Urinary tract infection in menopause is linked to low estrogens levels
Latest studies on urinary tract infections led by researchers at Karolinska Institutet show that estrogens stimulate the production of the body’s own antibiotics and strengthens the cells to fight urinary tract infection. These findings show that post-menopausal women are more prone to recurrent urinary tract infections and that estrogen supplements might help. The study results are published in the scientific journal Science Translational Medicine.
Urinary tract infection is defined as the presence and multiplication of bacteria in the urinary tract. There are two types of urinary tract infections: infection of the lower urinary tract, which refers to cystitis, pyelocystitis, urethritis, prostatitis, and upper urinary tract infection, which refers to infection of the renal parenchyma, that is pyelonephritis, which can be acute or chronic. The most common germs that cause urinary tract infections are Gram-negative bacteria such as E. coli, Klebsiella, Proteus, Pseudomonas aeruginosa. The main factors that lead to urinary tract infection are bacterial virulence (fimbriae, lipopolysaccharide, capsular agent) and host susceptibility (urinary tract abnormalities, systemic diseases).
Urinary tract infections are among the most common diseases that affect women as about half of them have at least one episode of urinary tract infection at some point in life, and 25% develop recurrences. It was found that women in post-menopause have a higher risk of recurrent urinary tract infection and this is due to low levels of estrogen. For an infection to occur, it is necessary that the bacteria come in contact with the bladder. Urinary bladder is made up of special epithelial cells that protects vulnerable tissue and produce antimicrobial peptides (which have an antibiotic-like effect).
These antimicrobial peptides are the first to act when the bladder comes in contact with bacteria. Because these peptides act very quickly, the bacteria do have time to multiply and thus no infection occurs. In contrast, in post-menopausal women, the bladder epithelium is more fragile and often damaged (which lead to gaps between cells that allow the dissemination of bacteria and infection).
In the study conducted by researchers at Karolinska Institutet, 14 post-menopausal women were given estrogen for 14 days. After treatment with estrogen, the researchers analyzed cells excreted in urine and saw that the gaps that were previously in bladder epithelium disappeared. Dr. Annelie Brauner at the Department of Microbiology, Tumor and Cell Biology, who is responsible for the study, said: “By treating post-menopausal women locally with estrogen the cells lining the bladder are strengthened and the body’s own defense against infection is improved, making women better suited to fight infections.”