Relationship And Mechanism Of Diabetic Cardiovascular Disease And Subclinical Disease

Part 1 Association of sICAM-1 with β-cell function in elderly type 2 diabetic patients with subclinical hypothyroidismObjective:To investigate the relationship between sICAM-1 and β-cell function in elderly type 2 diabetic patients with subclinical hypothyroidism.Methods:241 patients with type 2 diabetes were divided into subclinical hypothyroidism group and euthyroid group.Weight,height,blood pressure(BP),fasting plasma glucose(FPG),fasting insulin(FINS),FT3,FT4,TSH,HBAlc and sICAM-1 were determined in all patients.Homeostasis model assessment for insulin index(HOMA-IR),homeostasis model assessment for p-cell function index(HOMA-β),and insulin sensitivity index(ISI)were calculated.Results:Compared with euthyroid group,the level of FINS,HOMA-IR,sICAM-1 in subclinical hypothyroidism group were higher.TSH was positively associated with HOMA-IR,negatively associated with HOMA-Pand ISI.sICAM-1 was positively associated with HOMA-IR,negatively associated with HOMA-βand ISI.Conclusion:With increasing sICAM-1 level,insulin resistance increased and β-cell function decreased in elderly type 2 diabetic patients with subclinical hypothyroidism.Part 2 Vascular endothelial dysfunction and its relationship with levels of hypersensitive-C reactive protein and interleukin-6 in elderly type 2 diabetic patients with subclinical hypothyroidism Objective:To explore the relationship between vascular endothelial dysfunction and levels of hypersensitive-C reactive protein(hs-CRP)and interleukin-6(IL-6)in type 2 diabetic patients with subclinical hypothyroidism.Methods:The frequency color Doppler imaging was used to detect the endothelium-dependent FMD in 241 elderly type 2 diabetic patients with subclinical hypothyro-idism,levels of hs-CRP and IL-6 were tested.Results:(1)These two groups had no significant difference in term of risk factors including histories of smoking,hypertension,coronary heart disease(P<0.05).(2)FMD decreased while levels of hs-CRP and IL-6 increased in type 2 diabetic patients with subclinical hypothyroidism compared with those without subclinical hypothyroidism.(3)In type 2 diabetic patients with subclinical hypothyroidism group,FMD was negatively correlated with TSH,TG,TC,hs-CRP and IL-6(P<0.01).(4)Multiple regression analysis showed that,after adjusting other risk factors,the negative correlation between FMD and TSH still existed[P<0.01,OR=0.352,95%CI(0.217,0.694)],hs-CRP was negatively correlated with FMD[P<0.01,OR=0.239,95%CI(0.170,0.482)],and so was IL-6[P<0.01,OR=0.416,95%CI(0.221,0.753)].Conclusion:Subclinical hypothyroidism induced vascular endothelial damage in type 2 diabetic patients,and inflammation may be involved in the pathogenesis of vascular endothelial dysfunction.Part3 Effect of metformin on the thyroid axis hormones in type 2 diabetic patientsObjective:To assess the interplay between metformin treatment and thyroid function in type 2 diabetic patients.Methods:The effects of metformin on thyroid axis hormones were assessed in diabetic patients with primary hypothyroidism who were either untreated or treated with levothyroxine(L-T4),as well as in diabetic patients with normal thyroid function.Result:After one year of metformin administration,a significant thyrotropin(TSH)decrease was observed in diabetic subjects with hypothyroidism who were either treated or untreated with L-T4,but not in euthyroid subjects.No significant change in free T4 was observed in any group.Conclusions:Metformin administration influences TSH without change of FT4 in patients with type 2 diabetes and concomitant hypothyroidism.