1
|
Babić Leko M, Jureško I, Rozić I, Pleić N, Gunjača I, Zemunik T. Vitamin D and the Thyroid: A Critical Review of the Current Evidence. Int J Mol Sci 2023; 24:ijms24043586. [PMID: 36835005 PMCID: PMC9964959 DOI: 10.3390/ijms24043586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 02/15/2023] Open
Abstract
Vitamin D is necessary for the normal functioning of many organs, including the thyroid gland. It is, therefore, not surprising that vitamin D deficiency is considered a risk factor for the development of many thyroid disorders, including autoimmune thyroid diseases and thyroid cancer. However, the interaction between vitamin D and thyroid function is still not fully understood. This review discusses studies involving human subjects that (1) compared vitamin D status (primarily determined by serum calcidiol (25-hydroxyvitamin D [25(OH)D]) levels) with thyroid function assessed by thyroid stimulating hormone (TSH), thyroid hormones, and anti-thyroid antibody levels; and (2) evaluated the effect of vitamin D supplementation on thyroid function. Due to the many inconsistencies in the results between the studies, it is still difficult to draw a definite conclusion on how vitamin D status affects thyroid function. Studies in healthy participants observed either a negative correlation or no association between TSH and 25(OH)D levels, while the results for thyroid hormones showed high variability. Many studies have observed a negative association between anti-thyroid antibodies and 25(OH)D levels, but equally many studies have failed to observe such an association. Regarding the studies that examined the effect of vitamin D supplementation on thyroid function, almost all observed a decrease in anti-thyroid antibody levels after vitamin D supplementation. Factors that could contribute to the high variability between the studies are the use of different assays for the measurement of serum 25(OH)D levels and the confounding effects of sex, age, body-mass index, dietary habits, smoking, and the time of year when the samples were collected. In conclusion, additional studies with larger numbers of participants are needed to fully understand the effect of vitamin D on thyroid function.
Collapse
|
2
|
Brustad N, Yousef S, Stokholm J, Bønnelykke K, Bisgaard H, Chawes BL. Safety of High-Dose Vitamin D Supplementation Among Children Aged 0 to 6 Years: A Systematic Review and Meta-analysis. JAMA Netw Open 2022; 5:e227410. [PMID: 35420658 PMCID: PMC9011124 DOI: 10.1001/jamanetworkopen.2022.7410] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
IMPORTANCE Several health benefits of vitamin D have been suggested; however, the safety of high-dose supplementation in early childhood is not well described. OBJECTIVE To systematically assess the risk of adverse events after high-dose supplementation with vitamin D reported in published randomized clinical trials. DATA SOURCES PubMed and ClinicalTrials.gov were searched through August 24, 2021. STUDY SELECTION Randomized clinical trials of high-dose vitamin D supplementation in children aged 0 to 6 years, defined as greater than 1000 IU/d for infants (aged 0-1 year) and greater than 2000 IU/d for children aged 1 to 6 years. DATA EXTRACTION AND SYNTHESIS Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline, 2 reviewers independently extracted the data from the eligible studies. Summary risk ratio (RR), 95% CI, and P values were derived from random-effects meta-analysis. MAIN OUTCOMES AND MEASURES Adverse events, serious adverse events (SAEs), and/or levels of 25-hydroxyvitamin D, calcium, alkaline phosphatase, phosphate, parathyroid hormone, and/or the ratio of urine calcium to creatinine levels. RESULTS A total of 32 randomized clinical trials with 8400 unique participants were included. Different clinical outcomes of children receiving high-dose vitamin D supplements ranging from 1200 to 10 000 IU/d and bolus doses from 30 000 IU/week to a single dose of 600 000 IU were evaluated. Eight studies with 4612 participants were eligible for meta-analysis using a control group receiving either low-dose vitamin D supplementation (≤400 IU/d) or placebo when investigating the risk of SAEs such as hospitalization or death. No overall increased risk of SAEs in the high-dose vitamin D vs control groups was found (RR, 1.01 [95% CI, 0.73-1.39]; P = .89, I2 = 0%). In addition, risk of hypercalcemia (n = 726) was not increased (RR, 1.18 [95% CI, 0.72-1.93]; P = .51). Clinical adverse events potentially related to the vitamin D supplementation reported in the studies were rare. CONCLUSIONS AND RELEVANCE This meta-analysis and systematic review found that high-dose vitamin D supplementation was not associated with an increased risk of SAEs in children aged 0 to 6 years, and that clinical adverse events potentially related to the supplementation were rare. These findings suggest that vitamin D supplementation in the dose ranges of 1200 to 10 000 IU/d and bolus doses to 600 000 IU to young children may be well tolerated.
Collapse
Affiliation(s)
- Nicklas Brustad
- COPSAC (Copenhagen Prospective Studies on Asthma in Childhood), Herlev and Gentofte Hospital, University of Copenhagen, Gentofte, Denmark
| | - Sina Yousef
- COPSAC (Copenhagen Prospective Studies on Asthma in Childhood), Herlev and Gentofte Hospital, University of Copenhagen, Gentofte, Denmark
| | - Jakob Stokholm
- COPSAC (Copenhagen Prospective Studies on Asthma in Childhood), Herlev and Gentofte Hospital, University of Copenhagen, Gentofte, Denmark
- Section of Microbiology and Fermentation, Department of Food Science, University of Copenhagen, Copenhagen, Denmark
| | - Klaus Bønnelykke
- COPSAC (Copenhagen Prospective Studies on Asthma in Childhood), Herlev and Gentofte Hospital, University of Copenhagen, Gentofte, Denmark
| | - Hans Bisgaard
- COPSAC (Copenhagen Prospective Studies on Asthma in Childhood), Herlev and Gentofte Hospital, University of Copenhagen, Gentofte, Denmark
| | - Bo Lund Chawes
- COPSAC (Copenhagen Prospective Studies on Asthma in Childhood), Herlev and Gentofte Hospital, University of Copenhagen, Gentofte, Denmark
| |
Collapse
|
3
|
Gorvin CM. Genetic causes of neonatal and infantile hypercalcaemia. Pediatr Nephrol 2022; 37:289-301. [PMID: 33990852 PMCID: PMC8816529 DOI: 10.1007/s00467-021-05082-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/25/2021] [Accepted: 04/06/2021] [Indexed: 12/02/2022]
Abstract
The causes of hypercalcaemia in the neonate and infant are varied, and often distinct from those in older children and adults. Hypercalcaemia presents clinically with a range of symptoms including failure to thrive, poor feeding, constipation, polyuria, irritability, lethargy, seizures and hypotonia. When hypercalcaemia is suspected, an accurate diagnosis will require an evaluation of potential causes (e.g. family history) and assessment for physical features (such as dysmorphology, or subcutaneous fat deposits), as well as biochemical measurements, including total and ionised serum calcium, serum phosphate, creatinine and albumin, intact parathyroid hormone (PTH), vitamin D metabolites and urinary calcium, phosphate and creatinine. The causes of neonatal hypercalcaemia can be classified into high or low PTH disorders. Disorders associated with high serum PTH include neonatal severe hyperparathyroidism, familial hypocalciuric hypercalcaemia and Jansen's metaphyseal chondrodysplasia. Conditions associated with low serum PTH include idiopathic infantile hypercalcaemia, Williams-Beuren syndrome and inborn errors of metabolism, including hypophosphatasia. Maternal hypocalcaemia and dietary factors and several rare endocrine disorders can also influence neonatal serum calcium levels. This review will focus on the common causes of hypercalcaemia in neonates and young infants, considering maternal, dietary, and genetic causes of calcium dysregulation. The clinical presentation and treatment of patients with these disorders will be discussed.
Collapse
Affiliation(s)
- Caroline M. Gorvin
- Institute of Metabolism and Systems Research and Centre for Endocrinology, Diabetes and Metabolism, University of Birmingham, Birmingham, B15 2TT UK ,Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Birmingham, B15 2TT UK
| |
Collapse
|
4
|
Motlaghzadeh Y, Bilezikian JP, Sellmeyer DE. Rare Causes of Hypercalcemia: 2021 Update. J Clin Endocrinol Metab 2021; 106:3113-3128. [PMID: 34240162 DOI: 10.1210/clinem/dgab504] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT Primary hyperparathyroidism and malignancy are the etiologies in 90% of cases of hypercalcemia. When these entities are not the etiology of hypercalcemia, uncommon conditions need to be considered. In 2005, Jacobs and Bilezikian published a clinical review of rare causes of hypercalcemia, focusing on mechanisms and pathophysiology. This review is an updated synopsis of rare causes of hypercalcemia, extending the observations of the original article. EVIDENCE ACQUISITION Articles reporting rare associations between hypercalcemia and unusual conditions were identified through a comprehensive extensive PubMed-based search using the search terms "hypercalcemia" and "etiology," as well as examining the references in the identified case reports. We categorized the reports by adults vs pediatric and further categorized the adult reports based on etiology. Some included reports lacked definitive assessment of etiology and are reported as unknown mechanism with discussion of likely etiology. EVIDENCE SYNTHESIS There is a growing understanding of the breadth of unusual causes of hypercalcemia. When the cause of hypercalcemia is elusive, a focus on mechanism and review of prior reported cases is key to successful determination of the etiology. CONCLUSIONS The ever-expanding reports of patients with rare and even unknown mechanisms of hypercalcemia illustrate the need for continued investigation into the complexities of human calcium metabolism.
Collapse
Affiliation(s)
- Yasaman Motlaghzadeh
- Stanford University School of Medicine, Division of Endocrinology, Gerontology and Metabolism, Palo Alto, CA 94305, USA
| | - John P Bilezikian
- Division of Endocrinology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Deborah E Sellmeyer
- Stanford University School of Medicine, Division of Endocrinology, Gerontology and Metabolism, Palo Alto, CA 94305, USA
| |
Collapse
|
5
|
Stokes VJ, Nielsen MF, Hannan FM, Thakker RV. Hypercalcemic Disorders in Children. J Bone Miner Res 2017; 32:2157-2170. [PMID: 28914984 PMCID: PMC5703166 DOI: 10.1002/jbmr.3296] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 09/07/2017] [Accepted: 09/13/2017] [Indexed: 12/20/2022]
Abstract
Hypercalcemia is defined as a serum calcium concentration that is greater than two standard deviations above the normal mean, which in children may vary with age and sex, reflecting changes in the normal physiology at each developmental stage. Hypercalcemic disorders in children may present with hypotonia, poor feeding, vomiting, constipation, abdominal pain, lethargy, polyuria, dehydration, failure to thrive, and seizures. In severe cases renal failure, pancreatitis and reduced consciousness may also occur and older children and adolescents may present with psychiatric symptoms. The causes of hypercalcemia in children can be classified as parathyroid hormone (PTH)-dependent or PTH-independent, and may be congenital or acquired. PTH-independent hypercalcemia, ie, hypercalcemia associated with a suppressed PTH, is commoner in children than PTH-dependent hypercalcemia. Acquired causes of PTH-independent hypercalcemia in children include hypervitaminosis; granulomatous disorders, and endocrinopathies. Congenital syndromes associated with PTH-independent hypercalcemia include idiopathic infantile hypercalcemia (IIH), William's syndrome, and inborn errors of metabolism. PTH-dependent hypercalcemia is usually caused by parathyroid tumors, which may give rise to primary hyperparathyroidism (PHPT) or tertiary hyperparathyroidism, which usually arises in association with chronic renal failure and in the treatment of hypophosphatemic rickets. Acquired causes of PTH-dependent hypercalcemia in neonates include maternal hypocalcemia and extracorporeal membrane oxygenation. PHPT usually occurs as an isolated nonsyndromic and nonhereditary endocrinopathy, but may also occur as a hereditary hypercalcemic disorder such as familial hypocalciuric hypercalcemia, neonatal severe primary hyperparathyroidism, and familial isolated primary hyperparathyroidism, and less commonly, as part of inherited complex syndromic disorders such as multiple endocrine neoplasia (MEN). Advances in identifying the genetic causes have resulted in increased understanding of the underlying biological pathways and improvements in diagnosis. The management of symptomatic hypercalcemia includes interventions such as fluids, antiresorptive medications, and parathyroid surgery. This article presents a clinical, biochemical, and genetic approach to investigating the causes of pediatric hypercalcemia. © 2017 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Victoria J Stokes
- Academic Endocrine UnitRadcliffe Department of MedicineUniversity of OxfordOxfordUK
| | - Morten F Nielsen
- Academic Endocrine UnitRadcliffe Department of MedicineUniversity of OxfordOxfordUK
- Department of Clinical ResearchFaculty of HealthUniversity of Southern DenmarkOdenseDenmark
| | - Fadil M Hannan
- Academic Endocrine UnitRadcliffe Department of MedicineUniversity of OxfordOxfordUK
- Department of Musculoskeletal BiologyInstitute of Ageing and Chronic DiseaseUniversity of LiverpoolOxfordUK
| | - Rajesh V Thakker
- Academic Endocrine UnitRadcliffe Department of MedicineUniversity of OxfordOxfordUK
| |
Collapse
|
6
|
Léger J, Olivieri A, Donaldson M, Torresani T, Krude H, van Vliet G, Polak M, Butler G. European Society for Paediatric Endocrinology consensus guidelines on screening, diagnosis, and management of congenital hypothyroidism. Horm Res Paediatr 2015; 81:80-103. [PMID: 24662106 DOI: 10.1159/000358198] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Accepted: 09/18/2013] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE The aim was to formulate practice guidelines for the diagnosis and management of congenital hypothyroidism (CH). EVIDENCE A systematic literature search was conducted to identify key articles relating to the screening, diagnosis, and management of CH. The evidence-based guidelines were developed with the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system, describing both the strength of recommendations and the quality of evidence. In the absence of sufficient evidence, conclusions were based on expert opinion. CONSENSUS PROCESS Thirty-two participants drawn from the European Society for Paediatric Endocrinology and five other major scientific societies in the field of pediatric endocrinology were allocated to working groups with assigned topics and specific questions. Each group searched the literature, evaluated the evidence, and developed a draft document. These papers were debated and finalized by each group before presentation to the full assembly for further discussion and agreement. RECOMMENDATIONS The recommendations include: worldwide neonatal screening, approaches to assess the cause (including genotyping) and the severity of the disorder, the immediate initiation of appropriate L-T4 supplementation and frequent monitoring to ensure dose adjustments to keep thyroid hormone levels in the target ranges, a trial of treatment in patients suspected of transient CH, regular assessments of developmental and neurosensory functions, consulting health professionals as appropriate, and education about CH. The harmonization of diagnosis, management, and routine health surveillance would not only optimize patient outcomes, but should also facilitate epidemiological studies of the disorder. Individuals with CH require monitoring throughout their lives, particularly during early childhood and pregnancy.
Collapse
Affiliation(s)
- Juliane Léger
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Léger J, Olivieri A, Donaldson M, Torresani T, Krude H, van Vliet G, Polak M, Butler G. European Society for Paediatric Endocrinology consensus guidelines on screening, diagnosis, and management of congenital hypothyroidism. J Clin Endocrinol Metab 2014; 99:363-84. [PMID: 24446653 PMCID: PMC4207909 DOI: 10.1210/jc.2013-1891] [Citation(s) in RCA: 250] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE The aim was to formulate practice guidelines for the diagnosis and management of congenital hypothyroidism (CH). EVIDENCE A systematic literature search was conducted to identify key articles relating to the screening, diagnosis, and management of CH. The evidence-based guidelines were developed with the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system, describing both the strength of recommendations and the quality of evidence. In the absence of sufficient evidence, conclusions were based on expert opinion. CONSENSUS PROCESS Thirty-two participants drawn from the European Society for Paediatric Endocrinology and five other major scientific societies in the field of pediatric endocrinology were allocated to working groups with assigned topics and specific questions. Each group searched the literature, evaluated the evidence, and developed a draft document. These papers were debated and finalized by each group before presentation to the full assembly for further discussion and agreement. RECOMMENDATIONS The recommendations include: worldwide neonatal screening, approaches to assess the cause (including genotyping) and the severity of the disorder, the immediate initiation of appropriate L-T4 supplementation and frequent monitoring to ensure dose adjustments to keep thyroid hormone levels in the target ranges, a trial of treatment in patients suspected of transient CH, regular assessments of developmental and neurosensory functions, consulting health professionals as appropriate, and education about CH. The harmonization of diagnosis, management, and routine health surveillance would not only optimize patient outcomes, but should also facilitate epidemiological studies of the disorder. Individuals with CH require monitoring throughout their lives, particularly during early childhood and pregnancy.
Collapse
Affiliation(s)
- Juliane Léger
- Université Paris Diderot (J.L.), Sorbonne Paris Cité, F-75019 Paris, France; Assistance Publique-Hôpitaux de Paris (AP-HP), Hôpital Robert Debré, Service d'Endocrinologie Diabétologie Pédiatrique et Centre de Référence des Maladies Endocriniennes Rares de la Croissance, F-75019, Paris, France; Institut National de la Santé et de la Recherche Médicale (INSERM), Unité Mixte de Recherche 676, F-75019 Paris, France; Department of Cell Biology and Neurosciences (A.O.), Istituto Superiore di Sanità, 00161 Rome, Italy; Child Health Section of Glasgow University School of Medicine (M.D.), Royal Hospital for Sick Children, Yorkhill, Glasgow G3 8SJ, Scotland, United Kingdom; Swiss Neonatal Screening Laboratory (T.T.), University Children's Hospital, CH-8032 Zurich, Switzerland; Department of Pediatric Endocrinology and Diabetes (H.K.), Charite Children's Hospital, Berlin 10117, Germany; Endocrinology Service and Research Center (G.v.V.), Centre Hospitalier Universitaire Sainte-Justine and Department of Pediatrics, University of Montreal, Montreal, Canada H3T 1C5; AP-HP, Hôpital Necker Enfants-Malades, Endocrinologie, Gynécologie et Diabétologie Pédiatriques (M.P.), Centre de Référence des Maladies Endocriniennes Rares de la Croissance, Université Paris Descartes, Sorbonne Paris Cité, INSERM, Unité 845, F-75015 Paris, France; and Department of Paediatric and Adolescent Medicine and Endocrinology (G.B.), University College London Hospital, and University College London Institute of Child Health, London NW1 2PQ, United Kingdom
| | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Abstract
Congenital hypothyroidism is a rare and underdiagnosed congenital endocrine disorder in dogs and cats and the true incidence is unknown. The disorder may cause a range of clinical signs depending on the primary defect, which affect production of thyroid hormones; some cases present when adult. Hallmark clinical signs of congenital hypothyroidism are mental impairment and skeletal developmental abnormalities, resulting in disproportionate dwarfism; goitre may or may not be present. Documented causes of congenital hypothyroidism in dogs include deficiency of, or unresponsiveness to, thyrotropin-releasing hormone (TRH) or thyroid-stimulating hormone (TSH), thyroid dysgenesis, dyshormonogenesis and iodine deficiency. In cats, TSH unresponsiveness, thyroid dysgenesis, dyshormonogenesis and iodine deficiency have been confirmed. Adequate replacement therapy results in a successful outcome in the majority of cases, especially when started early in life, as permanent developmental abnormalities can be prevented. This review describes reported cases in dogs and cats, diagnostic investigation, and recommendations for treatment.
Collapse
Affiliation(s)
- K Bojanic
- Veterinary Clinic Fiziovet, Zagreb, Croatia.
| | | | | |
Collapse
|
9
|
Tran HA, Song S, Crock PA, Mattes J, Howard K. The A, B, C, D of hypercalcaemia in Down syndrome. BMJ Case Rep 2009; 2009:bcr06.2008.0232. [PMID: 21686893 DOI: 10.1136/bcr.06.2008.0232] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Hypercalcaemia in infants with Down syndrome is an uncommon condition with only five previous case reports. The patients often present in the toddler years with the classical triad of Down syndrome, biochemical hypercalcaemia, and nephrocalcinosis. We present the sixth case and second male with this condition and further review the clinical details of this under-recognised condition and stratify the diagnostic criteria. The management mandates a reduction in calcium intake as a first step. The natural history of the various aspects of this condition is also considered.
Collapse
Affiliation(s)
- Huy A Tran
- Hunter Area Pathology Service, Clinical Chemistry, Locked Bag 1, HRMC, Newcastle, New South Wales, 2310, Australia
| | | | | | | | | |
Collapse
|
10
|
Abstract
Hyperthyroidism is the most common endocrine disorder of cats, and hypothyroidism is the most common endocrine disorder of dogs. Little is known regarding the effects of hyperthyroidism, hypothyroidism, or treatment of these disorders on calcium metabolism in the dog or cat, however, especially any potential effects on bone. With better diagnostic tools, better treatments, and increased longevity of pets, the clinical impact of thyroid disorders on calcium metabolism and bone may be uncovered.
Collapse
Affiliation(s)
- Patricia A Schenck
- Diagnostic Center for Population and Animal Health, Department of Pathobiology and Diagnostic Investigation, Endocrine Diagnostic Section, Michigan State University, 4125 Beaumont Road, Lansing, MI 48910, USA.
| |
Collapse
|
11
|
Abstract
Endocrine and metabolic disorders affecting puppies and kittens from birth until 6 months of age may manifest as clinical problems related to growth or to water metabolism (polydipsia and polyuria). Most commonly,endocrine and metabolic disorders affect growth of the animal,and puppies are often presented to the veterinarian for assessment of delayed or aberrant growth. Other endocrine disorders of small animals,such as juvenile-onset diabetes insipidus or diabetes mellitus, affect water metabolism, resulting in excessive thirst and urination and resultant difficulty in house-breaking.
Collapse
Affiliation(s)
- Deborah S Greco
- The Animal Medical Center, 510 East 62nd Street, New York, NY 10021, USA.
| |
Collapse
|
12
|
Abstract
Whereas hyperthyroidism is the most common endocrine disorder in the cat, hypothyroidism is the least common feline endocrine disorder. This is a the result of several factors including low index of suspicion, rarity of the naturally occurring hypothyroidism in cats, and a lack of species specific tests for endogenous TSH and antithyroglobulin antibodies. Nonetheless, hypothyroidism does occur in cats, especially in kittens and after radioactive treatment for hyperthyroidism. The clinician should become familiar with the common presentations of congenital and adult-onset hypothyroidism in cats. In addition, some of the tests specific to dogs (such as endogenous canine TSH) may be utilized to diagnose subclinical hypothyroidism in cats. Fortunately, the treatment of feline hypothyroidism with synthetic levothyroxine is both straightforward and effective.
Collapse
Affiliation(s)
- Deborah S Greco
- The Animal Medical Center, 510 East 62nd Street, New York, NY 10021, USA.
| |
Collapse
|
13
|
Abstract
CONTEXT Although hypercalcemia is usually caused by primary hyperparathyroidism or malignancy, a number of other conditions can be important to consider. This review considers unusual causes of hypercalcemia that are generally not found in reviews on this subject. EVIDENCE ACQUISITION Articles describing rarely reported associations between hypercalcemia and unusual causes were identified through a computer search of the terms hypercalcemia/etiology and through the references listed in those articles. We grouped the 58 different reports into categories defined by a presumed etiology: increased levels of 1,25-dihydroxyvitamin D or PTHrP, occult milk-alkali syndrome, and undefined mechanisms. Reports in infants and children are listed separately, as are reports of pseudohypercalcemia, situations that are not truly hypercalcemic because the ionized calcium is normal. EVIDENCE SYNTHESIS In some situations, as this review points out, a number of unusual causes of hypercalcemia are important to consider. The search for an elusive cause of hypercalcemia is best accomplished by the most likely potential mechanism. An orderly search in this manner is likely to reveal the underlying cause. CONCLUSIONS That so many patients have been described with rare and usually poorly understood causes of hypercalcemia highlights our incomplete understanding of calcium metabolism in humans and suggests additional areas in which directed clinical investigation might improve our knowledge of the normal metabolism of calcium.
Collapse
Affiliation(s)
- Thomas P Jacobs
- Columbia University Medical Center, 161 Fort Washington Avenue, New York, New York 10032, USA.
| | | |
Collapse
|
14
|
Greco DS. Diagnosis and treatment of juvenile endocrine disorders in puppies and kittens. Vet Clin North Am Small Anim Pract 2001; 31:401-9, viii. [PMID: 11265499 DOI: 10.1016/s0195-5616(01)50212-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Endocrine and metabolic disorders affecting puppies and kittens from birth until 6 months of age may manifest as clinical problems related to growth, water metabolism (polydipsia or polyuria), or as episodic weakness. Endocrine and metabolic disorders that affect stature, such as pituitary or hypothyroid dwarfism, present to the veterinarian for assessment of delayed or aberrant growth. Conversely, juvenile-onset diabetes mellitus and diabetes insipidus cause excessive thirst, urination, and difficulty in house-breaking.
Collapse
Affiliation(s)
- D S Greco
- Department of Clinical Sciences, College of Veterinary Medicine and Biological Sciences, Colorado State University, Fort Collins, Colorado, USA.
| |
Collapse
|
15
|
Verrotti A, Greco R, Altobelli E, Morgese G, Chiarelli F. Bone metabolism in children with congenital hypothyroidism--a longitudinal study. J Pediatr Endocrinol Metab 1998; 11:699-705. [PMID: 9829223 DOI: 10.1515/jpem.1998.11.6.699] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In order to evaluate the effect of thyroid replacement therapy on bone metabolism in congenital hypothyroid children, we studied 23 (10 girls and 13 boys) consecutive patients. Their age ranged from 3 to 8 weeks. One of these patients had familiar dyshormonogenesis, 21 had ectopic glands and one hemiagenesis. As a control group, we studied 46 sex- and age-matched healthy newborns. Before the beginning of therapy, the hypothyroid patients showed higher values of calcium (2.78 +/- 0.04 vs 2.65 +/- 0.07 mmol/l; p < 0.05) and of 1,25-dihydroxy-vitamin D (159.7 +/- 31.6 vs 90.5 +/- 33.1 ng/l; p < 0.01), while they showed lower values of osteocalcin (1.9 +/- 0.8 vs 2.9 +/- 0.9 ng/ml; p < 0.01) than controls. After 3 months of therapy, we found a complete normalization of all these parameters and a progressive increase of osteocalcin. Our data show that in congenital hypothyroid children there are abnormalities in calcium metabolism which seem to be transient and reversible after L-thyroxine replacement therapy.
Collapse
Affiliation(s)
- A Verrotti
- Department of Pediatrics, University of Chieti, Italy
| | | | | | | | | |
Collapse
|
16
|
Weber G, Mora S, Bellini A, Bosco M, Prinster C, Siragusa V, di Natale B, Chiumello G. Bone mineral metabolism and thyroid replacement therapy in congenital hypothyroid infants and young children. J Endocrinol Invest 1995; 18:277-82. [PMID: 7560809 DOI: 10.1007/bf03347813] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Impairment of calcium metabolism and low bone density have been found in hypothyroid adults. We investigated the effect of thyroid replacement therapy on calcium metabolism and bone mineralization in congenital hypothyroid (CH) infants and children. One hundred and 16 Caucasian CH consecutive patients were studied and were grouped according to their age: 23 patients at diagnosis, 20 at 3 mo, 24 at 6 mo, 25 at 12 mo and 24 at 36 mo. Thyroid replacement therapy was started at an initial dose of 6-8 micrograms/kg/day of L-thyroxine, and then decreased progressively. Calcium, phosphorus, magnesium, alkaline phosphatase (AP), parathyroid hormone (PTH) and osteocalcin (BGP) were measured as calcium metabolism indices. Bone mineral content (BMC) was measured at the mid-portion of the right radius AP, PTH and BGP concentrations were significantly higher in subjects at 3 mo of age (p < 0.05). This rise coincided with the end of the period of maximum dosage of L-thyroxine. Mild asymptomatic hypercalcemia was observed in 20 patients. All the other indices did not differ between age groups. BMC values and BMC annual increment were not different from those calculated for age-matched controls. We found that L-thyroxine replacement therapy does not alter bone mineralization of CH infants and children. Only a transitory increase of osteoblastic function was observed after the first few months of therapy.
Collapse
Affiliation(s)
- G Weber
- Clinica Pediatrica III, Istituto Scientifico H San Raffaele, Università degli Studi di Milano, Italy
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Greco DS, Feldman EC, Peterson ME, Turner JL, Hodges CM, Shipman LW. Congenital hypothyroid dwarfism in a family of giant schnauzers. Vet Med (Auckl) 1991; 5:57-65. [PMID: 2061865 DOI: 10.1111/j.1939-1676.1991.tb00932.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Congenital hypothyroid dwarfism was diagnosed in a family of Giant Schnauzers. Three female and two male puppies from different litters were evaluated for dwarfism, lethargy, somnolence, gait abnormalities, and constipation. On physical examination, disproportionate dwarfism (n = 5), macroglossia (n = 3), hypothermia (n = 3), delayed dental eruption (n = 3), ataxia (n = 2), and abdominal distension (n = 1) were identified. Results of initial laboratory tests showed anemia (n = 4), hypercholesterolemia (n = 4), hypercalcemia (n = 2), and transudative abdominal effusion (n = 1). Radiographic skeletal surveys disclosed epiphyseal dysgenesis and delayed skeletal maturation (n = 5). A diagnosis of hypothyroidism was established on the basis of low basal serum thyroxine concentrations that failed to increase following the administration of TSH (n = 5) and markedly reduced to absent thyroid image when evaluated with gamma camera imaging of the thyroid gland (n = 4). In the two dogs that were most thoroughly evaluated, the results of thyroid histology, prolonged TSH testing, and repeat thyroid imaging, after three daily injections of TSH, were all consistent with secondary or tertiary, rather than primary, hypothyroidism. When TSH was administered over a period of 3 consecutive days (5 IU/day, subcutaneously), serum thyroid hormone response became normal and resulted in a normal thyroid image in the two dogs re-evaluated with gamma camera imaging. Daily treatment with oral levothyroxine (20 micrograms/kg) resulted in complete remission in puppies (n = 4) treated prior to 4 months of age. The other puppy failed to attain normal breed standards for height.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- D S Greco
- Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, Texas A&M University, College Station
| | | | | | | | | | | |
Collapse
|
18
|
Abstract
Ionized calcium is a physiologically critical calcium pool. It is easily determined, although accuracy depends on sample handling. As a clinical parameter, directly measured ionized calcium has particular import in the care of neonates, patients with sepsis or other cardiovascular instability, massively transfused patients, and those undergoing cardiopulmonary bypass or liver transplantation. Disturbances of calcium occur in many other settings, however, and accurate diagnosis and research conclusions may depend on using the best measurement available. Clinical and investigational use of ionized calcium determinations represent appropriate applications of current proven technology. In the future, clinical calcium manipulation may include modifying specific transmembrane transport processes and intracellular calcium pools and movements. At the current time we are largely restricted to studies of extracellular calcium concentration and its interactions. Much is known, but Mother Nature still has too many secrets. The interested reader is referred to discussions of ionized calcium and hemodynamics, reviews of the endocrine disturbances of calcium and phosphorus, textbook discussions pertinent to general calcium disturbances, and critical care issues.
Collapse
Affiliation(s)
- R E Lynch
- Pediatric Intensive Care Unit, Cardinal Glennon Children's Hospital, St. Louis, Missouri
| |
Collapse
|
19
|
Abstract
The mechanism of stone formation in the urinary tract is reviewed. Diet, urinary tract infection and metabolic disorders account for the different epidemiological patterns of stone formation. The diagnosis and management of renal tract calculi are discussed. Calcium stones are associated with hypercalciuria, urine acidification defects, the use of furosemide in premature babies, hypercalcaemia, hyperoxaluria, hyperuricosuria, an alkaline urine and hypocitraturia. Uric acid stones occur in acid urine, from increased purine synthesis with lympho- or myeloproliferative disorders or from several inborn errors of purine metabolism which can also cause xanthine or dihydroxyadenine stones. Cystinuria, inherited as an autosomal recessive disorder is best treated with a low sodium diet, a fluid intake exceeding 40 ml/kg per day maintaining urine pH between 7.5 and 8 and, if necessary, with oral penicillamine. Oxalate stones occur in relation to diet, bowel disease and primary inherited defects in oxalate metabolism. Urinary tract infection causing struvite and carbonate apatite formation is the commonest cause of stones in Europe.
Collapse
Affiliation(s)
- J Laufer
- Paediatric Nephrology Unit, Chaim Sheba Medical Centre, Sackler Faculty of Medicine, Tel Aviv University, Israel
| | | |
Collapse
|
20
|
Abstract
Two separate episodes of rickets developed in a female infant of 25 weeks gestation and birthweight 690 g, who had congenital hypothyroidism and required parenteral nutrition for more than 100 days. We speculate that there is a relationship between metabolic bone disease of prematurity and the preterm infant's thyroid status.
Collapse
Affiliation(s)
- P Macmahon
- Department of Paediatrics, Charing Cross Hospital, London, UK
| | | | | |
Collapse
|