1036Estrogen Hormone Replacement Therapy May Lower Risk of Recurrent Urinary Tract Infections in Postmenopausal Women

Background. Urinary tract infections (UTIs) are a frequent problem among postmenopausal women necessitating antimicrobial use, and resistance is increasing. Every year, 8-10% of postmenopausal women have 1 episode of a UTI; of these, 5% will have a recurrence in the next year. Most women have been taken off estrogen hormone replacement therapy (HRT). While studies have demonstrated systemic HRT does not reduce the incidence of UTIs, topical HRT reduced the number of UTIs in 2 small studies.To our knowledge no study has compared both treatment groups with a control. Methods. Retrospective charts (2011-2013) were randomly reviewed of women age 60-75 with a documented history of UTI (N = 448). Excluded were patients taking antibiotics for UTI prophylaxis; patients treated with antibiotics for other reasons than UTI for >2 weeks, patients on both topical and systemic HRT, and patients on chronic methenamine hippurate. Pts were separated into 3 groups (N = 75/group): those using systemic HRT, topical HRT, and control. The primary outcome was number of UTIs/ patient over 1 year. Results. UTIs/patient/year differed significantly between conditions (F (2,222) = 8.75, p < 0.001), with post-hoc Tukey tests showing a significant difference between topical and systemic (p < .001), and topical and control (p < .05), but not systemic and control. The control group had an average of 1.24 UTIs/patient/year, compared to 1.01 in the systemic group and 0.65 in the topical group. There were no significant differences in age or other baseline characteristics of incidence of diabetes mellitus, chronic kidney disease or urinary incontinence; however in the control group, 8% had a history/baseline diagnosis of atrophic vaginitis compared to 11% in the systemic HRT group and 72% in the topical HRT group (χ(2) = 93.24, p < 0.001). Conclusion. UTIs are one of the most common reasons that antibiotics are prescribed. Increasing antimicrobial resistance among pathogens associated with UTIs has been a real concern to the infectious disease community, and options for prevention are becoming increasingly more important. In our study, topical HRT was associated with a lower incidence of UTIs compared to the control group and may be beneficial when other preferred agents cannot be utilized. Future studies should evaluate dosing/duration of HRT for most effective outcomes. Disclosures. All authors: No reported disclosures.