Screening for thyroid diseases is not a routine in diabetes clinics. Hypothyroidism is clinically suspected when weight gain, lethargy, hypercholestrolemia etc. are observed. However, these findings are quite common in Type 2 diabetes subjects (T2DM) as well.
We screened type 2 diabetes patients, presenting at our clinic for first time, for thyroid disorders. Screening was done during the past 3 years, using the 'sensitive TSH test' in Cobas E411 Elecsys. During selection of 1000 consecutive T2DM subjects aged ≥ 21yrs; we encountered only 18 subjects with previously known thyroid disorders. 17% of 1000 newly-screened subjects showed abnormal TSH values, comprising of 14% with TSH values suggestive of subclinical and clinical hypothyroidism and 3% with low TSH values suggestive of hyperthyroidism. Abnormal TSH values showed significant association with female sex and >60yrs age group; c2 (1, N = 105) = 7.325, p=0.012), whereas distribution of other subgroups were not statistically significantly different. Among females >60 yrs, 27% had mildly increased TSH levels (5-10μIU/mL), 2% high TSH levels (>10μIU/mL) and 7% low TSH levels (<0.04 μIU/mL). Overall, subjects with newly detected hypothyroidism showed a trend of higher BMI (1.5 kg/m2) compared to others, but this was not statistically significant (p>0.05). The level of diabetes control was possibly confounded by treatment received and HbA1c did not significantly differ among hyperthyroid, euthyroid & sub-clinically hypothyroid patients (mean HbA1c=8.7%).The high prevalence of undiagnosed thyroid disorders suggests that it might be easily missed amidst the efforts to control T2DM, but might add to morbidity. The findings also suggest regular screening for thyroid disorder might be needed at least for female T2DM patients >60yrs. Furthermore, there is need to define screening & management guidelines for thyroid disorders with concomitant T2DM.