Assessing Postoperative Phosphate and Calcium/Phosphate Ratio as Surrogates for Parathyroid Hormone Following Total Thyroidectomy.

OBJECTIVE: Evaluate utility of postoperative phosphate and calcium/phosphate ratio (Ca/P) as surrogates for parathyroid hormone (PTH) following total thyroidectomy. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary care hospital. METHODS: We retrospectively reviewed patients 18 years or older who underwent total thyroidectomy in a tertiary care hospital by a single surgeon from 2015 through 2021. Patients with incomplete data, pre-existing hypoparathyroidism, vitamin D deficiency, or renal failure were excluded. All patients had PTH drawn within 4 hours of surgery and serum calcium, albumin, and phosphate levels on postoperative Day 1. Corrected calcium was used to calculate a Ca/P. Receiver operating characteristic (ROC) curves were generated to compare phosphate level or Ca/P with PTH. Each possible surrogate was assessed relative to PTH cutoffs of less than 5, 10, 15, and 20 pg/mL. A good screening test was defined as having an area under the curve (AUC) greater than 0.8. RESULTS: A total of 185 patients underwent total thyroidectomy with 1 fellowship-trained otolaryngologist. Most patients were female (62%), median age 48 years. Most surgeries were performed for cancer (68%). Six (3.2%) patients required IV calcium supplementation and 2 (1.1%) required readmission for symptomatic hypocalcemia. ROC curves comparing phosphate and Ca/P to PTH at the listed cutoffs demonstrated AUC ranging from 0.55 to 0.66 and 0.61 to 0.79, respectively. None met the threshold for a good screening test. CONCLUSION: Postoperative phosphate and Ca/P ratio are not surrogates for PTH levels following total thyroidectomy. More research is needed to identify cost-effective strategies for postoperative calcium monitoring in patients undergoing total thyroidectomy. LEVEL OF EVIDENCE: Retrospective cohort study.

Functional loss of tumor suppressor genes detected by loss of heterozygosity, but not driver mutations, predicts aggressive lymph node status in papillary thyroid carcinoma.

BACKGROUND: Recognizing aggressive tumor biology is essential to optimizing patient management for papillary thyroid carcinomas (PTC). Aggressive lymph node (ALN) status is one feature that influences decision-making. We evaluated genomic deletions in regions of tumor suppressor genes, detected by loss of heterozygosity (LOH) analysis, to understand causal alterations linked to thyroid cancer aggressiveness and to serve as a molecular diagnostic biomarker for ALN status. METHODS: We analyzed 105 primary PTC enriched for patients with ALN (64% with, 36% without). We also analyzed 39 positive lymph nodes (79% with, 21% without ALN). LOH was determined using a panel of 25 polymorphic microsatellite alleles targeting 10 genomic loci harboring common tumor suppressor genes. Additionally, ThyGeNEXT® and ThyraMIR® assays were performed. RESULTS: LOH was detected in 43/67 primary PTC from patients with ALN status, compared with only 5/38 primary PTC without ALN (minimal metastatic burden) (P=0.0000003). This is further supported by post hoc analyses of paired primary and metastatic samples. Paired samples from patients with ALN are more likely to harbor LOH, compared to the ALN negative group (P=0.0125). Additionally, 12/31 paired samples from patients with ALN demonstrated additional or different LOH loci in metastatic samples compared to the primary tumor samples. No association was seen between ALN and mutational, translocation, or microRNA data. CONCLUSIONS: LOH detected in primary PTC significantly predicts ALN status. Analysis of paired primary and metastatic samples from patients with / without ALN status further supports this relationship. The acquisition of LOH at additional loci is common in lymph nodes from patients with ALN status. SIMPLE SUMMARY: A subset of patients with papillary thyroid carcinoma (PTC) will develop recurrent disease. One known predictor of recurrence is the American Thyroid Association category "Aggressive Lymph Node" (ALN) disease, considering metastatic burden. Loss of heterozygosity (LOH) - chromosomal loss in regions of tumor suppressor genes - has yet to be investigated as a possible mechanism driving ALN status in PTC. The ability to predict ALN status prior to surgery can guide the extent of surgery and postoperative treatment options. We found that paired samples from patients with ALN are more likely to harbor LOH, compared to patients without ALN disease. 38% of patients with ALN demonstrated additional or different LOH loci in metastatic samples compared to the primary tumor samples. LOH complements current molecular analysis of thyroid cancer when searching for evidence of aggressive biology.

Late-Onset 22q11.2 Deletion Syndrome With Mild Cardiac Phenotype: A Unique Adult Presentation Diagnosed at 45 Years of Age.

This case report presents a detailed exploration of an adult-onset 22q11 deletion syndrome, a rare genetic disorder typically diagnosed in children. The report highlights the diagnostic challenges posed by this atypical presentation, emphasizing the need for clinicians to consider such conditions in differential diagnoses, especially in adults. This case is remarkable for its late onset and mild symptoms, which significantly deviated from the common pediatric presentation, including hypocalcemia due to hypoparathyroidism and a fenestrated atrial septal defect without significant hemodynamic implications. The importance of recognizing the broad phenotypic variability of the syndrome and the implications for clinical practice are discussed, providing insights into the genetic and phenotypic diversity of the condition. In conclusion, this case illuminates the diverse clinical spectrum of adult-onset 22q11 deletion syndrome, emphasizing its relevance to clinical practice.

Low-Dose ACTH Stimulation Test in Obesity: A Randomized Dose Assessment.

Background: The short cosyntropin test is widely used for adrenal insufficiency screening and diagnosis. Lower cosyntropin doses may have greater sensitivity vs. the standard dose in detecting adrenal dysfunction. Obesity and overweight are increasing, impacting the clinical presentation of some diseases. Currently more than 50% of the subjects diagnosed with autoimmune adrenal insufficiency have a BMI greater than 25, and hence individuals living with overweight and obesity are more frequently requiring evaluation of the adrenal cortical function. Fixed-dose cosyntropin stimulation may not be appropriate for individuals with obesity. Objective: The primary objective was to compare cortisol response to a weight-adapted cosyntropin dose vs. a fixed low dose (1 µg) and a more physiologically fixed dose (10 µg). Methods: Twenty individuals with obesity and 20 age-matched healthy controls underwent in a randomized sequence at least one-week apart, to the The short cosyntropin test with three different doses, 0.2 µg/kg of body weight, 1 or 10 µg fixed dose stimuli. The assessment and data analysis were blinded to the individual and the investigator. Results: Cortisol response was reduced in the group with obesity with the 1 µg fixed dose stimuli at 30 minutes (median, IQR) 649.6 µg, 567.3-738.4 µg for the control group vs. 568.6 µg, 528.4-623.13 µg, p=0.04; there was a lower cortisol peak at 60' in all the three evaluated doses, with a dose-dependent trend. A weight-adapted cosyntropin dose of 0.2 µg in obesity produces a similar response to the one observed in individuals without obesity. The 1 µg ACTH test falls short on stimulating the cortisol adrenal response in individuals with obesity.

Benefits and Harms of Levothyroxine/L-Triiodothyronine Versus Levothyroxine Monotherapy for Adult Patients with Hypothyroidism: Systematic Review and Meta-Analysis.

Background: Combined therapy with levothyroxine (LT4)/L-triiodothyronine (LT3) has garnered attention among clinicians and patients as a potential treatment alternative to LT4 monotherapy. The objective of this study was to compare the benefits and harms of LT4/LT3 combined therapy and LT4 monotherapy for patients with hypothyroidism. Methods: A systematic search in MEDLINE, Scopus, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials was performed by a librarian from inception date until September 2020. Randomized clinical trials and quasiexperimental studies comparing combined therapy (LT4/LT3) versus monotherapy (LT4) for adult patients with hypothyroidism were considered for inclusion. Independent data extraction was performed by paired reviewers. A meta-analysis comparing standardized mean differences of the effect of each therapy was performed on clinical outcomes and patient preferences. Proportions of adverse events and reactions were assessed narratively. Results: A total of 1398 references were retrieved, from which 18 fulfilled the inclusion criteria. Results supported by evidence at low-to-moderate certainty evidence did not display a difference in treatment effect between therapies on clinical status, quality of life, psychological distress, depressive symptoms, and fatigue; all measured with standardized questionnaires. Furthermore, meta-analysis of patient preferences revealed higher proportions of choice for combined therapy (43%) when compared with monotherapy (23%) or having no preference (30%). When evaluating treatment adverse events or adverse reactions, similar proportions were observed between treatment groups; meta-analysis was not possible. Conclusions: The available evidence at low-to-moderate certainty demonstrates that there is no difference in clinical outcomes between LT4/LT3 combined therapy and LT4 monotherapy for treating hypothyroidism in adults, except for a higher proportion of patient preferring combined therapy. Adverse events and reactions appear to be similar across both groups, however, this observation is only narrative. These results could inform shared decision-making conversations between patients with hypothyroidism and their clinicians. PROSPERO Registration ID: CRD42020202658.

Metastatic thyroid carcinoma to the parapharyngeal and retropharyngeal spaces: Systematic review with seven newly reported cases describing an uncommon presentation of a common disease.

BACKGROUND: Metastatic thyroid carcinoma to retropharyngeal and parapharyngeal (RP/PP) lymph nodes is rare. Literature suggests previous lateral neck dissection (LND) may alter patterns of lymphatic drainage in the neck, predisposing to these less common sites of spread. METHODS: PRISMA-guided systematic search for all published cases detailing RP/PP metastases of well-differentiated thyroid carcinoma from 1970 to 2019. RESULTS: Seventy articles were identified and 44 were included, along with seven cases treated at our institution, totaling 239 cases. Cases represented both retropharyngeal (60.7%) and parapharyngeal (39.3%) metastases identified in the initial (27.6%) and recurrent (72.4%) setting. CONCLUSION: RP/PP metastases generally present in the recurrent setting. RP/PP metastases often represent high-risk disease, and surgical treatment is recommended.

Metformin Use and Vitamin B12 Deficiency: Untangling the Association.

BACKGROUND: Current evidence linking vitamin B12 deficiency with metformin use is inconsistent. Hence, there is uncertainty regarding the diagnostic approach in this scenario. Furthermore, this possible association has not been studied in the complete spectrum of patients with diabetes. MATERIALS AND METHODS: We conducted a cross-sectional, controlled study with the objective of assessing differences in serum vitamin B12 levels among patients with and without diabetes with different metformin-treatment regimens. A total of 150 participants were recruited: patients with diabetes (group 1: metformin alone ≥850mg/day, group 2: patients with type 2 diabetes naive to treatment and group 3: metformin ≥850mg/day, in addition to any other oral glucose lowering agent or insulin, or both) and without diabetes (group 4: polycystic ovary syndrome or group 5: healthy individuals). Serum vitamin B12, folate levels and complete blood counts were obtained for the entire population. Methylmalonic acid and homocysteine were obtained for patients when vitamin B12 levels were found to be borderline or low. RESULTS: When patients with or without diabetes were compared, no significant difference was found in relation to their vitamin B12 levels (517.62 versus 433.83; P = 0.072). No difference in vitamin B12 levels was found among participants with metformin use and metformin naive participants (503.4 versus 462.3; P = 0.380). CONCLUSIONS: Irrespective of metformin use, no significant difference in the serum levels of vitamin B12 was observed, both in patients with and without diabetes. In the light of the body of evidence and the results of this study, a universal recommendation for vitamin B12 deficiency screening cannot be made.

Glucocorticoid functional reserve in full-spectrum intensity of primary hypothyroidism.

Adrenal function might be impaired in patients with primary hypothyroidism. The objective was to evaluate adrenocortical function using the low-dose cosyntropin test in patients with primary hypothyroidism. Consequently a prospective, longitudinal, controlled study of sixty adult patients with primary hypothyroidism was carried out. Patients naïve to L-T4 treatment were compared with control participants. A low-dose cosyntropin test was done before and after L-T4 therapy. Thirty and sixty minutes after the low-dose cosyntropin, the mean cortisol values were lower in the cases group (612.6 ± 133.1 and 603.4 ± 153.7 nmol/L) when compared to the control group (677.0 ± 82.4 and 669.9 ± 83.7 nmol/L) (P = 0.001 and 0.003), respectively. After L-T4 therapy, this difference was lost. Four out of 60 cases (6.7%) taking a cortisol cutoff value of 500 mmol/L and 11 out of 60 (18.3%) having 550 mmol/L as the cutoff had adrenal insufficiency before L-T4 therapy. After L-T4 therapy, 50% and 81% of the cases had normal cortisol response. In conclusion, patients with different degrees of intensity of primary hypothyroidism had improved cortisol response after reaching euthyroidism. The incidence of adrenal insufficiency was 6.7-18.3% and more than 50% of the cases had a normal cortisol response after L-T4 therapy.