Statin medications and the risk of gynecomastia.

Objective: Case reports have suggested an increased risk of gynecomastia with HMG-CoA reductase inhibitors (ie, statins). A recent meta-analysis also found that statins decrease circulating testosterone levels in men. We investigated whether statin use was associated with an increased risk of gynecomastia.
Design: Case-control study.
Patients: A cohort of patients from a random sample of 9 053 240 US subjects from the PharMetrics Plus ^™ health claims database from 2006 to 2016 was created.
Measurements: New cases of gynecomastia requiring at least two ICD-9 codes were identified from the cohort and matched to 10 controls by follow-up time and age using density-based sampling. Rate ratios (RRs) for users of statins were computed using conditional logistic regression adjusting for alcoholic cirrhosis, hyperthyroidism, testicular cancer, Klinefelter syndrome, obesity, hypogonadism, hyperprolactinemia and use of spironolactone, ketoconazole, H ₂ receptor antagonists (H ₂ blockers), risperidone, testosterone and androgen deprivation therapy.
Results: Our cohort included 6147 cases of gynecomastia and 61 470 corresponding matched controls. The adjusted RR for current, recent and past statin use with respect to gynecomastia was 1.19 (1.04-1.36), 1.38 (1.15-1.65) and 1.20 (1.03-1.40), respectively.
Conclusions: Statin use is associated with an increased risk of developing gynecomastia. Clinicians should be cognizant of this effect and educate patients accordingly.
(© 2018 John Wiley & Sons Ltd.)