RESUMO
Objective: To study the characteristics and clinical appearence of polymyositis (PM ) or dermatomyositis (DM)combined with thyroid diseases,and to analyze the clinical significance.Methods:Total 77 patients first diagnosed as PM or DM were selected.All the patients were divided into four groups according to their thyroid functions,which were normal thyroid function group,low T3 syndrome group,hypothyroidism group, and subclinical hypothyroidism group.Their clinical manifestations,laboratory features,immunological examination results and prognosis were collected and analyzed.Results:In all the PM/DM patients,there were 41 cases with thyroid disfunction, including 17 cases (41.46%)with low T3 syndrome (41.46%).Compared with normal thyroid function group,the patients in hypothyroidism group were more vulnerable to dysphagia and edema (P <0.05);the proportion of proteinuria was also significantly increased (P <0.05).The PM/DM patients with low T3 syndrome were more easier to have higher incidence of death,higher level of C-reactive protein and lower levels of albumin and calciumion as well as higher incidence of edema and pleural effusion (P < 0.05 ).Conclusion:The incidence of PM/DM combined with thyroid disfunction is higher,and low T3 syndrome is most common.The PM/DM patients with hypothyroidism and low T3 syndrome are more likely to suffer the digestive system,lung and kidney injuries.The patients with low T3 syndrome have a higher death rate.