PREDICTION OF RELAPSE FROM HYPERTHYROIDISM FOLLOWING ANTITHYROID MEDICATION WITHDRAWAL USING TECHNETIUM THYROID UPTAKE SCANNING.

OBJECTIVE: Technetium thyroid uptake (TTU) is not inhibited by antithyroid drugs (ATD) and reflects the degree of thyroid stimulation. We intended to predict the relapse rate from hyperthyroidism based on TTU measurement. METHODS: Out of 44 initially enrolled subjects, 38 patients aged 41.6 ± 14.6 with Graves disease (duration: 84 ± 78 months) completed the study. TTU was performed with 40-second imaging of the neck and mediastinum 20 minutes after injection of 1 mCi technetium-99m pertechnetate. TTU was measured as the percentage of the count of activity accumulated in the thyroidal region minus the mediastinal background uptake to the count of 1 mCi technetium-99m under the same acquisition conditions. Then methimazole was stopped and patients were followed. The optimal TTU cutoff value for Graves relapse prediction was calculated using Youden's J statistic. RESULTS: Hyperthyroidism relapsed in 11 (28.9%) patients 122 ± 96 (range: 15-290) days post-ATD withdrawal. The subjects in remission were followed for 209 ± 81 days (range: 88-390). TTU was significantly higher in patients with forthcoming relapse (12.0 ± 8.0 vs. 3.9 ± 2.0, P = .007). The difference was significant after adjustment for age, sex, history of previous relapse, disease duration, and thyroid-stimulating hormone (TSH) levels before withdrawal. The area under the receiver operative characteristic (ROC) curve was 0.87. The optimal TTU cutoff value for classification of subjects with relapse and remission was 8.7 with sensitivity, specificity, and positive and negative predictive value of 73%, 100%, 100%, and 90%, respectively (odds ratio [OR] = 10.0; 95% confidence interval [CI]: 3.4-29.3). CONCLUSION: TTU evaluation in hyperthyroid patients receiving antithyroid medication is an accurate and practical method for predicting relapse after ATD withdrawal. ABBREVIATIONS: ATD = antithyroid drugs RIU = radio-iodine uptake TSH = thyroid-stimulating hormone TSI = thyroid-stimulating immunoglobulin TTU = technetium thyroid uptake.

Folate therapy improves the stress-to-rest mean LV volume ratio in myocardial perfusion imaging in patients with diabetes.

OBJECTIVE: Patients with diabetes have higher stress-to-rest mean left ventricular volume (SRLVV) ratio in myocardial perfusion imaging (MPI) and hyperhomocysteinemia. We studied the effect of folate therapy on SRLVV ratio and plasma homocysteine levels in patients with diabetes. METHODS: Forty patients were enrolled and thirty-two completed the study. The patients underwent a 2-day pharmacological stress test and rest MPI before and 2 months after treatment with either 5 mg folic acid or placebo. SRLVV ratios were calculated, and plasma homocysteine levels were measured, before and after treatment. RESULTS: Among the 32 patients who completed the study, 15 received folic acid and 17 received placebo. The age of subjects (folate 51.5 ± 6.1 years; placebo 50.6 ± 8.1 years), male/female ratio (folate 6/11; placebo 9/6),or MPI findings (proportion of normal results: folate 80.0 %; placebo 94.1 %) were similar between the two groups. The baseline SRLVV ratio was similar between groups (folate: 1.00 ± 0.09 vs. placebo: 0.97 ± 0.13); however, the post-treatment SRLVV ratio was significantly lower (P < 0.001) in the folate group than in the placebo group (folate: 0.93 ± 0.10 vs. placebo: 1.04 ± 0.17). A general linear repeated-measures model showed a significant difference in the change in SRLVV ratio between participants receiving folate and those receiving placebo. Post-treatment homocysteine level was lower after folate treatment (from 14.5 ± 4.6 to 11.5 ± 5.3 µmol/L), as compared to placebo (from 13.7 ± 5.0 to 17.9 ± 4.5 µmol/L) (P = 0.01). The changes in SRLVV ratio and homocysteine level were correlated (r = 0.45; P = 0.016). CONCLUSIONS: Short-term folate therapy reduced SRLVV ratio and plasma homocysteine level.