title: Elevated level of nerve growth factor in the bladder pain syndrome/interstitial cystitis: a meta-analysis.
abstract: OBJECTIVE
  To elucidate the association between nerve growth factor (NGF) level and bladder pain syndrome/interstitial cystitis (BPS/IC) by conducting a meta-analysis.
  
  
  METHODS
  We conducted a systematic literature search to identify original studies of NGF level in BPS/IC before November 2015. Eligible studies were retrieved via both computer searches and manual review of references. The summary difference estimates between controlled group and BPS/IC group were calculated based on the weighted mean difference (WMD) with its 95 % confidence interval (CI). Sensitivity and publication analyses were performed after the pooled analysis.
  
  
  RESULTS
  Meta-analysis of 10 original studies involving 295 cases and 290 normal controls showed an increased level of urinary NGF in BPS/IC patients (z = 3.08, P = 0.002). The combined WMD was 36.39 (95 % CI 13.27-59.51). There was significant difference between controlled group and BPS/IC patients in the term of NGF/Cr level (WMD = 0.96, 95 % CI 0.58-1.35; z = 4.89, P < 0.01). There was no significant publication bias in the included studies (P for Begg's test = 0.73, P for egger's test = 0.13).
  
  
  CONCLUSIONS
  Our results demonstrated that there was an increased level of NGF in the BPS/IC patients.
authors.affiliation: Department of Urology, Zigong No.4 People's Hospital, Sichuan, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Urology, Zigong No.4 People's Hospital, Sichuan, China.
authors.forename: Da-Yong
authors.initials: DY
authors.lastname: Ye
authors.affiliation: Department of Urology, Zigong No.4 People's Hospital, Sichuan, China.
authors.forename: Deng-Jun
authors.initials: DJ
authors.lastname: Han
authors.affiliation: Department of Urology, Zigong No.4 People's Hospital, Sichuan, China.
authors.forename: Guang-Qing
authors.initials: GQ
authors.lastname: Fu
authors.affiliation: Department of Urology, Zigong No.4 People's Hospital, Sichuan, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Department of Urology, Zigong No.4 People's Hospital, Sichuan, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Lin
authors.affiliation: Department of Urology, Zigong No.4 People's Hospital, Sichuan, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liang
keywords: Bladder pain syndrome; Interstitial cystitis; Meta-analysis; Nerve growth factor