Collagen type 1 (COL1A1) Sp1 binding site polymorphism is associated with osteoporotic fractures but not with bone density in post-menopausal women from the Canary Islands: a preliminary study.
OBJECTIVE
An association between the polymorphism for transcription factor Sp1 in the gene COL1A1 and low bone density (BMD) and osteoporotic fractures has been described but not confirmed for all races and ages. The aim of this preliminary work was to ascertain whether this association is present in women from the Canary Islands.


METHODS
Polymerase chain reaction RFLP was used to determine COL1A1 polymorphism Sp1 in 199 consecutive outpatient post-menopausal Caucasian women from the Canary Islands, aged 50-70 years. BMD was measured at lumbar spine and hip by DXA and at third lumbar vertebrae by QCT. Prevalent vertebral fractures were recorded on standard lateral X-ray film. Non-vertebral osteoporotic fractures were registered by medical record and self-reported history. Biochemical markers (serum osteocalcin, tartrate-resistant acid phosphatase), blood calcium and phosphate were also assessed.


RESULTS
Distribution genotypes were 113 (50.8%) GG homozygotes, 73 (36.7%) Ss heterozygotes and 7 (3.5%) TT homozygotes. All patients with osteoporotic fractures carried the GG allele more frequently than TT homozygotic women. The odds ratio was 3.01 (95% CI 1.6-5.7) for prevalent vertebral fractures (n=62) and 2.33 (95% CI 1.2-4.4) for all osteoporotic fractures (n=65) for the T-carrying allele vs TT homozygotic women. There was no difference in BMD measured by DXA or QCT, nor in bone markers, blood calcium or phosphate.


CONCLUSIONS
This preliminary study confirmed that the presence of at least one copy of the T allele is associated with osteoporotic fractures, but not with low BMD, in women from the Canary Islands.
Navarro
Mary C
MC
University of Las Palmas de Gran Canaria, Osteoporosis Research Group, Bone Metabolic Unit, Hospital University Insular, Gran Canaria, Canary Islands, Spain.
Sosa
Manuel
M
del Pino-Montes
Javier
J
Torres
Armando
A
Salido
Eduardo
E
Saavedra
Pedro
P
Corral-Gudino
Luis
L
Montilla
Carlos A
CA
D000368:Aged; D001665:Binding Sites / Q000235:genetics; D015415:Biomarkers; D015519:Bone Density / Q000235:genetics*; D002118:Calcium / Q000378:metabolism; D024042:Collagen Type I / Q000235:genetics* / Q000378:metabolism; D000090602:Collagen Type I, alpha 1 Chain; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology / Q000235:genetics* / Q000378:metabolism; D020022:Genetic Predisposition to Disease / Q000453:epidemiology; D005838:Genotype; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000453:epidemiology / Q000235:genetics* / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D010865:Pilot Projects; D011110:Polymorphism, Genetic; D017698:Postmenopause / Q000235:genetics; D013030:Spain / Q000453:epidemiology
D015415:Biomarkers; D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D010710:Phosphates; D002118:Calcium