PHILADELPHIA, PA—Topical hormone replacement therapy (HRT) was associated with a lower incidence of urinary tract infections (UTIs) compared with both systemic HRT and no HRT, a retrospective study reported at IDWeek 2014.

“UTIs are a frequent problem among postmenopausal women necessitating antimicrobial use, and resistance is increasing,” reported Jana Kubrin Dickter, MD, Infectious Diseases, Kaiser Permanente Fontana Medical Center, Fontana, CA.

“Every year, 8–10% of postmenopausal women have 1 episode of a urinary tract infection; of these, 5% will have a recurrence in the next year,” she noted. “While studies have demonstrated systemic HRT does not reduce the incidence of UTIs, topical HRT reduced the number of UTIs in two small studies. To our knowledge, no study has compared both treatment groups with a control.”

To determine whether a difference existed in incidence of UTIs in women 60–75 years of age, Dr. Dickter and colleagues compared the number of UTIs per patient per year over 1 year in 3 groups of postmenopausal women: topical HRT, systemic HRT, and control (n=75 per group).

Women aged 60–75 years with a history of UTI (n=448) were identified from retrospective charts (2011–2013). Patients were excluded if they were taking antibiotics for UTI prophylaxis, treated with antibiotics for reasons other than UTI for 2 or more weeks, were on both topical and systemic HRT, or on chronic methenamine hippurate.

The number of UTIs per patient per year was significantly different among the 3 groups (F(2,222)=8.75, P<0.001). There was a significant difference between topical HRT and systemic HRT (P<0.001), and topical HRT and control (P<0.05), but not systemic HRT and control (post-hoc Tukey test). The control group had an average of 1.24 UTIs per patient per year, compared with 1.01 in the systemic group and 0.65 in the topical group.

Although age and other baseline characteristics (incidence of diabetes mellitus, chronic kidney disease, or urinary incontinence) did not differ between the groups, Dr. Dickter noted that 72% of patients in the topical HRT group had a history of or baseline diagnosis of atrophic vaginitis, compared with 8% of the control group and 11% in the systemic HRT group (χ2(2) =93.24, P<0.001).

“Topical HRT may be beneficial when other preferred agents cannot be utilized,” Dr. Dickter concluded, adding that future studies should evaluate dosing and duration of HRT.