NATIONAL HARBOR, Md. – Frequent hot flashes in menopausal women were significantly associated with higher levels of low-density lipoproteins, high-density lipoproteins, and triglycerides during a 7-year follow-up study of 3,201 women enrolled in an ongoing longitudinal study.
Women who reported 1-5 days of hot flashes or 6 or more days of hot flashes during the past 2 weeks were significantly more likely to have elevated levels of LDL cholesterol.
Previous investigations using the Study of Women’s Health Across the Nation (SWAN) database have shown that women with more hot flashes have an elevated risk for subclinical cardiovascular disease, said Rebecca Thurston, Ph.D., of the University of Pittsburgh. But "there is a lot we don’t know about this association, including what could possibly explain this," she said at the annual meeting of the North American Menopause Society.
Dr. Thurston and colleagues examined hot flashes as they related to lipid profiles in women enrolled in SWAN. The subjects’ median age was 46 years, 48% were white, 46% were in early or perimenopause, and 26% reported hot flashes within the past two weeks.
Hot flashes were analyzed in relation to six lipid profiles, after controlling for age, race, menopausal status/cycle day, alcohol use, physical activity, smoking, anxiety, body mass index, cardiovascular disease status and medications, lipid lowering medications, and estradiol.
Compared to women who reported no hot flashes, women who reported 1-5 days of hot flashes or 6 or more days of hot flashes during the past 2 weeks were significantly more likely to have elevated levels of LDL cholesterol, triglycerides, apolipoprotein B, and apolipoprotein A1. For example, LDL levels among women with 6 or more days of hot flashes peaked at approximately 125 mg/dL during a 2-week period, compared with a peak of approximately 120 mg/dL among women with 1-5 days of hot flashes and a peak of approximately 118 mg/dL among women with no reported days of hot flashes.
Levels of HDL cholesterol were significantly higher in women who reported 6 or more days of hot flashes during the past 2 weeks, compared with those who reported no hot flashes, but HDL levels were not significantly different between women who reported 1-5 days of hot flashes and those who reported no hot flashes.
By contrast, levels of lipoprotein(a) were not significantly different among women who reported no hot flashes, women who reported 1 to 5 days of hot flashes, and women who reported 6 or more days of hot flashes.
The positive relationships between hot flashes and lipoprotein(a), and between hot flashes and HDL in some women, were surprising, Dr. Thurston said. "The cardioprotective nature of HDL may depend on particle size," she noted. HDL particles become smaller as women transition through menopause, she added, which might explain the differences.
Additional studies are needed to address the findings on HDL and lipoprotein(a) and to explore how vasomotor symptoms may provide additional information about women’s vascular health, Dr. Thurston said. Future studies should be designed with improved measures of vasomotor symptoms, she added.
The study was supported by a grant from the National Institutes of Health. Dr. Thurston had no financial conflicts to disclose.