title: Significant association of insulin and proinsulin with clustering of cardiovascular risk factors.
abstract: OBJECTIVE
  To investigate the association between true insulin and proinsulin and clustering of cardiovascular risk factors.
  
  
  METHODS
  Based on the random stratified sampling principles, 1196 Chinese people (533 males and 663 females, aged 35-59 years with an average age of 46.69 years) were recruited. Biotin-avidin based double monoclonal antibody ELISA method was used to detect the true insulin and proinsulin, and a risk factor score was set to evaluate individuals according to the number of risk factors.
  
  
  RESULTS
  The median (quartile range) of true insulin and proinsulin was 4.91 mIu/L (3.01-7.09 mIu/L) and 3.49 pmol/L (2.14-5.68 pmol/L) respectively, and the true insulin level of female subjects was significantly higher than that of male subjects (P = 0.000), but the level of proinsulin displayed no significant difference between males and females (P = 0.566). The results of covariate ANOVA after age and sex were controlled showed that subjects with any of the risk factors had a significantly higher true insulin level (P = 0.002 for hypercholesterolemia, P = 0.021 for high low-density lipoprotein cholesterol, P = 0.003 for low high-density lipoprotein cholesterol, and P = 0.000 for other risk factors) and proinsulin level (P = 0.001 for low high-density lipoprotein cholesterol, and P = 0.000 for other risk factors) than those with no risk factors. Furthermore, subjects with higher risk factor scores had a higher true insulin and proinsulin level than those with lower risk factor scores (P = 0.000). The multiple linear regression models showed that true insulin and proinsulin were significantly related to cardiovascular risk factor scores respectively (P = 0.000).
  
  
  CONCLUSIONS
  True insulin and proinsulin are significantly associated with the clustering of cardiovascular risk factors.
authors.affiliation: Department of Cardiovascular Epidemiology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China. enzhijia@yahoo.com.cn
authors.forename: En-Zhi
authors.initials: EZ
authors.lastname: Jia
authors.forename: Zhi-Jian
authors.initials: ZJ
authors.lastname: Yang
authors.forename: Shi-Wei
authors.initials: SW
authors.lastname: Chen
authors.forename: Guang-Yao
authors.initials: GY
authors.lastname: Qi
authors.forename: Chun-Fa
authors.initials: CF
authors.lastname: You
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Ma
authors.forename: Jing-Xin
authors.initials: JX
authors.lastname: Zhang
authors.forename: Zhen-Zhen
authors.initials: ZZ
authors.lastname: Wang
authors.forename: Wei-Chong
authors.initials: WC
authors.lastname: Qian
authors.forename: Xin-Li
authors.initials: XL
authors.lastname: Li
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Wang
authors.forename: Wen-Zhu
authors.initials: WZ
authors.lastname: Ma
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D006946:Hyperinsulinism / Q000097:blood / Q000453:epidemiology*; D006973:Hypertension / Q000097:blood / Q000453:epidemiology*; D007328:Insulin / Q000097:blood*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000453:epidemiology; D011379:Prognosis; D011384:Proinsulin / Q000097:blood*; D012307:Risk Factors
chemical_list: D007328:Insulin; D011384:Proinsulin