Context: The aims of the study are to compare characteristics of subacute thyroiditis (SAT) related to different etiologies, and to identify predictors of recurrence of SAT and incident hypothyroidism. Methods: This nationwide, multicenter, retrospective cohort study included 53 endocrinology centers in Turkey. The study participants were divided into either COVID-19–related SAT (Cov-SAT), SARS-CoV-2 vaccine–related SAT (Vac-SAT), or control SAT (Cont-SAT) groups. Results: Of the 811 patients, 258 (31.8%) were included in the Vac-SAT group, 98 (12.1%) in the Cov-SAT group, and 455 (56.1%) in the Cont-SAT group. No difference was found between the groups with regard to laboratory and imaging findings. SAT etiology was not an independent predictor of recurrence or hypothyroidism. In the entire cohort, steroid therapy requirement and younger age were statistically significant predictors for SAT recurrence. C-reactive protein measured during SAT onset, female sex, absence of antithyroid peroxidase (TPO) positivity, and absence of steroid therapy were statistically significant predictors of incident (early) hypothyroidism, irrespective of SAT etiology. On the other hand, probable predictors of established hypothyroidism differed from that of incident hypothyroidism. Conclusion: Since there is no difference in terms of follow-up parameters and outcomes, COVID-19– and SARS-CoV-2 vaccine–related SAT can be treated and followed up like classic SATs. Recurrence was determined by younger age and steroid therapy requirement. Steroid therapy independently predicts incident hypothyroidism that may sometimes be transient in overall SAT and is also associated with a lower risk of established hypothyroidism.

Key words: Arterial stiffness; augmentation index; hyperthyroidism; pulse wave analysis

Objectives: Central venous sampling (CVS) with corticotropin-releasing hormone (CRH) stimulation is a crucial technique in evaluating adrenocorticotropic hormone (ACTH)-dependent Cushing’s syndrome (CS). We evaluated central venous sampling (CVS) and magnetic resonance imaging (MRI) findings in predicting the localization and lateralization of pituitary microadenomas. Methods: We analyzed 29 patients with CS who underwent CVS with CRH stimulation and examined with MRI retrospectively. Catheterization to central sinuses was successfully performed in 26 patients. Three patients with variant anatomy or inability to cannulate were diagnosed with CD after examination of pathology. Results: After CVS, among 26 patients, 23 patients were determined to have CD (88.4%) and 2 (7.7%) patients were diagnosed with ectopic ACTH syndrome. One patient was diagnosed with CD postoperatively. While the sensitivity of the CVS was 95.6%, sensitivity of the preoperative pituitary MRI was lower (69.5%). Also, the negative predictive value ratio was higher in CVS than in MRI (66% versus 22%). Diagnostic accuracy in the lateralization of the tumor was high as in CVS as in MRI (76.4% versus 73.9%). Conclusion: Central venous sampling with higher sensitivity in the localization of pituitary microadenoma, also has approximately similar diagnostic accuracy in lateralizing the tumor with MRI.

Summary: We assessed bone health in over 2500 adults with diabetes across Türkiye. T1DM patients had lower BMD, while T2DM patients showed higher fracture risk despite higher BMD. Several modifiable factors were linked to osteoporosis. These findings support personalized bone assessments in diabetic populations. Background: Diabetes mellitus (DM) is a recognized risk factor for bone fragility. While type 1 DM (T1DM) is typically associated with low bone mineral density (BMD), type 2 DM (T2DM) often presents with higher BMD despite increased fracture risk. Large-scale comparative studies remain limited. Objective: To evaluate bone health, including osteopenia, osteoporosis, and fracture risk, in adults with T1DM and T2DM. Methods: This multicenter, cross-sectional study included 2562 patients (224 with T1DM, 2338 with T2DM) from 27 centers across Türkiye. BMD was assessed using dual-energy X-ray absorptiometry (DXA) and fracture risk was estimated via the Turkish-adapted FRAX® algorithm in patients aged ≥ 40 years. Multinomial logistic regression was used to identify independent predictors of low BMD. Results: Osteoporosis prevalence was 5.5% in T1DM and 9.6% in T2DM (femoral neck T-score). Adjusted BMD was significantly lower in T1DM at all skeletal sites, while FRAX-based fracture risk and fall-related fractures were higher in T2DM. Independent predictors of osteoporosis included older age, female sex, lower BMI, reduced calcium levels, corticosteroid use, albuminuria, hypertension, and less frequent sodium-glucose cotransporter-2 (SGLT2) inhibitor use. T1DM was independently associated with osteopenia but not osteoporosis. Conclusion: This multicenter study demonstrates distinct patterns of BMD and fracture risk across diabetes subtypes and supports individualized bone health assessment in routine diabetes care.