Identifying Clinical Characteristics of Hypoparathyroidism in Turkey: HIPOPARATURK-NET Study.

Hypoparathyroidism is an orphan disease with ill-defined epidemiology that is subject to geographic variability. We conducted this study to assess the demographics, etiologic distribution, treatment patterns and complication frequency of patients with chronic hypoparathyroidism in Turkey. This is a retrospective, cross-sectional database study, with collaboration of 30 endocrinology centers located in 20 cities across seven geographical regions of Turkey. A total of 830 adults (mean age 49.6 ± 13.5 years; female 81.2%) with hypoparathyroidism (mean duration 9.7 ± 9.0 years) were included in the final analysis. Hypoparathyroidism was predominantly surgery-induced (n = 686, 82.6%). The insulting surgeries was carried out mostly due to benign causes in postsurgical group (SG) (n = 504, 73.5%) while patients in nonsurgical group (NSG) was most frequently classified as idiopathic (n = 103, 71.5%). The treatment was highly dependent on calcium salts (n = 771, 92.9%), calcitriol (n = 786, 94.7%) and to a lower extent cholecalciferol use (n = 635, 76.5%) while the rate of parathyroid hormone (n = 2, 0.2%) use was low. Serum calcium levels were most frequently kept in the normal range (sCa 8.5-10.5 mg/dL, n = 383, 46.1%) which might be higher than desired for this patient group. NSG had a lower mean plasma PTH concentration (6.42 ± 5.53 vs. 9.09 ± 7.08 ng/l, p < 0.0001), higher daily intake of elementary calcium (2038 ± 1214 vs. 1846 ± 1355 mg/day, p = 0.0193) and calcitriol (0.78 ± 0.39 vs. 0.69 ± 0.38 mcg/day, p = 0.0057), a higher rate of chronic renal disease (9.7% vs. 3.6%, p = 0.0017), epilepsy (6.3% vs. 1.6%, p = 0.0009), intracranial calcifications (11.8% vs. 7.3%, p < 0.0001) and cataracts (22.2% vs. 13.7%, p = 0.0096) compared to SG. In conclusion, postsurgical hypoparathyroidism is the dominant etiology of hypoparathyroidism in Turkey while the nonsurgical patients have a higher disease burden with greater need for medications and increased risk of complications than the postsurgical patients.

Free triiodothyronine to free thyroxine ratio in the differential diagnosis of thyrotoxicosis and hyperthyroidism: A retrospective study.

BACKGROUND: Thyroid ultrasound, thyroid scintigraphy and radioactive iodine uptake (RAIU) tests are helpful in the differential diagnosis of thyrotoxicosis and hyperthyroidism. In the setting where these techniques are unavailable or unusable more accessible, and cheaper techniques would be helpful. AIMS: We evaluated the capability of free triiodothyronine to free thyroxine ratio (FT3/FT4) to differentiate Graves' Disease (GD) and destructive thyroiditis (DT). METHODS: In total, 318 patients with GD and 140 patients with DT were included in the study. Patients were assigned to two groups: GD and DT (subacute thyroiditis, painless thyroiditis, postpartum thyroiditis). Serum thyroid-stimulating hormone (TSH), FT4, FT3 levels and FT3/FT4 ratio were evaluated in each group. To obtain the optimal diagnostic cut-off value of FT3, FT4 and FT3/FT4 ratio, ROC curve analysis was performed of all untreated thyrotoxicosis patients. RESULTS: The optimal FT3/FT4 ratio cut-off value was 2.96, with a sensitivity of 71.7%, the specificity of 88.6%. The area under the ROC curve of the FT3/FT4 ratio regarding the diagnosis of GD was 0.864 (95% CI: 0.830-0.894). The cut-off level of FT3 for GD was determined as 6.6 pg/mL which had a sensitivity of 72.3% and specificity of 68.6% (AUC = 0.771 P < .001). The cut-off level of FT4 for GD was determined as 3.65 ng/dl with a sensitivity of 35.5% and specificity of 83.6% (AUC = 0.615 P < .001). When a high specificity is needed, FT3/FT4 cut-off value increases to 3.63 with 99.3% specificity and 36.5% sensitivity. CONCLUSIONS: FT3/FT4 ratio helps distinguish GD and DT. In cases of situations where RAIU/scintigraphy and TRAb cannot be studied, the FT3/FT4 ratio is a viable diagnostic tool. Cut-off values with higher specificity can be more helpful in differential diagnosis of GD.