title: Association of osteoporosis with genetic variants of circadian genes in Chinese geriatrics.
abstract: This study was designed to investigate the association of circadian gene single nucleotide polymorphisms (SNPs) with the risk of osteoporosis. We found that the rs3781638 GG genotype was positively associated with osteoporosis prevalence in females, whereas the rs2292910 AC genotype was negatively associated with osteoporosis prevalence in a geriatric cohort.
  
  
  BACKGROUND
  Studies have shown that disruption of endogenous circadian rhythms may increase the risk of developing type II diabetes and obesity, which are reportedly associated with osteoporosis (OP). Thus, abnormalities of circadian genes may indirectly induce OP. Here, we investigated the association of OP with 14 SNPs located in seven circadian genes.
  
  
  METHODS
  The research subjects, geriatric residents of Shanghai Minhang, China, diagnosed with OP (N = 171) or osteopenia (N = 226) or without specific diseases (N = 200), were genotyped for 14 genetic variants of circadian genes by competitive allele-specific polymerase chain reaction. The prevalence of polymorphisms among the subject groups and the association between the SNPs and osteoporosis were investigated.
  
  
  RESULTS
  Among the 14 genotyped SNPs, we found an association between the CRY2 gene rs2292910 SNP and osteoporosis (r = -0.082, p = 0.045) in the geriatric cohort. We found a decreased risk between cryptochrome 2 rs2292910 and OP (A/C odds ratio = 0.647, p = 0.044) but an increased risk between MTNR1B rs3781638 and OP (G/G odds ratio = 2.058, p = 0.044).
  
  
  CONCLUSIONS
  For the first time, we show that Cry 2 rs2292910 and MTNR1B rs3781638 are associated with osteoporosis in a Chinese geriatric cohort. Therefore, targeting the abnormalities of the CRY2 and MTNR1B genes may be a potential strategy to treat and/or to prevent osteoporosis.
authors.affiliation: Central laboratory, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, 200240, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.affiliation: Central laboratory, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, 200240, China.
authors.forename: J
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Central laboratory, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, 200240, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Central laboratory, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, 200240, China.
authors.forename: T
authors.initials: T
authors.lastname: Lu
authors.affiliation: Central laboratory, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, 200240, China.
authors.forename: M
authors.initials: M
authors.lastname: Yuan
authors.affiliation: Central laboratory, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, 200240, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Central laboratory, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, 200240, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Central laboratory, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, 200240, China. yanggong@fudan.edu.cn.|Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai, 200032, China. yanggong@fudan.edu.cn.|Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China. yanggong@fudan.edu.cn.
authors.forename: G
authors.initials: G
authors.lastname: Yang
authors.affiliation: Central laboratory, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, 200240, China. hongyangcm@163.com.|Department of Osteology, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, 200240, China. hongyangcm@163.com.
authors.forename: Y
authors.initials: Y
authors.lastname: Hong
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000368:Aged; D044466:Asian People / Q000235:genetics; D015992:Body Mass Index; D015519:Bone Density / Q000235:genetics; D057906:Circadian Clocks / Q000235:genetics*; D056925:Circadian Rhythm Signaling Peptides and Proteins / Q000235:genetics*; D056931:Cryptochromes / Q000235:genetics; D005260:Female; D056726:Genetic Association Studies / Q000379:methods; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000235:genetics* / Q000503:physiopathology; D020641:Polymorphism, Single Nucleotide; D044123:Receptor, Melatonin, MT2 / Q000235:genetics
chemical_list: C538966:CRY2 protein, human; D056925:Circadian Rhythm Signaling Peptides and Proteins; D056931:Cryptochromes; C573871:MTNR1B protein, human; D044123:Receptor, Melatonin, MT2
keywords: Cryptochrome 2; Geriatrics; MTNR1B; Osteoporosis; SNP