Ultrasongraphyic Study On Elasticity Of Common Carotid Artery In Patients With Graves Hyperthyroidism

ObjectiveWith the echo-tracking(E-Tracking) technology, we attempt to determine the carotidstiffness and compliance in Graves deisease(GD) patients,and to explore the relationshipbetween carotid elasticity and clinical conditions.MethodsA total of45patients with Graves disease,hospitalized in Department ofEndocrinology,PLA88th hospital from July2010to December2011,were selected ashyperthyroidism group,in whom there were30cases were reexamined3months aftertreatment.40healthy subjects from physical examination were chosen as normal controlgroup.A set of examinations were carried out to remove thyroid diseases,hypertension andserious heart,liver or kidney diseases.With chemiluminescence method,we observed serumTT3、TT4、FT3、FT4、TSH of all subjects.The intima media thickness(IMT),the percentageof detection of arterial plaque and haemodynamic indexes of the superior thyroid arterywere tested by carotid sonography.Using E-Tracking technique,the carotid artery elasticindexes Ep, β,and AC in45GD patients and40healthy subjects were calculated andanalyzed.To record the symptoms,physical signs,disease course,nuclear examinationresults etc. of Graves patients before and after treatment.45GD patients were divided intodifferent groups according to the extent of thyroid goiter and the sevetity ofhyperthyroidism. The differences among the groups were compared with the one-wayANOVA.The correlation between the parameters of carotid artery and the course ofhyperthyroidism was analyzed with liner correlation analysis.Meanwhile,the changes ofsymptoms,the blood flow velocity of superior thyroid artery and the carotid artery elasticindexes were monitored before and after treatment.Results (1)The systolic blood pressure,the pulse pressure and the heart rate in hyperthyroidismgroup and normal control group were124±12mmHg VS112±17mmHg、47±9mmHg VS36±7mmHg and90±13/min VS67±8/min respectively.The level of the three parameters inhyperthyroidism group were obviously higher than that in controlgroup(P<0.01).Compared with control group,the diastolic blood pressure inhyperthyroidism group was significantly lower(62±11mmHg VS74±8mmHg,P<0.05).(2)No obvious difference was noted between the two groups in the IMT of carotidartery(0.70±0.15mm VS0.68±0.12mm, P>0.05).The elastic parameters of Ep， βsignificantly increased (117.97±28.70kPa VS93.56±32.87kPa、9.13±2.04VS6.70±2.12)while AC descended obviously (0.58±0.17mm2/kpa VS0.75±0.20mm2/kpa) comparedwith control group.(3)Correlative analysis showed that there was a remarkable positive correlationbetween Ep, β and FT3respectively(r=0.515,0.549,P<0.01),and a negative correlationbetween AC and FT3(r=-0.428，P<0.05).A weak correlation between elastic parameters andFT4was found in hyperthyroidism group(r=0.312,0.375,-0.262,P<0.05). But they had noobvious correlation with serum TSH(r=0.026，0.159，-0.047, P>0.05).(4) GD patients were divided into different subgroups according to the extent ofthyroid goiter and the sevetity of hyperthyroidism,respectively.There was no difference ofEp,β and AC between different subgroups.A remarkable correlation was found between thethree parameters and the disease course(r=0.618,0.490,-0.413,P<0.01).(5)After treatment, the blood flow velocity of superior thyroid artery and the clinicalsymptom score obviously descended(P<0.01),but Ep,β and AC did not changeapparenthly(P>0.05).Conclusion(1)The arterial elasticity decreased and the vascular endothelial function was hurt inGraves hyperthyroidism patients.(2) There was a positive correlation between Ep, β and FT3,FT4,and a negativecorrelation between AC and FT3, FT4, respectively.(3) The extent of thyroid goiter and the severity of hyperthyroidism may have noeffect on carotid elasticity.But the longer the disease course is,the worse the arterialelasticity may be.(4)The change of the arterial elasticity is formed under the long-term pathologicalstate,Its recovery time is later than the change of hemodynamics. So GD patients should be treated early and actively.(5)Echo-Tracking technology can reflect the vascular endothelial function earlier.Itis simple and reliable as a noninvasive method in evaluating the arterial elasticity forGraves hyperthyroidism patients.