Diurnal variation in ultrasonographic dimensions of thyroid gland

Day-night variations in thyroid stimulating hormone and its relation with clinical status and metabolic parameters in patients with cirrhosis of the liver

To investigate day-night variations in thyroid stimulating hormone (TSH) and its relation with clinical status and metabolic parameters in patients with cirrhosis. Forty-one patients with negative thyroid antibodies and normal thyroid function tests who were diagnosed with cirrhosis were included. Thirty-five age- and gender-matched healthy subjects were included in control group.TSH, fT3, and fT4 levels, which were measured both in the morning and late evening. The difference between nocturnal TSH and morning TSH (ΔTSH) were compared between groups. Relation between Child-Turcotte-Pugh, model for End-Stage Liver Disease (MELD) and MELD-Na scores and levels of thyroid hormones, ΔTSH and serum sodium (Na) levels was investigated. Relation between ΔTSH and clinical status and metabolic parameters was also evaluated. The mean morning fT3, nocturnal fT3, nocturnal TSH, and ΔTSH levels were significantly lower, morning and nocturnal fT4 levels were higher in patients with cirrhosis (p<0.001, p<0.001, p=0.004, p<0.001, and p<0.001). As the ROC analysis, day-night variation was detected to be impaired in the event that difference between nocturnal TSH level and morning TSH level was lower than 1 uIU/mL in patients with cirrhosis with a sensitivity of 92.7% and specificity of 71.4% (p<0.001).A significant positive correlation was found between serum Na levels and fT3 in patients with cirrhosis (r=0.479, p=0.001), and a significant negative correlation was found between the severity of clinical status and low levels of fT3 in patients with cirrhosis (p<0.001).Nocturnal TSH increase does not occur in cases of cirrhosis without known thyroid disease and with normal thyroid function tests, which may be an early finding of impaired thyroid functions in patients with cirrhosis.