Vaginal estrogen reduces the frequency of urinary tract infection (UTI) in hypoestrogenic women, a recent study finds.
In the 2009-2019 Kaiser Permanente Southern California system, 5638 women (mean age 70.4 years; 93.4% past menopause) received a prescription for off-label vaginal estrogen to prevent recurrent UTI. Prescriptions included vaginal ring, cream, or tablet, but not vaginal contraceptive hormones. The study enrolled women with comorbidities such as nonmenopausal hypoestrogenic conditions, diabetes, pelvic organ prolapse and voiding dysfunction, as well as previous hysterectomy or pelvic reconstructive surgery. Exclusion criteria included malignancy, anatomic abnormalities, or mesh erosion of the genitourinary tract.
Culture-proven UTI frequency significantly declined from a baseline of 3.9 in the prior year to 1.8 in the year following prescription – a 51.9% reduction, Jasmine Tan-Kim, MD, MAS, of Kaiser Permanente in San Diego, California, and colleagues reported in the American Journal of Obstetrics and Gynecology. During the 12 months after vaginal estrogen prescription, 55.3% of patients experienced 1 or fewer UTIs and 31.4% had no UTIs. The other 17.8% of women experienced no improvement or an increase in UTI frequency. Escherichia coli and Klebsiella species were the most common uropathogens.
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Specific groups had increased risks for recurrent UTI despite vaginal estrogen prescription. Women aged 75-84 years and older than 85 years had a significant 24% and 41% increased risk for recurrent UTI, respectively, compared with women younger than 55 years. Patients with higher UTI frequency at baseline, urinary incontinence, and urinary retention had a significant 22%, 14%, and 21% increased risk, respectively. Diabetes mellitus significantly increased the risk for recurrent UTI by 14%.
With respect to vaginal estrogen adherence, women with moderate (1 refill) or high (2 or more refills) adherence had a 32% and 33% increased risk for persistent UTI, respectively. High medication adherers had significantly more UTIs than low adherers in the 12 months after the first prescription (mean 2.2 vs 1.6). The investigators suggested that unmeasured confounders may be responsible for these paradoxical results. For example, they did not have information on the severity of patients’ medical comorbidities or functional status or use of other UTI therapies.
“Although antibiotics are the mainstay of treatment, a focus on prevention is important to avert disruption of the urinary microbiome, prevent multidrug resistance of bacterial pathogens, avoid adverse side effects, and reduce costs,” Dr Tan-Kim’s team noted.
The investigators cited research demonstrating that local estrogen can reduce vaginal pH and facilitate Lactobacillus colonization after 10 weeks of use.
Disclosure: This research was supported by Kaiser Permanente Southern California Regional Research Committee. Please see the original reference for a full list of disclosures.
Reference
Tan-Kim J, Shah NM, Do D, Menefee SA. Efficacy of vaginal estrogen for recurrent urinary tract infection prevention in hypoestrogenic women. Am J Obstet Gynecol. Published online May 11, 2023. doi:10.1016/j.ajog.2023.05.002
