) compared with 0.186 ng/mL (95% CI: 0.179, 0.194 ng/dL), respectively] after adjustment for age, race, percentage of body fat, daily vigorous exercise, perceived stress, depression, dietary factors, and alcohol intake. The highest tertiles compared with the lowest tertiles of caffeine and paraxanthine were also associated with reduced risk of anovulation [adjusted RRs (aRRs): 0.39 (95% CI: 0.18, 0.87) and 0.40 (95% CI: 0.18, 0.87), respectively]. Additional adjustment for self-reported coffee intake did not alter the reproductive hormone findings and only slightly attenuated the results for serum caffeine and paraxanthine and anovulation. Although reductions in the concentrations of total testosterone and free testosterone and decreased risk of anovulation were greatest in Asian women, there was no indication of effect modification by race. Conclusion: Caffeine intake, irrespective of the beverage source, may be associated with reduced testosterone and improved menstrual cycle function in healthy premenopausal women.
KW - 1,7-Dimethylxanthine
KW - Anovulation
KW - Biological markers
KW - Caffeine
KW - Menstrual cycle
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UR - http://www.scopus.com/inward/citedby.url?scp=84977085408&partnerID=8YFLogxK
U2 - 10.3945/ajcn.115.118430
DO - 10.3945/ajcn.115.118430
M3 - Article
C2 - 27225433
AN - SCOPUS:84977085408
SN - 0002-9165
VL - 104
SP - 155
EP - 163
JO - American Journal of Clinical Nutrition
JF - American Journal of Clinical Nutrition
IS - 1
ER -