[Diagnosis of peripheral thyroid hormone effect using sex hormone-binding globulin (SHBG) and systolic time intervals (STI)].

Only in rare cases with peripheral resistance to thyroid hormones, low T3 syndrome and inappropriate TSH secretion a laboratory determination of the effects of thyroid hormones on peripheral organs such as BMR, Achilles sinew reflex, cholesterol, SHBG, STI etc. is necessary. It was demonstrated that serum concentration of SHBG offered a clear and reliable parameter of the effects of thyroid hormones on liver cells. In a group of 31 patients with overt hyperthyroidism the level of SHBG being 136.5 nmol@l was significantly higher (p less than 0.001) than in control patients showing 36.3 nmol/l SHBG. The hypothyroid group (32 patients) showed a rather significant reduction (p less than 0.01) in SHBG level with a median of 27.5 nmol/l. Among the systolic time intervals the preejection period (PEP) and the LVET/PEP ratio were the most striking parameters. In the hyperthyroid group there was a highly significant shorter interval of PEP (p less than 0.001) and a significant rise of the LVET/PEP ratio (p less than 0.01) compared with the control patients. In the hypothyroid group a hardly perceptible extension of PEP (p less than 0.01) was observed, but a highly significant decrease of the LVET/PEP ratio (p less than 0.001) could be demonstrated.