Pituitary Thyroid Hormone Resistance Syndrome With Diabetes Mellitus:A Research Report

Background:Thyroid hormone resistance syndrome(THRS)is a disorder characterized by targeted tissues hyposensitivity to thyroid hormone.According to the sites where thyroid hormone resistance occurs,THRS can be categorized into global resistance to thyroid hormone(GRTH),pituitary resistance to thyroid hormone(PRTH),and peripheral resistance to thyroid hormone(PrRTH).Patients with PRTH demonstrate mainly mild to moderate hyperthyroidism.Most of THRS is caused by thyroid hormone receptor(THR)β gene mutation.Thyroid disorders and diabetes mellitus are the most common endocrine and metabolic diseases.Thyroid hormones play an important role in the regulation of the glucose metabolism.Impaired glucose tolerance and overt diabetes mellitus have frequently been associated with hyperthyroidism.In this study,we detect the THR genes of the male patient with clinical manifestation of PRTH and diabetes mellitus and explore the interactions between these two orders.Methods:A 50-year-old man was referred to our hospital for repeated palpitations for eight months.The clinical database of the patient was collected,thyroid hormone levels,oral glucose tolerance test(OGTT),insulin release test and pituitary imaging examination were performed.Collect the peripheral blood samples of the patient and then extract genomic DNA.PCR amplification of 1~10 exons of THRβ gene and2~10 exons of THRα gene,purification of products,and directly DNA sequencing were carried out.Result:Physical examination of the patient included: thyroid enlargement(degree I),soft and several nodules,no tenderness,tremor or vascular murmur;heart rate 120beats/min,no arrhythmias,no edema in lower extremities,with hands shaking(+).Laboratory investigation showed free triiodothyronine(FT3)and free thyroxin(FT4)levels higher than the upper normal limits with non-suppressed thyroid stimulatinghormone(TSH).Pituitary magnetic resonance imaging(MRI)showed no evidence of tumor.OGTT and insulin release test indicated diabetes mellitus with insulin resistance(IR),and thus anti-diabetes drugs were administered to the patient.No mutation was found in coding sequences of THRβ and THRα gene.Conclusions:The patient was diagnosed with PRTH whose THR gene mutations were not found,and further investigations are needed to ascertain anomalies in THR cofactors.In addition,we explore the interactions between RTH and IR,and suggest that the glucose metabolism should be investigated in all THRS patients.