BACKGROUND: Men who regularly consume caffeinated drinks have a lower risk of PD than do nondrinkers, but this relation has not been found in women. Because this sex difference could be due to hormonal effects, the authors examined prospectively the risk of PD according to use of postmenopausal hormones and caffeine intake among participants in the Nurses' Health Study. METHODS: The study population comprised 77,713 women free of PD, stroke, or cancer at baseline, who were postmenopausal at baseline or reached menopause before the end of the study. During 18 years of follow-up the authors documented 154 cases of PD. RESULTS: Overall, the risk of PD was similar in women using hormones and women who never used hormones (relative risk 1.02, 95% CI 0.69 to 1.52). Use of hormones, however, was associated with a reduced risk of PD among women with low caffeine consumption (RR 0.39, 95% CI 0.13 to 1.17), and with increased risk among women with high caffeine consumption (RR 2.44, 95% CI 0.75 to 7.86; p for interaction = 0.01). Among hormone users, women consuming six or more cups of coffee per day had a fourfold higher risk of PD (RR 3.92, 95% CI 1.49 to 10.34; p = 0.006) than did women who never drink coffee. CONCLUSION: These results suggest that caffeine reduces the risk of PD among women who do not use postmenopausal hormones, but increases risk among hormone users. Clinical trials of caffeine or estrogens in women should avoid the combined use of these agents.
BACKGROUND:Men who regularly consume caffeinated drinks have a lower risk of PD than do nondrinkers, but this relation has not been found in women. Because this sex difference could be due to hormonal effects, the authors examined prospectively the risk of PD according to use of postmenopausal hormones and caffeine intake among participants in the Nurses' Health Study. METHODS: The study population comprised 77,713 women free of PD, stroke, or cancer at baseline, who were postmenopausal at baseline or reached menopause before the end of the study. During 18 years of follow-up the authors documented 154 cases of PD. RESULTS: Overall, the risk of PD was similar in women using hormones and women who never used hormones (relative risk 1.02, 95% CI 0.69 to 1.52). Use of hormones, however, was associated with a reduced risk of PD among women with low caffeine consumption (RR 0.39, 95% CI 0.13 to 1.17), and with increased risk among women with high caffeine consumption (RR 2.44, 95% CI 0.75 to 7.86; p for interaction = 0.01). Among hormone users, women consuming six or more cups of coffee per day had a fourfold higher risk of PD (RR 3.92, 95% CI 1.49 to 10.34; p = 0.006) than did women who never drink coffee. CONCLUSION: These results suggest that caffeine reduces the risk of PD among women who do not use postmenopausal hormones, but increases risk among hormone users. Clinical trials of caffeine or estrogens in women should avoid the combined use of these agents.
Authors: Jessica I Lundin; Thanh G N Ton; Andrea Z LaCroix; W T Longstreth; Gary M Franklin; Phillip D Swanson; Terri Smith-Weller; Brad A Racette; Harvey Checkoway Journal: Mov Disord Date: 2014-09-25 Impact factor: 10.338
Authors: Thanh G N Ton; Mary Lou Biggs; Diane Comer; Lesley Curtis; Shu-Ching Hu; Evan L Thacker; Susan Searles Nielsen; Joseph A Delaney; Douglas Landsittel; William T Longstreth; Harvey Checkoway; Samay Jain Journal: Pharmacoepidemiol Drug Saf Date: 2013-12-13 Impact factor: 2.890
Authors: Xiang Gao; Honglei Chen; Teresa T Fung; Giancarlo Logroscino; Michael A Schwarzschild; Frank B Hu; Alberto Ascherio Journal: Am J Clin Nutr Date: 2007-11 Impact factor: 7.045
Authors: Crystal N Holick; Scott G Smith; Edward Giovannucci; Dominique S Michaud Journal: Cancer Epidemiol Biomarkers Prev Date: 2010-01 Impact factor: 4.254
Authors: Jeanne C Latourelle; Merete Dybdahl; Anita L Destefano; Richard H Myers; Timothy L Lash Journal: BMC Neurol Date: 2010-04-12 Impact factor: 2.474