Objective: The aim of this study was to determine the relation of plasma interleukin-12 (IL-12) concentration to major risk factors of atherosclerosis and other personal characteristics in well-documented, stable ischaemic heart disease (IHD) patients. The hypothesis was that IL-12 is positively associated with inflammatory markers and risk factors of atherosclerosis.
Materials and methods: Clinical data were collected from 51 IHD patients by a questionnaire and from basic laboratory blood tests. The association of IL-12 with the biochemical, personal, health status and lifestyle determinants was investigated by regression analysis and analysis of variance.
Results: Plasma IL-12 concentration was associated inversely with the plasma concentration of triglycerides (P=0.001) and homocysteine (P=0.04). However, IL-12 was associated directly with the concentration of high-density lipoprotein cholesterol (P=0.03). IL-12 concentration was not strongly associated with other biochemical parameters nor with the health status, medication or lifestyle determinants.
Conclusion: The results suggest that, contrary to the hypothesis, IL-12 was associated inversely with plasma levels of two known risk factors of coronary atherosclerosis (triglycerides, homocysteine) in stable, statin-medicated IHD patients. The lack of association of IL-12 with high-sensitivity C-reactive protein, erythrocyte sedimentation rate and the number of inflammatory cells in blood suggests that moderately elevated IL-12 did not imply ongoing systemic inflammation in these patients. Although increased IL-12 production is a sign of proinflammatory activity, it was associated directly with the plasma high-density lipoprotein cholesterol concentration. Overall, moderately elevated plasma IL-12 concentration may even be a good sign in stable IHD patients.
aKymenlaakso Hospital Services, Laboratory of Clinical Chemistry
bKymenlaakso University of Applied Sciences, Technology
cDepartment of Social and Health Care, Kymenlaakso University of Applied Sciences
dDepartment of Internal Medicine, Kymenlaakso Central Hospital, Kotka
eDepartment of Environmental Health, National Institute for Health and Welfare (THL)
fDepartment of Environmental Science, University of Eastern Finland, Kuopio, Finland
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Correspondence to Iiris Salonen, MD, PhD, Kymenlaakso Hospital Services, Laboratory of Clinical Chemistry, Kotkantie 41, Kotka FI-48220, Finland Tel: +358 20633 3202; fax: +358 20633 5518; e-mail: email@example.com
Received August 12, 2013
Accepted February 3, 2014