Different Age-Related Trends of Bone and Nonbone Forms of Alkaline Phosphatase in Chinese Men and Women

Bone alkaline phosphatase (b-ALP; EC 3.1.3.1) is a tetrameric glycoprotein found on the cell surface of osteoblasts. Previous studies have shown that both b-ALP (1) and total ALP (2) can be considered markers of bone formation. Because postmenopausal osteoporosis in women and senile osteoporosis in both sexes are global epidemiological problems, biochemical markers of bone turnover have become important clinical tests. Such markers are used to identify subjects with rapid bone turnover (and thus bone loss) (3) and to monitor the therapeutic efficacy of various drugs (4). These two purposes mandate separate reference ranges for different sexes and age groups. To evaluate the age-related changes of these two markers in Chinese men and women, we measured both total ALP and b-ALP of healthy Chinese men (n = 156, ages 20–90 years) and women (n = 385, ages 40–70 years; 118 premenopausal and 267 postmenopausal), …