Linked Life Data

9262505

Source:http://linkedlifedata.com/resource/pubmed/id/9262505

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-10-22
pubmed:abstractText
Recent evidence suggests that regulatory peptides such as insulin-like growth factor-I (IGF-I) are released locally from bone during resorption, and may then act in a sequential manner to regulate the cellular events required for the coupling of bone formation to resorption. Among other factors, a decrease in bone-associated IGF-I levels could therefore result in remodeling imbalance and contribute to the gradual loss of bone that occurs with age. As the femoral neck region is of primary concern for the clinical manifestations of osteoporosis, the current study was intended to assess the IGF-I contents in femoral neck cortical and trabecular bone from aging individuals. Bone samples from the neck region were obtained at postmortem from 39 females and 35 males, aged 23-92 years. Concentrations of IGF-I and osteocalcin were measured by radioimmunoassay in the supernatants obtained after EDTA and guanidine hydrochloride extraction. The total amount of protein present in the extracts was determined by spectrophotometry. IGF-I levels were significantly lower in trabecular compared with cortical bone. Though femoral neck total protein did not vary with donor age, both IGF-I and osteocalcin were found to decline markedly. Between the ages of 23 and 92 years, average yearly rates of loss of 0.30 and 0.21 ng IGF-I/mg protein were observed in cortical and trabecular bone, respectively, corresponding with net losses of nearly 35% of the cortical skeletal content of IGF-I and 41% of the trabecular skeletal content of IGF-I. These changes in bone-associated IGF-I paralleled those of osteocalcin, consistent with an overall decrease in osteoblast function with aging. In women, the rate of decline was significantly faster for trabecular than for cortical IGF-I, however in men, age-dependent changes in cortical and trabecular IGF-I were similar. These findings support the hypothesis that changes in the local IGF regulatory system over time could be a pathophysiologic component of the age-related (type II) femoral neck osteoporotic syndrome.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0171-967X
pubmed:author
pubmed:issnType
Print
pubmed:volume
61
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
173-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Age-associated decline in human femoral neck cortical and trabecular content of insulin-like growth factor I: potential implications for age-related (type II) osteoporotic fracture occurrence.
pubmed:affiliation
Arthritis and Metabolic Bone Disease Research Unit, Katholieke Universitat Leuven, Leuven, Belgium.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't