Serum cystatin C level and its risk factors in Chinese healthy adults: a population based cross-section study

Abstract

Objective To investigate the average serum level and risk factors of serum cystatin C in Chinese healthy adults. Methods A total of 15 918 healthy adults who received health assessments in Peking Union Medical College Hospital during January 2012 and March 2013 were enrolled in this cross-section study. Serum cystatin C was measured. Estimated glomerular filtration rate was calculated by creatinine (eGFRCr). Multivariable linear regression analysis was used to assess factors that contribute to cystatin C variability. Results The mean serum cystatin C level was (0.79±0.14) mg/L (95% reference interval (RI) was 0.56-1.08 mg/L). Male showed significantly higher cystatin C level than female (mean (0.84±0.13) vs (0.73±0.13) mg/L; RI 0.64-1.11 mg/L and 0.54-1.03 mg/L, respectively; P=0.000). Differences between genders are still significant after subgrouped by age. In the young-age group (age≤44 years old), the mean serum cystatin C level was (0.81±0.11)mg/L in male and (0.68±0.09) mg/L in female, P=0.000. In the middle-age group (45-59 years old), the mean cystatin C level was (0.85±0.12) mg/L in male and (0.75±0.12) mg/L in female, P=0.000. In the elderly group (≥60 yrs), the mean serum cystatin C level was (0.97±0.18) mg/L in male and (0.89±0.19) mg/L in female, P=0.000. Serum cystain C was increased with ages (in male: r=0.274, P=0.000; in femal, r=0.470, P=0.000). Differences between each two age groups are all significant for both gender, P=0.000. Cystatin C level in male is respectively (0.81±0.11)mg/L, (0.85±0.12) mg/L and (0.97±0.18) mg/L in the young-age, middle-age and elderly group. Cystatin C level in female is respectively (0.68±0.09) mg/L, (0.75±0.12) mg/L and (0.89±0.19) mg/L in the young-age, middle-age and elderly group. Male gender, older age, lower body weight, lower eGFRCr, lower high-density lipoprotein cholesterol, lower fasting blood glucose, increased mean blood pressure, higher body mass index and triglyceride were significantly associated with increased serum cystatin C level. Body weight, total cholesterol and low-density lipoprotein cholesterol were not risk factors of cystatin C. Conclusion Serum cystatin C level may be influenced by gender, age and other factors in Chinese healthy adults. Key words: Adult; Regression analysis; Cystatin C