Relationships of plasma interleukin-18 concentrations to hyperhomocysteinemia and carotid intimal-media wall thickness in patients with type 2 diabetes.
OBJECTIVE
We compared plasma interleukin (IL)-18 concentrations in patients with type 2 diabetes with those in age-matched control subjects and investigated whether plasma IL-18 was associated with plasma total homocysteine (tHcy) concentration or carotid intimal-media wall thickness (IMT), an early marker of atherosclerosis, in these patients.


METHODS
We measured plasma IL-18 in 103 type 2 diabetic patients and 45 age-matched control subjects. We also measured patients' plasma tHcy and serum high-sensitivity C-reactive protein (hs-CRP). IMT was evaluated for both common carotid arteries.


RESULTS
Plasma IL-18 was significantly higher in diabetic patients than in control subjects (203 +/- 153 vs. 118 +/- 37 pg/ml, P < 0.001). High IL-18 was defined as equaling or exceeding the mean + 2 SD of plasma IL-18 in control subjects (192 pg/ml). Patients with high IL-18 showed a greater carotid IMT than those with normal IL-18. Carotid plaques were more numerous in diabetic patients with high IL-18 than in those with normal IL-18. Plasma tHcy concentrations were significantly higher in patients with high IL-18 than in those with normal IL-18. Univariate and multivariate analyses showed a strong independent association between tHcy and IL-18. Plasma IL-18 also correlated positively with serum hs-CRP.


CONCLUSIONS
In patients with type 2 diabetes, plasma IL-18 concentrations are greater than in nondiabetic subjects. Plasma IL-18 is an independent determinant of plasma tHcy, which is linked independently with atherosclerotic carotid wall thickening.
Aso
Yoshimasa
Y
Department of Internal Medicine, Koshigaya Hospital, Dokkyo University School of Medicine, Koshigaya, Saitama, Japan. yaso@dokkyomed.ac.jp
Okumura
Ki-Ichi
K
Takebayashi
Kohzo
K
Wakabayashi
Sadao
S
Inukai
Toshihiko
T
D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D002339:Carotid Arteries / Q000473:pathology*; D016893:Carotid Stenosis / Q000097:blood*; D002784:Cholesterol / Q000097:blood; D003404:Creatinine / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D003925:Diabetic Angiopathies / Q000097:blood; D006710:Homocysteine / Q000097:blood; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood*; D020382:Interleukin-18 / Q000097:blood*; D008875:Middle Aged; D012016:Reference Values; D017539:Tunica Intima / Q000473:pathology*; D017540:Tunica Media / Q000473:pathology*
D015415:Biomarkers; D020382:Interleukin-18; D006710:Homocysteine; D002097:C-Reactive Protein; D002784:Cholesterol; D003404:Creatinine