Lower urinary tract symptoms (LUTS) can be categorized into storage symptoms and voiding symptoms which may be produced by bladder and/or bladder outlet dysfunction. Invasive urodynamic evaluation with pressure flow study is the gold standard diagnostic tool, but it is labor intensive and time-consuming. Previous studies have shown several non-invasive urine biomarkers in diagnosing value of overactive bladder and interstitial cystitis. Thus, we investigated whether urine biomarkers could be useful in differential diagnosis of bladder and bladder outlet dysfunction in male with LUTS.

After the Institutional Review Board and Ethics Committee of the hospital approved the study, a total of 228 male patients who received videourodynamic study for LUTS were enrolled into this study. Patients were diagnosed as normal sensation, hypersensitive bladder (HSB) detrusor overactivity (DO), bladder outlet obstruction (BOO) and non-BOO according to ICS definition. Clinical evaluation included age, PSA, prostate size, IPSS-S, IPSS-V, IPSS-T, QOL, PPBC, OABSS and USS questionnaires. Urine biomarkers investigation mainly included inflammatory cytokines and chemokines: IL-1b, IL-2, IL-6, IL-8, TNFa, VEGF, NGF, BDNF, MMP-1, MMP-13, EGF, and MCP-1. We compared the differences of urine biomarkers in patients with different bladder and bladder outlet dysfunction. In addition, the clinical parameters were correlated with the level of urine biomarkers.

The mean age of male patients was 65.6 ± 14.1 years old. The mean prostate size was 35.6 ± 18.3mL. The mean IPSS was 14.9 ± 8.1. Patients with HSB and DO had significantly higher urine NGF and MMP-1 levels than patients with normal bladder sensation. However, no significantly differences in urine inflammatory cytokines and chemokines were found between patient with BOO and non-BOO. PPBC was correlated with urine IL-1, VEGF and MMP-1. OABSS was correlated with urine NGF. Voided volume was correlated with urine EGF and MCP-1.

Our findings demonstrated that some urine cytokines could be useful biomarkers in making differential diagnosis of bladder dysfunction. Previous studies have showed that urine NGF, ATP, and BDNF are increased in many OAB patients. Different OAB phenotypes may imply different underlying pathophysiology of OAB and need different therapeutic strategies. Combined with clinical factors and urine biomarkers may lead to tailored treatment of OAB. In addition, though no differences were noted in patients with and without BOO, further comparison in urine biomarkers for patients before and after surgical treatment of BOO might provide new understanding the roles of urine cytokines in bladder outlet dysfunction.

Several urine cytokines and chemokines were associated with bladder dysfunction, but not bladder outlet dysfunction.

Jian YU, et al.  urine biomarkers in bladder outlet obstruction-related detrusor underactivity.Tzu Chi Med J [Epub ahead of print] [cited 2021 May 2].