title: Plasma tissue kallikrein level is negatively associated with incident and recurrent stroke: a multicenter case-control study in China.
abstract: OBJECTIVE
  Tissue kallikrein (TK) cleaves kininogen to produce the potent bioactive compounds kinin and bradykinin, which lower blood pressure and protect the heart, kidneys, and blood vessels. Reduction in TK levels is associated with cardiovascular disease and diabetes in animal models. In this study, we investigated the association of TK levels with event-free survival over 5 years in Chinese first-ever stroke patients.
  
  
  METHODS
  We conducted a case-control study with 1,268 stroke patients (941 cerebral infarction, 327 cerebral hemorrhage) and 1,210 controls. Plasma TK levels were measured with an enzyme-linked immunosorbent assay. We used logistic regression and Cox proportional hazards models to assess the relationship between TK levels and risk of first-time or recurrent stroke.
  
  
  RESULTS
  Plasma TK levels were significantly lower in stroke patients (0.163 ± 0.064mg/l vs 0.252 ± 0.093mg/l, p < 0.001), especially those with ischemic stroke. After adjustment for traditional risk factors, plasma TK levels were negatively associated with the risk of first-ever stroke (odds ratio [OR], 0.344; 95% confidence interval [CI], 0.30-0.389; p < 0.001) and stroke recurrence and positively associated with event-free survival during 5 years of follow-up (relative risk, 0.82; 95% CI, 0.74-0.90; p < 0.001). Compared with the first quartile of plasma TK levels, the ORs for first-ever stroke patients were as follows: second quartile, 0.77 (95% CI, 0.56-1.07); third quartile, 0.23 (95% CI, 0.17-0.32); fourth quartile, 0.04 (95% CI, 0.03-0.06).
  
  
  CONCLUSIONS
  Lower plasma TK levels are independently associated with first-ever stroke and are an independent predictor of recurrence after an initial stroke.
authors.affiliation: Institute of Hypertension and Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhang
authors.forename: Hu
authors.initials: H
authors.lastname: Ding
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Yan
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Aiqun
authors.initials: A
authors.lastname: Ma
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Zhu
authors.forename: Katherine
authors.initials: K
authors.lastname: Cianflone
authors.forename: Frank B
authors.initials: FB
authors.lastname: Hu
authors.forename: Rutai
authors.initials: R
authors.lastname: Hui
authors.forename: Dao Wen
authors.initials: DW
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D016022:Case-Control Studies; D002681:China; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012307:Risk Factors; D020521:Stroke / Q000097:blood* / Q000517:prevention & control*; D020840:Tissue Kallikreins / Q000097:blood*
chemical_list: D020840:Tissue Kallikreins