BPH with coexisting overactive bladder dysfunction--an everyday urological dilemma.

The aim of this study was to use a systematic schedule, including urodynamics, to describe the rate of coexisting overactive bladder (OB) in patients with bladder outlet obstruction (BOO) caused by benign prostatic hyperplasia (BPH). We also identified differences between the patients with pure BOO compared with those with BOO combined with OB (BOO + OB). One hundred and sixty-two men referred to our clinic due to LUTS were included. Patients with a history that might affect their bladder function were excluded. After cystometry and pressure-flow studies, the patients were divided into pure BOO and BOO + OB. Of the 162 men, 55% had pure BOO. BOO + OB was found in 45%. Age, s-PSA, voided volume, and obstruction grade differed significantly between the groups. The patients with BOO + OB were older, had a higher s-PSA, voided smaller volumes, and were more obstructed. We found no differences in TRUS-volume, Q-max, IPS score, or PVR. There was a strong association between OB and BOO, the percentage of OB increasing with increased obstruction. TRUS-volume, Q-max, IPS score, and PVR did not predict whether the patients had a combined BOO + OB or not. These findings indicate that BOO is a progressive disease, which in time causes pronounced obstruction and perhaps in itself contributes to the development of OB.