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Hou L, Li X, Liu L, Wei H, Xiong F, Du H, Yang Y, Zhang H, Zhang Q, Yao H, Fu J, Yan X, Cui L, Liu G, Li T, Chen S, Li P, Xin Y, Liang X, Yu B, Dong Z, Chen R, Ma H, Cheng X, Luo F, Gong C, Song W, Chen X, Zhang Z, Peng X, Li G, Liang L, Maimaiti M, Cheung PT, Luo X. A Multicenter Survey of Type I Diabetes Mellitus in Chinese Children. Front Endocrinol (Lausanne) 2021; 12:583114. [PMID: 34211433 PMCID: PMC8239384 DOI: 10.3389/fendo.2021.583114] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 05/17/2021] [Indexed: 01/17/2023] Open
Abstract
PURPOSE To investigate the features and treatment status of children with type 1 diabetes mellitus (T1DM) in China. METHODS We recruited patients <14 years of age with T1DM from 33 medical centers in 25 major cities of China between January 2012 and March 2015. All patients completed a questionnaire that was conducted by their pediatric endocrinologists at all centers. RESULTS A total of 1,603 children (755 males and 848 females) with T1DM participated in this survey. Of these, 834 (52.03%) of the patients exhibited diabetic ketoacidosis (DKA) at onset, while 769 patients (47.97%) did not exhibit DKA (non-DKA) at onset. There was a higher proportion of females (55.71%) in the cohort of patients exhibiting DKA at onset than in the non-DKA cohort (49.33%). The mean age of patients exhibiting DKA at presentation was 7.12 ± 0.14 years; this was significantly younger than that in non-DKA group (7.79 ± 0.15 years; P < 0.005). The frequency of DKA in 3 years old, 3-7 years old, and 7 years old or more was 77.21%, 26.17%, and 37.62%, respectively. Upon initial diagnosis, 29.4%, 15.2% and 11.8% of patients showed positivity for glutamic acid decarboxylase antibody (GADA), Insulin autoantibodies (IAA), or islet cell antibody (ICA), respectively. During six months follow-up, 244 patients (15.21%) reported receiving insulin pump therapy, and more than 60% of patients monitored their blood glucose levels less than 35 times per week. Although the majority of patients had no problems with obtaining insulin, 4.74% of the children surveyed were not able to receive insulin due to financial reasons, a shortage of insulin preparations, or the failure of the parents or guardians to acquire the appropriate medicine. CONCLUSION DKA is more common in very young children. Treatment and follow-up of T1DM in China still face very serious challenges.
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Affiliation(s)
- Ling Hou
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiuzhen Li
- Department of Genetics and Endocrinology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Li Liu
- Department of Genetics and Endocrinology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Hanyang Wei
- Department of Endocrinology and Genetic, Henan Provincial Children’s Hospital, Zhengzhou, China
| | - Feng Xiong
- Department of Endocrine and Genetic Metabolism Disease, Children’s Hospital of Chongqing Medical University, Chongqing, China
| | - Hongwei Du
- Department of Pediatrics, The First Affiliated Hospital, Jilin University, Changchun, China
| | - Yu Yang
- Department of Endocrinology, Metabolism, and Genetics, Children’s Hospital of Nanchang University & Jiangxi Provincial Children’s Hospital, Nanchang, China
| | - Huifeng Zhang
- Department of Pediatrics, The Second Affiliated Hospital of Hebei Medical University, Shijiazhuang, China
| | - Qin Zhang
- Department of Endocrinology, Shenzhen Children’s Hospital, Shenzhen, China
| | - Hui Yao
- Department of Endocrinology, Wuhan Children’s Hospital, Wuhan, China
| | - Junfen Fu
- Department of Endocrinology, Children’s Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaoli Yan
- Department of Pediatrics Endocrinology, Xi’an Children’s Hospital, Xi’an, China
| | - Lanwei Cui
- Department of Pediatrics, The First Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Geli Liu
- Department of Pediatrics, General Hospital of Tianjin Medical University, Tianjin, China
| | - Tang Li
- Department of Pediatrics, Qingdao Women and Children’s Hospital, Qingdao University, Qingdao, China
| | - Shaoke Chen
- Department of Pediatrics, The Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Pin Li
- Department of Endocrinology, Shanghai Children’s Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Ying Xin
- Department of Pediatrics Endocrinology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Xiangrong Liang
- Department of Endocrinology, Qilu Children’s Hospital, Shandong University, Jinan, China
| | - Baosheng Yu
- Department of Pediatrics, The Second Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Zhiya Dong
- Department of Pediatrics, Ruijin Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Ruimin Chen
- Department of Endocrinology, Fuzhou Children’s Hospital, Fuzhou, China
| | - Huamei Ma
- Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xinran Cheng
- Department of Endocrinology and Metabolism, Chengdu Women’s and Children’s Central Hospital, Chengdu, China
| | - Feihong Luo
- Department of Pediatric Endocrinology and Inherited Metabolic Diseases, Children’s Hospital of Fudan University, Shanghai, China
| | - Chunxiu Gong
- Endocrinology, Genetics, and Metabolism, Beijing Diabetes Center for Children and Adolescents, Medical Genetics Department, Beijing Children’s Hospital, Beijing, China
| | - Wenhui Song
- Department of Pediatric Endocrinology, Shanxi Provincial Children’s Hospital, Taiyuan, China
| | - Xiaobo Chen
- Department of Endocrinology, Children’s Hospital of Capital Institute of Pediatrics, Beijing, China
| | - Zhixin Zhang
- Department of Pediatrics, China-Japan Friendship Hospital, Beijing, China
| | - Xiangyun Peng
- Department of Endocrinology, Hunan Provincial Children’s Hospital, Changsha, China
| | - Guimei Li
- Department of Pediatrics, Shandong Provincial Hospital, Jinan, China
| | - Liyang Liang
- Department of Pediatrics, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Mireguli Maimaiti
- Department of Pediatrics, The First Affiliated Hospital, Xinjiang Medical University, Urumqi, China
| | - Pik To Cheung
- Paediatric Endocrinology, Genetics, and Metabolism, Virtus Medical Group and The University of Hong Kong, Hong Kong SAR, China
| | - Xiaoping Luo
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Ponsonby AL, Pezic A, Cameron FJ, Rodda C, Kemp AS, Carlin JB, Hyoty H, Sioofy-Khojine A, Dwyer T, Ellis JA, Craig ME. Higher parental occupational social contact is associated with a reduced risk of incident pediatric type 1 diabetes: Mediation through molecular enteroviral indices. PLoS One 2018; 13:e0193992. [PMID: 29664909 PMCID: PMC5903611 DOI: 10.1371/journal.pone.0193992] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 02/22/2018] [Indexed: 01/08/2023] Open
Abstract
We aimed to examine the association between parental occupational social contact and hygiene factors on type 1 diabetes (T1D) risk and possible mediation of these effects through child enteroviral infection. We interviewed 333 incident T1D cases and 660 controls from 2008–2011 in Melbourne, Australia. Enteroviral indices (ribonucleic acid by reverse transcription polymerase chain reaction and Coxsackie B virus antibody levels) in peripheral blood were measured in nested case control samples. Parent occupational social contact was assessed by the number of well or sick children, adults or animals contacted daily through work. Higher parental occupational social contact was strongly associated with reduced T1D risk with evidence of dose response (contact with the well or sick score, Adjusted odds ratio (AOR) per category: 0.73 (95% Confidence Interval (CI): 0.66, 0.81); P<0.001 or AOR 0.63 (95% CI: 0.53, 0.75); P<0.001) respectively). Nine of the ten parental social contact indices, were significant mediated through one or more enteroviral indices. The strength of association between enterovirus presence and T1D onset increased with child age (1.2 fold increase per year; P = 0.05). Lower child hand hygiene enhanced the adverse effect of low parental occupational contact with the sick; Synergy Index 5.16 (95% CI: 3.61, 7.36). The interaction between hand washing and parental occupational contact is more consistent with protection against parental enteroviral shedding than the sharing of a protective infectious agent or microbiome.
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Affiliation(s)
- Anne-Louise Ponsonby
- Murdoch Children’s Research Institute, Royal Children’s Hospital, University of Melbourne, Flemington Rd, Parkville, Victoria, Australia
- National Centre for Epidemiology, Australian National University, Canberra, Australia
- * E-mail:
| | - Angela Pezic
- Murdoch Children’s Research Institute, Royal Children’s Hospital, University of Melbourne, Flemington Rd, Parkville, Victoria, Australia
| | - Fergus J. Cameron
- Murdoch Children’s Research Institute, Royal Children’s Hospital, University of Melbourne, Flemington Rd, Parkville, Victoria, Australia
| | - Christine Rodda
- Murdoch Children’s Research Institute, Royal Children’s Hospital, University of Melbourne, Flemington Rd, Parkville, Victoria, Australia
- Western Centre for Health Research and Education, Sunshine Hospital, St Albans, Victoria, Australia
| | - Andrew S. Kemp
- Murdoch Children’s Research Institute, Royal Children’s Hospital, University of Melbourne, Flemington Rd, Parkville, Victoria, Australia
| | - John B. Carlin
- Murdoch Children’s Research Institute, Royal Children’s Hospital, University of Melbourne, Flemington Rd, Parkville, Victoria, Australia
| | - Heikki Hyoty
- School of Medicine, Virology, University of Tampere, Lääkärinkatu, Finland
| | | | - Terence Dwyer
- Murdoch Children’s Research Institute, Royal Children’s Hospital, University of Melbourne, Flemington Rd, Parkville, Victoria, Australia
- The George Institute for Global Health, Oxford Martin School, University of Oxford, Oxford, United Kingdom
| | - Justine A. Ellis
- Murdoch Children’s Research Institute, Royal Children’s Hospital, University of Melbourne, Flemington Rd, Parkville, Victoria, Australia
- Centre for Social and Early Emotional Development, Faculty of Health, Deakin University, Burwood, Victoria, Australia
| | - Maria E. Craig
- School of Women’s and Children’s Health, University of New South Wales, New South Wales, Australia
- Discipline of Child and Adolescent Health, University of Sydney, New South Wales, Australia
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Thorsen SU, Pipper CB, Johannesen J, Mortensen HB, Pociot F, Svensson J. '25-Hydroxyvitamin D, Autoantigenic and Total Antibody Concentrations: Results from a Danish Case-control Study of Newly Diagnosed Patients with Childhood Type 1 Diabetes and their Healthy Siblings'. Scand J Immunol 2017; 87:46-53. [PMID: 29125655 DOI: 10.1111/sji.12632] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Accepted: 11/05/2017] [Indexed: 01/03/2023]
Abstract
B cells have recently entered the stage as an important accessory player in type 1 diabetes (T1D) etiopathogenesis. Experimental studies suggest regulatory functions of vitamin D on B cells. However, only a few human studies, with considerable methodological limitations, have been conducted within this field. Our objective was to investigate whether higher 25-hydroxyvitamin D (25(OH)D) concentrations were inversely associated with β-cell autoantigens glutamic acid decarboxylase (isoform 65) (GADA) and insulinoma-associated antigen-2A (IA-2A). Further, we also wanted to examine the relationship between 25(OH)D and total antibody concentrations. We randomly selected 500 patients with newly diagnosed T1D and 500 siblings for 25(OH)D, antibody and genetic analysis from the population-based Danish Registry of Childhood and Adolescent Diabetes. The relative change (RC) in the mean concentration of GADA, IA-2A and antibody isotypes by a 10 nmol/l increase in 25(OH)D concentration was modelled by a robust log-normal regression model. We found no association between 25(OH)D and GADA [adjusted RC per 10 nmol/l increase: 1.00; 95% confidence interval (CI): 0.98-1.02] and IA-2A [adjusted RC per 10 nmol/l increase: 0.92; CI: 0.76-1.12]. Further, 25(OH)D was not associated with the total concentration of antibody isotypes [immunoglobulin (Ig)A, IgE, IgG and IgM]. All null findings were unaltered after adjustment for genetic variation in the vitamin D pathway. Physiological concentrations of 25(OH)D are unlikely to have a clinically important effect on antibody concentrations in a paediatric population of newly diagnosed patients with T1D and their healthy siblings.
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Affiliation(s)
- S U Thorsen
- Copenhagen Diabetes Research Center (CPH-DIRECT), Department of Paediatrics, Herlev Hospital, University of Copenhagen, Herlev, Denmark
| | - C B Pipper
- Department of Public Health, Section of Biostatistics, University of Copenhagen, Copenhagen K, Denmark
| | - J Johannesen
- Copenhagen Diabetes Research Center (CPH-DIRECT), Department of Paediatrics, Herlev Hospital, University of Copenhagen, Herlev, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - H B Mortensen
- Copenhagen Diabetes Research Center (CPH-DIRECT), Department of Paediatrics, Herlev Hospital, University of Copenhagen, Herlev, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - F Pociot
- Copenhagen Diabetes Research Center (CPH-DIRECT), Department of Paediatrics, Herlev Hospital, University of Copenhagen, Herlev, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - J Svensson
- Copenhagen Diabetes Research Center (CPH-DIRECT), Department of Paediatrics, Herlev Hospital, University of Copenhagen, Herlev, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark
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4
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Bima A, Pezic A, Sun C, Cameron FJ, Rodda C, van der Mei I, Chiaroni-Clarke R, Dwyer T, Kemp A, Qu J, Carlin J, Ellis JA, Ponsonby AL. Environmental and genetic determinants of two vitamin D metabolites in healthy Australian children. J Pediatr Endocrinol Metab 2017; 30:531-541. [PMID: 28315849 DOI: 10.1515/jpem-2016-0088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 01/31/2017] [Indexed: 01/08/2023]
Abstract
BACKGROUND Vitamin D deficiency has been associated with adverse health outcomes. We examined genetic and environmental determinants of serum 25(OH)D3 and 1,25(OH)2D3 in childhood. METHODS The study sample consisted of 322 healthy Australian children (predominantly Caucasians) who provided a venous blood sample. A parental interview was conducted and skin phototype and anthropometry measures were assessed. Concentrations of 25(OH)D3 and 1,25(OH)2D3 were measured by selective solid-phase extraction-capillary liquid chromatography-tandem mass spectrometry. These concentrations were deseasonalised where relevant to remove the effect of month of sampling. RESULTS Deseasonalised log 25(OH)D3 and 1,25(OH)2D3 concentrations were only moderately correlated (r=0.42, p<0.001). The following predicted both 25(OH)D3 and 1,25(OH)2D3: UVR 6 weeks before the interview, natural skin and eye colour, height and vitamin D allelic metabolism score. The following predicted 25(OH)D3 only: lifetime sunburns and vitamin D allelic synthesis score. Overall, 43.5% and 25.6% of variation in 25(OH)D3 and 1,25(OH)2D3 could be explained. After accounting for 25(OH)D3 concentrations, higher UVR 6 weeks before the interview and vitamin D allelic metabolism score further predicted 1,25(OH)2D3 concentrations. CONCLUSIONS Environmental factors and genetic factors contributed to both vitamin D metabolite concentrations. The intriguing finding that the higher ambient UVR contributed to higher 1,25(OH)2D3 after accounting for 25(OH)D3 concentrations requires further evaluation.
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Affiliation(s)
- Abdulhadi Bima
- Murdoch Childrens Research Institute, Melbourne, Victoria
| | - Angela Pezic
- Murdoch Childrens Research Institute, Melbourne, Victoria
| | - Cong Sun
- Murdoch Childrens Research Institute, Melbourne, Victoria
| | | | - Christine Rodda
- Department of Endocrinology, Sunshine Hospital, University of Melbourne, Melbourne, Victoria
| | | | | | - Terence Dwyer
- Menzies Research Institute, University of Tasmania, Hobart, Tasmania
| | - Andrew Kemp
- Murdoch Childrens Research Institute, Melbourne, Victoria
| | - Jun Qu
- Department of Pharmaceutical Sciences, University at Buffalo, State University of New York, Amherst, NY
| | - John Carlin
- Murdoch Childrens Research Institute, Melbourne, Victoria
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5
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Sun C, Pezic A, Mackey DA, Carlin JB, Kemp A, Ellis JA, Cameron FJ, Rodda CP, Dwyer T, Coroneo MT, Ponsonby AL. Conjunctival Ultraviolet Autofluorescence as a Measure of Past Sun Exposure in Children. Cancer Epidemiol Biomarkers Prev 2017; 26:1146-1153. [PMID: 28446546 DOI: 10.1158/1055-9965.epi-16-0846] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 12/20/2016] [Accepted: 04/04/2017] [Indexed: 11/16/2022] Open
Abstract
Background: Conjunctival ultraviolet autofluorescence (CUVAF) area detected from UVAF photographs is a recently developed potential marker for past sun exposure, but its relationship with sun-related factors has not been fully investigated.Methods: The study included 339 healthy children ages 5 to 15 years in Melbourne, Australia. Data were collected by questionnaire and examination at school. CUVAF area was measured using a computer program and analyzed as a continuous and dichotomous outcome (any/none).Results: Fifty-three children (15.6%) had detectable CUVAF, and the youngest age at which a child showed sun damage was 8 years. Compared with silicone skin cast score, there was good inter-grader agreement on CUVAF grading, with Cohen kappa 0.85 [95% confidence interval (CI), 0.65-1.00] for total CUVAF area using both eye photographs. Perfect intra-grader agreement was achieved. Fairer pigmentation, including medium/fair skin color [adjusted odds ratio (AOR), 3.42; 95% CI, 1.02-11.48 vs. dark/olive] and blue/gray eye color (AOR, 4.07; 95% CI, 1.73-9.55 vs. brown) was associated with increased odds of CUVAF. Increasing lifetime sunburn number (e.g., AOR, 2.89; 95% CI, 1.14-7.35 and 4.29; 1.04-17.76 for sunburns 2 to 4 and ≥ 5 times, respectively, vs. no sunburns, trend P = 0.004) and freckling by the end of last summer were associated with increased odds of CUVAF.Conclusions: CUVAF area can be an a priori objective measure of past sun exposure in pediatric populations for future research.Impact: To our knowledge, this is the first pediatric study that evaluated associations of sun-related risk factors with CUVAF. Cancer Epidemiol Biomarkers Prev; 26(7); 1146-53. ©2017 AACR.
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Affiliation(s)
- Cong Sun
- Murdoch Children's Research Institute, Melbourne, Victoria, Australia.
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Angela Pezic
- Murdoch Children's Research Institute, Melbourne, Victoria, Australia
| | - David A Mackey
- Lions Eye Research Institute, Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Western Australia, Australia
- Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Melbourne, Victoria, Australia
| | - John B Carlin
- Murdoch Children's Research Institute, Melbourne, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Andrew Kemp
- Murdoch Children's Research Institute, Melbourne, Victoria, Australia
| | - Justine A Ellis
- Murdoch Children's Research Institute, Melbourne, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
- Centre for Social and Early Emotional Development (SEED), Faculty of Health, Deakin University, Melbourne, Victoria, Australia
| | - Fergus J Cameron
- Murdoch Children's Research Institute, Melbourne, Victoria, Australia
- Department of Endocrinology and Diabetes, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Christine P Rodda
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
- Australian Institute for Musculo-Skeletal Science, Sunshine Hospital, Melbourne, Victoria, Australia
- Department of Paediatrics, Monash University, Melbourne, Victoria, Australia
| | - Terence Dwyer
- Murdoch Children's Research Institute, Melbourne, Victoria, Australia
- The George Institute for Global Health, Oxford University, Oxford, United Kingdom
| | - Minas T Coroneo
- University of New South Wales, Sydney, New South Wales, Australia
- Department of Ophthalmology, Prince of Wales Hospital, Sydney, New South Wales, Australia
| | - Anne-Louise Ponsonby
- Murdoch Children's Research Institute, Melbourne, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
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Smith CA, Sun C, Pezic A, Rodda C, Cameron F, Allen K, Craig ME, Carlin J, Dwyer T, Lucas RM, Eyles DW, Kemp AS, Ellis JA, Ponsonby AL. Determinants of Neonatal Vitamin D Levels as Measured on Neonatal Dried Blood Spot Samples. Neonatology 2017; 111:153-161. [PMID: 27756067 DOI: 10.1159/000448680] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 07/26/2016] [Indexed: 11/19/2022]
Abstract
BACKGROUND Vitamin D deficiency is linked to adverse childhood health outcomes, yet data on the distribution and quantifiable determinants of neonatal 25-hydroxyvitamin D3 (25OHD) concentration, a vitamin D biomarker, are limited. OBJECTIVE Our aim was to identify determinants of neonatal 25OHD concentration, measured using neonatal dried blood spots (DBS). METHODS A total of 259 ethnically diverse children aged 0-16 years born in Victoria, Australia, were recruited. Data included maternal sun exposure, skin type, 25OHD concentration on stored neonatal DBS, and genotypes at the target genes. Associations were investigated using multiple linear regression models. RESULTS The median 25OHD concentration was 29.2 nmol/l (IQR 18.0-47.4). Measured 25OHD was <50 nmol/l in almost half of the neonatal sample. Ambient ultraviolet radiation (UVR) 6 weeks before birth was the strongest predictor of neonatal 25OHD, accounting for 23% of its variation. A further 10% was explained by infant genetic variants at GC (rs2282679), the gene encoding the vitamin D binding protein, and DHCR7 (rs12785878), a gene required for synthesis of 7-dehydrocholesterol, a precursor to 25OHD. DBS age explained 7%, and patterns of maternal sun exposure and clothing choices accounted for 4%. A child's skin colour was strongly associated with GC gene variants and not independent of these variants in predicting 25OHD. The final model explained 43% of the total variance in neonatal 25OHD concentration. CONCLUSION Maternal lifestyle factors and infant genetic variants predict neonatal 25OHD levels; the importance of maternal UVR exposure in late pregnancy is highlighted.
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Affiliation(s)
- Chloe A Smith
- Murdoch Childrens Research Institute, Royal Children's Hospital, and University of Melbourne, Melbourne, Vic., Australia
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