title: The impact of LRP5 polymorphism (rs556442) on calcium homeostasis, bone mineral density, and body composition in Iranian children.
abstract: Failure to achieve optimal bone mass in childhood is the primary cause of decreased adult bone mineral density (BMD) and increased bone fragility in later life. Activating and inactivating LRP5 gene mutations has been associated with extreme bone-related phenotypes. Our aim was to investigate the role of LRP5 polymorphism on BMD, mineral biochemical parameters, and body composition in Iranian children. This cross-sectional study was performed on 9-18 years old children (125 boys, 137 girls). The serum level of calcium, phosphorous, alkaline phosphatase, and vitamin D parameters were checked. The body composition and BMD variables were measured by the Hologic system DXA. The rs566442 (V1119V) coding polymorphism in exon 15 of LRP5 was performed using PCR-RFLP method. Linear regression analysis, with adjustment for age, gender, body size parameters, and pubertal status was used to determine the association between LRP5 polymorphism (rs556442) and bone and body composition parameters. The allele frequency of the rs566442 gene was 35.5 % A and 63.9 % G. Our study revealed that LRP5 (rs556442) has not any significant influence on serum calcium, phosphorus, 25OHvitD, and serum alkaline phosphatase (P > 0.05). Total lean mass was greater in GG genotype (P = 0.028). Total body less head area (P = 0.044), spine BMD (P = 0.04), and total femoral BMC (P = 0.049) were lower in AG heterozygote genotype. This study show LRP5 polymorphism may associate with body composition and BMD in Iranian children. However, further investigations should be done to evaluate the role of other polymorphism.
authors.affiliation: Shiraz Endocrinology and Metabolism Research Center, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Elham
authors.initials: E
authors.lastname: Ashouri
authors.affiliation: Shiraz Institute for Cancer Research (ICR), Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Elham Mahmoodi
authors.initials: EM
authors.lastname: Meimandi
authors.affiliation: Shiraz Endocrinology and Metabolism Research Center, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Forough
authors.initials: F
authors.lastname: Saki
authors.affiliation: Shiraz Endocrinology and Metabolism Research Center, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran. dabbaghm@sums.ac.ir.
authors.forename: Mohammad Hossein
authors.initials: MH
authors.lastname: Dabbaghmanesh
authors.affiliation: Shiraz Endocrinology and Metabolism Research Center, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Gholamhossein Ranjbar
authors.initials: GR
authors.lastname: Omrani
authors.affiliation: Shiraz Endocrinology and Metabolism Research Center, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran. nahendo2@sums.ac.ir.
authors.forename: Marzieh
authors.initials: M
authors.lastname: Bakhshayeshkaram
mesh_terms: D015502:Absorptiometry, Photon; D000469:Alkaline Phosphatase / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D001823:Body Composition / Q000235:genetics*; D015519:Bone Density / Q000235:genetics*; D002118:Calcium / Q000097:blood*; D002648:Child; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006706:Homeostasis / Q000235:genetics*; D006801:Humans; D007492:Iran; D060492:Low Density Lipoprotein Receptor-Related Protein-5 / Q000235:genetics*; D008297:Male; D008903:Minerals / Q000097:blood; D010758:Phosphorus / Q000097:blood; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*
chemical_list: D015415:Biomarkers; D060492:Low Density Lipoprotein Receptor-Related Protein-5; D008903:Minerals; D010758:Phosphorus; D000469:Alkaline Phosphatase; D002118:Calcium
keywords: Body composition; Bone mineral density; LRP5