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Zhu A, Kuznia S, Niedermaier T, Holleczek B, Schöttker B, Brenner H. Vitamin D-binding protein, total, "nonbioavailable," bioavailable, and free 25-hydroxyvitamin D, and mortality in a large population-based cohort of older adults. J Intern Med 2022; 292:463-476. [PMID: 35373871 DOI: 10.1111/joim.13494] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Epidemiological studies consistently find low concentrations of 25-hydroxyvitamin D (25(OH)D) in blood to be associated with increased mortality, and a recent large-scale Mendelian randomization study strongly supports a causal relationship among individuals with low vitamin D status. Evolving evidence suggested that bioavailable or free 25(OH)D may better predict mortality. We aimed to compare the prognostic values of vitamin D-binding protein (VDBP), total, bioavailable, complementary "nonbioavailable", and free 25(OH)D for total and cause-specific mortality in a large population-based cohort study of older adults from Germany. METHODS Bioavailable, complementary "nonbioavailable", and free 25(OH)D concentrations were calculated among 5899 participants aged 50-75 years, based on serum concentrations of total 25(OH)D, VDBP, and albumin. The cohort was followed with respect to total and cause-specific mortality from recruitment in 2001-2002 up to the end of 2018. Multivariable Cox proportional hazards regression models were used to assess the associations between various vitamin D biomarkers and mortality, and further stratified by vitamin D status. RESULTS During a median follow-up of 17.1 years, 1739 participants died, of whom 575, 584, and 94 died of cardiovascular diseases, cancer, and respiratory diseases, respectively. Very similar inverse associations with total mortality (hazard ratio (HR) per standard deviation decrease: 1.17, 95% confidence interval (CI): 1.11, 1.24 for total 25(OH)D; HR: 1.14, 95% CI: 1.08, 1.21 for bioavailable 25(OH)D; HR: 1.12, 95% CI: 1.06, 1.18 for free 25(OH)D) and cause-specific mortalities were seen for all biomarkers of vitamin D status. The strongest associations were consistently seen for respiratory mortality. These inverse associations were strongest among participants with low vitamin D levels (<50 nmol/L). No significant associations were seen between VDBP and mortality. CONCLUSIONS Total, nonbioavailable, bioavailable, and free 25(OH)D showed very similar inverse associations with total and cause-specific mortality, which were strongest among those with low vitamin D status in this large population-based cohort.
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Affiliation(s)
- Anna Zhu
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Sabine Kuznia
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Tobias Niedermaier
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | | | - Ben Schöttker
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Network Aging Research, Heidelberg University, Heidelberg, Germany
| | - Hermann Brenner
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Network Aging Research, Heidelberg University, Heidelberg, Germany.,Division of Preventive Oncology, German Cancer Research Center (DKFZ) and National Center for Tumor Diseases (NCT), Heidelberg, Germany.,German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), Heidelberg, Germany
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2
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Zhu A, Kuznia S, Niedermaier T, Holleczek B, Schöttker B, Brenner H. Consistent Inverse Associations of Total, “Bioavailable”, Free, and “Non-Bioavailable” Vitamin D with Incidence of Diabetes among Older Adults with Lower Baseline HbA1c (≤6%) Levels. Nutrients 2022; 14:nu14163282. [PMID: 36014788 PMCID: PMC9413175 DOI: 10.3390/nu14163282] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/04/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022] Open
Abstract
Background: Serum 25-hydroxyvitamin (25(OH)D) levels are inversely associated with risk of diabetes. The “free hormone hypothesis” suggests potential effects to be mainly related to concentrations of “bioavailable” and free rather than total 25(OH)D. We assessed associations of serum concentrations of vitamin D-binding protein (VDBP), as well as total “bioavailable”, complementary “non-bioavailable”, and free 25(OH)D, with the risk of developing diabetes among non-diabetic older adults in a large population-based cohort study in Germany. Methods: We included 4841 non-diabetic older adults aged 50–75 years at the baseline exam from the ESTHER cohort conducted in Saarland, Germany, in 2001–2002. Concentrations of “bioavailable” and free 25(OH)D were derived from serum concentrations of VDBP, total 25(OH)D, and albumin. Incidence of diabetes was ascertained during up to 14 years of follow-up. Associations were quantified by multivariable Cox proportional hazards regression models with comprehensive confounder adjustment. Results: During a median follow-up of 10.6 years, 837 non-diabetic participants developed diabetes. We observed similar inverse associations with developing diabetes for VDBP (hazard ratio (HR) for lowest versus highest quintile: 1.37, 95% confidence interval (CI): 1.09, 1.72), total 25(OH)D (HR: 1.31, 95% CI: 1.03, 1.66), and “non-bioavailable” 25(OH)D (HR: 1.30, 95% CI: 1.02, 1.65). Associations were smaller and statistically insignificant for “bioavailable” and free 25(OH)D. However, associations of total “non-bioavailable”, “bioavailable”, and free 25(OH)D with incidence of diabetes were much stronger among, and essentially restricted to, participants with lower baseline HbA1c (≤6%) levels. Conclusions: This large prospective cohort study of older Caucasian adults, in agreement with results from randomized trials and Mendelian randomization studies, supports a protective effect of vitamin D against development of diabetes. The “free hormone theory” may not be relevant in this context. However, our results underline the importance of adequate vitamin D status among those who have not yet shown any sign of impaired glucose tolerance.
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Affiliation(s)
- Anna Zhu
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Medical Faculty Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
| | - Sabine Kuznia
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Medical Faculty Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
| | - Tobias Niedermaier
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | | | - Ben Schöttker
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Network Aging Research, Heidelberg University, 69115 Heidelberg, Germany
| | - Hermann Brenner
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Network Aging Research, Heidelberg University, 69115 Heidelberg, Germany
- Division of Preventive Oncology, German Cancer Research Center (DKFZ) and National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Correspondence: ; Tel.: +49-6221421300
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3
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Fernández-Araque A, Giaquinta-Aranda A, Moreno-Sainz C, Martínez-Martínez MC, Velasco-González V, Sainz-Gil M, Martín-Arias LH, Carretero-Molinero S, García-Hidalgo M, Verde Z. Haplotypes in the GC, CYP2R1 and CYP24A1 Genes and Biomarkers of Bone Mineral Metabolism in Older Adults. Nutrients 2022; 14:259. [PMID: 35057442 PMCID: PMC8778395 DOI: 10.3390/nu14020259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 12/07/2022] Open
Abstract
Candidate gene studies have analyzed the effect of specific vitamin D pathway genes on vitamin D availability; however, it is not clear whether genetic variants also affect overall bone metabolism. This study evaluated the association between genetic polymorphisms in GC, CYP2R1 and CYP24A1 and serum levels of total 25(OH)D, iPTH and other mineral metabolism biomarkers (albumin, total calcium and phosphorus) in a sample of 273 older Spanish adults. We observed a significant difference between CYP2R1 rs10741657 codominant model and total 25(OH)D levels after adjusting them by gender (p = 0.024). In addition, the two SNPs in the GC gene (rs4588 and rs2282679) were identified significantly associated with iPTH and creatinine serum levels. In the case of phosphorus, we observed an association with GC SNPs in dominant model. We found a relationship between haplotype 2 and 25(OH)D levels, haplotype 4 and iPTH serum levels and haplotype 7 and phosphorus levels. In conclusion, genetic variants in CYP2R1 and GC could be predictive of 25(OH)D and iPTH serum levels, respectively, in older Caucasian adults. The current study confirmed the role of iPTH as one of the most sensitive biomarkers of vitamin D activity in vivo.
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Affiliation(s)
- Ana Fernández-Araque
- Department of Nursery, Campus Duques de Soria, University of Valladolid, 42004 Soria, Spain; (A.F.-A.); (A.G.-A.); (S.C.-M.)
- Grupo de Investigación Reconocido “Pharmacogenetics, Cancer Genetics, Genetic, Polymorphisms and Pharmacoepidemiology”, University of Valladolid, 47005 Valladolid, Spain; (V.V.-G.); (M.S.-G.); (L.H.M.-A.)
| | - Andrea Giaquinta-Aranda
- Department of Nursery, Campus Duques de Soria, University of Valladolid, 42004 Soria, Spain; (A.F.-A.); (A.G.-A.); (S.C.-M.)
- Department of Hemodialysis, Hospital Santa Bárbara, 42005 Soria, Spain
| | - Carmelo Moreno-Sainz
- Department of Clinic Biochemistry, Hospital Santa Bárbara, 42005 Soria, Spain; (C.M.-S.); (M.C.M.-M.)
| | | | - Verónica Velasco-González
- Grupo de Investigación Reconocido “Pharmacogenetics, Cancer Genetics, Genetic, Polymorphisms and Pharmacoepidemiology”, University of Valladolid, 47005 Valladolid, Spain; (V.V.-G.); (M.S.-G.); (L.H.M.-A.)
- Department of Nursery, University of Valladolid, 47005 Valladolid, Spain
- Centro de Farmacovigilancia de Castilla y León, University of Valladolid, 47005 Valladolid, Spain
| | - María Sainz-Gil
- Grupo de Investigación Reconocido “Pharmacogenetics, Cancer Genetics, Genetic, Polymorphisms and Pharmacoepidemiology”, University of Valladolid, 47005 Valladolid, Spain; (V.V.-G.); (M.S.-G.); (L.H.M.-A.)
- Centro de Farmacovigilancia de Castilla y León, University of Valladolid, 47005 Valladolid, Spain
- Centro de Estudios sobre la Seguridad de los Medicamentos (CESME), University of Valladolid, 47005 Valladolid, Spain
| | - Luis H. Martín-Arias
- Grupo de Investigación Reconocido “Pharmacogenetics, Cancer Genetics, Genetic, Polymorphisms and Pharmacoepidemiology”, University of Valladolid, 47005 Valladolid, Spain; (V.V.-G.); (M.S.-G.); (L.H.M.-A.)
- Centro de Farmacovigilancia de Castilla y León, University of Valladolid, 47005 Valladolid, Spain
- Centro de Estudios sobre la Seguridad de los Medicamentos (CESME), University of Valladolid, 47005 Valladolid, Spain
| | - Silvia Carretero-Molinero
- Department of Nursery, Campus Duques de Soria, University of Valladolid, 42004 Soria, Spain; (A.F.-A.); (A.G.-A.); (S.C.-M.)
| | | | - Zoraida Verde
- Grupo de Investigación Reconocido “Pharmacogenetics, Cancer Genetics, Genetic, Polymorphisms and Pharmacoepidemiology”, University of Valladolid, 47005 Valladolid, Spain; (V.V.-G.); (M.S.-G.); (L.H.M.-A.)
- Centro de Farmacovigilancia de Castilla y León, University of Valladolid, 47005 Valladolid, Spain
- Departamento de Bioquímica, Biología Molecular y Fisiología, Campus Duques de Soria, University of Valladolid, 42004 Soria, Spain
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de Alarcón R, Alburquerque-González B, Fernández-Valera Á, Molina-Nuñez M, Álvarez Fernandez G, Consuegra-Sánchez L, Luengo-Gil G, Conesa-Zamora P. Pharmacogenetic role of vitamin D-binding protein and vitamin D receptor polymorphisms in the treatment response of dialysis patients with secondary hyperparathyroidism. Nephrol Dial Transplant 2021; 37:792-795. [PMID: 34888693 DOI: 10.1093/ndt/gfab353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Indexed: 11/14/2022] Open
Affiliation(s)
- Rosa de Alarcón
- Nephrology Department, Santa Lucia University Hospital, Cartagena, Spain
| | | | | | | | | | | | - Ginés Luengo-Gil
- Pathology Department. Santa Lucía General University Hospital (HGUSL), Cartagena, Spain.,Group of Molecular Pathology and Pharmacogenetics, Instituto Murciano de Investigación Biosanitaria (IMIB), Hospital Universitario Santa Lucía, Cartagena, Spain.,Clinical Analysis Department, Santa Lucia University Hospital, Cartagena, Spain
| | - Pablo Conesa-Zamora
- Facultad de Ciencias de la Salud, Universidad Católica de Murcia (UCAM), Guadalupe, Spain.,Group of Molecular Pathology and Pharmacogenetics, Instituto Murciano de Investigación Biosanitaria (IMIB), Hospital Universitario Santa Lucía, Cartagena, Spain.,Clinical Analysis Department, Santa Lucia University Hospital, Cartagena, Spain
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5
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Zhu A, Kuznia S, Niedermaier T, Holleczek B, Schöttker B, Brenner H. Distribution and Determinants of Vitamin D-Binding Protein, Total, "Non-Bioavailable", Bioavailable, and Free 25-Hydroxyvitamin D Concentrations among Older Adults. Nutrients 2021; 13:3982. [PMID: 34836237 PMCID: PMC8624653 DOI: 10.3390/nu13113982] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/04/2021] [Accepted: 11/05/2021] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND serum 25-hydroxyvitamin D (25(OH)D) ("total 25 OH(D)") is the most commonly used indicator of vitamin D status. However, 25(OH)D is mostly bound to the vitamin D binding protein (VDBP) or albumin in blood, and it has been suggested that the remaining bioavailable or free 25(OH)D may be more relevant for vitamin D associated health outcomes. We aimed to explore distributions and determinants of VDBP, total, bioavailable, complementary "non-bioavailable", and free 25(OH)D in a large cohort of older adults in Germany. METHODS total 25(OH)D, VDBP, and albumin concentrations were measured in blood samples of 5899 men and women aged 50-75 years and used to calculate bioavailable (and complementary "non-bioavailable") and free 25(OH)D concentrations. Linear regression models were used to evaluate associations of potential determinants of the various vitamin D biomarkers. RESULTS mean concentrations of VDBP, total, non-bioavailable, bioavailable, and free 25(OH)D were 323.6 µg/mL, 49.8 nmol/L, 43.4 nmol/L, 2.5 ng/mL, and 5.7 pg/mL, respectively. Seasonal variations were observed for all markers, with peak values in spring for VDBP and in summer for total, non-bioavailable, bioavailable, and free 25(OH)D. Consistent inverse associations were seen with age and body mass index for all markers, but divergent associations were seen with C-reactive protein. Strong variations by VDBP genotypes were seen for bioavailable and free 25(OH)D, and, in opposite direction for non-bioavailable 25(OH)D. CONCLUSION commonalities and differences in determinants of various markers of vitamin D status were observed, which may help to enable a better understanding of their potential role for various vitamin D related health outcomes.
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Affiliation(s)
- Anna Zhu
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (A.Z.); (S.K.); (T.N.); (B.S.)
- Medical Faculty Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
| | - Sabine Kuznia
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (A.Z.); (S.K.); (T.N.); (B.S.)
- Medical Faculty Heidelberg, Heidelberg University, 69120 Heidelberg, Germany
| | - Tobias Niedermaier
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (A.Z.); (S.K.); (T.N.); (B.S.)
| | | | - Ben Schöttker
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (A.Z.); (S.K.); (T.N.); (B.S.)
- Network Aging Research, Heidelberg University, 69115 Heidelberg, Germany
| | - Hermann Brenner
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; (A.Z.); (S.K.); (T.N.); (B.S.)
- Network Aging Research, Heidelberg University, 69115 Heidelberg, Germany
- Division of Preventive Oncology, German Cancer Research Center (DKFZ) and National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany
- German Cancer Consortium (DKTK), German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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6
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Enlund-Cerullo M, Koljonen L, Holmlund-Suila E, Hauta-Alus H, Rosendahl J, Valkama S, Helve O, Hytinantti T, Viljakainen H, Andersson S, Mäkitie O, Pekkinen M. Genetic Variation of the Vitamin D Binding Protein Affects Vitamin D Status and Response to Supplementation in Infants. J Clin Endocrinol Metab 2019; 104:5483-5498. [PMID: 31365099 DOI: 10.1210/jc.2019-00630] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/25/2019] [Indexed: 02/04/2023]
Abstract
CONTEXT Single nucleotide polymorphisms (SNPs) of the vitamin D binding protein encoding the GC (group component) gene affect 25-hydroxyvitamin D (25OHD) concentrations, but their influence on vitamin D status and response to vitamin D supplementation in infants is unknown. OBJECTIVE To study GC genotype-related differences in 25OHD concentrations and the response to supplementation during a vitamin D intervention study in infants. DESIGN In this randomized controlled trial, healthy term infants received vitamin D3 (10 or 30 μg/d) from 2 weeks to 24 months of age. GC SNPs rs2282679, rs4588, rs7041, and rs1155563 were genotyped. rs4588/7041 diplotype and haplotypes of rs2282679, rs4588, and rs7041 (Haplo3SNP) and of all four SNPs (Haplo4SNP) were determined. MAIN OUTCOME MEASURES 25OHD measured in cord blood at birth and at 12 and 24 months during intervention. RESULTS A total of 913 infants were included. Minor allele homozygosity of all studied GC SNPs, their combined haplotypes, and rs4588/rs7041 diplotype 2/2 were associated with lower 25OHD concentrations at all time points in one or both intervention groups [analysis of covariance (ANCOVA) P < 0.043], with the exception of rs7041, which did not affect 25OHD at birth. In the high-dose supplementation group receiving 30 μg/d vitamin D3, but not in those receiving 10 µg/d, genotype of rs2282679, rs4588, and rs7041; diplotype; and Haplo3SNP significantly affected intervention response (repeated measurement ANCOVA Pinteraction < 0.019). Minor allele homozygotes had lower 25OHD concentrations and smaller increases in 25OHD throughout the intervention. CONCLUSIONS In infants, vitamin D binding protein genotype affects 25OHD concentration and efficiency of high-dose vitamin D3 supplementation.
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Affiliation(s)
- Maria Enlund-Cerullo
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Folkhälsan Research Center, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Laura Koljonen
- Folkhälsan Research Center, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Elisa Holmlund-Suila
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Helena Hauta-Alus
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Jenni Rosendahl
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Saara Valkama
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Otto Helve
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Timo Hytinantti
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Heli Viljakainen
- Folkhälsan Research Center, Helsinki, Finland
- The Department of Food and Nutrition, University of Helsinki, Helsinki, Finland
| | - Sture Andersson
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Outi Mäkitie
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Folkhälsan Research Center, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Center for Molecular Medicine, Karolinska Institutet, and Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Minna Pekkinen
- Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Folkhälsan Research Center, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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7
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Saarnio E, Pekkinen M, Itkonen ST, Kemi V, Karp H, Ivaska KK, Risteli J, Koivula MK, Kärkkäinen M, Mäkitie O, Sievänen H, Lamberg-Allardt C. Low free 25-hydroxyvitamin D and high vitamin D binding protein and parathyroid hormone in obese Caucasians. A complex association with bone? PLoS One 2018; 13:e0192596. [PMID: 29489840 PMCID: PMC5831036 DOI: 10.1371/journal.pone.0192596] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 01/28/2018] [Indexed: 12/16/2022] Open
Abstract
Background Studies have shown altered vitamin D metabolism in obesity. We assessed differences between obese and normal-weight subjects in total, free, and bioavailable 25-hydroxyvitamin D (25(OH)D, 25(OH)DFree, and 25(OH)DBio, respectively), vitamin D binding protein (DBP), parathyroid hormone (PTH) and bone traits. Methods 595 37-47-year-old healthy Finnish men and women stratified by BMI were examined in this cross-sectional study. Background characteristic and intakes of vitamin D and calcium were collected. The concentrations of 25(OH)D, PTH, DBP, albumin and bone turnover markers were determined from blood. 25(OH)DFree and 25(OH)DBio were calculated. pQCT was performed at radius and tibia. Results Mean±SE (ANCOVA) 25(OH)DFree (10.8±0.6 vs 12.9±0.4 nmol/L; P = 0.008) and 25(OH)DBio (4.1±0.3 vs 5.1±0.1 nmol/L; P = 0.003) were lower in obese than in normal-weight women. In men, 25(OH)D (48.0±2.4 vs 56.4±2.0 nmol/L, P = 0.003), 25(OH)DFree (10.3±0.7 vs 12.5±0.6 pmol/L; P = 0.044) and 25(OH)DBio (4.2±0.3 vs 5.1±0.2 nmol/L; P = 0.032) were lower in obese. Similarly in all subjects, 25(OH)D, 25(OH)DFree and 25(OH)DBio were lower in obese (P<0.001). DBP (399±12 vs 356±7mg/L, P = 0.008) and PTH (62.2±3.0 vs 53.3±1.9 ng/L; P = 0.045) were higher in obese than in normal-weight women. In all subjects, PTH and DBP were higher in obese (P = 0.047and P = 0.004, respectively). In obese women, 25(OH)D was negatively associated with distal radius trabecular density (R2 = 0.089, P = 0.009) and tibial shaft cortical strength index (CSI) (R2 = 0.146, P = 0.004). 25(OH)DFree was negatively associated with distal radius CSI (R2 = 0.070, P = 0.049), radial shaft cortical density (CorD) (R2 = 0.050, P = 0.045), and tibial shaft CSI (R2 = 0.113, P = 0.012). 25(OH)DBio was negatively associated with distal radius CSI (R2 = 0.072, P = 0.045), radial shaft CorD (R2 = 0.059, P = 0.032), and tibial shaft CSI (R2 = 0.093, P = 0.024). Conclusions The associations between BMI and 25(OH)D, 25(OH)DFree, and 25(OH)DBio, DBP, and PTH suggest that obese subjects may differ from normal-weight subjects in vitamin D metabolism. BMI associated positively with trabecular bone traits and CSI in our study, and slightly negatively with cortical bone traits. Surprisingly, there was a negative association of free and bioavailable 25(OH)D and some of the bone traits in obese women.
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Affiliation(s)
- Elisa Saarnio
- Calcium Research Unit, Department of Food and Nutrition, University of Helsinki, Helsinki, Finland
| | - Minna Pekkinen
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland
- Children's Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland
| | - Suvi T Itkonen
- Calcium Research Unit, Department of Food and Nutrition, University of Helsinki, Helsinki, Finland
| | - Virpi Kemi
- Calcium Research Unit, Department of Food and Nutrition, University of Helsinki, Helsinki, Finland
| | - Heini Karp
- Calcium Research Unit, Department of Food and Nutrition, University of Helsinki, Helsinki, Finland
| | - Kaisa K Ivaska
- Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Juha Risteli
- Department of Clinical Chemistry, University of Oulu, Oulu, Finland
- Northern Finland Laboratory Centre Nordlab, Oulu, Finland
- Medical Research Center, Oulu, Finland
| | - Marja-Kaisa Koivula
- Department of Clinical Chemistry, University of Oulu, Oulu, Finland
- Northern Finland Laboratory Centre Nordlab, Oulu, Finland
- Medical Research Center, Oulu, Finland
- Tykslab, the Hospital District of Southwest Finland, Turku, Finland
- Department of Clinical Chemistry, University Hospital Turku, Turku, Finland
| | - Merja Kärkkäinen
- Calcium Research Unit, Department of Food and Nutrition, University of Helsinki, Helsinki, Finland
| | - Outi Mäkitie
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland
- Children's Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland
| | - Harri Sievänen
- The UKK Institute for Health Promotion Research, Tampere, Finland
| | - Christel Lamberg-Allardt
- Calcium Research Unit, Department of Food and Nutrition, University of Helsinki, Helsinki, Finland
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