Tags

Type your tag names separated by a space and hit enter

Vitamin K status among children with cystic fibrosis and its relationship to bone mineral density and bone turnover.
Pediatrics 2005; 115(5):1325-31Ped

Abstract

OBJECTIVE

The aim of this study was to assess vitamin K status in an unselected population of children with cystic fibrosis (CF) and to investigate any vitamin K effect on bone turnover and bone mineral status.

METHODS

Children > or =5 years of age who were attending the CF unit were invited to enter the study. Fasting blood samples were analyzed for levels of vitamin K1 and prothrombin produced in vitamin K absence; total, undercarboxylated, and carboxylated osteocalcin (OC); and bone-specific alkaline phosphatase and procollagen I carboxy-terminal propeptide (bone formation markers). Levels of N-telopeptide and free pyridinoline and deoxypyridinoline (bone breakdown products) were measured in urine samples. Bone mineral density and bone mineral content were measured at the lumbar spine and for the total body with a GE Lunar Prodigy densitometer. Statistical analyses were performed with Minitab version 9.1.

RESULTS

One hundred six children entered the study. Sixty-five of 93 children (70%) from whom blood samples were obtained showed suboptimal vitamin K status, on the basis of low serum vitamin K1 levels, increased prothrombin produced in vitamin K absence levels, or both abnormalities. Vitamin K1 levels showed a significant negative correlation with undercarboxylated OC levels but showed no significant correlation with any marker of bone turnover or measurement of bone mineral status. Undercarboxylated OC levels were correlated significantly with bone turnover markers, which themselves showed a significant negative correlation with measurements of bone mineral density and content. There were no significant correlations between carboxylated or undercarboxylated OC levels and bone density measurements.

CONCLUSIONS

Vitamin K1 deficiency is common among children with CF, and routine supplements should be considered. Through its role in the carboxylation of OC, vitamin K deficiency may be associated with an uncoupling of the balance between bone resorption and bone formation. A cause-effect relationship between vitamin K deficiency and low bone mass has not been proved.

Authors+Show Affiliations

Pediatric Cystic Fibrosis Unit, St James' University Hospital, Leeds, United Kingdom. steven.conway@leedsth.nhs.ukNo affiliation info availableNo affiliation info availableNo 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

15867043

Citation

Conway, Steven P., et al. "Vitamin K Status Among Children With Cystic Fibrosis and Its Relationship to Bone Mineral Density and Bone Turnover." Pediatrics, vol. 115, no. 5, 2005, pp. 1325-31.
Conway SP, Wolfe SP, Brownlee KG, et al. Vitamin K status among children with cystic fibrosis and its relationship to bone mineral density and bone turnover. Pediatrics. 2005;115(5):1325-31.
Conway, S. P., Wolfe, S. P., Brownlee, K. G., White, H., Oldroyd, B., Truscott, J. G., ... Shearer, M. J. (2005). Vitamin K status among children with cystic fibrosis and its relationship to bone mineral density and bone turnover. Pediatrics, 115(5), pp. 1325-31.
Conway SP, et al. Vitamin K Status Among Children With Cystic Fibrosis and Its Relationship to Bone Mineral Density and Bone Turnover. Pediatrics. 2005;115(5):1325-31. PubMed PMID: 15867043.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Vitamin K status among children with cystic fibrosis and its relationship to bone mineral density and bone turnover. AU - Conway,Steven P, AU - Wolfe,Susan P, AU - Brownlee,Keith G, AU - White,Helen, AU - Oldroyd,Brian, AU - Truscott,John G, AU - Harvey,Julia M, AU - Shearer,Martin J, PY - 2005/5/4/pubmed PY - 2005/9/28/medline PY - 2005/5/4/entrez SP - 1325 EP - 31 JF - Pediatrics JO - Pediatrics VL - 115 IS - 5 N2 - OBJECTIVE: The aim of this study was to assess vitamin K status in an unselected population of children with cystic fibrosis (CF) and to investigate any vitamin K effect on bone turnover and bone mineral status. METHODS: Children > or =5 years of age who were attending the CF unit were invited to enter the study. Fasting blood samples were analyzed for levels of vitamin K1 and prothrombin produced in vitamin K absence; total, undercarboxylated, and carboxylated osteocalcin (OC); and bone-specific alkaline phosphatase and procollagen I carboxy-terminal propeptide (bone formation markers). Levels of N-telopeptide and free pyridinoline and deoxypyridinoline (bone breakdown products) were measured in urine samples. Bone mineral density and bone mineral content were measured at the lumbar spine and for the total body with a GE Lunar Prodigy densitometer. Statistical analyses were performed with Minitab version 9.1. RESULTS: One hundred six children entered the study. Sixty-five of 93 children (70%) from whom blood samples were obtained showed suboptimal vitamin K status, on the basis of low serum vitamin K1 levels, increased prothrombin produced in vitamin K absence levels, or both abnormalities. Vitamin K1 levels showed a significant negative correlation with undercarboxylated OC levels but showed no significant correlation with any marker of bone turnover or measurement of bone mineral status. Undercarboxylated OC levels were correlated significantly with bone turnover markers, which themselves showed a significant negative correlation with measurements of bone mineral density and content. There were no significant correlations between carboxylated or undercarboxylated OC levels and bone density measurements. CONCLUSIONS: Vitamin K1 deficiency is common among children with CF, and routine supplements should be considered. Through its role in the carboxylation of OC, vitamin K deficiency may be associated with an uncoupling of the balance between bone resorption and bone formation. A cause-effect relationship between vitamin K deficiency and low bone mass has not been proved. SN - 1098-4275 UR - https://www.unboundmedicine.com/medline/citation/15867043/Vitamin_K_status_among_children_with_cystic_fibrosis_and_its_relationship_to_bone_mineral_density_and_bone_turnover_ L2 - http://pediatrics.aappublications.org/cgi/pmidlookup?view=long&pmid=15867043 DB - PRIME DP - Unbound Medicine ER -