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Coley-Grant D, Jawad M, Ashby HL, Cornes MP, Kumar B, Hallin M, Nightingale PG, Ford C, Gama R. The Relationship Between Intact Parathyroid Hormone and 25-Hydroxyvitamin D in United Kingdom Resident South Asians and Whites: A Comparative, Cross-Sectional Observational Study. Horm Metab Res 2021; 53:672-675. [PMID: 34233374 DOI: 10.1055/a-1521-5026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Ethnic differences in intact parathyroid hormone (iPTH) at similar total 25 hydroxyvitamin D [25(OH)D] concentrations have been reported between US resident Whites, Blacks, and Hispanics, but this has not been studied between South Asians and Whites. We, therefore, compared the iPTH relationship to 25(OH)D in UK resident South Asians and Whites. A comparative, cross-sectional observational study in which demographic and laboratory data on South Asian and White residents of Wolverhampton, UK were analyzed. Log-log models measured the association between 25(OH)D and the interaction term of ethnicity and iPTH. Seven hundred and seventy-two patients consisting of 315 white subjects (208 women) and 457 South Asian subjects (331 women) were studied. Compared to South Asians, White subjects were older, had higher serum concentrations of 25(OH)D, creatinine (lower eGFR), adjusted calcium and magnesium, but similar concentrations of iPTH and phosphate. In an adjusted model, variables significantly associated with 25(OH)D included age, creatinine, adjusted calcium and ethnicity; but not iPTH and the interaction term of ethnicity and iPTH (beta coefficient -0.071, 95% CI -0.209, 0.067, p=0.32). In our study cohort, iPTH was not, per se, influenced by 25 (OH)D. We found no ethnic differences in the association between iPTH and 25(OH)D between South Asians and White UK residents.
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Affiliation(s)
- Deon Coley-Grant
- Blood Sciences, Black Country Pathology Services, New Cross Hospital, Wolverhampton, United Kingdom
| | - Mohammed Jawad
- Blood Sciences, Black Country Pathology Services, New Cross Hospital, Wolverhampton, United Kingdom
| | - Helen L Ashby
- Blood Sciences, Black Country Pathology Services, New Cross Hospital, Wolverhampton, United Kingdom
| | - Michael P Cornes
- Blood Sciences, Black Country Pathology Services, New Cross Hospital, Wolverhampton, United Kingdom
| | - Bharan Kumar
- Blood Sciences, Black Country Pathology Services, New Cross Hospital, Wolverhampton, United Kingdom
| | - Magnus Hallin
- Blood Sciences, Black Country Pathology Services, New Cross Hospital, Wolverhampton, United Kingdom
| | - Peter G Nightingale
- Wellcome Trust Clinical Research Facility, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Clare Ford
- Blood Sciences, Black Country Pathology Services, New Cross Hospital, Wolverhampton, United Kingdom
| | - Rousseau Gama
- Blood Sciences, Black Country Pathology Services, New Cross Hospital, Wolverhampton, United Kingdom
- School of Medicine and Clinical Practice, Wolverhampton University, Wolverhampton, United Kingdom
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Banjabi AA, Al-Ghafari AB, Kumosani TA, Kannan K, Fallatah SM. Genetic influence of vitamin D receptor gene polymorphisms on osteoporosis risk. Int J Health Sci (Qassim) 2020; 14:22-28. [PMID: 32694969 PMCID: PMC7346971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
OBJECTIVE Osteoporosis is the most common type of bone disorder characterized by low bone mineral density (BMD). It is a multifactorial disease and caused by the interaction of environmental and genetic factors. It has been reported that mutations in the vitamin D receptor (VDR) gene highly affect the metabolism of minerals, which reduces bone density. Therefore, this study aimed to determine the association of VDR gene polymorphisms TaqI (rs731236) and ApaI (rs7975232) with osteoporosis risk in the Saudi population. METHODS This case-control study involved 73 individuals with osteoporosis and 73 healthy controls in Jeddah, KSA. DNA extracted from peripheral blood was used to determine the genotypes and allele frequencies of VDR variants by polymerase chain reaction-restriction fragment length polymorphisms. Osteoporosis was confirmed by measuring BMD using dual-energy X-ray absorptiometry. The results were interpreted using the Hardy-Weinberg equilibrium assumption with P < 0.05 considered as significant. RESULTS A significant increase in the genotype frequencies of the ApaI (Aa) and (aa) was observed among osteoporotic patients compared to controls (P = 0.002 and P < 0.0001, respectively). Only the homozygous (tt) genotype of TaqI was significantly higher in those with osteoporosis than in the controls (P = 0.001). The minor "a" allele of ApaI and the "t" allele of TaqI were significantly more common in the patients as compared to controls (P < 0.0001 and P = 0.01, respectively). CONCLUSION VDR polymorphisms ApaI and TaqI were found to be significantly determinant risk factors for osteoporosis progression in the Saudi population.
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Affiliation(s)
- Abeer A. Banjabi
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia,Address for correspondence: Abeer A. Banjabi, Department of Biochemistry, Faculty of Science, King Abdulaziz University, P. O. Box 80200, Jeddah 21589, Saudi Arabia. Tel.: +966500655771. E-mail:
| | - Ayat B. Al-Ghafari
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Taha A. Kumosani
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia,Food and Nutrition Central Lab, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia,House of Expertise of Food and Nutrition, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia,Experimental Biochemistry Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Kurunthachalam Kannan
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia,Experimental Biochemistry Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia,Wadsworth Center, New York State Department of Health, Albany, New York 12201, USA,Department of Pediatrics, New York University School of Medicine, New York, New York 100016, USA
| | - Salah M. Fallatah
- Department of Orthopedics, Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia
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Tsuprykov O, Chen X, Hocher CF, Skoblo R, Hocher B. Why should we measure free 25(OH) vitamin D? J Steroid Biochem Mol Biol 2018; 180:87-104. [PMID: 29217467 DOI: 10.1016/j.jsbmb.2017.11.014] [Citation(s) in RCA: 132] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/30/2017] [Accepted: 11/30/2017] [Indexed: 11/21/2022]
Abstract
Vitamin D, either in its D2 or D3 form, is essential for normal human development during intrauterine life, kidney function and bone health. Vitamin D deficiency has also been linked to cancer development and some autoimmune diseases. Given this huge impact of vitamin D on human health, it is important for daily clinical practice and clinical research to have reliable tools to judge on the vitamin D status. The major circulating form of vitamin D is 25-hydroxyvitamin D (25(OH)D), although it is not the most active metabolite, the concentrations of total 25-hydroxyvitamin D in the serum are currently routinely used in clinical practice to assess vitamin D status. In the circulation, vitamin D - like other steroid hormones - is bound tightly to a special carrier - vitamin D-binding protein (DBP). Smaller amounts are bound to blood proteins - albumin and lipoproteins. Only very tiny amounts of the total vitamin D are free and potentially biologically active. Currently used vitamin D assays do not distinguish between the three forms of vitamin D - DBP-bound vitamin D, albumin-bound vitamin D and free, biologically active vitamin D. Diseases or conditions that affect the synthesis of DBP or albumin thus have a huge impact on the amount of circulating total vitamin D. DBP and albumin are synthesized in the liver, hence all patients with an impairment of liver function have alterations in their total vitamin D blood concentrations, while free vitamin D levels remain mostly constant. Sex steroids, in particular estrogens, stimulate the synthesis of DBP. This explains why total vitamin D concentrations are higher during pregnancy as compared to non-pregnant women, while the concentrations of free vitamin D remain similar in both groups of women. The vitamin D-DBP as well as vitamin D-albumin complexes are filtered through the glomeruli and re-uptaken by megalin in the proximal tubule. Therefore, all acute and chronic kidney diseases that are characterized by a tubular damage, are associated with a loss of vitamin D-DBP complexes in the urine. Finally, the gene encoding DBP protein is highly polymorphic in different human racial groups. In the current review, we will discuss how liver function, estrogens, kidney function and the genetic background might influence total circulating vitamin D levels and will discuss what vitamin D metabolite is more appropriate to measure under these conditions: free vitamin D or total vitamin D.
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Affiliation(s)
- Oleg Tsuprykov
- IFLB, Institute for Laboratory Medicine, Berlin, Berlin, Germany; Institute of Nutritional Sciences, University of Potsdam, Potsdam, Germany
| | - Xin Chen
- Departments of Embryology and Nephrology, The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Carl-Friedrich Hocher
- Departments of Embryology and Nephrology, The First Affiliated Hospital, Jinan University, Guangzhou, China; First Medical Faculty, Charles University of Prague, Prague, Czech Republic
| | - Roman Skoblo
- IFLB, Institute for Laboratory Medicine, Berlin, Berlin, Germany
| | - Berthold Hocher
- Institute of Nutritional Sciences, University of Potsdam, Potsdam, Germany; Departments of Embryology and Nephrology, The First Affiliated Hospital, Jinan University, Guangzhou, China.
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