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Molecularly defined lactose malabsorption, peak bone mass and bone turnover rate in young finnish men.
Calcif Tissue Int 2004; 75(6):488-93CT

Abstract

Lactose malabsorption (LM; adult-type hypolactasia), an autosomal recessive condition, results from the down-regulation of the activity of lactase enzyme in the intestinal wall. In previous studies the effect of LM on bone mass, bone turnover rate, development of osteoporosis and osteoporotic fractures has remained controversial. We have recently identified a single nucleotide polymorphism (SNP), a C to T change residing 13910 base pairs upstream of the lactase (LCT) gene at chromosome 2q21-22, which shows complete association with lactase persistence, with the C/C-13910 genotype defining LM and the genotypes C/T-13910 and T/T-13910 lactase persistence. The present study was undertaken to examine the relationship of the C/T-13910 polymorphism to peak bone mass, bone turnover rate, and stress fractures among young Finnish men. The study population comprised 234 young men, aged 18.3 to 20.6 years, 184 men were recruits of the Finnish Army, and 50 were men of similar age who had postponed their military service for reasons not related to health. Bone mineral content (BMC), density (BMD), and scan area were measured in the lumbar spine and upper femur by dual-energy X-ray absorptiometry (DXA). Blood was sampled for genotyping of the C/T-13910 polymorphism and determination of serum 25-hydroxyvitamin D (25OHD), intact parathyroid hormone (iPTH), type I procollagen aminoterminal propeptide (PINP), and tartrate-resistant acid phosphatase 5b (TRACP5b). Second-void urine samples were collected for the determination of type I collagen aminoterminal telopeptide (NTX). The prevalence of the C/C-13910-genotype of these young adults did not differ significantly from the corresponding population prevalence of C/C-13910 (17.1% vs 18.1%) among Finnish blood donors. Fifteen recruits of the army experienced a stress fracture; 3 of them (20%) had the C/C-13910-genotype. Calcium intake was similar for the three genotypes as were the unadjusted BMCs, scan areas, and BMDs at different measurement sites. The adjustments for age, height, weight, smoking, alcohol consumption, and physical exercise in the multiple regression analysis did not reveal any significant relationships between the lactase genotypes and BMDs at lumbar (P = 0.16), femoral neck (P = 0.99) or total hip (P = 0.96) sites. Serum 25OHD, iPTH, and bone marker levels were similar for the C/C-13910 C/T-13910 and T/T-13910 genotypes. In summary, in young Finnish men, molecularly defined lactose malabsorption does not alter bone turnover rate and impair the acquisition of peak bone mass. Moreover, the C/C-13910 genotype does not seem to be a risk factor for stress fractures in army recruits.

Authors+Show Affiliations

Department of Medical Genetics, University of Helsinki, Helsinki, Finland.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15365657

Citation

Enattah, N, et al. "Molecularly Defined Lactose Malabsorption, Peak Bone Mass and Bone Turnover Rate in Young Finnish Men." Calcified Tissue International, vol. 75, no. 6, 2004, pp. 488-93.
Enattah N, Välimäki VV, Välimäki MJ, et al. Molecularly defined lactose malabsorption, peak bone mass and bone turnover rate in young finnish men. Calcif Tissue Int. 2004;75(6):488-93.
Enattah, N., Välimäki, V. V., Välimäki, M. J., Löyttyniemi, E., Sahi, T., & Järvelä, I. (2004). Molecularly defined lactose malabsorption, peak bone mass and bone turnover rate in young finnish men. Calcified Tissue International, 75(6), pp. 488-93.
Enattah N, et al. Molecularly Defined Lactose Malabsorption, Peak Bone Mass and Bone Turnover Rate in Young Finnish Men. Calcif Tissue Int. 2004;75(6):488-93. PubMed PMID: 15365657.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Molecularly defined lactose malabsorption, peak bone mass and bone turnover rate in young finnish men. AU - Enattah,N, AU - Välimäki,V-V, AU - Välimäki,M J, AU - Löyttyniemi,E, AU - Sahi,T, AU - Järvelä,I, Y1 - 2004/09/16/ PY - 2004/02/06/received PY - 2004/04/16/accepted PY - 2004/9/15/pubmed PY - 2005/4/22/medline PY - 2004/9/15/entrez SP - 488 EP - 93 JF - Calcified tissue international JO - Calcif. Tissue Int. VL - 75 IS - 6 N2 - Lactose malabsorption (LM; adult-type hypolactasia), an autosomal recessive condition, results from the down-regulation of the activity of lactase enzyme in the intestinal wall. In previous studies the effect of LM on bone mass, bone turnover rate, development of osteoporosis and osteoporotic fractures has remained controversial. We have recently identified a single nucleotide polymorphism (SNP), a C to T change residing 13910 base pairs upstream of the lactase (LCT) gene at chromosome 2q21-22, which shows complete association with lactase persistence, with the C/C-13910 genotype defining LM and the genotypes C/T-13910 and T/T-13910 lactase persistence. The present study was undertaken to examine the relationship of the C/T-13910 polymorphism to peak bone mass, bone turnover rate, and stress fractures among young Finnish men. The study population comprised 234 young men, aged 18.3 to 20.6 years, 184 men were recruits of the Finnish Army, and 50 were men of similar age who had postponed their military service for reasons not related to health. Bone mineral content (BMC), density (BMD), and scan area were measured in the lumbar spine and upper femur by dual-energy X-ray absorptiometry (DXA). Blood was sampled for genotyping of the C/T-13910 polymorphism and determination of serum 25-hydroxyvitamin D (25OHD), intact parathyroid hormone (iPTH), type I procollagen aminoterminal propeptide (PINP), and tartrate-resistant acid phosphatase 5b (TRACP5b). Second-void urine samples were collected for the determination of type I collagen aminoterminal telopeptide (NTX). The prevalence of the C/C-13910-genotype of these young adults did not differ significantly from the corresponding population prevalence of C/C-13910 (17.1% vs 18.1%) among Finnish blood donors. Fifteen recruits of the army experienced a stress fracture; 3 of them (20%) had the C/C-13910-genotype. Calcium intake was similar for the three genotypes as were the unadjusted BMCs, scan areas, and BMDs at different measurement sites. The adjustments for age, height, weight, smoking, alcohol consumption, and physical exercise in the multiple regression analysis did not reveal any significant relationships between the lactase genotypes and BMDs at lumbar (P = 0.16), femoral neck (P = 0.99) or total hip (P = 0.96) sites. Serum 25OHD, iPTH, and bone marker levels were similar for the C/C-13910 C/T-13910 and T/T-13910 genotypes. In summary, in young Finnish men, molecularly defined lactose malabsorption does not alter bone turnover rate and impair the acquisition of peak bone mass. Moreover, the C/C-13910 genotype does not seem to be a risk factor for stress fractures in army recruits. SN - 0171-967X UR - https://www.unboundmedicine.com/medline/citation/15365657/Molecularly_defined_lactose_malabsorption_peak_bone_mass_and_bone_turnover_rate_in_young_finnish_men_ L2 - https://dx.doi.org/10.1007/s00223-004-0029-9 DB - PRIME DP - Unbound Medicine ER -