Published in:
01-06-2012 | Article
Soluble CD163: a biomarker linking macrophages and insulin resistance
Authors:
T. Parkner, L. P. Sørensen, A. R. Nielsen, C. P. Fischer, B. M. Bibby, S. Nielsen, B. K. Pedersen, H. J. Møller
Published in:
Diabetologia
|
Issue 6/2012
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Abstract
Aims/hypothesis
Soluble CD163 (sCD163) was recently identified as a strong risk marker for developing type 2 diabetes. We hypothesised that sCD163 independently associates with insulin resistance.
Methods
This cross-sectional study includes 234 participants: 96 with type 2 diabetes, 34 with impaired glucose tolerance (IGT) and 104 with normal glucose tolerance (NGT), matched for sex and BMI. Glucose-lowering medication was paused for 1 week before plasma samples were obtained for determination of sCD163 and other inflammatory and metabolic variables. Insulin resistance was estimated by homeostasis model assessment of insulin resistance (HOMA-IR).
Results
Concentrations of sCD163 were 1.95 mg/l (0.63–6.97) in individuals with type 2 diabetes, 1.64 mg/l (0.58–4.19) in those with IGT, and 1.48 mg/l (0.48–4.11) (median [range]) in those with NGT (p < 0.0001). In univariate analyses, sCD163 correlated significantly with HOMA-IR (R = 0.44), insulin (R = 0.41), glucose (R = 0.30), triacylglycerol (R = 0.29) and HDL-cholesterol (R = −0.34) (all p < 0.0001). All but glucose remained significant when adjusting for age, sex, BMI and glycaemic group. In univariate regression analyses, HOMA-IR was associated with sCD163, C-reactive protein (CRP), TNF-α and IL-6 (all p ≤ 0.0001). An increase of 50% in sCD163 resulted in an estimated increase in HOMA-IR of 36% (95% CI 26, 48; p < 0.0001). In multiple linear regression analyses, sCD163 (p = 0.001) and CRP (p = 0.01) remained independent predictors of HOMA-IR, whereas TNF-α and IL-6 did not.
Conclusions/interpretation
Macrophage-specific sCD163 was strongly associated with insulin resistance independently of TNF-α and other predictors. Moreover, sCD163 was associated with well-known variables of the metabolic syndrome.