The purpose of this study is to determine whether medical treatment for bladder outlet obstruction is effective in improvement of glomerular filtration rate and/or proteinuria.

Urodynamic parameters including maximal flow rate, compliance (infused volume gradient divided by bladder pressure gradient during cystometry), maximal detrusor pressure, bladder outlet obstruction index and Schäfer grade will be checked.

Estimated glomerular filtration rate and urinary protein to creatinine ratio will be checked.

International prostate symptom score will be checked.

Inclusion Criteria:

• Men with low urinary tract symptoms aged between 40 and 80
• Estimated glomerular filtration rate < 60 or evidence of proteinuria
• Bladder outlet obstruction index > 40, Schäfer grade 2 or more, maximal flow rate lower than 10 cc/s or postvoid residual urine > 100cc

Exclusion Criteria:

• Bladder outlet obstruction index less than 40, Schäfer grade 0 or 1, maximal flow rate higher than 10 ml/s and postvoid residual urine less than 100cc
• Want surgical procedure
• Evidence of prostate cancer or bladder cancer
• Major depressive disorder, Dementia, Parkinson's disease or neurological deficits
• History of pelvic irradiation
• Uncontrolled diabetes mellitus or hypertension
• Symptomatic orthostatic hypotension