The Relationship of Thyroid Functions With ADMA, IMA, and Metabolic Laboratory Parameters in Euthyroid Adults With and Without Autoimmune Thyroiditis

Abstract

Objective To investigate the relationship between thyroid functions and asymmetric dimethylarginine (ADMA), ischemia-modified albumin (IMA), and other metabolic laboratory markers in euthyroid adults and whether narrower thyroidal targets are required for lower metabolic risk. Materials and Methods Thyroid functions, antithyroid autoantibodies, and metabolic parameters were measured for 115 patients. Forty-seven had autoimmune thyroiditis (AIT). Analyses were performed according to cutoff values of 1, 2, 2.5, and 3 mIU/L for thyrotropin, 0.84 ng/dL for free thyroxine (fT(4)), and 3.59 ng/dL for free tri-iodothyronine (fT(3)). Results There was no relationship between thyrotropin and fT(3) cutoff values and metabolic parameters. Only C-reactive protein was lower in the group with thyrotropin <= 2.5 mu IU/L. A weak positive correlation was found between fT(4) with IMA and IMA corrected for albumin (r = 0.187, P = .05; r = 0.204, P = .034, respectively). There was no difference between AIT and the metabolic laboratory parameters examined in the study. Conclusion This study is the first to evaluate ADMA in AIT. Narrower thyroid function targets are not required for better metabolic control in euthyroid adults.