title: Cystatin C: a strong marker for lower limb ischemia in Chinese type 2 diabetic patients?
abstract: OBJECTIVE
  Cystatin C is growing to be an ideal indicator for renal function and cardiovascular events. The aim of this study was to investigate the relationship between serum cystatin C levels and peripheral arterial disease and to explore its diagnostic value for lower limb ischemia (LLI) in type 2 diabetic population.
  
  
  METHODS
  A total of 1609 T2DM patients were included in this cross-sectional study. Their clinical and biochemical characteristics, ankle-brachial index (ABI), carotid and lower extremity arterial ultrasound were detected. LLI was defined by ABI <0.9 and lower extremity arterial stenosis >50% by ultrasound examination. Patients were divided to two groups: with LLI and without. The risk factors of LLI were explored by binary logistic regression analysis.
  
  
  RESULTS
  The serum concentrations of cystatin C were 1.53±0.60 and 1.08±0.30 mg/L in patients with and without LLI, respectively. Binary logistic regression analysis showed that the significant risk factors were cystatin C (P = 0.007, OR = 5.081), the presence of hypertension (P = 0.011, OR = 3.527), age (P<0.001, OR = 1.181), GA (P = 0.002, OR = 1.089) and diabetes duration (P = 0.008, OR = 1.074). The prevalence of coronary artery disease, cerebral infarction and LLI increased with cystatin C (P<0.01), and the prevalence of LLI in patients with cystatin C >1.2 mg/L was much higher than other three quartile groups. Receiver operating characteristic curve analysis revealed the cut point of cystatin C for LLI was 1.2 mg/L. The risk of LLI dramatically increased in patients with cystatin C >1.2 mg/L (OR = 21.793, 95% confidence interval 10.046-47.280, P<0.001). After adjusting for sex, age, duration, HbA1c, GA and hypertension, its OR still remained 3.395 (95% confidence interval 1.335-8.634).
  
  
  CONCLUSIONS
  There was a strong and independent association between cystatin C and limb arterial disease in diabetic population, and cystatin C >1.2 mg/L indicated a great increased risk of LLI.
authors.affiliation: Department of Endocrinology & Metabolism, Shanghai Jiaotong University Affiliated Sixth People's Hospital, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Key Clinical Center for Metabolic Diseases, Shanghai, China. liufangstar@163.com
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Shen
authors.forename: Jun
authors.initials: J
authors.lastname: Zhao
authors.forename: Hui
authors.initials: H
authors.lastname: Zeng
authors.forename: Lianxi
authors.initials: L
authors.lastname: Li
authors.forename: Jungong
authors.initials: J
authors.lastname: Zhao
authors.forename: Fengdi
authors.initials: F
authors.lastname: Lu
authors.forename: Yuqian
authors.initials: Y
authors.lastname: Bao
authors.forename: Weiping
authors.initials: W
authors.lastname: Jia
mesh_terms: D000367:Age Factors; D000368:Aged; D001158:Arteries / Q000000981:diagnostic imaging / Q000473:pathology*; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D055316:Cystatin C / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000000981:diagnostic imaging / Q000473:pathology; D017719:Diabetic Foot / Q000097:blood* / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D007511:Ischemia / Q000097:blood* / Q000000981:diagnostic imaging / Q000473:pathology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014463:Ultrasonography
chemical_list: D015415:Biomarkers; D055316:Cystatin C