3,3'-Diiodothyronine concentrations in hospitalized or thyroidectomized patients: results from a pilot study.

OBJECTIVE: To determine if various medical conditions affect the serum concentrations of 3,3'-diiodothyronine (3,3'-T2). METHODS: A total of 100 patients who were recruited from a group of inpatients and outpatients with a diverse range of medical conditions, donated a single blood sample that was assayed for thyroid hormone derivatives using liquid-chromatography tandem mass spectrometry (LC-MS/MS). The associations between 3,3'-T2 concentrations and physiologic data and medical conditions were assessed. RESULTS: Higher quartiles of 3,3'-T2 concentrations (quartile 1: 2.01-7.48, quartile 2: 7.74-12.4, quartile 3: 12.5-17, quartile 4: 17.9-45.8 pg/mL) were associated with decreasing occurrence of critical illness (58%, 11%, 0%, 8%), stroke (29%, 7.7%, 4%, 0%), critical care unit hospitalization (75%, 39%, 8.3 %, 12%), and inpatient status (83%, 42%, 8%, 12%) (all P<.001). The same quartiles were associated with increasing frequency of thyroidectomy (4%, 12%, 17%, 60%). In multivariate analyses, after adjustment for age and sex, inpatient status was associated with decreasing concentrations of 3,3'-T2 (46% decrease for inpatients with 95% confidence interval [CI] 32-57%, P<.0001). Thyroidectomy was associated with increasing concentrations of 3,3'-T2 (29% increase (CI 0.5-66%, P = .049). CONCLUSION: We observed associations between inpatient status and reduced 3,3'-T2 concentrations. This appears to be a global change associated with illness, rather than an association with specific medical conditions. We also observed higher 3,3'-T2 concentrations in athyreotic outpatients receiving thyroid-stimulating hormone (TSH) suppression therapy. This demonstrates that there is production of 3,3'-T2 from levothyroxine (LT4) in extrathyroidal tissues. Conversion of thyroxine (T4) to 3,3'-T2 via both triiodothyronine (T3) and reverse triiodothyronine (rT3) pathways may prevent excessive T3 concentrations in such patients.

Pelvic ultrasonography in the evaluation of central precocious puberty: comparison with leuprolide stimulation test.

OBJECTIVE: To compare the ovarian and uterine structure demonstrated sonographically with baseline and leuprolide-stimulated luteinizing hormone (LH) and estradiol values in females with suspected precocious puberty. STUDY DESIGN: Retrospective chart review. Fifty females (age 3.1 to 9.5 years) underwent stimulation testing with leuprolide (20 µg/kg) and pelvic ultrasonography. Subjects were grouped as (1) prepubertal (baseline and stimulated LH and estradiol in prepubertal range); (2) early pubertal (baseline LH and estradiol in prepubertal range but stimulated LH or estradiol in pubertal range); and (3) pubertal (baseline and stimulated LH or estradiol in pubertal range). Sonographic data were compared with baseline and leuprolide-stimulated LH and estradiol. RESULTS: Baseline and stimulated LH and stimulated estradiol significantly correlated with ovarian and uterine volumes. Ovarian and uterine volumes were significantly higher in females in the pubertal group than in females in the prepubertal group. No significant differences were noted in the ovarian or uterine dimensions between the prepubertal and early pubertal groups. There was significant overlap in ovarian and uterine volumes among females in all three groups. CONCLUSION: Contrary to leuprolide stimulation, pelvic ultrasonography alone cannot distinguish between prepubertal females and those in the early stages of puberty.

Leuprolide stimulation testing for the evaluation of early female sexual maturation.

CONTEXT: Low concentrations of serum LH and/or oestradiol (E(2)) in girls with early physical signs of precocious puberty pose a diagnostic challenge. OBJECTIVE: To assess the diagnostic value of the leuprolide stimulation test in female precocious puberty. DESIGN: Retrospective Chart Review. SETTING: Outpatient clinic. PATIENTS AND INTERVENTION: Thirty-nine girls, 6.9 (1.4) years, with premature stage II-III breast development, with or without pubarche, underwent stimulation testing with subcutaneous leuprolide (20 microg/kg) with the following hormonal measurements in serum: FSH, LH, oestradiol at baseline; FSH and LH at 1 and 2 h; oestradiol at 24 h. Twelve girls with isolated pubarche were also tested with leuprolide. MAIN OUTCOME MEASURE: A pubertal hormonal pattern was defined as at least one of the following: a baseline serum level of LH > or = 0.3 U/l, a baseline oestradiol > or = 37 pmol/l (10 ng/l), a stimulated (peak) LH > or = 5.0 U/l, a stimulated oestradiol > or = 184 pmol/l (50 ng/l) to leuprolide. The hormonal response was related to the clinical course during a period of observation of at least 6 months. RESULTS: Following leuprolide stimulation, the hormonal response was concordant with pubertal progression (n = 23) or lack thereof (n = 16) in all children. At baseline, pubertal serum concentrations of LH and/or oestradiol were associated with pubertal progression in all, while serum prepubertal LH and/or oestradiol concentrations were associated with pubertal progression in approximately 50% of the patients. CONCLUSIONS: In girls with early clinical signs of precocious puberty and low serum concentrations of LH and oestradiol in random samples, the LH and oestradiol responses to leuprolide stimulation accurately predict pubertal progression.

Transient neonatal hyperparathyroidism: a presenting feature of mucolipidosis type II.

The phenotype of mucolipidosis type II (ML II), a disorder of lysosomal enzyme transport, includes mucopolysaccharidosis type I (Hurler syndrome)-like features and dysostosis multiplex, usually apparent after 6 months of age. We describe here the natural history of neonatal hyperparathyroidism, a recently described presentation of ML II. A female neonate presented with multiple fractures and radiological features of osteopenia and 'rickets-like' changes. Longitudinal evaluation, while the patient was treated with vitamin D 800-3,000 IU/day orally, indicated secondary hyperparathyroidism which resolved, biochemically and radiologically, by age 4 months. Neonatal hyperparathyroidism in ML II is severe, transient, and probably secondary to impaired placental calcium transport, simulating a condition observed in the offspring of chronically hypocalcemic mothers.

Total and free thyroxine and triiodothyronine: measurement discrepancies, particularly in inpatients.

OBJECTIVE: We compared the performance of tandem mass spectrometry versus immunoassay for measuring thyroid hormones in a diverse group of inpatients and outpatients. METHODS: Thyroxine (T4), triiodothyronine (T3), free thyroxine (FT4), and free triiodothyronine (FT3) were measured by liquid chromatography tandem mass spectrometry and immunoassay in 100 patients and the two assays were compared. RESULTS: T4 and T3 values measured by the two different assays correlated well with each other (r=0.91-0.95). However, the correlation was less good at the extremes (r=0.51-0.75). FT4 and FT3 concentrations measured by the two assays correlated less well with each other (r=0.75 and 0.50 respectively). The studied analytes had poor inverse correlation with the log-transformed TSH values (r=-0.22-0.51) in the population as a whole. The strongest correlations were seen in the groups of outpatients (r=-0.25-0.61). The weakest degree of correlation was noted in the inpatient group, with many correlations actually being positive. CONCLUSION: The worst between-assay correlation was demonstrated at low and high hormone concentrations, in the very concentration ranges where accurate assay performance is typically most clinically important. Based on the lesser susceptibility of mass spectrometry to interferences from conditions such as binding protein abnormalities, we speculate that mass spectrometry better reflects the clinical situation. In this mixed population of inpatients and outpatients, we also note failure of assays to conform to the anticipated inverse linear relationship between thyroid hormones and log-transformed TSH.

Treatment recommendations for prediabetes.

A variety of definitions and diagnostic cutpoints have been promulgated for prediabetes without universal agreement. Professional organizations agree that current scientific evidence justifies intervention in high-risk populations for the delay or prevention of progression to diabetes. Lifestyle intervention is universally accepted as the primary intervention strategy. Secondary intervention is advocated in high-risk individuals or in the absence of a clinical response to lifestyle modification.

Recent consensus statements in pediatric endocrinology: a selective review.

Clinical guidelines and consensus statements serve to summarize and organize current knowledge on diverse subjects and provide practical guidelines for proper clinical management. Recommendations should be based on research and evidence derived from appropriate sources. In 2008, more than 20 consensus statements were published in the pediatric literature alone. This article summarizes the salient points of the latest consensus statements jointly developed by multiple endocrine societies including the Lawson Wilkins Society for Pediatric Endocrinology and the European Society for Pediatric Endocrinology. As much as possible, the original intent and language of the statements was respected and paraphrased.

Recent consensus statements in pediatric endocrinology: a selective review.

Clinical guidelines and consensus statements serve to summarize and organize current knowledge on diverse subjects, and provide practical guidelines for proper clinical management. Recommendations should be based on research and evidence derived from appropriate sources. In 2008, more than 20 consensus statements were published in the pediatric literature alone. This article summarizes the salient points of the latest consensus statements jointly developed by multiple endocrine societies including the Lawson Wilkins Society for Pediatric Endocrinology and the European Society for Pediatric Endocrinology. As much as possible, the original intent and language of the statements was respected and paraphrased.