Introduction: Iodine containing thyroid hormones regulate a variety of biochemical reactions in almost all tissues of the body. These hormones are known to be important factors in regulating gene expression in tissues such as the brain, liver, muscle, and adipose tissue. Several studies have shown that thyroid hormones regulate the activity of the Glucose-6-Phosphate Dehydrogenase (G6PD) enzyme, and this study aimed to investigate the relationship between the plasma levels of TSH and Free T4 hormones and the activity of the G6PD enzyme in adults.
Methods: In this cross-sectional study, blood samples were taken from 120 subjects referred to Shahid Motahari Clinic and also hospitalized in Shahid Dastgheib Hospital in Shiraz between July 2019 and August 2020, consisting of 60 individuals with glucose-6-phosphate dehydrogenase deficiency and 60 individuals with normal glucose-6-phosphate enzyme activity, and their plasma levels of thyroid enzymes TSH and free T4 were measured. Finally, the results were statistically analyzed using SPSS software.
Results: The mean plasma TSH level in individuals with normal G6PD enzyme activity was 3.46 ± 2.14 and in individuals with G6PD enzyme deficiency it was 4.09 ± 2.27. This difference in mean plasma TSH level between the two groups of patients and healthy individuals was not statistically significant. The difference in mean plasma free T4 level between individuals with normal G6PD enzyme activity and individuals with this enzyme deficiency was very small; so that the plasma free T4 level in normal individuals was 11.68 ± 1.61 and in patients was 11.66 ± 1.90, which was not statistically significant.
Discussion & Conclusion: This study showed that the plasma TSH level in individuals with G6PD deficiency was higher than in individuals with normal G6PD enzyme activity and the plasma free T4 level was slightly lower than in individuals with normal G6PD enzyme activity; Although these differences were not statistically significant, this study showed for the first time in Iran that there is no significant relationship between thyroid hormone levels and the G6PD enzyme