Objective: The aim of this study was to analyze the determinants of breast discomfort among postmenopausal women initiating menopausal hormone therapy (HT).
Methods: We analyzed questionnaire, anthropometric, and serum estrone data from the Postmenopausal Estrogen/Progestin Interventions (PEPI) Trial, a randomized trial comparing placebo, conjugated equine estrogens (CEE) alone, or CEE with a progestogen (continuous or cyclical medroxyprogesterone acetate or cyclical micronized progesterone) among postmenopausal women. HT users could join the PEPI Trial after stopping HT for 2 months. We modeled the relation between smoking, body weight, alcohol consumption, age, quitting HT for the PEPI Trial, physical activity, and α-tocopherol consumption and new-onset breast discomfort at the 12-month follow-up among 662 participants without baseline breast discomfort.
Results: The associations of new-onset breast discomfort with weight and with strenuous exercise varied by treatment assignment. Among women assigned to CEE + progestogen, strenuous exercise was associated with a 49% lower odds of new-onset breast discomfort (odds ratio, 0.51; 95% CI, 0.29-0.89; P = 0.02), whereas among women assigned to placebo or CEE alone, strenuous exercise was not significantly associated with new-onset breast discomfort. Surprisingly, among women taking CEE alone, each kilogram higher weight was associated with a 6% lower odds of new-onset breast discomfort (P = 0.04), whereas among women taking placebo, the association was in the opposite direction (P = 0.04). Adjustment for estrone level had negligible effects on odds ratios. α-Tocopherol intake, age, smoking, and alcohol intake were not significantly associated with new-onset breast discomfort in adjusted analyses.
Conclusions: Strenuous exercise and higher body weight may decrease the odds of new-onset breast discomfort among postmenopausal women initiating HT.
This study analyzed data from a trial comparing the effects of placebo, conjugated equine estrogens alone, or conjugated equine estrogens plus progestogen among postmenopausal women. Self-reported strenuous exercise and higher body weight were each associated with significantly lower odds of experiencing new-onset of breast tenderness after hormone therapy initiation.
From the Departments of 1Medicine and 2Biomathematics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA.
Received August 21, 2009; revised and accepted September 22, 2009.
Funding/support: Dr. Crandall's work was supported by National Institute on Aging grant AG1004. All authors received support from Public Health Service grant R01CA77708 (National Cancer Institute, Department of Health and Human Services).
Financial disclosure/conflicts of interest: None reported.
Address correspondence to: Carolyn J. Crandall, MD, MS, David Geffen School of Medicine, University of California, Los Angeles, UCLA Medicine/GIM, 1st Floor, 911 Broxton Ave., Los Angeles, CA 90024. E-mail: firstname.lastname@example.org