title: Association between serum C-peptide as a risk factor for cardiovascular disease and high-density lipoprotein cholesterol levels in nondiabetic individuals.
abstract: OBJECTIVE
  Objective: Although serum C-peptide has increasingly received attention as a new and important risk factor for cardiovascular disease (CVD), the potential mechanisms remain unclear. This study aimed to investigate the association between serum C-peptide as a risk factor for CVD and high-density lipoprotein cholesterol (HDL-C) levels.
  
  
  METHODS
  The present study included 13,185 participants aged ≥20 years. Serum C-peptide and HDL-C levels were measured according to a standard protocol. Stratified analysis of covariance was used to compare serum HDL-C levels between different quartiles of serum C-peptide levels. Logistic regression analysis was used to determine the association between serum C-peptide and HDL-C levels. Cox proportional hazard regression analysis was conducted to determine the hazard ratio of serum HDL-C for CVD-related mortality.
  
  
  RESULTS
  The results of the ANCOVA analysis showed a significant linear trend between the mean serum HDL-C level and the different quartiles of serum C-peptide. Compared to the first quartile (25th percentile), the second, third, and fourth quartiles had gradual reduction in serum HDL-C levels. Logistic regression analyses showed a strong negative association between serum C-peptide levels and HDL-C levels; the p value for the linear trend was <0.001. In men, compared with the lowest quartile of the serum C-peptide level, the relative risk was 1.75, 2.79, and 3.07 for the upper three quartiles of the serum C-peptide level. The relative risk was 1.60, 2.61, and 3.67 for women. The results of the survival analysis showed that serum HDL-C levels were negatively associated with CVD-related death in both men and women.
  
  
  CONCLUSIONS
  Serum C-peptide as a risk factor for CVD was significantly and negatively associated with serum HDL-C levels in individuals without diabetes. These findings suggest that serum C-peptide levels association with CVD death can be caused, at least in part, by the low serum HDL-C level.
authors.affiliation: Department of Social Medicine, School of Public Health, Zhejiang University, Zhejiang, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Basic Medical Sciences, Zhejiang University, Zhejiang, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Social Medicine, School of Public Health, Zhejiang University, Zhejiang, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Meng
authors.affiliation: School of Basic Medical Sciences, Zhejiang University, Zhejiang, China.
authors.forename: LianShun
authors.initials: L
authors.lastname: Zheng
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002096:C-Peptide / Q000097:blood*; D002318:Cardiovascular Diseases / Q000097:blood* / Q000175:diagnosis; D008076:Cholesterol, HDL / Q000097:blood*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D016016:Proportional Hazards Models; D018570:Risk Assessment / Q000379:methods* / Q000706:statistics & numerical data; D012307:Risk Factors; D016019:Survival Analysis; D055815:Young Adult
chemical_list: D002096:C-Peptide; D008076:Cholesterol, HDL