Hormone Therapy May Bolster Immune Defense in Postmenopausal Women

Recent research from Queen Mary University of London has identified a potential link between menopause and reduced immune efficiency in women, offering new insights into how hormonal changes may impact the body's ability to fight infections. The study, published in the journal Aging Cell, compared blood samples from adults under 40 years old with those from adults over 65, focusing specifically on variations between men and women.

The findings indicate that postmenopausal women exhibit a notable increase in pro-inflammatory monocytes--immune cells that are less efficient in eliminating bacteria. This cellular change is coupled with a decline in the concentration of complement C3, a protein crucial to the immune response. Complement C3 assists monocytes in destroying harmful bacteria, and lower levels of this protein may leave individuals more susceptible to infections. Notably, these immune changes were not observed in men of a similar age group, suggesting that menopause itself may play a significant role in diminishing immune defense in women.

To explore possible interventions, the research team examined the effects of hormone replacement therapy (HRT) on women undergoing menopause or who had completed the transition. Those receiving HRT demonstrated a healthier immune profile compared to women of similar age who were not undergoing hormone therapy. Specifically, HRT recipients had fewer inflammatory monocytes and higher levels of complement C3, bringing their immune parameters closer to those seen in younger women.

The data suggests that hormonal changes during menopause may accelerate the natural decline in immune function, but that HRT could help restore certain aspects of immune health. Restoration of complement C3 levels and reduction in inflammatory monocytes could enhance the body's ability to defend against bacterial infections, potentially lowering infection risks for postmenopausal women.

Despite these encouraging results, researchers caution against the routine use of hormone replacement therapy solely to improve immune health. The study underscores the need for further investigation to confirm whether these immune profile changes translate into lowered infection rates in real-life settings. Additionally, the long-term effects of different types and modes of hormone therapy administration on immune health remain to be fully understood.

This research highlights a previously underexplored aspect of menopause and its systemic effects on health, emphasizing the importance of ongoing studies to better understand how hormonal interventions may influence immune aging. As the global population ages, such findings are increasingly relevant for public health strategies aimed at improving quality of life and reducing infection-related complications among older women.

Further studies are needed to determine the most effective and safe ways to support immune function in postmenopausal women and to establish whether hormone replacement therapy should become part of broader clinical recommendations aimed at reducing infection risk in this demographic.