The Value Of Plasma SCD40L In Predicting The Risk Of Prediabetic Vasculopathy

Objective: Cardiovascular disease accounts for three fourth death of diabetes mellitus and is often present even in prediabetic stage. The platelet activation plays an important role in atherothrombosis. Soluble CD40 ligand (sCD40L) has been proposed to be related to platelet acitivation. Therefore, the aim of this study is to analyze the level of plasma sCD40L in different glucose metabolic conditions and its association with metabolic indexes, i.e. insulin resistance index, glucose, body mass index (BMI).Methods: 105 subjects were enrolled in the study. 75g oral glucose tolerance test was undertaken with fasting and 2 hour plasma glucose (2hPG) were available. The subjects were divided into five groups: normal glucose tolerance (NGT, FPG<5.6mmol/L and 2hPG<7.8mmol/L, n=20), impaired fasting glucose (IFG, FPG≥5.6, <7.0mmol/L and 2hPG<7.8mmol/L, n=20), isolated impaired glucose tolerance (i-IGT, FPG<5.6mmol/L and 2hPG≥7.8, <11.1mmol/L, n=22), combined IFG and IGT (c-IGT, FPG≥5.6, <7.0mmol/L and 2hPG≥7.8, <11.1mmol/L, n=23), and newly diagnosed diabetic patients (NDM, FPG≥7.0mmol/L and 2hPG≥11.1mmol/L, n=20). Body weight (BW), height (H), waist circumference (WC), blood pressure (BP), body mass index (BMI) and waist-to-hip ratio(WHR) were calculated. Fasting blood samples were drawn to measure levels of triglyceride (TG), glucose, cholesterol (TC). The level of sCD40L was determined with ELISA, The level of fasting insulin (FINS) and 2 hour plasma insulin (2hINS) was measured by radio immunoassay, insulin resistance index was calculated using minimal model of homeostasis (HOMA-IR=(FPG×FINS)/22.5). The statistic analysis was performed by SPSS13.0 software. A two-tailed P<0.05 was taken as statistically significant. Results:(1) The levels of sCD40L in different glucose tolerant groups were: NGT 0.96(0.80-1.57)ng/m1, IFG 1.12(0.88-2.26)ng/m1, i-IGT 1.37 (1.02-1.60)ng/m1, c-IGT 1.40(1.08-1.78)ng/m1 and NDM 1.20(1.10-2.8 4 )ng/m1 respectively. Compared with NGT group, sCD40L levels in all the glucose intolerant groups except the IFG were significant higher (P<0.05), there were no significant difference among the three glucose intolerant groups. sCD40L level in NDM group was not different from the other three glucose intolerant groups (P>0.05).(2) sCD40L level was not correlate significantly with HOMA-IR, but positively correlated with FPG. sCD40L level was not associated with TG, TC, FINS, and BP. sCD40L was positively correlated with BMI, WHR, and WC.Conclusion: (1) The plasma sCD40L levels are higher in prediabetic group (i-IGT,c-IGT) than in NGT group, and the increased sCD40L might be one of the mechanism of the increasing incidence of cardiovascular mor- tality in prediabetes and diabetes states. (2) Increaser FPG, higher BMI, central obesity may activate platelets to release sCD40L and increase the state of coagulation. (3) Determination of sCD40L might be a useful index in predicting cardiovascular risk in diabetes mellitus.