Loss of renal function is associated with high mortality from cardiovascular disease (CVD). Patients with chronic kidney disease (CKD) have altered circulating adipokine and non-esterified fatty acid concentrations and insulin resistance, which are features of disturbed adipose tissue metabolism. Since dysfunctional adipose tissue contributes to the development of CVD, we hypothesize that adipose tissue dysfunctionality in patients with CKD could explain, at least in part, their high rates of CVD. Therefore we characterised adipose tissue from patients with CKD, in comparison to healthy controls, to search for signs of dysfunctionality.
Biopsies of subcutaneous adipose tissue from 16 CKD patients and 11 healthy controls were analysed for inflammation, fibrosis and adipocyte size. Protein composition was assessed using two-dimensional gel proteomics combined with multivariate analysis.
Adipose tissue of CKD patients contained significantly more CD68-positive cells, but collagen content did not differ. Adipocyte size was significantly smaller in CKD patients. Proteomic analysis of adipose tissue revealed significant differences in the expression of certain proteins between the groups. Proteins whose expression differed the most were alpha-1-microglobulin/bikunin precursor (AMBP, higher in CKD) and vimentin (lower in CKD). Vimentin is a lipid droplet-associated protein and changes in its expression may impair fatty acid storage/mobilisation in adipose tissue, while high levels of AMBP may reflect oxidative stress.
These findings demonstrate that adipose tissue of CKD patients shows signs of inflammation and disturbed functionality, thus potentially contributing to the unfavourable metabolic profile and increased risk of CVD in these patients.
- chronic kidney disease
- adipose tissue
- cardiovascular disease
- alpha-1-microglobulin/bikunin precursor