Urinary Hydroxyproline Excretion Research Articles

Urinary collagen peptides: Source of markers for bone metabolic processes in kidney transplant recipients.

Kidney transplant recipients (KTRs) are at an increased risk of fractures. Total urinary hydroxyproline excretion served as marker for bone resorption (BR) but was replaced by β-CrossLaps (CTX), a C-terminal collagen α-1(I) chain (COL1A1) telopeptide. We investigated the low-molecular-weight urinary proteome for peptides associated with changes in bone metabolism after kidney transplantation. Clinical and laboratory data including serum levels of CTX in 96 KTR from two nephrology centers were correlated with signal intensities of urinary peptides identified by capillary electrophoresis mass spectrometry. Eighty-two urinary peptides were significantly correlated with serum CTX levels. COL1A1 was the predominant peptide source. Oral bisphosphonates were administered for decreased bone density in an independent group of 11 KTR and their effect was evaluated on the aforementioned peptides. Study of the peptides cleavage sites revealed a signature of Cathepsin K and MMP9. Seventeen of these peptides were significantly associated with bisphosphonate treatment, all showing a marked reduction in their excretion levels compared to baseline. This study provides strong evidence for the presence of collagen peptides in the urine of KTR that are associated with BR and that are sensitive to bisphosphonate treatment. Their assessment might become a valuable tool to monitor bone status in KTR.

STUDY OF SERUM URIC ACID, CALCIUM AND ALPAND URINARY HYDROXYPROLINE CREATININE RATIO IN POSTMENOPAUSAL WOMEN

During menopause women succumb to physiological and biochemical changes along with middle age health hazards. In view of sudden fall in Estrogens during menopause Osteoporosis of aging is fortied by Estrogen deciency. The present study was done to evaluate bone health through biochemical parameters in Guntur Urban area between September 2021 and January 2022. 50 Premenopausal women and 60 postmenopausal women were selected for the study after screening verbally . Serum Calcium, Phosphorus, Alk, Phosphatase and Uric acid along with 24Hrs urinary excretion of Creatinine, Calcium and Hydroxyproline were estimated in both groups. We could not nd wide difference in the mean values of serum Ca , P, ALP& UAbut Urine 24 Hrs Ca was lower in postmenopausal women (104.55±23.86) compared to premenopausal group (124.42 ±17.78 ). Urine Hydroxyproline(HOP) showed higher values in postmenopausal women (25.79±1.44 ) than in Premenopausal women.(18.00 ± 2.55). All the analytes showed statistically signicant values between the groups and within the groups with P value value of <0.0001. 24Hrs urine Hydroxyproline , which is collagen degradation product correlated with 24hrs urine Ca and Creatinine.With P value < 0.0001 Serum ALP , Ca & Uric acid as shown by ANOVA, both within groups and between groups was statistically signicant P <0.0001. We conclude that collagen degradation product like HOPcan be evaluated and considered as marker for assessment of bone health in postmenopausal women.

Tactics for treating young children with pyelonephritis and vesicoureteral reflux associated with impaired fibrillogenesis.

The purpose of this study is to substantiate the choice and evaluate the effectiveness of therapeutic tactics aimed at suppressing collagen formation and improving metabolic processes in the kidney parenchyma in young children with pyelonephritis against the background of vesicoureteral reflux associated with undifferentiated tissue dysfunction. 67 children from 2weeks to 3years old with pyelonephritis and vesicoureteral reflux were examined. All children during the period of remission of the inflammatory process were examined for the content of oxyproline in the urine. Urine crystallinity and urinary excretion were determined, and markers of the morphofunctional state of the cytomembranes of the renal epithelium were determined: calcification test-the presence of polar lipids in the urine and test for the presence of lipid peroxidation products in the urine. Children with high urinary hydroxyproline excretion prior to protocol treatment of pyelonephritis during the remission of the inflammatory process at the stage of maintenance therapy were recommended to receive metabolic preparations that can inhibit collagen formation and improve parenchyma metabolic processes during the month-vitamin E 10% and L-carnitine in age-related doses. After 6months, a study was made on the functional state of the renal parenchyma in the dynamics of treatment. After metabolic antihypoxic and membrane-protective therapy, there was a significant positive dynamic of all markers of tissue hypoxia and membrane destruction in the kidney parenchyma, which confirms the inhibition of collagen formation processes and a decrease in tissue hypoxia with vitamin E and L-carnitine in age-related doses.

Роль метаболической терапии в лечении гипоксии паренхимы почек у детей с пиелонефритом, ассоциированным с недифференцированной дисплазией соединительной ткани

Цель: обосновать выбор и оценить эффективность применения метаболического лечебного комплекса (витамин Е и L-карнитин), направленного на уменьшение тканевой гипоксии и улучшение метаболических процессов в паренхиме почек в терапии острого пиелонефрита на фоне пузырно-мочеточникового рефлюкса как висцерального проявления недифференцированной дисплазии соединительной ткани у детей раннего возраста. Материалы и методы. Обследованы 67 детей с пиелонефритом и пузырно-мочеточниковым рефлюксом (ПМР), ассоциированным с недифференцированной дисплазией соединительной ткани (НДСТ), в возрасте от 3 месяцев до 3 лет. В контрольную группу вошли 65 детей раннего возраста с острым пиелонефритом, у которых после обследования не было выявлено ПМР и признаков НДСТ. Вторую группу контроля составили 40 соматически здоровых детей этого же возраста. С целью диагностики наличия недифференцированной дисплазии соединительной ткани всем детям в периоде ремиссии воспалительного процесса проводился тест на содержание оксипролина в моче. Определялись маркеры недифференцированной тканевой гипоксии паренхимы почек: тест на антикристаллобразующую функцию мочи и суточную экскрецию солей в моче по методике Ю.Е.Вельтищева и Э.А.Юрьевой. Исследовались маркеры морфофункционального состояния цитомембран почечного эпителия: проба на кальцификацию — наличие полярных липидов в моче и тест на наличие продуктов перекисного окисления липидов в моче. Детям раннего возраста с пиелонефритом, ПМР и НДСТ, в моче которых была установлена высокая экскреция оксипролина, в дополнение к протокольному лечению в периоде ремиссии воспалительного процесса был рекомендован прием в течение месяца комплекса витамина Е и L-карнитина в возрастных дозах, способного улучшать метаболические процессы в паренхиме почек. Результаты. После метаболической терапии с антигипоксантным и мембранопротекторным действием у обследованных детей наблюдалась значительная положительная динамика изучаемых маркеров тканевой гипоксии и мембранодеструкции паренхимы почек. Выводы. Выявлено положительное влияние метаболического комплекса (витамин Е и L-карнитин) в периоде ремиссии воспалительного процесса почек, который выразился в уменьшении степени тканевой гипоксии и мембранодеструкции, что подтверждает возможность уменьшения тканевой гипоксии у детей с пиелонефритом и пузырно-мочеточниковым рефлюксом, ассоциированным с недифференцированной дисплазией соединительной ткани, при применении витамина Е и L-карнитина в возрастных дозах в течение месяца и позволяет рекомендовать этим детям проведение метаболической терапии.

Comparison of Bone Turnover Markers on Osteoporosis in Pre and Postmenopausal Women

Osteoporosis, a major public health problem, is becoming increasingly prevalent with the aging of theworld population. Rapid bone loss occurs in postmenopausal women due to hormonal factors whichlead to increased risk of fractures. Biochemical markers of bone metabolism are used to assess skeletalturnover. Bone formation markers (Total Calcium, Ionised calcium,Alkaline phosphatase), and boneresorption markers (Urinary Hydroxyproline) were analysed in pre and post menopausal women. A crosssectional study of 200pre- and post menopausal women was carried out at Sree Balaji Medical Collegeand Hospital,chennai. Bone formation markers (Total Calcium, Ionised calcium, Alkaline phosphatase),and bone resorption markers (Urinary Hydroxyproline) were analysed in pre and post menopausal women.Bone formation markers, Total and Ionised calcium were significantly decreased (p<0.001) and Alkalinephosphatase was significantly increased (p<0.001) in postmenopausal women compared to premenopausalwomen. Bone resorption markers, Urinary hydroxyproline excretion was significantly increased (p<0.001)in postmenopausal women. The results from this study suggests that simple, easy, common biochemicalmarkers such as age, years after menopause,urinary hydroxyproline, total serum ALP, total serum calciumand ionized calcium could be used as indicators of increased bone turnover, to enable early intervention soas to minimize fracture due to osteoporotic changes.

MODERN CONCEPTS IN REGULATORY MECHANISMS OF INDUCTION OF LABOR

In modern conditions of the development of obstetric science, one of the leading factors ensuring the reduction of maternal and perinatal morbidity and mortality is the solution of the problem of labor disorders by improving knowledge of the biological mechanisms of the birth process. The urgency of the problem of violations of labor is due to the frequency of distribution in the population, reaching 30%. The outcome of childbirth for the mother and fetus depends on the biological readiness of the woman’s body for childbirth. There is no doubt that the study of the mechanisms of preparation for physiological childbirth at the cellular-molecular level can provide important progress in this direction.The aim of research is to determine new mechanisms for regulating the preparation of a pregnant woman’s body for childbirth by studying the influence of hormonal and immunological factors on the maturation of the cervix.Materials and research methods. To achieve the goal, 80 primary pregnant women were examined at 38- 40 weeks of gestation, which, depending on the degree of ripe of the cervix upon admission to the hospital, were divided into the main and control groups. All pregnant women underwent anamnesis collection, a complete clinical and laboratory examination, regulated by the Order of the Ministry of Health of Ukraine No. 417 of 15.07.2011. The woman’s body readiness for childbirth was determined taking into account the assessment of the degree of “ripe” of the cervix using the scale proposed by E.H. Bishop. Immunological studies: the concentration of serum relaxin, the content of matrix metalloproteinases (MMP-1, MMP-9) in the peripheral blood serum were determined. The daily urinary excretion of information biochemical parameters, in particular, hydroxyproline and glycosaminoglycans, markers of collagen catabolism, was studied. The results were statistically processed on a personal computer using the STATISTICA-6 program.Research results and their discussion. The results of the study make it possible to identify the most significant factors characterizing the processes of preparing the body for childbirth, which include the “labor hormone” relaxin, as well as the immune mechanisms of regulation of the “ripe” of the cervix before childbirth. The data obtained allow us to regard relaxin as a positive regulator of the production of the main types of MMPs that affect type I collagen. Such a positive regulation of MMP-1 and MMP-9 due to increased levels of relaxin may be of unique importance for the development of remodeling processes of the connective tissue of the cervix, as evidenced by the change in the content of markers of metabolic processes in the cervix.Conclusions: Relaxin is an important factor in preparing the body of a pregnant woman for childbirth, due to the regulation of the production of proteolytic enzymes, matrix metalloproteinases, at the end of the gestational process. The investigated factors can be regarded as new markers of the onset of timely physiological labor, as well as the effectiveness of complex therapeutic measures for the induction of labor.

Urinary Hydroxyproline Is Only Suitable As a Biomarker for Acute Intake, Up to 6hr Postingestion of Collagen Proteins in "Free-Living," Healthy, Active Males.

The urinary excretion of hydroxyproline (Hyp), abundant in collagen protein, may serve as a biomarker of habitual collagen intake, assisting with investigations of current interest in the role of dietary collagen intake in supporting the synthesis of collagenous body tissues. This study investigated the time course of urinary Hyp excretion in "free-living," healthy, active males following the ingestion of a standardized bolus (20 g) of collagenous (gelatin and a hydrolyzed collagen powder) and dairy (calcium caseinate and hydrolyzed casein) proteins. The excretion of Hyp was assessed over a 24-hr period, separated into three collection periods: 0-6, 6-12, and 12-24hr. Hyp was elevated for 0-6hr after the consumption of collagen-containing supplements (gelatin 31.3 ± 8.8mmol/mol and hydrolyzed collagen 33.7 ± 22.0mmol/mol vs. baseline: gelatin 2.4 ± 1.7mmol/mol and hydrolyzed collagen 2.8 ± 1.5mmol/mol; p < .05), but not for the dairy protein supplements (calcium caseinate 3.4 ± 1.7mmol/mol and hydrolyzed casein 4.0 ± 3.7mmol/mol; p > .05). Therefore, urinary Hyp reflects an acute intake of collagenous protein, but is not suitable as a biomarker for quantifying habitual collagen intake, provided through regular dietary practices in "free-living," healthy, active males.

URINARY HYDROXY-PROLINE ESTIMATION IS CHEAP BIOCHEMICAL MARKER OF BONE TURNOVER IN POST MENOPAUSAL WOMEN

Aim: To estimate urinary hydroxy- proline in pre and post menopausal Women as a marker of bone resorption. Materials and methods: This is a prospective, observational study of 25 healthy post menopausal women with 25 healthy premenopausal women as control conducted at Gandhi Hospital Secunderabad. The study period was between June 2008 to June 2010. 24 hours urinary Hydroxyproline was measured in both cases and controls. Results: The mean urinary Hydroxyproline in Post menopausal women was 31.64 with standard deviation of 3.37. The mean urinary Hydroxyproline in Pre menopausal women was 19.61 with standard deviation of 2.34. It has got the statistical significance with p value of <0.0001 Discussion: Fibrillar collagens are rich in the amino acid hydroxyproline, which is excreted in the urine after collagen degradation and are considered to be markers of bone resorption. The urinary excretion of hydroxy proline is increased in states of physiologically high turnover, such as somatic growth, during menopause and high turnover osteopathies.This increased excretion is due to increase in bone loss which was a characteristic feature of the postmenopausal period.Our results show that urinary hydroxy proline was increased in postmenopausal women compared to premenopausal controls and also urinary hydroxy proline levels were increased more in late postmenopausal women than in early postmenopausal women. Conclusion: In Postmenopausal women with osteoporosis biochemical markers of bone formation decrease and biochemical markers of bone resorption increases. This is because there is more osteoclastic activity.In our study in post-menopausal women urinary hydroxy proline level was found to be elevated when compared to pre-menopausal group. Key words : Post menopausal women, Pre menopausal women, Hydroxyproline, Osteoporosis.

SOURCE, CHEMISTRY, METABOLISM, PHYSIOLOGICAL FUNCTION: ASCORBIC ACID WITH HUMAN HEALTH

Ascorbic acid commonly known as Vitamin C and it is water soluble vitamin having Antioxidant characteristics, abound in nature and highly labile.it is very important Vitamin for biosynthesis of collagen, carnitine and neurotransmitters. Some plants and animals synthesised this Vitamin but human, apes and some other are not able to synthesis this Vitamin due to lack of Gulonolactone oxidase enzyme. So, this Vitamin is supplemented by outer source like fruit, vegetable and synthetic pharmaceutical products. The current US recommended dietary allowances (RDA) for Ascorbic acid is 100-120 mg/day. Ascorbic acid has many biochemical functions like Antioxidant, Anti-antherogenic, Anti-carcinogenic, immunodulator and its preventing cold. It’s also associated with reduction of incidence of cancer, immunity, blood pressure, drug metabolism and urinary hydroxyproline excretion, tissue regeneration. Mainly it shows effective result in gastric cancer. Ascorbic acid decreases the death risk. Now day, This Vitamin is used in nutraceutical in human biology and health. Keywords: Ascorbic acid, Gulonolactone oxidase, antiantherogenic.

Studies on the Effect of Antidiabetic Drugs on Collagen in Rats

To assess the effects of antidiabetic drugs on collagen, the study has been carried out. However, at present, no conclusive data available on the In vivo effect of antidiabetic drugs in collagen. It was therefore thought worthwhile to undertake a systemic study on the metabolic turnover of connective tissue proteins, particularly collagen which will help to understand the various changes taking place in conventional antidiabetic drug treated rats. The hydroxyproline content was determined by the method of Neumann and Logan. There was no significant difference in mean body weight of animals in treated groups when compared to control animals on 50th day. In drug treated group G5, urinary excretion of hydroxyproline was slightly increased in contrast to that of the rats in other groups and showed a significant difference (p < 0.001) between control and G5 group. The proportion of soluble collagen in treated group was somewhat higher than in the control but while taking the significance value there are no statistically significant changes. Liver showed the highest concentration of 0.98 g collagen/100 g tissue, whereas kidney and heart showed 0.57 and 0.72 g collagen/100 g tissue. Observations of the present study collectively indicate that the anabolic rate of collagen metabolism is not altered significantly by the administration of antidiabetic drugs in normal rats.

Zinc as a nutritional approach to bone loss prevention in an ovariectomized rat model

In this study, we have investigated the role of zinc supplementation (a nutritional antioxidant) in an ovariectomized osteopenic rat model. Forty-eight female Wistar rats were assigned to four groups: control, zinc, ovariectomy (OVX), and OVX + zinc. Analysis was performed to compare the study groups on bone metabolism markers, bone antioxidant enzymes, and zinc and copper levels in serum and bone tissues. Electron microscopy was also performed to assess morphological changes. Estradiol levels decreased and tartarate-resistant acid phosphatase 5b levels increased in the OVX group. In the OVX + zinc group, these levels were regulated; however, estradiol levels were still significantly lower than those in controls. The OVX group showed significantly higher urinary excretion of hydroxyproline, which recovered upon zinc supplementation but was higher than normal levels. The activities of catalase and superoxide dismutase decreased in ovariectomized animals and up-regulated upon zinc supplementation. Zinc supplementation in the OVX group revoked reduced glutathione levels and elevated malondialdehyde levels. Reduction in zinc and copper levels was observed in the bone tissues and serum of the OVX group. Zinc administration restored these levels to normal. Electron microscopic studies revealed a looser structure and resorbed areas in ovariectomized rat cortical bone. Zinc administration restored bone tissue morphology. These findings suggest that changes in cortical bone attributed to estrogen deficiency are arrested by zinc supplementation, which can be a sustainable approach to improving bone health.

Bone Demineralization in Postmenopausal Women: Role of Anamnestic Risk Factors

This study evaluated the effects of LT4 administration on the bone mineral density (BMD) in physiological postmenopausal women after two years of continuative treatment. 110 postmenopausal women with nodular goiter aged between 50 and 55 years were examined before and after 2 years of therapy with a fixed dose of LT4 (1.6 mcg/kg/die) for the treatment of nodular thyroid disease. The results showed that the patients on treatment with LT4 have a slight, but significant reduction of the BMD after 2 years of treatment, associated with increased serum levels of alkaline phosphatase and urinary excretion of hydroxyproline, confirming our data conducted on the same group after one year of therapy. Comparison between patients receiving LT4 (group A) or not (group B) showed that group A patients had significantly lower BMD. We demonstrated the statistically significant influence of the following risk factors on BMD: (1) body mass index <19 kg/m2; (2) the onset of menarche after the age of 15 years; (3) positive history for period of amenorrhoea; (4) nulliparity.

Role of common biochemical markers for the assessment of fracture union.

The progress of fracture union requires close monitoring. Whereas, clinical examination and radiographic studies assess the outcome, biochemical markers like serum alkaline phosphatase and urinary hydroxyproline reflect the actual status of bone resorption and bone formation over a short time frame. 36 patients of long bone fracture were randomly allocated for the study. When the patient reported to the Department of Orthopedics after fracture, serum and urinary samples were collected and X-ray of the affected part were taken. Subsequent samples were collected and X-ray taken just after management (either operative or conservative), after 3rd, 5th, 8th and 12th week, respectively after onset of fracture. According to the course of callus formation the patients were divided into two groups that progressed to proper union or malunion. The levels of serum alkaline phosphatase, urinary total and free hydroxyproline levels were measured and statistically analysed and compared. A statistically significant positive correlation between total urinary hydroxyproline excretion and serum alkaline phosphatase indicate progress towards satisfactory union. Thus, serial monitoring of biochemical markers of bone turnover can be used as an adjunct to clinical and radiological evidence of fracture healing.

Serum total estrogen levels and urinary excretion of calcium and hydroxyproline in premenopausal and postmenopausal Chinese women.

Ruey-Jian Chen, MD1 Abstract The study subjects included 26 normal young women with regular menstruation cycles and 30 postmenopausal women. The blood and fasting morning urine samples of premenopausal women were taken between the 4th to 11th day of menstrual cycle. In postmenopausal women the blood and urine specimens were taken at least one year after natural menopause, two months after surgical castration, and two months after completion of radiation therapy for cervical cancer. Serum total estrogen level was measured by radioimmunoassay. The urine hydroxyproline concentration was determined by Kivirikko's method. The mean concentrations of serum total estrogens levels were 185.5 pg/ml and 71.7 pg/ml in premenopausal and postmenopausal women respectively. The mean values of urinary calcium/creatinine (Ca/Cr) molar ratio in premenopausal and postmenopausal women were 0.139 and 0.249 respectively. The mean value of hydroxyproline/creatinine (HOPr/Cr) molar ratio was 0.012 in premenopausal women and 0.028 in postmenopausal women. The parameters of bone loss, such as Ca/Cr ratio and HOPr/Cr ratio, are inversely related with the circulating total estrogen concentration. Therefore, decreased endogenous estrogen production seems to be the major pathophysiologic basis for the enhanced rate of urinary calcium and hydroxyproline excretion in Chinese postmenopausal women.

Urinary hydroxyproline excretion in pneumoconiosis (author's transl)

Urinary hydroxyproline excretion in pneumoconiosis (author's transl)

Effect of Isoflavone-Enriched Milk on Bone Mass in Ovariectomized Rats

This study examined the effect of isoflavone-enriched milk on bone loss in ovariectomized (OVX) rats. Thirty 6-week-old Sprague-Dawley female rats were divided into two groups: sham-operated and OVX. The OVX group was subdivided into three dietary groups (OVX, non-isoflavone-enriched milk; OVX+Iso, isoflavone-enriched milk; and OVX+Iso+Vit+Ca, isoflavone-, vitamins D and K-, and Ca-enriched mik). After 19 weeks of feeding, the food efficiency ratio and body weight gain in the sham-operated group were significantly lower compared with those in the other groups. The bone alkaline phosphatase and total alkaline phosphatase activities were significantly higher in isoflavone-enriched groups (OVX+Iso and OVX+Iso+Vit+Ca) when compared with the sham-operated group. Urinary excretions of deoxypyridinoline and hydroxyproline were significantly higher with ovariectomy, but mostly normalized in the OVX+Iso and OVX+Iso+Vit+Ca groups. The rats in the OVX+Iso and OVX+Iso+Vit+Ca groups showed higher femur and tibia weights. A significant increase was found in bone density of femur and trabecular bone area in the OVX+Iso+Vit+Ca group, which almost reached that of the sham-operated group, whereas no difference was found among the OVX and OVX+Iso groups. The histological areas of the proximal tibia sections showed highly filled trabecular bone in both isoflavone-enriched groups (OVX+Iso and OVX+Iso+Vit+Ca). The present study indicated that isoflavone-enriched milk may have a partial preventive effect on ovariectomy-induced bone loss; however, vitamins D and K and Ca enrichment with isoflavone may enhance effectiveness for increasing bone mass in OVX rats.

The activity of the bone isoenzyme of serum alkaline phosphatase and urinary hydroxyproline excretion in premenopausal and postmenopausal women with primary hyperparathyroidism.

Estrogen deficiency might increase responsiveness of bone to circulating endogenous parathormone. To explore a possible relationship between parathormone action on bone and estrogens we studied the activity of the bone isoenzyme of serum alkaline phosphatase and the urinary excretion of hydroxyproline in 16 premenopausal and 24 postmenopausal women with primary hyperparathyroidism with hyperparathyroid osteodystrophy. The postmenopausal women with primary hyperparathyroidism had the B-ALP 4.30 +/- 0.54 mukat/l, the urinary hydroxyproline excretion 205.2 +/- 22.2 mmol/mol creatinine and urinary calcium excretion 8.9 +/- 0.5 mmol/24 hours, significantly increased in comparison with the group of women with menstrual cycle and primary hyperparathyroidism who had B-ALP 2.12 +/- 0.43 mukat/l, the urinary hydroxyproline excretion 119.0 +/- 14.9 mmol/mol creatinine and urinary calcium excretion 7.7 +/- 0.4 mmol/24 hours. Evidence supporting that estrogen deficiency might increase responsiveness of bone to circulating endogenous parathormone was provided by the demonstration that postmenopausal women with primary hyperparathyroidism had increased bone turnover assessed by urinary hydroxyproline excretion and bone isoenzyme of alkaline phosphatase in comparison with the group of premenopausal women with primary hyperparathyroidism.

Correlation between mass of parathyroid adenoma and biochemical indicators of bone turnover in patients with primary hyperparathyroidism.

We related the weight of the parathyroid adenoma to biochemical variables of bone turnover in 53 patients submitted to parathyroidectomy for primary hyperparathyroidism. There was a positive correlation (r = 0.61, p less than 0.01) between iPTH (c-assay) and adenoma weight. No correlations were found between either concentration of circulating iPTH or weight of parathyroid adenoma and severity of skeletal change expressed by total activity of serum alkaline phosphatase and its bone isoenzyme and urinary excretion of hydroxyproline. We conclude that the severity of bone changes in individual patients with primary hyperparathyroidism does not result from the direct tissue effect of a single hormone (parathyroid hormone).

Urinary excretion of hydroxy-pyridinium cross-links of collagen reflects skeletal growth velocity in normal children.

Two new markers of bone resorption, the collagen cross-linking amino acids pyridinoline (PYD) and deoxypyridinoline (DPD), were measured in 24-h urine collections from 88 healthy children (45 females, 43 males; age 4 to 18 years) and 17 adults. Normal values for pediatric use were established for these parameters. Related to daily excretion of creatinine PYD and DPD were about 3 to 6 fold higher in the pediatric groups than in adults. The collagen cross-links showed a highly significant correlation to the urinary excretion of hydroxyproline (OHP): r = 0.65 for PYD and r = 0.60 for DPD (p < 0.001). Both collagen cross-links and OHP excretion related to creatinine were significantly correlated to growth velocity (r = 0.67, 0.62 and 0.51 for PYD, DPD and OHP respectively; p < 0.001 in each case). PYD and DPD may be useful for the monitoring of growth in children.

Relation of bone mineral density with clinical and laboratory parameters in pre‐pubertal children with cystic fibrosis

To study bone mineral density (BMD) of pre-pubertal cystic fibrosis (CF) children, and its relation with clinical and laboratory parameters, we enrolled 16 CF (8 girls) (4-8 years), and 16 control children (8 girls) (4-8 years). After anthropometric measurements, BMD, serum calcium, phosphorus, total alkaline phosphatase (ALP), 25-hydroxy vitamin D (25-OHD), parathyroid hormone, osteocalcin, tumor necrosis factor (TNF)-alpha, soluble TNF-alpha receptor 2 (sTNFR2), and soluble IL-2 receptor (sIL-2R) levels, and urinary calcium and hydroxyproline excretions were assessed. Disease severity of CF patients was determined with Shwachman-Kulczycki clinical and Brasfield radiological scoring systems.The mean Shwachman-Kulczycki and Brasfield scores of CF patients were indicating well-controlled disease. The anthropometric measurements, mean BMD values, and serum calcium, phosphorus and parathyroid hormone levels were within normal range and similar in both groups. Serum osteocalcin levels were lower, and ALP and 25-OHD levels were higher in CF. Although 24-hr urinary calcium excretions was higher in CF patients, hydroxyproline excretions were similar in both groups. There was no difference between two groups for the serum levels of sIL-2R, TNF-alpha and sTNFR2. Children with low vertebral z-scores had higher serum sIL-2R levels in both groups, but the same relation could not be shown for TNF-alpha and sTNFR2.We may speculate that younger, healthier and well-nourished patients with CF may have normal BMD, but the bone disease develop as patients get older because of the other contributing factors. Future well-designed longitudinal studies with large cohorts might show a relation with BMD and cytokines in CF.