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Jada K, Djossi SK, Khedr A, Neupane B, Proskuriakova E, Mostafa JA. The Pathophysiology of Anorexia Nervosa in Hypothalamic Endocrine Function and Bone Metabolism. Cureus 2021; 13:e20548. [PMID: 35103128 PMCID: PMC8776521 DOI: 10.7759/cureus.20548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 12/20/2021] [Indexed: 11/20/2022] Open
Abstract
Anorexia nervosa (AN) is a persistent psychiatric disorder that is marked by abnormal reduced weight and amenorrhea, which may be primary or secondary. AN affects multiple endocrine axes such as gonadal, thyroid, and adrenal axis, growth hormone, and insulin-like growth factor-1, adipokines such as leptin, gut peptides like ghrelin, peptide YY, and amylin. As a result of these changes bone mineral density is reduced, which increases the risk of bone fracture in patients. In this review, we focus on substantial endocrine alterations in AN with a particular emphasis on the severe bone loss associated with this condition and current bone therapies. The disorder primarily affects girls and women, who are the focus of this review. Although the majority of AN-related endocrinopathies improve over time, long-term consequences such as short stature, osteoporosis, and infertility may occur. To avoid serious consequences, nutrition therapy in these patients requires a full understanding of bone complications, and new therapeutic options for treatment should be researched.
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Gurevich E, Segev Y, Landau D. Growth Hormone and IGF1 Actions in Kidney Development and Function. Cells 2021; 10:cells10123371. [PMID: 34943879 PMCID: PMC8699155 DOI: 10.3390/cells10123371] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 11/16/2021] [Accepted: 11/24/2021] [Indexed: 01/17/2023] Open
Abstract
Growth hormone (GH) exerts multiple effects on different organs including the kidneys, either directly or via its main mediator, insulin-like-growth factor-1 (IGF-1). The GH/IGF1 system plays a key role in normal kidney development, glomerular hemodynamic regulation, as well as tubular water, sodium, phosphate, and calcium handling. Transgenic animal models demonstrated that GH excess (and not IGF1) may lead to hyperfiltration, albuminuria, and glomerulosclerosis. GH and IGF-1 play a significant role in the early development of diabetic nephropathy, as well as in compensatory kidney hypertrophy after unilateral nephrectomy. Chronic kidney disease (CKD) and its complications in children are associated with alterations in the GH/IGF1 axis, including growth retardation, related to a GH-resistant state, attributed to impaired kidney postreceptor GH-signaling and chronic inflammation. This may explain the safety of prolonged rhGH-treatment of short stature in CKD.
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Affiliation(s)
- Evgenia Gurevich
- Department of Nephrology, Schneider Children’s Medical Center of Israel, 14 Kaplan Street, Petach Tikva 4920235, Israel;
| | - Yael Segev
- Shraga Segal Department of Microbiology and Immunology, Ben Gurion University, Beer Sheva 8410501, Israel;
| | - Daniel Landau
- Department of Nephrology, Schneider Children’s Medical Center of Israel, 14 Kaplan Street, Petach Tikva 4920235, Israel;
- Sackler School of Medicine, Tel Aviv University, P.O. Box 39040, Tel Aviv 6997801, Israel
- Correspondence: ; Tel.: +972-3925-3651
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Haffner D, Grund A, Leifheit-Nestler M. Renal effects of growth hormone in health and in kidney disease. Pediatr Nephrol 2021; 36:2511-2530. [PMID: 34143299 PMCID: PMC8260426 DOI: 10.1007/s00467-021-05097-6] [Citation(s) in RCA: 25] [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: 03/23/2021] [Accepted: 04/27/2021] [Indexed: 12/29/2022]
Abstract
Growth hormone (GH) and its mediator insulin-like growth factor-1 (IGF-1) have manifold effects on the kidneys. GH and IGF receptors are abundantly expressed in the kidney, including the glomerular and tubular cells. GH can act either directly on the kidneys or via circulating or paracrine-synthesized IGF-1. The GH/IGF-1 system regulates glomerular hemodynamics, renal gluconeogenesis, tubular sodium and water, phosphate, and calcium handling, as well as renal synthesis of 1,25 (OH)2 vitamin D3 and the antiaging hormone Klotho. The latter also acts as a coreceptor of the phosphaturic hormone fibroblast-growth factor 23 in the proximal tubule. Recombinant human GH (rhGH) is widely used in the treatment of short stature in children, including those with chronic kidney disease (CKD). Animal studies and observations in acromegalic patients demonstrate that GH-excess can have deleterious effects on kidney health, including glomerular hyperfiltration, renal hypertrophy, and glomerulosclerosis. In addition, elevated GH in patients with poorly controlled type 1 diabetes mellitus was thought to induce podocyte injury and thereby contribute to the development of diabetic nephropathy. This manuscript gives an overview of the physiological actions of GH/IGF-1 on the kidneys and the multiple alterations of the GH/IGF-1 system and its consequences in patients with acromegaly, CKD, nephrotic syndrome, and type 1 diabetes mellitus. Finally, the impact of short- and long-term treatment with rhGH/rhIGF-1 on kidney function in patients with kidney diseases will be discussed.
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Affiliation(s)
- Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
- Pediatric Research Center, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | - Andrea Grund
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
- Pediatric Research Center, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Maren Leifheit-Nestler
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Pediatric Research Center, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
- Pediatric Research Center, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
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Esposito S, Leonardi A, Lanciotti L, Cofini M, Muzi G, Penta L. Vitamin D and growth hormone in children: a review of the current scientific knowledge. J Transl Med 2019; 17:87. [PMID: 30885216 PMCID: PMC6421660 DOI: 10.1186/s12967-019-1840-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 03/09/2019] [Indexed: 12/23/2022] Open
Abstract
Background Human growth is a complex mechanism that depends on genetic, environmental, nutritional and hormonal factors. The main hormone involved in growth at each stage of development is growth hormone (GH) and its mediator, insulin-like growth factor 1 (IGF-1). In contrast, vitamin D is involved in the processes of bone growth and mineralization through the regulation of calcium and phosphorus metabolism. Nevertheless, no scientific study has yet elucidated how they interact with one another, especially as a dysfunction in which one influences the other, even if numerous biochemical and clinical studies confirm the presence of a close relationship. Main body We reviewed and analyzed the clinical studies that have considered the relationship between vitamin D and the GH/IGF-1 axis in pediatric populations. We found two main areas of interest: the vitamin D deficiency status in patients affected by GH deficit (GHD) and the relationship between serum vitamin D metabolites and IGF-1. Although limited by some bias, from the analysis of the studies presented in the scientific literature, it is possible to hypothesize a greater frequency of hypovitaminosis D in the subjects affected by GHD, a reduced possibility of its correction with only substitution treatment with recombinant growth hormone (rGH) and an improvement of IGF-1 levels after supplementation treatment with vitamin D. Conclusions These results could be followed by preventive interventions aimed at reducing the vitamin D deficit in pediatric age. In addition, further research is needed to fully understand how vitamin D and growth are intertwined.
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Affiliation(s)
- Susanna Esposito
- Pediatric Clinic, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, Piazza Menghini 1, 06129, Perugia, Italy.
| | - Alberto Leonardi
- Pediatric Clinic, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, Piazza Menghini 1, 06129, Perugia, Italy
| | - Lucia Lanciotti
- Pediatric Clinic, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, Piazza Menghini 1, 06129, Perugia, Italy
| | - Marta Cofini
- Pediatric Clinic, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, Piazza Menghini 1, 06129, Perugia, Italy
| | - Giulia Muzi
- Pediatric Clinic, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, Piazza Menghini 1, 06129, Perugia, Italy
| | - Laura Penta
- Pediatric Clinic, Department of Surgical and Biomedical Sciences, Università degli Studi di Perugia, Piazza Menghini 1, 06129, Perugia, Italy
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Adema AY, de Roij van Zuijdewijn CLM, Hoenderop JG, de Borst MH, Ter Wee PM, Heijboer AC, Vervloet MG. Influence of exogenous growth hormone administration on circulating concentrations of α-klotho in healthy and chronic kidney disease subjects: a prospective, single-center open case-control pilot study. BMC Nephrol 2018; 19:327. [PMID: 30442108 PMCID: PMC6238285 DOI: 10.1186/s12882-018-1114-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 10/22/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The CKD-associated decline in soluble α-Klotho (α-Klotho) levels is considered detrimental. Some studies suggest a direct induction of α-Klotho concentrations by growth hormone (GH). In the present study, the effect of exogenous GH administration on α-Klotho concentrations in a clinical cohort with mild chronic kidney disease (CKD) and healthy subjects was studied. METHODS A prospective, single-center open case-control pilot study was performed involving 8 patients with mild CKD and 8 healthy controls matched for age and sex. All participants received subcutaneous GH injections (Genotropin®, 20 mcg/kg/day) for 7 consecutive days. α-Klotho concentrations were measured at baseline, after 7 days of therapy and 1 week after the intervention was stopped. RESULTS α-Klotho concentrations were not different between CKD-patients and healthy controls at baseline (554 (388-659) vs. 547 (421-711) pg/mL, P = 0.38). Overall, GH therapy increased α-Klotho concentrations from 554 (405-659) to 645 (516-754) pg/mL, P < 0.05). This was accompanied by an increase of IGF-1 concentrations from 26.8 ± 5.0 nmol/L to 61.7 ± 17.7 nmol/L (P < 0.05). GH therapy induced a trend toward increased α-Klotho concentrations both in the CKD group (554 (388-659) to 591 (358-742) pg/mL (P = 0.19)) and the healthy controls (547 (421-711) pg/mL to 654 (538-754) pg/mL (P = 0.13)). The change in α-Klotho concentration was not different for both groups (P for interaction = 0.71). α-Klotho concentrations returned to baseline levels within one week after the treatment (P < 0.05). CONCLUSIONS GH therapy increases α-Klotho concentrations in subjects with normal renal function or stage 3 CKD. A larger follow-up study is needed to determine whether the effect size is different between both groups or in patients with more severe CKD. TRIAL REGISTRATION This trial is registered in EudraCT ( 2013-003354-24 ).
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Affiliation(s)
- Aaltje Y Adema
- Department of Nephrology, VU University Medical Center, De Boelelaan 1117, 1081, HV, Amsterdam, The Netherlands
| | | | - Joost G Hoenderop
- Department of Physiology, Radboud University Medical Center Nijmegen, Nijmegen, The Netherlands
| | - Martin H de Borst
- Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, Groningen, The Netherlands
| | - Piet M Ter Wee
- Department of Nephrology, VU University Medical Center, De Boelelaan 1117, 1081, HV, Amsterdam, The Netherlands
| | - Annemieke C Heijboer
- Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands
| | - Marc G Vervloet
- Department of Nephrology, VU University Medical Center, De Boelelaan 1117, 1081, HV, Amsterdam, The Netherlands. .,Amsterdam Cardiovascular Sciences (ACS), Amsterdam, The Netherlands.
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Zhou X, Sun D, Guang X, Ma S, Fang X, Mariotti M, Nielsen R, Gladyshev VN, Yang G. Molecular Footprints of Aquatic Adaptation Including Bone Mass Changes in Cetaceans. Genome Biol Evol 2018; 10:967-975. [PMID: 29608729 PMCID: PMC5952927 DOI: 10.1093/gbe/evy062] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/13/2018] [Indexed: 01/04/2023] Open
Abstract
Cetaceans (whales, dolphins, and porpoises) are a group of specialized mammals that evolved from terrestrial ancestors and are fully adapted to aquatic habitats. Taking advantage of the recently sequenced finless porpoise genome, we conducted comparative analyses of the genomes of seven cetaceans and related terrestrial species to provide insight into the molecular bases of adaptation of these aquatic mammals. Changes in gene sequences were identified in main lineages of cetaceans, offering an evolutionary picture of cetacean genomes that reveal new pathways that could be associated with adaptation to aquatic lifestyle. We profiled bone microanatomical structures across 28 mammals, including representatives of cetaceans, pinnipeds, and sirenians. Subsequent phylogenetic comparative analyses revealed genes (including leptin, insulin-like growth factor 1, and collagen type I alpha 2 chain) with the root-to-tip substitution rate significantly correlated with bone compactness, implicating these genes could be involved in bone mass control. Overall, this study described adjustments of the genomes of cetaceans according to lifestyle, phylogeny, and bone mass.
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Affiliation(s)
- Xuming Zhou
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, China.,Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Di Sun
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, China
| | - Xuanmin Guang
- BGI-Shenzhen, Shenzhen, China.,The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Siming Ma
- Genome Institute of Singapore, Singapore
| | | | - Marco Mariotti
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Rasmus Nielsen
- Department of Integrative Biology, University of California, Berkeley
| | - Vadim N Gladyshev
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Guang Yang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, China
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Abstract
The prevalence of severe vitamin D deficiency (VDD) in adolescents is variable but considerably high in many countries, especially in Middle-east and Southeast Asia. Different factors attribute to this deficiency including lack of sunlight exposure due to cultural dress codes and veiling or due to pigmented skin, and less time spent outdoors, because of hot weather, and lower vitamin D intake. A potent adaptation process significantly modifies the clinical presentation and therefore clinical presentations may be subtle and go unnoticed, thus making true prevalence studies difficult. Adolescents with severe VDD may present with vague manifestations including pain in weight-bearing joints, back, thighs and/or calves, difficulty in walking and/or climbing stairs, or running and muscle cramps. Adaptation includes increased parathormone (PTH) and deceased insulin-like growth factor-I (IGF-I) secretion. PTH enhances the tubular reabsorption of Ca and stimulates the kidneys to produce 1, 25-(OH) 2D3 that increases intestinal calcium absorption and dissolves the mineralized collagen matrix in bone, causing osteopenia and osteoporosis to provide enough Ca to prevent hypocalcaemia. Decreased insulin like growth factor-I (IGF-I) delays bone growth to economize calcium consumption. Radiological changes are not uncommon and include osteoporosis/osteopenia affecting long bones as well as vertebrae and ribs, bone cysts, decalcification of the metaphysis of the long bones and pseudo fractures. In severe cases pathological fractures and deformities may occur. Vitamin D treatment of adolescents with VDD differs considerably in different studies and proved to be effective in treating all clinical, biochemical, and radiological manifestations. Different treatment regiments for VDD have been discussed and presented in this mini-review for practical use. Adequate vitamin D replacement after treating VDD, improving calcium intake (milk and dairy products), encouraging adequate exposure to the sun and possible enrichment of the stable food with vitamin D in areas with high prevalence of VDD are important measures to prevent the harmful consequences of VDD.
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Affiliation(s)
- Ashraf T. Soliman
- Department of Pediatrics, University of Alexandria, Alexandria, Egypt
| | - Vincenzo De Sanctis
- Pediatric and Adolescent Outpatients Clinic, Quisisana Hospital, Ferrara, Italy
| | - Rania Elalaily
- Department of Primary Health Care, AbuNakhla Hospital, Doha, Qatar
| | - Said Bedair
- Department of Radiology, AlKhor Hospital, Hamad Medical Center, Doha, Qatar
| | - Islam Kassem
- Department of Faciomaxillay Surgery, University of Alexandria, Alexandria, Egypt
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Vitamin d status in thalassemia major: an update. Mediterr J Hematol Infect Dis 2013; 5:e2013057. [PMID: 24106607 PMCID: PMC3787712 DOI: 10.4084/mjhid.2013.057] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 08/20/2013] [Indexed: 01/17/2023] Open
Abstract
The survival of patients with thalassemia major has progressively improved with advances in therapy; however, osteoporosis and cardiac dysfunction remain frequent complications. Adequate circulating levels of vitamin D are essential for optimal skeletal health and reducing fracture risk. Vitamin D deficiency and insufficiency is reported to be high in thalassemic patients in many countries despite the presence of good sunshine and routine prescription of 400-1,000 IU vitamin D per day. The risk of vitamin D deficiency in thalassemia and its relation to bone disease; including osteoporosis, rickets, scoliosis, spinal deformities and fractures as well as to cardiac dysfunction is discussed in this mini-review. Monitoring and maintaining normal serum level of 25-OH vitamin D through oral intake of vitamin D and early correction of VDD by oral or parental use of vitamin D may significantly improve bone mineral accretion and ameliorate cardiac function.
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Affiliation(s)
- Ashraf Soliman
- Department of Pediatrics and Endocrinology, Hamad Medical Center, Doha, Qatar
| | - Sanjay Kalra
- Department of Endocrinology, Bharti Hospital and B.R.I.D.E, Karnal, India
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Shah R, Licata A, Oyesiku NM, Ioachimescu AG. Acromegaly as a cause of 1,25-dihydroxyvitamin D-dependent hypercalcemia: case reports and review of the literature. Pituitary 2012; 15 Suppl 1:S17-22. [PMID: 21188640 DOI: 10.1007/s11102-010-0286-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Growth hormone excess has been associated with hypercalciuria and nephrolithiasis. Hypercalcemia in acromegaly is rare and usually due to coexistent primary hyperparathyroidism. To report two cases of 1,25-dihydroxyvitamin D (1,25 (OH)(2) D)-dependent hypercalcemia in cromegaly. A 50 year-old female with 2 years history of hypercalcemia presented with features of acromegaly. Serum calcium (Ca) was 10.9 mg/dl (8.6-10.2), parathyroid hormone (PTH) 20 pg/ml (10-65), PTH-related peptide undetectable, and 1,25 (OH)(2) D 119 pg/ml (15-75). Insulin-like growth factor 1 (IGF1) was 911 ng/ml (49-292) and growth hormone (GH) 14.5 ng/ml (0.03-10). MRI showed a 1.7 cm pituitary tumor. Transsphenoidal adenectomy (TSA) resulted in normalization of IGF1, GH, Ca, and 1,25 (OH)(2) D (50 pg/ml) and complete tumor resection. A 52-year-old female was diagnosed with visual field deficits on routine exam. MRI showed a 3 cm invasive pituitary macroadenoma. IGF1 was 416 ng/ml (87-238) and GH 75.8 (0-6.0) ng/ml. Incidentally, she was found with high Ca of 10.8 mg/dl (8.9-10.3) associated with PTH 19 pg/ml and 1,25 (OH)(2) D66 pg/ml. Postoperatively, IGF1 and GH remained abnormal (440 and 12.8 ng/ml, respectively), while MRI showed parasellar tumor residue. Ca remained high (10.1-11.1 mg/dl), along with elevated 1,25 (OH)(2) D level (81.3 pg/ml). In both cases, other causes of hypercalcemia were ruled out. We present 2 cases of 1,25 (OH)(2) D-dependent hypercalcemia associated with growth hormone excess. Complete resection of tumor produced biochemical remission of acromegaly and normalization of calcium and 1,25 (OH)(2) D levels, while incomplete resection was associated with persistent 1,25 (OH)(2) D-dependent hypercalcemia. Acromegaly should be considered a cause of 1,25 (OH)(2) D-dependent hypercalcemia.
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Affiliation(s)
- Reshma Shah
- Division of Endocrinology, Diabetes and Lipids. Department of Medicine, Emory University School of Medicine, 1365 B Clifton Rd NE, Atlanta, GA 30329, USA
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Kumar R, Tebben PJ, Thompson JR. Vitamin D and the kidney. Arch Biochem Biophys 2012; 523:77-86. [PMID: 22426203 PMCID: PMC3361542 DOI: 10.1016/j.abb.2012.03.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 03/01/2012] [Accepted: 03/02/2012] [Indexed: 12/22/2022]
Abstract
The kidney is essential for the maintenance of normal calcium and phosphorus homeostasis. Calcium and inorganic phosphorus are filtered at the glomerulus, and are reabsorbed from tubular segments by transporters and channels which are regulated by 1α,25-dihydroxyvitamin (1α,25(OH)(2)D) and parathyroid hormone (PTH). The kidney is the major site of the synthesis of 1α,25(OH)(2)D under physiologic conditions, and is one of the sites of 24,25-dihydroxyvitamin D (24,25(OH)(2)D) synthesis. The activity of the 25(OH)D-1α-hydroxylase, the mixed function oxidase responsible for the synthesis of 1α,25(OH)(2)D, is regulated by PTH, 1α,25(OH)(2)D, fibroblast growth factor 23 (FGF23), inorganic phosphorus and other growth factors. Additionally, the vitamin D receptor which binds to, and mediates the activity of 1α,25(OH)(2)D, is widely distributed in the kidney. Thus, the kidney, by regulating multiple transport and synthetic processes is indispensible in the maintenance of mineral homeostasis in physiological states.
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Affiliation(s)
- Rajiv Kumar
- Division of Nephrology and Hypertension, Mayo Clinic and Foundation, Rochester, MN 55905, USA.
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Elis S, Courtland HW, Wu Y, Fritton JC, Sun H, Rosen CJ, Yakar S. Elevated serum IGF-1 levels synergize PTH action on the skeleton only when the tissue IGF-1 axis is intact. J Bone Miner Res 2010; 25:2051-8. [PMID: 20499370 PMCID: PMC3118256 DOI: 10.1002/jbmr.100] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
There is growing evidence that insulin-like growth factor 1 (IGF-1) and parathyroid hormone (PTH) have synergistic actions on bone and that part of the anabolic effects of PTH is mediated by local production of IGF-1. In this study we analyzed the skeletal response to PTH in mouse models with manipulated endocrine or autocrine/paracrine IGF-1. We used mice carrying a hepatic IGF-1 transgene (HIT), which results in a threefold increase in serum IGF-1 levels and normal tissue IGF-1 expression, and Igf1 null mice with blunted IGF-1 expression in tissues but threefold increases in serum IGF-1 levels (KO-HIT). Evaluation of skeletal growth showed that elevations in serum IGF-1 in mice with Igf1 gene ablation in all tissues except the liver (KO-HIT) resulted in a restoration of skeletal morphology and mechanical properties by adulthood. Intermittent PTH treatment of adult HIT mice resulted in increases in serum osteocalcin levels, femoral total cross-sectional area, cortical bone area and cortical bone thickness, as well as bone mechanical properties. We found that the skeletal response of HIT mice to PTH was significantly higher than that of control mice, suggesting synergy between IGF-1 and PTH on bone. In sharp contrast, although PTH-treated KO-HIT mice demonstrated an anabolic response in cortical and trabecular bone compartments compared with vehicle-treated KO-HIT mice, their response was identical to that of PTH-treated control mice. We conclude that (1) in the presence of elevated serum IGF-1 levels, PTH can exert an anabolic response in bone even in the total absence of tissue IGF-1, and (2) elevations in serum IGF-1 levels synergize PTH action on bone only if the tissue IGF-1 axis is intact. Thus enhancement of PTH anabolic actions depends on tissue IGF-1.
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Affiliation(s)
- Sebastien Elis
- Division of Endocrinology, Diabetes and Bone Disease, Mount Sinai School of Medicine, New York, NY 10029-6574, USA
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Alvarez JA, Ashraf A. Role of vitamin d in insulin secretion and insulin sensitivity for glucose homeostasis. Int J Endocrinol 2010; 2010:351385. [PMID: 20011094 PMCID: PMC2778451 DOI: 10.1155/2010/351385] [Citation(s) in RCA: 253] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Accepted: 06/16/2009] [Indexed: 02/06/2023] Open
Abstract
Vitamin D functions are not limited to skeletal health benefits and may extend to preservation of insulin secretion and insulin sensitivity. This review summarizes the literature related to potential vitamin D influences on glucose homeostasis and insulin sensitivity. Cross-sectional data provide some evidence that circulating 25-hydroxyvitamin D (25(OH)D) is inversely associated with insulin resistance, although direct measurements of insulin sensitivity are required for confirmation. Reported associations with insulin secretion, however, are contradictory. Available prospective studies support a protective influence of high 25(OH)D concentrations on type 2 diabetes mellitus risk. There is a general lack of consistency in vitamin D intervention outcomes on insulin secretion and sensitivity, likely due to differences in subject populations, length of interventions, and forms of vitamin D supplementation. Vitamin D receptor gene polymorphisms and vitamin D interactions with the insulin like growth factor system may further influence glucose homeostasis. The ambiguity of optimal vitamin D dosing regimens and optimal therapeutic concentrations of serum 25(OH)D limit available intervention studies. Future studies, including cross-sectional and prospective, should be performed in populations at high risk for both vitamin D deficiency and type 2 diabetes mellitus. Well-designed, placebo-controlled, randomized intervention studies are required to establish a true protective influence of vitamin D on glucose homeostasis.
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Affiliation(s)
- Jessica A. Alvarez
- Department of Nutrition Sciences, University of Alabama at Birmingham, AL 35233, USA
| | - Ambika Ashraf
- Department of Pediatrics, Division of Pediatric Endocrinology and Metabolism, The Children's Hospital, University of Alabama at Birmingham, AL 35233, USA
- *Ambika Ashraf:
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Abstract
OBJECTIVE To describe the hormonal adaptations and alterations in anorexia nervosa. METHODS We performed a PubMed search of the English-language literature related to the pathophysiology of the endocrine disorders observed in anorexia nervosa, and we describe a case to illustrate these findings. RESULTS Anorexia nervosa is a devastating disease with a variety of endocrine manifestations. The effects of starvation are extensive and negatively affect the pituitary gland, thyroid gland, adrenal glands, gonads, and bones. Appetite is modulated by the neuroendocrine system, and characteristic patterns of leptin and ghrelin concentrations have been observed in anorexia nervosa. A thorough understanding of refeeding syndrome is imperative to nutrition rehabilitation in these patients to avoid devastating consequences. Although most endocrinopathies associated with anorexia nervosa reverse with recovery, short stature, osteoporosis, and infertility may be long-lasting complications. We describe a 20-year-old woman who presented with end-stage anorexia nervosa whose clinical course reflects the numerous complications caused by this disease. CONCLUSIONS The effects of severe malnutrition and subsequent refeeding are extensive in anorexia nervosa. Nutrition rehabilitation is the most appropriate treatment for these patients; however, it must be done cautiously.
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Affiliation(s)
- Lisa S Usdan
- Section of Endocrinology, Diabetes, and Nutrition Boston University School of Medicine, Boston, MA, USA.
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