SWAN study links perimenopause to rising cardiovascular risk

In the Study of Women’s Health Across the Nation, lipids, blood pressure and vascular markers shifted during the same years that sleep got choppy and periods became irregular. The menopausal transition belongs in a heart-health conversation, not only a menopause one.

Why SWAN matters

The Study of Women’s Health Across the Nation began in 1994 and enrolled 3,302 women across seven U.S. sites: Ypsilanti/Inkster, Boston, Chicago, Oakland, Los Angeles, Newark and Pittsburgh. The cohort included African American, Caucasian, Hispanic, Chinese and Japanese women, giving the study unusual reach across racial and ethnic groups and across the years when menopause unfolds.

SWAN was launched with support from the National Institute on Aging, the National Institute of Nursing Research and the Office of Research on Women’s Health. Its first participants were seen in California in January 1996, and baseline records date to 1996-1997. The long follow-up tracks how the body changes as women move through the transition.

What changes during the transition

Total cholesterol and LDL cholesterol rise during the transition years, and newer analyses have gone further by looking at LDL subclasses rather than LDL-C alone. A 2023 paper in Menopause examined LDL subclasses over the menopausal transition in the SWAN Heart and HDL ancillary studies and found that perimenopausal women experience a steep increase in LDL-C linked to a higher risk of carotid plaque later in life.

The study connected changes in LDL biology with coronary calcification and carotid atherosclerosis.

HDL has its own menopause story. A 2022 SWAN study on HDL subclasses, lipid content and cholesterol efflux capacity found that the menopause transition could trigger low-grade chronic inflammation that may modify HDL particles. A 2021 AHA paper found that as women traverse menopause, the relationship between HDL-C and cardiovascular disease risk appears to switch from protective to harmful.

Hot flashes can be a risk marker

Vasomotor symptoms are not just a quality-of-life issue. In a 2021 SWAN study of menopausal hot flashes and night sweats, women with frequent or persistent symptoms had a 50% to 77% higher risk of future cardiovascular disease events. University of Queensland researchers linked hot flushes and night sweats to a 70% increase in cardiovascular disease risk in 2020.

That does not mean hot flashes cause heart disease. It does mean they can function as a marker, especially when they are frequent, persistent or disruptive. SWAN’s hot flash fact sheet puts the share at up to 80%, and symptoms can begin before periods stop, after they stop, or both before and after.

What to screen for now

Perimenopause is a good time to stop treating heart health as an abstract future issue. Blood pressure, LDL-C, triglycerides, waist circumference, glucose and smoking status are the core factors that overlap with menopause-related change. Those are the numbers and habits that can quietly move in the wrong direction while the obvious menopause symptoms dominate the appointment.

A practical screening conversation should include:

• blood pressure, ideally tracked over time rather than checked once
• a lipid panel with attention to LDL-C and triglycerides
• glucose screening, especially if weight distribution is changing
• waist circumference, not just body weight
• smoking status, because it remains one of the most important modifiable risk factors

Blood pressure deserves special attention. SWAN research on blood pressure trajectories found that pressure tends to climb around the menopausal transition, which is one reason this is a smart time to ask for repeat readings or use a validated home cuff.

What to ask your GP

The most useful doctor conversation in this stage is specific. Ask whether your current blood pressure, LDL-C, triglycerides and glucose fit with your age and overall risk profile, and ask how often they should be rechecked while your periods are changing. If you have frequent hot flashes or night sweats, bring that up as a possible risk marker, not just a symptom to endure.

It is also worth asking whether your waist circumference and smoking status are being folded into the assessment, because they are part of the same cardiometabolic picture. Many women in midlife still have a modest absolute risk, but perimenopause can reveal risk that was not obvious before.

The lifestyle moves that fit the moment

The transition does not call for a miracle plan. It calls for the same interventions that lower cardiovascular risk in any midlife adult, applied early enough to matter. That means moving regularly, keeping body composition in view rather than chasing a single scale number, and treating smoking cessation as a priority if it applies.

It also means not waiting for a lab result to start paying attention. If your blood pressure is rising, if LDL-C is climbing, if hot flashes are frequent and sleep is fragmented, or if glucose and waist size are drifting upward together, the years around perimenopause are the time to act on the trend.