UAER, MDA, and 8-OHdG levels were greater, but SOD activity was reduced in DN patients with SCH compared to DN patients. UAER, MDA, and 8-OHdG levels in the LT4 group declined dramatically to levels no longer distinguishable from the euthyroid group. SOD activity rose noticeably. However, after 24 weeks of follow-up, the levels of mAlb, MDA, and 8-OHdG in the SCH group were higher than in the euthyroid group. SOD activity in the SCH group dropped considerably. This evidence concerns the gene SOD1 and spindle cell hemangioma.