Hormone Therapy Linked to Increased Risk of Autoimmune Diseases in Postmenopausal Women

Researchers have discovered a strong association between hormone therapy (HT) use and the incidence of autoimmune diseases in postmenopausal women, with a significant increase in risk observed across various autoimmune conditions. The retrospective cohort study, presented at the Menopause Society annual meeting, examined the link between HT use and autoimmune disease development among postmenopausal women. The findings suggest that HT users are more likely to develop autoimmune diseases, with a higher incidence rate and a significant increase in risk compared to non-HT users.

Key Takeaways:

• The study found a higher incidence of autoimmune disease in HT users compared to non-HT users, with a difference of 1.4% at five years, 2.3% at 10 years, and 1.9% across the postmenopausal period.
• The risk for developing any autoimmune disease was significantly increased in association with HT use, with risk ratios ranging from 1.03 for psoriasis to 2.90 for lichen sclerosis.
• For all autoimmune diseases except Graves disease and autoimmune hepatitis, significant increases in risk were seen.
• Among HT users, the hazard of developing any autoimmune disease during the full follow-up period was significantly increased.
• The absolute risk increase was relatively small, varying by condition.

Statistics:

• 889,413 postmenopausal women were included in the HT and non-HT cohorts.
• HT users had a 6.7% incidence of autoimmune disease at five years, compared to 5.3% in non-HT users.
• At 10 years, the incidence rate was 8.6% in HT users and 6.7% in non-HT users.
• The risk ratio for developing any autoimmune disease was 1.29 at five years, 1.28 at 10 years, and 1.27 at any point after menopause.

Sources:

• Ameera Syed et al., "Association between hormone therapy and autoimmune diseases in postmenopausal women." (Presentation at the Menopause Society annual meeting, Oct. 21-25, 2025).
• Press Release, More Information.