Kaiser Permanente has contributed data to multisite study of menopause for nearly 30 years
National Women’s Health Week is May 10-16
By Jan Greene
This summer about 330 women, most in their 70s, will be invited to undergo exams and fill out surveys by researchers at the Kaiser Permanente Division of Research. It should be familiar; after all, they’ve been returning to the Oakland study site for the past 27 years.
The women participate in the NIH-funded Study of Women’s Health Across the Nation (SWAN). The Northern California study site is one of 7 around the country and was started by Kaiser Permanente investigators in 1994 in partnership with researchers at UC Davis. The partners recently received $2.3 million from the National Institute on Aging for the next 4-year cycle, out of a total of $11 million for SWAN overall.
Over the years, SWAN investigators have produced hundreds of scientific papers from the study’s shared data pool, which includes information on about 2,500 women. Participants represent 5 racial/ethnic groups, so researchers can study potential disparities and make comparisons among groups of women.
SWAN has followed the women from midlife and through the menopausal transition, and will now focus on the experience of aging, with an emphasis on how post-menopausal hormonal changes affect cognition and psychological well-being, cardiovascular functioning, and musculoskeletal health.
Division of Research investigator Monique Hedderson, PhD, recently took over as co-principal investigator for SWAN’s UC Davis/Kaiser Permanente site. “The SWAN study provides exciting research opportunities in women’s health,” Hedderson said. One of her research topics is whether hormonal changes and symptoms during the menopause transition affect later risk of developing diabetes.
Hedderson is working on a paper about women who have vasomotor symptoms – hot flashes, night sweats – with menopause and whether they later had increased risk of developing Type 2 diabetes. “The newly funded study will also examine whether characteristics of the menopause transition, such as timing, patterns of sex hormones and vasomotor symptoms, affect later cognitive function and potential precursors to Alzheimer’s disease and dementia,” Hedderson said.
The investigators have access to a rich set of data about the women, including blood samples collected nearly annually since 1995. “We have historical data on these women, including hormone changes over time, changes in biomarkers and cardiometabolic factors over time,” Hedderson said. “Also, this is a dynamic field. If we find an interesting novel biomarker that hasn’t been measured yet, we could potentially go back and measure it in the stored samples.”
Women’s health in midlife is generally understudied, so the SWAN data give investigators opportunity to fill in blanks on a wide variety of health topics. For instance, co-principal investigator for Northern California Ellen Gold, MA, PhD, an emeritus professor of epidemiology at UC Davis, has published significant papers on topics such as the connection between age at menopause and risk of later health problems, and risk factors for vasomotor symptoms. Gold has been with SWAN from the start, and has handed over SWAN duties at UC Davis to colleague Elaine Waetjen, MD, professor of obstetrics and gynecology, whose research focus includes urinary incontinence, vaginal symptoms, and the vaginal microbiome.
At the Kaiser Permanente Division of Research, Hedderson took over leadership of the project from Laurel Habel, PhD, a breast cancer researcher who, along with overseeing DOR’s participation from 2016 to 2020, led a SWAN ancillary study from 2004-2008 examining the potential association of several lifestyle and behavioral factors and mammographic density, a strong risk factor for breast cancer.
“At the time, mammographic density was considered a potentially good intermediate marker for breast cancer risk, and I wanted to see what modifiable risk factors for breast cancer were associated with density,” Habel said. “And SWAN’s cohorts were a really good population to address these questions.” The ancillary study produced 10 papers, and others are in progress. However, while the study found racial/ethnic differences and associations with several reproductive factors and with some behaviors, such as smoking, findings suggested that density is not strongly associated with many of the other modifiable risk factors she studied.
Gold originally set up the Northern California study site with Kaiser Permanente emeritus research scientist Barbara Sternfeld, PhD, who retired in 2015. Sternfeld has been author or co-author on about 60 papers from SWAN, with a focus on physical activity, and continues to collaborate with SWAN investigators around the country. Her most recent paper found that addressing inequality could reduce some racial and ethnic disparities in functional limitations of women as they age.
The Northern California site recruited both white and Chinese women, while other sites recruited white women in addition to Black, Hispanic or Japanese women at each site. Nearly three quarters of these participants stayed with the study, returning to share their health data 15 times over the years for the benefit of both the researchers and younger women yet to reach midlife. “We have a really dedicated group of women,” Hedderson said.