The rate of primary hypothyroidism in diabetic patients is greater than in the non-diabetic population. An observational study

Background and objective: The aim of our study was to identify the rate of diabetic patients treated for hypothyroidism and compare them with a group without type 2 diabetes mellitus (T2DM). Patients and methods: We reviewed the computerized clinical records of 5161 patients. We identified diabetic patients treated with L-thyroxine. We compared the prevalence of PH with those patients under treatment with levothyroxine without T2DM. We excluded patients with a thyroid neoplasia, thyroid surgery, panhypopituitarism, or surgical complications of multinodular goiter or a thyroid nodule. Subclinical hypothyroidism was not considered. Results: We included 1848 adult patients with T2DM in the study group, 58% women and 42% men. For the control group, we included 3313 non-diabetic patients, 55% women and 45% men. The mean age in the study group was 52 +/- 7 years, and 47 +/- 4 years in the control group (p < .001). The rate of hypothyroidism in the study group was 5.7%, and in the control group 1.8% (odds ratio of 3.45; 95% confidence interval 2.51-4.79) (p < .001). Conclusion: A strong association between T2DM and hypothyroidism was found. We recommend a thyroid profile in all patients with T2DM, similar to the recommendation in type 1 diabetes mellitus. (C) 2011 Elsevier Espana, S.L. All rights reserved.