Interleukin-18 levels are associated with low-density lipoproteins size.
BACKGROUND
Both low-density lipoproteins (LDL) size and serum interleukin (IL)-18 levels have been shown to be predictors of cardiovascular morbidity and mortality. However, it is still unknown whether IL-18 levels are independently associated with LDL size.


METHODS
In this cross-sectional study including 53 premenopausal women (18-45 years), LDL size (by gradient gel electrophoresis), serum IL-18, high-sensitivity C-reactive protein (hs-CRP), serum lipids, insulin sensitivity (S(I), by frequently sampled intravenous glucose tolerance test) were measured.


RESULTS
LDL size correlated with IL-18 (r = -0.38, P = 0.006), hs-CRP (r = -0.40, P = 0.003), S(I) (r = 0.36, P = 0.011), serum triglycerides (r = -0.32, P = 0.018) and high-density lipoproteins (HDL)-cholesterol (r = 0.40, P = 0.003). When these variables were entered into a regression model, serum IL-18 (beta = -0.26, P = 0.04), triglycerides (beta = -0.29, P = 0.02) and HDL-cholesterol (beta = 0.34, P = 0.01) levels were independently associated with LDL size, accounting for 42% of the variance (P < 0.001). Serum hs-CRP levels and S(I) were not significant independent predictors of LDL size in this model.


CONCLUSIONS
This is the first report showing that elevated IL-18 levels are associated with reduced LDL size, independent of other inflammatory and metabolic risk factors. Future prospective studies are needed to evaluate the predictive role of IL-18 as an inflammatory marker of LDL size and the development of subclinical and/or clinical atherosclerosis.
Berneis
K
K
University Hospital Zurich, Zurich, Switzerland.
Rizzo
M
M
Evans
J
J
Rini
G B
GB
Spinas
G A
GA
Goedecke
J H
JH
D000293:Adolescent; D000328:Adult; D002097:C-Reactive Protein / Q000032:analysis; D002318:Cardiovascular Diseases / Q000097:blood* / Q000209:etiology; D002784:Cholesterol / Q000097:blood; D003430:Cross-Sectional Studies; D004587:Electrophoresis, Agar Gel; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D020382:Interleukin-18 / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood*; D008875:Middle Aged; D014280:Triglycerides / Q000097:blood; D055815:Young Adult
D020382:Interleukin-18; D008077:Lipoproteins, LDL; D014280:Triglycerides; D002097:C-Reactive Protein; D002784:Cholesterol