Lack of Correlation between Levels of Osteocalcin and Bone Alkaline Phosphatase in Healthy Control and Postmenopausal Osteoporotic Women

Abstract

The determination of bone alkaline phosphatase (bAR) by IRMA and the measure of intact osteocalcin (BGP) andlor different fragments by IRMA and/or RIA are new commercially available methods for the evaluation of osteoblast activity. The aim of this work was to study the possible correlation among serum bAR and levels of BGP measured by two different methods: an IRMA which only detects intact-BGP and a RIA which detects intact-BGP and carboxyterminal fragments (C-terminal BGP) in healthy postmenopausal control women and in a group of patients with postmenopausal osteoporosis. Serum samples from 42 consecutive osteoporotic postmenopausal women, aged 62 11 years, between 39-76, and 14 control women age matched, were drawn after an overnight fasting. Levels of total alkaline phosphatase (AR), bAR, intact BGP, and intact BGP and carboxy terminal fragments were measured. In both groups we found a significant linear correlation between the levels of AP and bAP (r = 0.79, p <0.001) and intact-BGP and C-terminal BGP (r = 0.97, p<O.OOl), but surprisingly we did not find a significant linear correlation between AR or bAR levels and BGP measured in any of the two methods. These results suggest that AR release from osteoblast vesicles and BGP synthesis in these cells are not necessarily simultaneous, reflecting different stages of osteoblast activity.

Comparison of bone and total alkaline phosphatase activity on bone turnover during menopause and in patients with established osteoporosis

“…970) between bAP (Tandem-R Ostase IRMA) and tAP in Paget's disease, where the values of bAP varied widely. High or moderate correlations between bAP measured by IRMA or wheat germ agglutinin (WGA) have been reported in post-menopausal women (Diego et al, 1995;Bouman et al, 1995). In this study, because the correlation coefficient was high even in the healthy subjects in whom the data were less variable, the variations of the data did not greatly affect the correlation between tAP and bAP.…”

Simultaneous alterations in ovaries and bone as a result of Polycystic Ovary Syndrome

“…Significant associations between ALP and bone mineral density, after controlling for other variables, suggested that ALP might interacts with other factors, leading to alteration of bone metabolism 63 . In contrast, no relationship was found between ALP and bone density in elderly men, suggesting that ALP was not useful for monitoring bone integrity 64 , while no correlations were found between levels of osteocalcin and bone alkaline phosphatase in healthy and postmenopausal osteoporotic women 65 . The results of the present study showed that plasma ALP levels were elevated in PCOS-induced animals.…”

Current knowledge of bone-derived factor osteocalcin: its role in the management and treatment of diabetes mellitus, osteoporosis, osteopetrosis and inflammatory joint diseases

“…Several studies indicated a higher level of tOC in PMO cases [ 113 – 121 ]. However, there are also researches reporting the same or even lower tOC level in osteoporotic patients [ 122 – 125 ]. Biver et al [ 126 ] and Liu et al [ 127 ] performed meta-analyses to compare several markers of bone turnover and found no significant difference in tOC level between osteoporotic and healthy individuals.…”