Research On Plasma Visfatin In Metabolic Syndrome And The Association With Carotid Intima-media Thickness

Objective: Metabolic syndrome (MS) is a clustering of some clinical syndrome, which involves abdominal obesity, dyslipidemia, hypertension and abnormal glucose tolerance. It gathers various metabolic and vascular risk factors in one as a characteristic. Each of the components is the risk factor of coronary artery disease (CAD) at the same time. The more components cause the more serious conditions. At present, epidemiological data shows that MS correlated closely with CAD and atherosclerosis. The morbidity and mortality of CAD in MS increases significantly. As a metabolic abnormal status before diagnosed CAD, it may has great value for predicting the incidence and prognosis of CAD, the similar risk factors between them may be the root of the transition and progression. What is the forming mechanism of these risk factors? Adipocytokines may bring us a new consideration.Adipose tissue is a functional active endocrine organ. Recent years, mu- tiple bioactive adipocytokine has been found, such as resistin, adiponectin, omentin and so on. Visfatin, a newly recognized adipocytokine who has the insulin mimic effect was found that closely associated with vascular proliferation, inflammation,endothelial dysfunction and vulnerable plaques rupture,which is closely related to the occurrence and development of atherosclerosis.Atherosclerosis is a progressive developmental disease which affects the whole arterial system. Carotid atherosclerosis diseases happen commonly and the pathological changes may start at the same times as aortic, but much earlier than coronary. However, peripheral vascular ultrasonic technology could make intuitive evaluation of the severity.Intima-media thickness(IMT), which may used as a surface window to reflects systemic atherosclerosis, has been brought into the"European Hypertension Guidelines"as the evaluation index of subclinical organ damag- ed to predict cardiovascular events.Visfatin is considered as a pro-inflammatory cytokine to induce the expression of MMP-9, TNF-αand IL-8, these cytokines interact each other, play a significant role in atherosclerosis and instability of plaques. At the moment, research between visfatin and atherosclerosis is not more, to say nothing of the comparative study on visfatin and IMT. This study is to investigate the association of plasma visfatin with carotid intima-media thick- ness, and to explore the possibility of visfatin as a predictor of atherosclerosis, accordingly provide the basis for early clinical intervention of the risk factors of atherosclerosis.Methods: 41patients, diagnosed as MS according to the diagnostic criteria of 2005 IDF, who were hospitalized in the Cardiology Department and Endocrinology Department of the second hospital of Hebei medicine univer- sity from December 2009 to November 2010 were enrolled in this study (29 males, 12 females). Selected cases accepted carotid ultrasound after be in hospital, and then grouped according to the value of IMT. All patients were divided into IMT Normal group(IMT<1.0 mm), IMT Thickening group (1.0mm≤IMT<1.5mm) and IMT Plaques group(IMT≥1.5 mm or 50% of the surrounding IMT value or plaques encroaching into the arterial lumen at least 0.5 mm). Set another 33 cases outpatient service medical healthy crowd as a control group matching. In the next morning took blood from median cubital vein after fasting for 12 hours for testing plasma visfatin, fasting blood glucose (FBG), blood lipid and so on. All the cases were measured body height, weight, waistline and hip circumference, and then calculated BMI and WHR. All statistical analyses were performed using the SPSS 13.0 program package. Data were expressed as x±s. Data between two groups were compared by t-test, and data between multigroups were compared by single-factor analysis of variance. The relationship between visfatin, FBG, blood lipid, age, gender, BMI and IMT were analyzed by Pearson linear correlation and multiple linear stepwise regression. p<0.05 was considered statistically significant.Results:1.1 The differences of Age and gender were no significant whether in groups of MS or between MS and Controls(p>0.05).1.2 Visfatin levels in MS group was significantly higher than Controls(78.88±12.7 vs 22.36±3.22μg/L,p<0.01). After data logarithmic transformation, there were significant differences statistically in comparison between Controls and each group of MS(1.85±0.05 vs 1.30±0.06,1.89±0.07 vs 1.30±0.06,1.93±0.04 vs 1.30±0.06,p<0.05). Within MS group, the visfatin levels raised with the increase of carotid lesion severity, there were significant differences between Normal and Plaque(s1.85±0.05 vs 1.93±0.04,p<0.05), but the differences did not appear between Normal and Thickening, Thickening and Plaques(p>0.05).1.3 Carotid IMT in MS group was significantly higher than Controls(1.12±0.22 vs 0.78±0.15 mm,p<0.01). Within MS group, each group was significantly higher than Controls except for Normal group(1.16±0.16 vs 0.78±0.15 mm,1.37±0.12 vs 0.78±0.15 mm,p<0.05; 0.87±0.12 vs 0.78±0.15 mm,p>0.05). The IMT values increased gradually within MS group and there were significant differences statistically in comparison between any two groups: Normal and Thickening(0.87±0.12 vs 1.16±0.16 mm,p<0.05), Normal and Plaques(0.87±0.12 vs 1.37±0.12 mm,p<0.05), Thickening and Plaques (1.16±0.16 vs 1.37±0.12 mm,p<0.05).1.4 The differences of TG, TC and LDL in comparison between MS and Controls were significant(TC:5.06±0.47 vs 4.21±0.51mmol/L,TG:1.76±0.44 vs 1.17±0.26mmol/L,LDL:2.87±0.48 vs 2.54±0.41mmol/L,p<0.01). Compared with Controls,HDL levels of MS group decreased obviously, there were differences with high significant(1.42±0.14 vs 1.09±0.22 mmol/L,p<0.01). The levels of TG and TC increased gradually within MS group(TC:4.73±0.41,5.12±0.46,5.39±0.29mmol/L;TG:1.49±0.45,1.83±0.31,1.99±0.56mmol/L), differences were both significantly in comparison of Control(sp<0.05). Groups compared with each other in MS, except for Thickening and Plaques(TC:5.12±0.46 vs 5.39±0.29 mmol/L,TG:1.83±0.31 vs 1.99±0.56 mmol/L,p>0.05), differences of any two compared were significant(p<0.05). In addition, compared with Controls, there were significant differences of the LDL levels for Thickening group and Plaques group(2.90±0.51 vs 2.54±0.41mmol/L,3.12±0.34 vs 2.54±0.41mmol/L,p<0.05). But for Normal group, differences with no significant(2.66±0.44 vs 2.54±0.41mmol/L,p>0.05). Within MS group, there were only significant differences between Normal and Plaques(2.66±0.44 vs 3.12±0.34mmol/L,p<0.05). However, the levels of HDL decreased with the severity of carotid lesion, each one of MS compared with another, differences were no significant; but compared with Controls, the differences were statistically significan(t1.14±0.13 vs 1.42±0.14mmol/L,1.09±0.25 vs 1.42±0.14mmol/L,0.99±0.20 vs 1.42±0.14mmol/L,p<0.05).1.5 Other indexes, including SBP, DBP, FBG, BMI and WHR, MS group were much higher than Controls and with differences significant(p<0.01), but there were no significant differences between any groups of MS in SBP, DBP, FBG and BMI. Finally, compared with Controls, differences of WHR were significant(p<0.01), but in MS group, each one compared with another, differences reached the statistically criteria except for the comparison between Thickening and Normal(0.87±0.07 vs 0.85±0.08,p>0.05).2.1 After data logarithmic transformation for Normality and homogeneity, linear correlation revealed that visfatin, TG, WHR, SBP and Age were significant positively associated with carotid IMT, p<0.05, r=0.369, 0.319, 0.325, 0.310, 0.327.2.2 Multiple linear stepwise regression analysis showed that visfatin, TG and Age entered the regression equation: IMT=-2.268+1.342 lg(visfatin)+0.192 TG+ 0.009Age. Standardized regression coefficients were: 0.417, 0.375, 0.317, which suggested that in the factors mentioned above, visfatin has the greatest effect on IMT.Conclusion:1 Visfatin levels in MS group were significantly higher than that of Controls, and raised with the increasing severity of carotid lesion. visfatin were significant positively associated with carotid IMT, in addition, the differences of visfatin between Normal and Controls have reached the significant criteria, but the differences of IMT have not appeared yet. It suggested that the change of plasma visfatin was much earlier than that of carotid IMT, which might be involved in the formation of the early atherosclerosis.2 Age, WHR, TG, SBP and visfatin were significantly positively associated with carotid IMT, which hinted that these factors may take part in MS patients suffering from atherosclerosis.3 Multiple linear stepwise regression analysis showed that visfatin, TG and Age were factors affecting the severity of carotid lesion, it seemed that visfatin had the greatest influence on carotid atherosclerosis, and it may be used as an important indicator of predicting early atherosclerosis.