Abstract
BackgroundIncreased circulating levels of prolactin have been associated with increased risk of both in situ and invasive breast cancer. We investigated whether or not physical activity had a dose–response effect in lowering plasma levels of prolactin in postmenopausal women.MethodsFour hundred previously inactive but healthy postmenopausal women aged 50–74 years of age were randomized to 150 or 300 min per week of aerobic physical activity in a year-long intervention. Prolactin was measured from fasting samples with a custom-plex multiplex assay.ResultsA high compared to moderate volume of physical activity did not reduce plasma prolactin levels in intention-to-treat (Treatment Effect Ratio (TER) 1.00, 95% Confidence Interval (CI) 0.95 – 1.06) or per-protocol analyses (TER 1.02, 95% CI 0.93 – 1.13).ConclusionsIt is unlikely that changes in prolactin levels mediate the reduced risk of breast cancer development in post-menopausal women associated with increased levels of physical activity.Trial registrationclinicaltrials.gov identifier: NCT01435005.
Highlights
The primary hypothesized mechanisms underlying the associations between physical activity and reduced breast cancer include reductions in adiposity, sex hormone levels, insulin resistance and chronic inflammation [1]
Prolactin is a luteotropic peptide hormone involved in regular lactation which is produced by the anterior pituitary gland
Women were eligible for randomization if they were between 50–74 years of age, with no previous diagnosis of invasive cancer, no major comorbidities, Brenner et al European Review of Aging and Physical Activity (2017) 14:10 obtained physical approval for participation, had a body mass index of 22–40, were moderately sedentary, not a current smoker or excessive drinker, not currently on a weight loss program, English speaking and not planning to be out of the study site areas for more than 4 consecutive weeks during the subsequent 18 months
Summary
The primary hypothesized mechanisms underlying the associations between physical activity and reduced breast cancer include reductions in adiposity, sex hormone levels, insulin resistance and chronic inflammation [1]. These pathways only explain some portion of the association and additional mechanisms require identification and further investigation. Increased circulating levels of prolactin have been associated with increased risk of both in situ and invasive. Increased circulating levels of prolactin have been associated with increased risk of both in situ and invasive breast cancer. We investigated whether or not physical activity had a dose–response effect in lowering plasma levels of prolactin in postmenopausal women. Prolactin was measured from fasting samples with a custom-plex multiplex assay
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
