Residual urine in an elderly female population: novel implications for oral estrogen replacement and impact on recurrent urinary tract infection

While the distribution of post-void residual urine volume (PVR) has been well studied in men, scant literature is available concerning PVR in women. We characterized any relationship between PVR and urinary tract infection (UTI). We also characterized other factors that could impact bladder emptying, including oral estrogen replacement therapy.Inclusion criteria were at least 2 clinic visits and no antimicrobial prophylaxis in the last year. Women with a history of diabetes or cystocele were excluded. In a 17-month period 204 women met inclusion criteria. PVR was measured by catheterized specimen. Patients were categorized into groups by UTI history, namely 94 of those with no UTIs in the last year (group 1) and 110 with 1 or more documented UTIs in the last year (group 2). Factors that could affect bladder emptying were tested for the impact on PVR.Mean PVR in the study group was 53.13 ml. The mean PVR in groups 1 and 2 was 33 and 70.25 ml, respectively. The difference between these 2 groups was significant (p0.0001). Estrogen status data were available on 186 patients. The 62 patients on estrogen replacement therapy had a mean PVR of 39.33 ml. The 124 patients not on estrogen replacement therapy had a mean PVR of 66.67 ml. The difference between these 2 groups was significant (p = 0.002) and independent of UTI history.Of elderly women those with high PVR were more likely to have recurrent UTIs. Improved bladder function was documented in women receiving oral estrogen replacement therapy.