Potential contribution of adipose tissue to elevated serum cystatin C in human obesity

Obesity (Silver Spring). 2009 Dec;17(12):2121-6. doi: 10.1038/oby.2009.96. Epub 2009 Apr 9.


Cystatin C, an endogenous inhibitor of cathepsin proteases has emerged as a biomarker of cardiovascular risk and reduced renal function. Epidemiological studies indicate that serum cystatin C increased in human obesity. Here, we evaluated the contribution of adipose tissue to this elevation, based on our previous observation that cystatin C is produced by in vitro differentiated human adipocytes. We measured serum cystatin C in 237 nonobese (age: 51 +/- 0.8 years; BMI: 22.8 +/- 0.11 kg/m(2)) and 248 obese subjects (age: 50 +/- 0.8 years; BMI: 34.7 +/- 0.29 kg/m(2)). Creatinine-based estimated glomerular filtration rate (eGFR) was calculated to account for renal status. Cystatin C gene expression and secretion were determined on surgical adipose tissue biopsies in a distinct group of subjects. Serum cystatin C is elevated in obese subjects of both genders, independently of reduced eGFR. Cystatin C mRNA is expressed in subcutaneous and omental adipose tissue, at twice higher levels in nonadipose than in adipose cells. Gene expression and cystatin C release by adipose tissue explants increase two- to threefold in obesity. These data confirm elevation of serum cystatin C in human obesity and strongly argue for a contribution of increased production of cystatin C by enlarged adipose tissue. Because cystatin C has the potential to affect adipose tissue and vascular homeostasis through local and/or systemic inhibition of cathepsins, this study adds a new factor to the list of adipose tissue secreted bioactive molecules implicated in obesity and obesity-linked complications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / metabolism*
  • Case-Control Studies
  • Cathepsins / antagonists & inhibitors
  • Cystatin C / blood*
  • Cystatin C / genetics
  • Cystatin C / metabolism
  • Gene Expression
  • Humans
  • Obesity / blood*
  • Obesity / metabolism
  • Omentum / metabolism
  • RNA, Messenger / metabolism
  • Reference Values
  • Subcutaneous Fat / metabolism


  • Cystatin C
  • RNA, Messenger
  • Cathepsins