Comparison of TSH Levels From Several Types Of Blood Collection Device and Description of TSH Levels Based on Gender and Age

Thyroid-stimulating hormone (TSH) is an important parameter in diagnosing thyroid disease, using serum according to World Health Organization’s (WHO) recommendations. The use of plasma can help improving turnaround time (TAT) but the discrepancy with serum is unknown. A cross-sectional study using 89 blood samples was done to compare TSH levels using serum tubes with clot activator (Tube I), plasma tubes with heparin (Tube II), and plasma tubes with heparin-gel separator (Tube III); and to show an overview of TSH levels according to gender and age. The median TSH levels in tubes I, II, and III were 1.380 (0.032-7.420) µIU/mL, 1.380 (0.030-7.480) µIU/mL, and 1.360 (0.030-7.460) µIU/mL respectively. There were no statistically significant differences in TSH levels of the three tubes. The median TSH levels differences of tubes II and III compared to tube I were -0.9% (-7.2 - 2.2) and -1.7% (-8.0 - 1.6) respectively. Biases of the measurement results obtained were in accordance with the spesicified desirable bias according to Ricos. The median TSH levels of the male and female groups was 1.500 (0.032-4.250) µIU/mL and 1.345 (0.058-7.420) µIU/mL respectively. Median TSH levels of 31-40 years old age group and >61 years old age group were 1.190 (0.609-3.240) µIU/mL and 1.730 (0.088-5.760) µIU/mL respectively. Specimens from three tubes could be used to examine TSH levels. Measurement of TSH levels showed higher median in the male and older group.