Cytosine-adenine repeat polymorphism at calcitonin gene locus associated with serum osteocalcin level in Japanese women.
Bone mineral density and the serum concentration of osteocalcin are influenced by multiple genetic factors, including hormone and genes. Our aim was to evaluate the correlation between the dinucleotide (cytosine (C)-adenine (A)) repeat polymorphism at the calcitonin locus and bone mineral density and serum osteocalcin levels. Sixty-six healthy Japanese women over 50 years of age were included in this study. The bone mineral density of the second to fourth lumbar vertebrae was measured using dual-energy X-ray absorptiometry and serum osteocalcin was measured using an immunoradiometric assay. We isolated DNA from peripheral leukocytes and genotyped the cytosine-adenine repeats at the calcitonin locus using the polymerase chain reaction. We found that bone mineral density was not correlated with the number of cytosine-adenine repeats. However, the circulating osteocalcin level was significantly different among the different cytosine-adenine repeat groups. The osteocalcin level of the 10/17 (C-A) heterozygote group was significantly lower than those of the other groups (p<0.01). The 10/17 (C-A) and 17/17 (C-A) genotypes are common in the Japanese population, and the osteocalcin levels of the 10/17 heterozygotes were significantly lower than those of the 17/17 homozygote (p<0.05). Our findings suggest that the cytosine-adenine repeat at the calcitonin gene locus may be one of the genetic factors that regulate serum osteocalcin levels in Japanese women.
Nakamura
M
M
Department of Pathology, Wakayama Medical University, Kimiidera, Wakayama, Japan. marumisa@wakayama-med.ac.jp
Morimoto
S
S
Ishii
A
A
Higuchi
T
T
Ogihara
T
T
Kakudo
K
K
D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015519:Bone Density / Q000235:genetics*; D002116:Calcitonin / Q000235:genetics*; D018900:Dinucleotide Repeats / Q000235:genetics*; D005260:Female; D006801:Humans; D015592:Immunoradiometric Assay; D007564:Japan; D008159:Lumbar Vertebrae / Q000737:chemistry; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood*; D011110:Polymorphism, Genetic
D015675:Osteocalcin; D002116:Calcitonin