Adipokines, insulin resistance, and coronary artery calcification.
OBJECTIVE
We evaluated the hypothesis that plasma levels of adiponectin and leptin are independently but oppositely associated with coronary artery calcification (CAC), a measure of subclinical atherosclerosis. In addition, we assessed which biomarkers of adiposity and insulin resistance are the strongest predictors of CAC beyond traditional risk factors, metabolic syndrome, and plasma C-reactive protein (CRP).


BACKGROUND
Adipokines are fat-secreted biomolecules with pleiotropic actions that converge in diabetes and cardiovascular disease.


METHODS
We examined the association of plasma adipocytokines with CAC in 860 asymptomatic, nondiabetic participants in the SIRCA (Study of Inherited Risk of Coronary Atherosclerosis).


RESULTS
Plasma adiponectin and leptin levels had opposite and distinct associations with adiposity, insulin resistance, and inflammation. Plasma leptin was positively (top vs. bottom quartile) associated with higher CAC after adjustment for age, gender, traditional risk factors, and Framingham risk scores (tobit regression ratio 2.42 (95% confidence interval [CI]: 1.48 to 3.95; p = 0.002) and further adjustment for metabolic syndrome and CRP (tobit regression ratio: 2.31; 95% CI: 1.36 to 3.94; p = 0.002). In contrast, adiponectin levels were not associated with CAC. Comparative analyses suggested that levels of leptin, interleukin-6, and soluble tumor necrosis factor receptor-2, as well as the homeostasis model assessment of insulin resistance (HOMA-IR) index, predicted CAC scores, but only leptin and HOMA-IR provided value beyond risk factors, metabolic syndrome, and CRP.


CONCLUSIONS
In SIRCA, although both leptin and adiponectin levels were associated with metabolic and inflammatory markers, only leptin was a significant independent predictor of CAC. Of several metabolic markers, leptin and the HOMA-IR index had the most robust, independent associations with CAC.
Qasim
Atif
A
Cardiovascular Institute and Institute for Translational Medicine and Therapeutics, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA.
Mehta
Nehal N
NN
Tadesse
Mahlet G
MG
Wolfe
Megan L
ML
Rhodes
Thomas
T
Girman
Cynthia
C
Reilly
Muredach P
MP
D054392:Adipokines / Q000097:blood*; D050154:Adiposity; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D002114:Calcinosis / Q000097:blood*; D003324:Coronary Artery Disease / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D020738:Leptin / Q000097:blood; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood*; D008875:Middle Aged; D018570:Risk Assessment; D012307:Risk Factors
D054392:Adipokines; D015415:Biomarkers; D020738:Leptin; D002097:C-Reactive Protein