An analysis of the relative risk for hypothyroidism in patients with Type 2 diabetes

AIMS: We aimed to assess the relative risk for hypothyroidism in patients with Type 2 diabetes. METHODS: In this study, 1112 patients with Type 2 diabetes (58% women, mean age 66.7 years, median duration of diabetes 10 years, 179 with previous history of thyroid disease) and 911 subjects without diabetes were evaluated. RESULTS: The gender-, age- and weight-adjusted relative risk (odds ratio) of newly identified hypothyroidism in patients with Type 2 diabetes in comparison with control subjects was 2.81 (1.77-4.48). This odds ratio was significant in patients over 65 years [4.02 (1.95-8.31)], as well as in both men [4.84 (1.58-14.80)] and women [2.60 (1.54-4.38)], in obese patients [2.56 (1.36-4.82)] and non-obese patients [3.11 (1.56-6.20)] and in individuals with [4.26 (1.73-10.46)] and without [2.93 (1.50-5.75)] thyroid autoantibodies. Logistic regression analysis showed that newly diagnosed hypothyroidism was significantly and directly related not only with thyroid autoimmunity [19.15 (8.73-42.01)], but also with the presence of macroangiopathy [2.85 (1.51-5.35)] and metformin treatment [2.51 (1.28-4.92)]. CONCLUSIONS: Our results favour screening for hypothyroidism in patients with Type 2 diabetes older than 65 years, especially in the presence of diabetic macroangiopathy or treatment with metformin.