Bone mass and biochemical parameters of bone metabolism in men with spinal osteoporosis

With advancing age both sexes have an increased incidence of osteoporotic fractures, although fractures are more common in women than in men. Whereas in women several potential risk factors have been identified, less is known about osteoporosis in men. A total of 27 Austrian men (mean age: 65 +/- 2 years) with atraumatic spine fractures were studied. In all patients, medical history gave no evidence of disease or medications causing osteoporosis. Peripheral bone mass was determined by single-photonabsorptiometry on the distal non-dominant forearm; lumbal bone density was measured by quantitative computed tomography. Serum levels of calcium, phosphate, alkaline phosphatase, osteocalcin, testosterone, estrogen, parathyroid hormone and 25-hydroxy-vitamin D as well as 2-h-urinary-OH proline and calcium excretion were measured. All data were compared with those of an age and sex matched control group consisting of 19 healthy males. A significant difference in mean peripheral and axial bone mass (SPA: P less than 0.004; QCT: P less than 0.0001) was observed between osteoporotic men and controls. When compared to controls, serum levels of alkaline phosphatase (P less than 0.012), urinary OH proline (P less than 0.05) and urinary calcium excretion (P less than 0.003) were significantly higher in the osteoporotic males. Additionally, there was a significant positive correlation between serum alkaline phosphatase and urinary OH proline excretion (r = 0.32; P less than 0.04) in the osteoporotics. All other biochemical parameters showed no significant differences. Our results may lead to the assumption that osteopenia in men is related to increased bone turnover.     

Changes in cortical thickness of the clavicle and serum bone gamma-carboxyglutamic acid-containing protein in the elderly in an island community in western Japan

The cortical thickness of the clavicle (CTC), concentrations of bone gamma-carboxyglutamic acid-containing (Gla) protein (s-BGP, osteocalcin), alkaline phosphatase (s-ALP), calcium (s-Ca) and inorganic phosphorus (s-P) in serum, and calcium/creatinine (u-Ca/Cr) and inorganic phosphorus/creatinine (u-P/Cr) ratios in urine were examined in 211 subjects aged over 40 years in Oshima Island in Nagasaki prefecture. CTC decreased and s-BGP increased with age in both sexes, especially in women. Serum BGP was significantly higher in women than in men at the ages of 50's and over. Serum ALP in women increased until the ages of 60's. Serum Ca at the ages of 50's and s-P at the ages of 60's and over were higher in women than in men. As the increase in s-BGP is reported to be coincident with active bone formation, our findings do not support the view that age-related bone loss, especially in women, primarily results from decrease in bone formation.     

阿仑磷酸钠联合复方丹参片治疗绝经后骨质疏松症患者的效果评价

目的 探讨复方丹参片联合福善美(阿仑磷酸钠)治疗妇女绝经后骨质疏松症,评价其疗效及安全性.方法 将180例绝经后骨质疏松症患者随机分为福善美组、丹参组和复方丹参片联合福善美组(简称联合组).分别采用相应药物进行治疗,疗程6个月,比较2组碱性磷酸酶、骨钙素、尿钙、尿肌酐、尿羟脯氨酸含量及腰1～5骨密度值.结果 联合组的碱性磷酸酶、骨钙素、尿钙、尿肌酐、尿羟脯氨酸、腰1～5骨密度值与其他2组比较差异显著.结论 福善美联合复方丹参片治疗绝经后妇女骨质疏松症安全有效.

Abstract：

Objective To assess whether treatment with compound danshen tablets plus alendronate would be safe and effective in women with postmenopausal osteoporosis. Methods 180 women with postmenopausal osteoporosis were randomized to receive combination therapy and independent therapy with compound danshen tablets and alendronate for 6 months. Scores of VRS were assessed,mean serum alkaline phosphatase, serum osteocalcin, urinary creatinine, urinary hydroxyproline, urinary calcium were detected. Bone mineral density of lumbar vertebra 1 ~5 was determined by dual X - ray absorptiometry. Results Mean serum alkaline phosphatase, serum osteocalcin, and urinary creatinine, urinary hydroxyproline, urinary calcium were statistically different between the combination therapy group and the independent therapy group, and bone mineral densities increased in all therapy groups while there was higher elevated level in the combination therapy group. Conclusions The combination therapy of compound danshen tablets with alendronate has a favorable influence on women with postmenopausal osteoporosis.     

Serum concentrations of MMP-1, MMP-2, and TIMP-1 in Chinese women: age-related changes, and the relationships with bone biochemical markers, bone mineral density

BACKGROUND: Osteoblast-derived matrix metalloproteinse-1 (MMP-1), MMP-2 and tissue inhibitor of metalloproteinase-1 (TIMP-1) play a role in bone metabolism by degrading bone matrix. METHODS: We measured MMP-1, MMMP-2, TIMP-1 and associated results with age and bone metabolism in 591 Chinese women aged 20-80 y. RESULTS: Serum MMP-1, MMP-2, and TIMP-1 concentrations exhibited positive correlation with age. Serum concentrations of MMP-1 were higher in 40-69 y old women. The concentrations of MMP-2 were significantly increased in the 50-69 y olds. Serum TIMP-1 concentrations were significantly lower in women aged 30-59 y, and then these were followed by an increase at >60 y olds. We found a significant negative weaker correlation between MMP-2 and BMD. But multiple linear stepwise regression analysis showed that MMP-2 was not a determinant factor for BMD. There were significant positive correlations between MMP-2 and bone alkaline phosphatase (BAP), osteocalcin (OC), and cross-linked N-telopeptides of type I collagen (NTX). CONCLUSIONS: The serum concentrations of MMP-1, MMP-2, and TIMP-1 exhibit age-related changes, and circulating MMP-2 and bone turnover are related.     

Measurements of whole body retention of diphosphonate and other indices of bone metabolism in 125 normals: dependency on age, sex and glomerular filtration

Measurements of 24-h whole body retention of 99m-Tc-MDP (WBR) has been performed in 125 normal volunteers, together with determinations of serum alkaline phosphatase, urinary hydroxyproline excretion and creatinine clearance. WBR decreased slightly from the 3rd to the 4th decade, after which it increased gradually in the older age-groups. Serum alkaline phosphatase followed an identical pattern, while the urinary hydroxyproline excretion demonstrated a marked but temporary rise in the post-menopausal age-groups. Finally, the creatinine clearance decreased gradually in the older age groups. Analysis of variance demonstrated that WBR varied independently with serum alkaline phosphatase and creatinine clearance, while no relationship between WBR and the hydroxyproline excretion was found. It seems likely that the increasing retention of diphosphonate in elderly persons reflects rising osteoblastic activity as well as decreasing glomerular filtration.     

Assessment of four biochemical markers of bone metabolism in postmenopausal osteoporosis

In order to sudy the specificity and sensitivity of markers of bone metabolism in postmenopausal osteoporosis we investigated bone alkaline phosphatase, osteocalcin and carboxyl-terminal propeptide of procollagen type I in sera as markers of bone formation, and deoxypyridinoline in urine as a marker of bone resorption. The investigated parameters were determined in 53 women with confirmed osteoporosis and in a control group consisting of 45 healthy postmenopausal women without bone changes who were 40 to 79 years old. All biochemical markers were determined by monoclonal competitive enzyme immunoassay tests obtained by Metra Biosystems. The activity of bone alkaline phosphatase and the concentration of osteocalcin, procollagen type IVC-terminal propeptide (PICP), and deoxypyridinoline were grouped according to age of postmenopausal healthy and osteoporotic women. The values of all bone markers gradually increased with age, but significantly higher values were obtained in groups of postmenopausal osteoporotic women. By using receiver operator characteristic curve analysis, a very high specificity and sensitivity of the investigated biochemical markers in the diagnosis of postmenopausal osteoporosis were proven. The areas under the PICP curve and the osteocalcin curve were significantly higher than the area under the deoxypyridinoline curve, demonstrating a higher discriminating power of PICP and osteocalcin than deoxypyridinoline (p < 0.05).     

Wheat-germ agglutinin method for measuring bone and liver isoenzymes of alkaline phosphatase assessed in postmenopausal osteoporosis

In the method of Rosalki and Foo (Clin Chem 1984;30:1182-6) bone and liver isoenzymes of alkaline phosphatase (EC 3.1.3.1) are quantified by using wheat-germ agglutinin (WGA). I suggest standardizing the procedure by using a WGA concentration that precipitates half of the alkaline phosphatase activity of serum pooled from an equal number of healthy women and men. By applying knowledge of the precipitation pattern in serum samples containing predominantly or exclusively bone or liver sources of alkaline phosphatase, I obtained results for the isoenzymes in healthy subjects that agreed with those by the heat-inactivation methods, as reported earlier in the literature. I then assessed the utility of the standardized procedure in a clinical study of prevention of postmenopausal bone loss. In patients receiving hormone replacement therapy, which is known to decrease bone turnover, the decrease in total alkaline phosphatase activity in serum was entirely ascribable to decreases in the bone isoenzyme activity, probably reflecting reduced bone formation, whereas the activity concentration of liver alkaline phosphatase remained unchanged.     

Inherited occurrence of a heat stable alkaline phosphatase in the absence of malignant disease

We describe a family with an inherited persistent elevation of serum alkaline phosphatase activity in the absence of malignant disease, observed for at least 15 yr. Isoenzyme studies revealed that this increased activity was due to an enzyme which showed similarities to serum placental alkaline phosphatase from pregnant women having the following properties: high heat stability; reactivity to anti-placental alkaline phosphatase antiserum; lack of inhibition by L-homoarginine; moderate inhibition by EDTA; and lack of interaction with wheat germ lectin. The enzyme was less sensitive than placental alkaline phosphatase to inhibition by L-phenylalanine, L-tryptophan, L-leucine, L-leucyl-glycyl-glycine and L-phenylalanyl-glycyl-glycine. The enzyme also differed from the placental alkaline phosphatase in its electrophoretic mobility, isoelectric heterogeneity and apparent molecular mass. We conclude that the enzyme is an inherited heat stable alkaline phosphatase variant which might correspond to a rare phenotype of placental alkaline phosphatase.     

Homologous radioimmunoassay of human osteocalcin.

Osteocalcin or bone gamma-glutamic acid-containing protein (GLA protein) was isolated from human bone and used to develop a homologous radioimmunoassay of human osteocalcin. The effect of age on serum osteocalcin was studied in 380 normal children and adolescents and 330 normal adults. The mean (+/- SD) values in adults were higher in men [25 +/- 5 micrograms/L (4.3 +/- 0.8 nmol/L)] than in premenopausal women [20 +/- 6 micrograms/L (3.4 +/- 1.0 nmol/L); P < 0.01], but both were lower than in postmenopausal women [29 +/- 2 micrograms/L (5.0 nmol/L)]. The highest concentrations were seen in girls [ages 10-12 years: 99 +/- 38 micrograms/L (17.0 nmol/L)] and boys [ages 14-16 years: 107 +/- 57 micrograms/L (18.4 nmol/L)]. These mean values were substantially higher than those previously reported for results of heterologous osteocalcin radioimmunoassays but the correlation (r = 0.87, n = 77, P < 0.001) between both sets of results was excellent. In patients with metabolic bone diseases characterized by high or low bone turnover, the increase or decrease in serum osteocalcin observed was as expected. This homologous radioimmunoassay of human osteocalcin thus reflects bone turnover but reports serum concentrations higher than previously suspected.     

Suitability of tartrate-resistant acid phosphatase type 5b as a screening marker for bone mineral density in community-dwelling elderly individuals

Osteoporosis is a common disorder in aging populations that imposes considerable health problems. Tartrate-resistant acid phosphatase type 5b (TRAP-5b) is derived from osteoclasts, and is involved in normal bone homeostasis. Recently, a novel assay system for TRAP-5b, the fragments absorbed immunocapture enzymatic assay method, has been developed. To evaluate the suitability of TRAP-5b as a screening marker for bone mineral density (BMD), we explored the correlations between serum TRAP-5b concentrations and laboratory findings, body mass index, or BMD in 462 community-dwelling elderly individuals (249 men and 213 women, age 73.4±6.5 years) who participated in a regular medical screening program. By multivariate linear regression analysis adjusted for confounding factors, TRAP-5b was significantly correlated with body mass index (β=-0.005, p=0.043), alkaline phosphatase, a marker for osteoid formation and calcification (β=0.001, p<0.001), and triglyceride (β=-0.097, p=0.016) in men, and with body mass index (β=-0.009, p=0.025), alkaline phosphatase (β=0.001, p<0.001), calcium (β=-0.059, p=0.039), and bone trabecular area ratio (β=-0.47, p=0.025) in women. In conclusion, the elevated serum level of TRAP-5b is independently correlated with the decreased BMD in women, but not in men. Because measurement of TRAP-5b is not affected by food intake, and blood samples can be collected at any time of the day, we suggest the suitability of serum TRAP-5b as a simple marker for the evaluation of BMD in women.     

重庆地区骨质疏松患者25-羟维生素D与骨代谢的相关性分析

目的对25-羟维生素D和甲状旁腺激素(PTH)、N端骨钙素(N-MID)、降钙素(CT)、骨碱性磷酸酶(BALP)的相关性进行统计学分析,并探讨其在临床疾病的诊断、预防及治疗中的应用价值。方法收集2014年1-9月重庆医科大学附属第二医院住院患者411例,其中女316例,男95例;平均(69.29±12.21)岁。采用免疫电化学发光法检测住院患者25-羟维生素D、PTH、N-MID、CT、BALP的水平,探讨骨质疏松患者25-羟维生素D与骨代谢标志物的关系。结果25-羟维生素D与PTH、BALP均呈负相关关系(P0.05),而与CT、N-MID则无显著相关(P0.05)。回归分析显示,25-羟维生素D与骨代谢标志物回归方程为Y=19.02-0.066PTH-0.09BALP。结论骨质疏松患者25-羟维生素D水平的升高、降低与PTH、BALP均有一定相关性,通过对这些指标的检测,可以为临床骨质疏松患者的诊断、预防和控制提供基础数据。     

Calcium-phosphorus metabolism and bone metabolism in postmenopausal patients with the thyroid gland pathology

Bone metabolism markers (bone alkaline phosphatase, ionized calcium, inorganic phosphorus, serum osteocalcin) and urinary excretion of hydroxyproline, Ca2+ and P after overnight fasting and of creatinine were studied in 52 female patients with endemic goiter and hypothyrosis (18 of these with decompensated hypothyrosis, 34 treated with thyroid hormones) and 48 women without thyroid diseases aged 45-60 years with menopause of no longer than 10 years (6.4 +/- 0.43 years). Clinical and x-ray examinations were carried out in all women; hormonal status, basal serum levels of parathyroid hormone and calcitonin were evaluated. A trend to deceleration of bone remodeling was detected in the patients with untreated hypothyrosis in comparison with women without thyroid disease. Signs of increased bone resorption were detected in patients with endemic goiter and hypothyrosis receiving substitute hormone therapy; this gave grounds to refer patients of menopausal age with endemic goiter and hypothyrosis treated with oral thyroxin for a long time to a group at a high risk of osteoporosis and bone fractures and to start preventive osteotropic therapy from the first day of substitute thyroid hormone therapy.     

An evaluation of several biochemical markers for bone formation and resorption in a protocol utilizing cyclical parathyroid hormone and calcitonin therapy for osteoporosis.

Female patients (n = 20) with osteoporosis, aged 66 +/- 5 yr were studied during a 24-h infusion of parathyroid hormone (PTH [1-34]) at a rate of 0.5 IU equivalents/kg.h, and then during a 28-d period of subcutaneous injections, at a dose of 800 IU equivalents per day. Thereafter half the patients received subcutaneous injections of calcitonin, 75 U/d for 42 d, and all patients were followed to the end of a 90-d cycle. Biochemical markers of bone formation (serum alkaline phosphatase, osteocalcin, and the carboxy-terminal extension peptide of pro-collagen 1) and bone resorption (fasting urine calcium, hydroxyproline, and deoxypyridinoline) were compared during treatment by the intravenous and subcutaneous route of PTH administration, and subsequently during calcitonin therapy. During intravenous PTH infusion there were significant reductions in all three bone formation markers, despite expected rises in urinary calcium and hydroxyproline. By contrast, the circulating markers of bone formation increased rapidly by > 100% of baseline values during daily PTH injections (P < 0.001). Significant increases in bone resorption markers were only seen at the end of the 28 d of injections, but were < 100% over baseline values, (P < 0.05). Quantitative bone histomorphometry from biopsies obtained after 28 d of PTH treatment confirmed that bone formation at both the cellular and tissue levels were two to five times higher than similar indices measured in a control group of biopsies from untreated osteoporotic women. Subsequent treatment of these patients with calcitonin showed no significant changes in the biochemical markers of bone formation and only a modest attenuation of bone resorption. Thus, PTH infusion may inhibit bone formation, as judged by circulating biochemical markers, whereas daily injections confirm the potent anabolic actions of the hormone. Sequential calcitonin therapy does not appear to act synergistically with PTH in cyclical therapeutic protocols.     

Assessment of vitamin D and calcium status in healthy adult Austrians

BACKGROUND: Because there is reason to assume that also in Austria calcium and vitamin D malnutrition is wide-spread, we initiated a comprehensive study on calcium and vitamin D status in relation to bone health in a large group of the normal adult population. SUBJECTS AND METHODS: We assessed dietary calcium and vitamin D intake, serum concentrations of Ca2+, phosphate, alkaline phosphatase, 25(OH)D, 1,25(OH)2D, parathyroid hormone (PTH), follicle-stimulating hormone (FSH), sex hormones and bone mineral density (BMD) by double-energy X-ray absorptiometry at five different skeletal sites in 648 females and 400 males (age 21-76 years). RESULTS: Mean daily intake of vitamin D (101 IU, range 0.2-320) and calcium (569 mg, range 40-2170) was significantly less than the respective recommended dietary allowances. Two hundred and seventy-one (26%) individuals had hypovitaminosis D with serum 25(OH)D < 12 ng mL(-1), while serum Ca2+ was less than normal in 82 (7.8%) subjects. Multiple regression analysis revealed significant correlations between mean calcium intake and BMD in the femoral region in the men (r = 0.13, P < 0.05) though not in the women. No consistent data could be obtained for associations between BMD and vitamin D status, except for 25(OH)D and BMD at the spine in the men (r = 0.10, P < 0.05). 25(OH)D correlated negatively (P < 0.05) with age in the women (r = -0.11) and with PTH in the women (r = -0.11) and men (r = -0.16). Inversely, a significant (P < 0.001) age-related increase in PTH was observed in both sexes (men, r = 0.19; women, r = 0.14). CONCLUSIONS: Prevalence of hypovitaminosis D in adult Austrians is an imminent risk for development of secondary hyperparathyroidism with advancing age, and requires timely correction of nutritional deficits.     

Multiple forms of alkaline phosphatase in plasma of hemodialysis patients.

We used quantitative assays to measure the activity of the bone, liver, and intestinal forms of alkaline phosphatase in plasma in 75 patients with endstage chronic renal failure undergoing hemodialysis. The results were correlated with radiological and other biochemical indices of bone disease and with biochemical indices of liver disease. The total activity of alkaline phosphatase in plasma increased in 28 patients. In 10 of these patients, nine of whom had increased activity of gamma-glutamyltransferase in plasma, the increase in total activity of alkaline phosphatase was from the liver isoenzyme alone (nine patients) or from the liver and bone isoenzymes together (one patient). Intestinal alkaline phosphatase in plasma, although greater than 23 U/L in eight patients, was solely responsible for the increase in total alkaline phosphatase in one patient (who had normal gamma-glutamyltransferase). Bone alkaline phosphatase in plasma was increased in 25 patients, seven of whom had normal total alkaline phosphatase, and was closely correlated (r = 0.78) with osteocalcin concentration in plasma, which was increased in a much greater proportion of patients (99%). Both total and bone alkaline phosphatase were correlated with parathyrin in plasma (r = 0.46 and 0.50, respectively) and with osteocalcin (r = 0.60 and 0.78, respectively). Osteocalcin and bone alkaline phosphatase, but not parathyrin, decreased with age, implying that the skeletal response to parathyrin may be age dependent. In patients with increased total alkaline phosphatase undergoing hemodialysis, the concurrent measurement of gamma-glutamyltransferase may help identify whether the enzyme increase originates from the liver or bone, but this approach wrongly identified the source of the increase in three of 28 patients. Therefore, we recommend a separate measurement of the bone isoenzyme of alkaline phosphatase.     

Determination of bone Gla protein (osteocalcin) by enzyme-linked immunosorbent assay

Bone Gla protein (BGP, osteocalcin) is a marker of bone formation. We present a novel enzyme-linked immunosorbent assay for measuring BGP in plasma and serum. The antibody used was raised in rabbits following immunisation with highly purified bovine BGP conjugated with keyhole limpet hemocyanin. The binding of the antibody to BGP was calcium-dependent. The sensitivity, inaccuracy, and imprecision of the assay equal or exceed existing radioimmunoassays, and the present assay is less tedious. Plasma BGP in 249 healthy adults, aged from 20 to 93 yr, was 8.3 +/- 6.6 micrograms/l (mean +/- 2 SD). A significant decrease was seen in both sexes from the third to the forth decade of life. A subsequent significant increase was seen with age in women. but not in men. Plasma BGP was significantly higher in young men than in young women, and significantly higher in elderly women than in elderly men. Values were in the same range as those found with existing radioimmunoassays.     

Serum undercarboxylated osteocalcin is a marker of the risk of hip fracture in elderly women.

It has been previously shown that the level of circulating undercarboxylated osteocalcin (ucOC) is elevated in elderly women in comparison with young, healthy, premenopausal ones. To understand the mechanism of the increase in the ucOC in the elderly and to assess its potential consequences on bone fragility, we have measured ucOC in the sera of 195 elderly institutionalized women 70-101 yr of age. In 45 women (23%) serum ucOC was above the upper limit of the normal range for young women. The level of ucOC was negatively correlated with 25OHD (r = -0.32, P < 0.001) even after excluding the effect of age, parathyroid hormone (PTH), and creatinine by partial correlation (r = -0.24, P < 0.002). During an 18-mo follow-up, 15 women sustained a hip fracture and their baseline ucOC level was higher (P < 0.01) in women who subsequently sustained hip fracture than in the nonfracture group contrasting with no significant differences for serum calcium, phosphate, alkaline phosphatase, creatinine, PTH, 250HD, and total and carboxylated OC. The risk of hip fracture was increased in women with elevated ucOC (relative ratio 5.9, 99.9% Cl 1.5-22.7, P < 0.001). During 1 yr of calcium/vitamin D2 treatment, ucOC decreased (P < 0.05), especially in those with the initially increased values (from 2.22 +/- 0.35 to 1.41 +/- 0.29 ng/ml, P <0.005) contrasting with an increase in the placebo group (P < 0.05). In conclusion, the increase in ucOC in the elderly reflects not only some degree of vitamin K deficiency but also their poor vitamin D status, suggesting that vitamin D may be important, either directly or indirectly through its effect on bone turnover, for achieving a normal gamma-carboxylation of OC. The ucOC, but not conventional calcium metabolism parameters, predicts the subsequent risk of hip fracture, suggesting that serum ucOC reflects some changes in bone matrix associated with increased fragility.     

Inorganic pyrophosphate in plasma in normal persons and in patients with hypophosphatasia, osteogenesis imperfecta, and other disorders of bone

An isotope dilution method, using (32)P-labeled pyrophosphate, has been developed for the measurement of inorganic pyrophosphate (PP(1)) in human plasma. The specificity of the method was better than 90% as assessed by elution patterns during ion-exchange chromatography, by paper chromatography, and by incubation with inorganic pyrophosphatase. The 99% confidence limits for a single estimation of plasma PP(1) was +/-13%. There were no differences in plasma PP(1) between men and women, but the values in young people (0-15 yr) were slightly higher than in older people. The mean concentration (+/-SE) of PP(1) in the plasma of 73 men and women was 3.50 +/-0.11 mumoles/liter (0.217 +/-0.007 mug P/ml) and the normal range (99% limits) was 1.19-5.65 mumoles/liter (0.074-0.350 mug P/ml).It has been suggested that PP(1) may be important in calcium metabolism because PP(1) can prevent the precipitation of calcium phosphates in vitro and in vivo, and can slow the rates at which hydroxyapatite crystals grow and dissolve. Plasma PP(1) was therefore measured in several disorders of bone. Normal values were found in osteogenesis imperfecta, osteopetrosis, "acute" osteoporosis, and primary hyperparathyroidism. Plasma PP(1) was invariably raised in hypophosphatasia. The excess of PP(1) in plasma might be the cause of the defective mineralization in hypophosphatasia and the function of alkaline phosphatase in bone may be to act as a pyrophosphatase at sites of calcium deposition.     

Plasma osteocalcin: biological variations and reference limits

Osteocalcin, the most abundant non-collagenous protein in the bone matrix, is partly released in blood. We have measured its concentration by a radio-immunoassay procedure in 1096 apparently healthy subjects from both sexes who came for a health screening examination. Their ages varied from 4 years to over 65 years. Venous blood was drawn in the morning from fasting subjects. Plasma osteocalcin was higher in men than in women. Its level increased significantly with age, body weight, height and bone age until age 12-13 years in girls and 14-15 years in boys. In women, osteocalcin level increased after the age of 50 years and was higher than in men. It remained constant over age 60 years in both sexes, but was higher in women. There was no effect of menstrual cycle in girls at puberty. Plasma osteocalcin did not vary with follicular and luteal phases or with the use of oral contraceptive drugs in women. The usual nonsteroid anti-inflammatory drugs had no effect on blood osteocalcin level. Reference limits according to age and sex are provided.     

Characterization of serum alkaline phosphatase isoenzymes by affinity electrophoresis in agarose gel containing lectin combined with agar gel electrophoresis

The combined use of affinity electrophoresis in agarose gel containing lectin and of agar gel electrophoresis for the quantitation of liver, bone, biliary and intestinal alkaline phosphatase isoenzymes is described. Sera from patients with various diseases and from normal subjects (blood donors) have been analyzed. Data from normal subjects show that the bone isoenzyme is the predominant fraction (about 62%) in adults. The relative proportions of the alkaline phosphatase isoenzymes are similar in both sexes in adulthood (21-50 years). The higher alkaline phosphatase activity found in men than in women (ages 21-50 years) is due to higher values for both liver and bone isoenzymes. The difference between men and women tends to decrease after the age of 50 mainly due to an increase of the bone isoenzyme in women.