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Age‐related changes in bone density, serum parathyroid hormone, calcium absorption and other indices of bone metabolism in Chinese women
Author(s) -
Chan E. L. P.,
Lau E.,
Shek C. C.,
MacDonald D.,
Woo J.,
Leung P. C.,
Swamlnathan R.
Publication year - 1992
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1111/j.1365-2265.1992.tb01463.x
Subject(s) - endocrinology , medicine , parathyroid hormone , calcium metabolism , calcium , creatinine , urinary calcium , bone density , bone mineral , bone remodeling , osteoporosis , chemistry
SUMMARY objective To study the age‐related changes in bone density, serum parathyroid hormone, calcium absorption and other indices of calcium metabolism in Chinese women who habitually have a low calcium intake design Cross‐sectional study subjects One hundred and fifty‐six healthy Chinese women aged 20–83 years. None were on any medication or vitamin supplements. Subjects over the age of 60 years were all living in a hostel; younger subjects were nurses or subjects attending a family clinic for minor illnesses measurements Fasting blood and urine samples were collected for biochemical measurements and calcium absorption was measured using Ca by the method of Marshall and Nordin. Bone density was measured by dual energy X‐ray densitometry (Norland X R20 X‐ray bone densitometer) at the left hip and lumbar spine. Serum parathyroid hormone was measured by a chemiluminometric assay results Plasma Ionized calcium concentration, alkaline phosphatase, bicarbonate, plasma creatinine and serum B 2 microgiobulin were significantly higher in the elderly than in the young, whereas plasma phosphate and the anion gap were higher in the young. Urinary excretion of calcium, phosphate and hydroxyproiine were all higher in older women. Plasma parathyroid hormone concentration was positively correlated with age even after taking into account the decline in renal function (as indicated by the rise in B 2 microglobulin ( r = 0·506, P > 0·001). Serum concentrations of 25‐hydroxyvitamin D and 1,25‐dihydroxyvitamin D were not lower In the older women. Fractional calcium absorption from an oral load of radlolabelled calcium was slgnificantly lower in the older women and 37% of the older women were below the 2.5 percentile found in the younger women. Bone density measured by dual energy X‐ray densitometry was also significantly lower in the elderly. conclusion In Chinese women there is an Increase in PTH and a decrease in calcium absorption with age in spite of the presence of normal vitamin D metabolites