Lactase gene c/t(-13910) polymorphism, calcium intake, and pQCT bone traits in Finnish adults.
Genetic lactase nonpersistence may influence calcium intake and thereby bone health. We investigated in the Cardiovascular Risk in Young Finn Study whether young adults aged 31-46 years with the C/C(-13910) genotype are more susceptible to reduced bone phenotypes, low-energy fractures, and low calcium intake than subjects with other lactase genotypes. We also analyzed the gene-environment interactions on bone with calcium intake and physical activity. Peripheral quantitative computed tomography bone traits were measured from the distal and shaft sites of the radius and tibia. The total number of those subjects whose nondominant forearm was measured and the lactase genotype was defined was 1551. Information on diet, lifestyle factors, and fractures was collected with questionnaires. The mean intake of calcium was the lowest in men with the C/C(-13910) genotype (P = 0.001). Men with the T/T(-13910) genotype had ~3% higher trabecular density at the distal radius and distal tibia compared to other lactase genotypes (P = 0.03 and 0.02, respectively). In women, we found no evidence of the gene effect at the radius and tibia. No major interactions of the C/T(-13910) polymorphism with calcium intake or physical activity on bone phenotypes were found in either sex. In conclusion, the C/T(-13910) polymorphism was associated with trabecular density at the distal radius and tibia in men. These differences may be due to the differences in calcium intake between the lactase genotypes.
Division of Nutrition, Department of Food and Environmental Sciences, University of Helsinki, P.O. Box 66, 00014 Helsinki, Finland. sanna.tolonen@helsinki.fi
Sanna
S
Tolonen
Marika
M
Laaksonen
Vera
V
Mikkilä
Harri
H
Sievänen
Nina
N
Mononen
Leena
L
Räsänen
Jorma
J
Viikari
Olli T
OT
Raitakari
Mika
M
Kähönen
Terho J
TJ
Lehtimäki
D000328:Adult; D015519:Bone Density / Q000235:genetics*; D002136:Calcium, Dietary / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000235:genetics; D015331:Cohort Studies; D005260:Female; D005387:Finland; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000235:genetics; D005838:Genotype; D006801:Humans; D043322:Lactase / Q000235:genetics*; D007787:Lactose Intolerance / Q000235:genetics; D008297:Male; D011110:Polymorphism, Genetic; D012306:Risk; D013977:Tibia / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D044465:White People
D002136:Calcium, Dietary; D043322:Lactase