Efficacy of wheat germ lectin-precipitated alkaline phosphatase in serum as an estimator of bone mineralization rate: comparison to serum total alkaline phosphatase and serum bone Gla-protein.
Serum levels of total alkaline phosphatase activity (S-T-AP), wheat germ lectin-precipitated alkaline phosphatase activity (S-L-AP), and bone Gla-protein immunoreactivity (S-BGP) were measured in 26 patients (23 females and 3 males) aged 35-73 years (mean 59 years) with primary hyperparathyroidism (n = 7), hyperthyroidism (n = 9), and hypothyroidism (n = 10) in whom the bone mineralization rate (m) was determined by 47Ca-kinetics (continuously expanding calcium pool model). A weak positive correlation (r = 0.42, P less than 0.05) was found between S-T-AP and m, which in the range from 0-18 mmol Ca/day could be estimated with a standard error of 4.6 mmol/day. A closer correlation (r = 0.65, P less than 0.001) was found between S-L-AP and m which was estimated with an error of 3.9 mmol Ca/day. The AP activity in the supernatant showed no significant correlation to m (r = 0.11, P greater than 0.50). The highest correlation coefficient (r = 0.81, P less than 0.001) was found between S-BGP and m which could be predicted with an error of 3.4 mmol Ca/day. S-BGP showed a closer correlation to S-L-AP (r = 0.71, P less than 0.001) than to S-T-AP (r = 0.58, P less than 0.01). We concluded that S-L-AP predicts bone mineralization at organ level better than S-T-AP in selected metabolic bone disorders and that the supernatant activity shows no relation to bone turnover.(ABSTRACT TRUNCATED AT 250 WORDS)
University Department of Endocrinology, Aarhus Municipal Hospital, Denmark.
K
K
Brixen
H K
HK
Nielsen
E F
EF
Eriksen
P
P
Charles
L
L
Mosekilde
D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood*; D001842:Bone and Bones / Q000378:metabolism*; D002132:Calcium Radioisotopes; D002135:Calcium-Binding Proteins / Q000097:blood*; D011232:Chemical Precipitation; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000097:blood / Q000378:metabolism; D006980:Hyperthyroidism / Q000097:blood / Q000378:metabolism; D007037:Hypothyroidism / Q000097:blood / Q000378:metabolism; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D008903:Minerals / Q000378:metabolism*; D015675:Osteocalcin; D014909:Wheat Germ Agglutinins
D002132:Calcium Radioisotopes; D002135:Calcium-Binding Proteins; D008903:Minerals; D014909:Wheat Germ Agglutinins; D015675:Osteocalcin; D000469:Alkaline Phosphatase