The A1330V polymorphism of the low-density lipoprotein receptor-related protein 5 gene (LRP5) associates with low peak bone mass in young healthy men.
BACKGROUND
Polymorphisms in the gene coding for low-density lipoprotein receptor-related protein 5 (LRP5) contribute to variation in bone mass in the general population. Whether this is due to influence on bone mass acquisition or on bone loss thereafter has not been established.


METHODS
We studied the association of LRP5 polymorphisms with peak bone mass in young men. The study included 235 Finnish men, aged 18.3 to 20.6 years. Lifestyle factors and fracture history were recorded. Bone mineral content (BMC), density (BMD) and scan area were measured for the lumbar spine and proximal femur by dual energy X-ray absorptiometry (DXA). Blood and urine were collected for determination of bone turnover markers, serum 25-OHD and PTH. Genomic DNA was extracted from peripheral blood for genetic analysis of LRP5. Ten single nucleotide polymorphisms in LRP5 were analyzed and correlated with bone parameters.


RESULTS
Only the A1330V polymorphism of LRP5 significantly associated with bone parameters. In comparison with subjects with the AlaAla genotype (n=215), those with AlaVal genotype (n=20) had lower femoral neck BMC (P=0.029) and BMD (P=0.012), trochanter BMC (P=0.0067) and BMD (P=0.015), and total hip BMC (P=0.0044) and BMD (P=0.0089). Fracture history was similar for the genotypes.


CONCLUSIONS
The polymorphic valine variant at position 1330 of LRP5 was significantly associated with reduced BMC and BMD values in healthy young Finnish men. The results provide evidence for the crucial role of LRP5 in peak bone mass acquisition.
Saarinen
Anne
A
Folkhälsan Institute of Genetics and Department of Medical Genetics, University of Helsinki, Helsinki, Finland.
Välimäki
Ville-Valtteri
VV
Välimäki
Matti J
MJ
Löyttyniemi
Eliisa
E
Auro
Kirsi
K
Uusen
Piia
P
Kuris
Mairi
M
Lehesjoki
Anna-Elina
AE
Mäkitie
Outi
O
D000293:Adolescent; D000328:Adult; D000483:Alleles; D015519:Bone Density / Q000235:genetics*; D002112:Calcifediol / Q000097:blood; D005387:Finland; D050723:Fractures, Bone / Q000209:etiology / Q000235:genetics; D005787:Gene Frequency; D006801:Humans; D026502:LDL-Receptor Related Proteins / Q000235:genetics*; D060492:Low Density Lipoprotein Receptor-Related Protein-5; D008297:Male; D008889:Military Personnel; D010024:Osteoporosis / Q000209:etiology / Q000235:genetics; D010281:Parathyroid Hormone / Q000097:blood; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors
D026502:LDL-Receptor Related Proteins; C555482:LRP5 protein, human; D060492:Low Density Lipoprotein Receptor-Related Protein-5; C470125:PTH protein, human; D010281:Parathyroid Hormone; D002112:Calcifediol