Changes in carotid artery intima-media thickness 3 years after cessation of menopausal hormone therapy: follow-up from the Kronos Early Estrogen Prevention Study.

OBJECTIVE: Little is known regarding the progression of preclinical atherosclerosis upon cessation of menopausal hormone therapy (MHT). This study evaluated changes in carotid artery intima-media thickness (CIMT) in a subgroup of participants during 4 years and 3 years after the Kronos Early Estrogen Prevention Study (KEEPS).

METHODS: Of the women enrolled in KEEPS at Mayo Clinic (n = 118), a subset (n = 76) agreed to participate in this follow-up study. KEEPS MHT assignments were placebo (PBO), n = 33; transdermal 17β-estradiol (tE2), n = 23; and oral conjugated equine estrogens group (oCEE), n = 20. CIMT was measured by B-mode ultrasonography. Longitudinal analysis of CIMT was performed using all available data from pre-, on-, and post-treatment periods.

RESULTS: At 7 years, median age of participants was 60.2 years; median time since menopause was 8.5 years. The mean difference in rates of increase was significantly greater over the post- than on-treatment period within the oCEE group (0.010 [0.002-0.017] mm/y), but not within the PBO (0.006 [-0.001 to 0.012] mm/y; P = 0.072) or tE2 (0.002 [-0.005 to 0.010] mm/y; P = 0.312) groups. There were, however, no significant treatment differences in the linear trends over those intervals (P = 0.524).

CONCLUSIONS: Cessation of MHT at the lower doses and formulations used in KEEPS did not appear to alter the trajectory of CIMT over a 3-year follow-up period. CIMT, however, increased in all groups over the entire 7-year timeframe as expected with age and timing of menopause possibly key contributors.This is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. https://creativecommons.org/licenses/by-nc-nd/4.0.