title: Age- and gender-related differences in bone mineral status and biochemical markers of bone metabolism in Northern Chinese men and women.
abstract: The aim of this study was to provide insight into the bone mineral status and biochemical markers of bone metabolism in a Chinese population from Shenyang, in the north of China, where hip fracture incidence is low. A total of 194 healthy men and women, aged 25-35 years and 65-75 years, were studied. Bone mineral density (BMD) at the lumbar spine (LS) and femoral neck (FN) was measured using dual-energy X-ray absorptiometry. Fasting blood and 24 h urine samples were collected for bone alkaline phosphatase (bAP), osteocalcin, calcium, phosphate, and free deoxypyridinoline (Dpd). Both older women and men had lower BMD compared with younger women and men by 27.2 +/- 3.0% (mean +/- SE) and 9.8 +/- 3.0% at the LS and 22.0 +/- 3.4% and 12.8 +/- 3.4% at the FN, respectively, after adjusting for bone and body size (p < 0.01). BMD at the two sites was lower in older women than in older men by 10.7 +/- 4.1% and 10.2 +/- 4.2%, respectively, after size correction (p < 0.05). Plasma bAP, osteocalcin, calcium, and phosphate concentrations were higher in older women than younger women by 69.3 +/- 9.7%, 77.2 +/- 11.1%, 7.5 +/- 2.3%, and 8.0 +/- 3.8%, respectively, and older men by 67.6 +/- 11.1%, 72.1 +/- 11.0%, 7.7 +/- 2.3%, and 23.8 +/- 3.8%, respectively (p < 0.01). However, plasma osteocalcin, calcium, and phosphate concentrations were lower in older men compared with their younger counterparts by 35.6 +/- 11.0%, 8.7 +/- 2.3%, and 14.1 +/- 3.8%, respectively (p < 0.05). Urinary calcium and phosphate output were lower in older men compared with younger men by 48.0 plus minus 10.3% and 27.6 +/- 6.9%, respectively (p < 0.01), whereas there were no differences between older and younger women. No differences in Dpd between older and younger groups were found. This study demonstrates that bone mineral status is lower in older people in Shenyang, as has been shown in populations elsewhere. The pronounced low bone mineral status in older women may be associated with increased bone turnover, which was not observed in older men.
authors.affiliation: Medical Research Council Human Nutrition Research, Elsie Widdowson Laboratory, Cambridge, UK. liya.yan@mrc-hnr.cam.ac.uk
authors.forename: L
authors.initials: L
authors.lastname: Yan
authors.forename: A
authors.initials: A
authors.lastname: Prentice
authors.forename: B
authors.initials: B
authors.lastname: Zhou
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.forename: D M
authors.initials: DM
authors.lastname: Stirling
authors.forename: A
authors.initials: A
authors.lastname: Laidlaw
authors.forename: Y
authors.initials: Y
authors.lastname: Han
authors.forename: A
authors.initials: A
authors.lastname: Laskey
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000469:Alkaline Phosphatase / Q000032:analysis; D044466:Asian People; D015415:Biomarkers; D015519:Bone Density; D001842:Bone and Bones / Q000737:chemistry* / Q000201:enzymology*; D002118:Calcium / Q000097:blood / Q000652:urine; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000032:analysis; D010710:Phosphates / Q000097:blood / Q000652:urine; D012727:Sex Characteristics
chemical_list: D015415:Biomarkers; D010710:Phosphates; D015675:Osteocalcin; D000469:Alkaline Phosphatase; D002118:Calcium