Hot flashes and carotid intima media thickness among midlife women

Emerging evidence suggests associations between menopausal hot flashes and cardiovascular risk. However, whether hot flashes are associated with intima media thickness (IMT) or IMT changes over time is unknown. We hypothesized that reported hot flashes would be associated with greater IMT cross-sectionally and with greater IMT progression over 2 years.

Participants were 432 women aged 45 to 58 years at baseline participating in the Study of Women's Health Across the Nation (SWAN) Heart, an ancillary study to the SWAN. Measures at the SWAN Heart baseline and follow-up visit 2 years later included a carotid artery ultrasound, reported hot flashes (past 2 weeks: none, 1-5 d, ≥6 d), and a blood sample for measurement of estradiol.

Women reporting hot flashes for 6 days or more in the prior 2 weeks had significantly higher IMT than did women without hot flashes at the baseline (mean [SE] difference, 0.02 [0.01] mm; P=0.03) and follow-up (mean [SE] difference, 0.02 [0.01] mm; P=0.04) visits, controlling for demographic factors and cardiovascular risk factors. Reporting hot flashes at both study visits was associated with higher follow-up IMT relative to reporting hot flashes at neither visit (mean [SE] difference, 0.03 [0.01] mm; P=0.03). Associations between hot flashes and IMT largely remained after adjusting for estradiol. An interaction between hot flashes and obesity status was observed (P=0.05) such that relations between hot flashes and IMT were observed principally among overweight/obese women. Hot flashes were not associated with IMT progression.

These findings provide some indication that women reporting hot flashes for 6 days or more in the prior 2 weeks may have higher IMT than do women without hot flashes, particularly for women who are overweight or obese. Further work should determine whether hot flashes mark adverse underlying vascular changes.