Study Links Different Menopause Hormone Regimens to Minor Variations in Autoimmune Risk
Recent research presented at the Menopause Society annual meeting suggests a minor difference in autoimmune disease incidence between women taking systemic estrogen-only therapy compared with those receiving estrogen-progestogen combinations. Investigators emphasize that while the statistical signals are present, the absolute differences are small and require further investigation before any clinical guidelines change.
Retrospective Cohort Findings
The retrospective study, conducted by medical student Hadia Saroya and Xuezhi Daniel Jiang, MD, PhD, of Drexel University College of Medicine, evaluated data from more than 100,000 women aged 45 to 70 using the TriNetX U.S. Collaborative Network. Researchers propensity score-matched two groups of 54,692 women each: one receiving systemic estrogen-only menopausal hormone therapy and the other taking estrogen-progestogen therapy. Women with preexisting autoimmune conditions, prior chemotherapy or immunotherapy, and certain other medical complications were excluded from the analysis.
According to the findings, the overall incidence of a composite autoimmune disease measure was 4.9 percent in the estrogen-only group versus 4.5 percent in the estrogen-progestogen group. When looking at 20 individual autoimmune conditions, the team observed significantly increased hazards for five specific disorders among the estrogen-only cohort:
- Systemic lupus erythematosus
- Psoriasis
- Psoriatic arthritis
- Multiple sclerosis
- Lichen sclerosis
Despite these statistical findings, the authors stressed that absolute differences remain minimal and might not translate to meaningful clinical impact for individual patients.
Expert Perspectives and Limitations
Commenting on the study, Xuezhi Daniel Jiang noted that the research does not establish whether either hormone therapy regimen increases or decreases risk relative to women who do not use hormone therapy at all. The primary clinical takeaway, he suggested, is to foster informed discussions and individualized care between patients and clinicians rather than prompting immediate changes to existing treatment plans.
Other prominent experts in the field have called for caution when interpreting the results. JoAnn E. Manson, MD, MPH, DrPH, of Harvard Medical School and a past president of the Menopause Society, pointed out that the findings are provocative but necessitate replication and testing through large-scale randomized trials. Manson noted that past literature, including pivotal work from the Women’s Health Initiative, has shown complex and sometimes inconsistent relationships between postmenopausal hormone therapy and immune system outcomes.
Similarly, Stephanie Faubion, MD, MBA, medical director of the Menopause Society, highlighted that observational studies of this nature serve primarily to inform future prospective research. Because autoimmune conditions are known to affect women at higher rates than men, understanding how sex hormones interact with immune function remains an important area of ongoing medical inquiry.
Key Study Constraints
The researchers acknowledged several inherent limitations within their design. As a retrospective evaluation relying on electronic medical records, the work carries a risk of residual confounding and potential misclassification. Furthermore, the database lacked granular details regarding the specific routes of administration, precise dosages, and exact formulations of estrogen or progestin used by participants.
Future prospective studies are needed to determine how various hormone regimens compare against non-users, whether natural micronized progesterone differs from synthetic progestins, and how factors such as age, timing of initiation, and surgical versus natural menopause might influence overall risk.
