TPO and type 2 diabetes mellitus: NAFLD: non-alcoholic fatty liver disease; TSH: thyroid-stimulating hormone; T4: thyroxine; FT4: free thyroxine; TT4: total thyroxine; T3: triiodothyronine; TT3; total triiodothyronine; TPOAb: thyroid peroxidase antibody; TGAb: thyroglobulin antibody; SCH: subclinical hypothyroidism; OHT: overt hypothyroidism; T2DM: type 2 diabetes mellitus