An epigenetic aging analysis of randomized metformin and weight loss interventions in overweight postmenopausal breast cancer survivors

Metformin and weight loss relationships with epigenetic age measures—biological aging biomarkers—remain understudied. We performed a post-hoc analysis of a randomized controlled trial among overweight/obese breast cancer survivors (N = 192) assigned to metformin, placebo, weight loss with metformin, or weight loss with placebo interventions for 6 months. Epigenetic age was correlated with chronological age (r = 0.20–0.86; P < 0.005). However, no significant epigenetic aging associations were observed by intervention arms. Consistent with published reports in non-cancer patients, 6 months of metformin therapy may be inadequate to observe expected epigenetic age deceleration. Longer duration studies are needed to better characterize these relationships. Trial Registration: Registry Name: ClincialTrials.Gov. Registration Number: NCT01302379. Date of Registration: February 2011. URL: https://clinicaltrials.gov/ct2/show/NCT01302379 SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13148-021-01218-y.