Vitamin D supplementation to healthy children does not affect serum osteocalcin or markers of type I collagen turnover

AIM: New serum markers have recently been introduced in the assessment of bone turnover. Such measures are osteocalcin, the C-terminal propeptide of type I procollagen (PICP), the N-terminal propeptide of type I procollagen (PINP) and the C-terminal pyridinoline cross-linked telopeptide of type I collagen (ICTP). This study aimed to determine whether supplementation with vitamin D3 to healthy children during the winter affects bone turnover in healthy children measured by serum osteocalcin, PICP, PINP or ICTP. METHODS: 12 girls and 8 boys aged 6.2-13.7 (mean 9.8) y, all proven healthy by medical examination and history, were enrolled in a double-blind, randomized, placebo-controlled, cross-over study with two 4 wk treatment periods and 2 wk washout. Vitamin D3 600 IU was given in one tablet of ABCDin daily. On the last day of the 4 wk periods blood was sampled for assessment of serum osteocalcin, PICP, PINP, ICTP, 25-OH-vitamin D, 1,25-diOH-vitamin D and parathyroid hormone (PTH). RESULTS: During supplementation and placebo periods serum osteocalcin (mean +/- SEM) was 53.9 +/- 5.7 and 54.4 +/- 3.8 microg l(-1) (p = 0.70), PICP was 437+/- 44 and 429 +/- 41 microg l(-1) (p = 0.73), PINP was 579 +/- 56 and 619 +/- 64 microg l(-1) (p = 0.33) and ICTP was 13.4 +/- 0.9 and 13.6 +/- 0.7 microg l(-1) (p = 0.52), respectively. Mean +/- SEM serum 25-OH-vitamin D was 47.0 +/- 2.3 and 33.0 +/- 3.0 nmol l(-1) during vitamin D3 supplementation and placebo (p < 0.001, t = 8.10, 95% CI = 10.3 to 17.6 nmol l(-1)), 1,25-diOH-vitamin D and PTH were 87.5 +/- 4.3 and 92.0 +/- 5.3 pmol l(-1) (p = 0.38), and 3.97 +/- 0.5 and 4.21 +/- 0.4 micromol l(-1) (p = 0.37), respectively. CONCLUSION: Supplementation with 600 IU vitamin D3 to healthy children in the winter does not affect bone turnover as measured by serum osteocalcin, PICP, PINP or ICTP. Vitamin D supplementation to healthy children may not be recommended on the ground of concern for bone turnover.     

Biochemical markers of bone metabolism in relation to adrenocortical and growth suppression during the initiation phase of inhaled steroid therapy

Growth suppression is usually most evident during the first year of inhaled steroid therapy. Steroid-induced changes in bone metabolism may contribute to this growth suppression. The aim of the present study was to evaluate the changes in biochemical markers of bone metabolism in relation to adrenal and growth suppression during the initiation phase of inhaled steroid therapy. Seventy-five school-aged children with new asthma were enrolled into budesonide (BUD, n = 30), fluticasone propionate (FP, n = 30) or cromone (CROM, n = 15) treatment groups. BUD dose was 800 microg/d during the first two months and 400 microg/d thereafter. The respective FP doses were 500 and 200 microg/d. Biochemical markers of bone metabolism were measured before treatment and after 2 and 4 mo of therapy. In the control (CROM) group, the mean concentrations of serum osteocalcin (OC), carboxyterminal propeptide of type I procollagen (PICP) (formation markers) and type I collagen carboxyterminal telopeptide (ICTP) (degradation marker) tended to increase. In the BUD group, OC and PICP decreased during the 4 mo by a mean of 23% (p < 0.001) and 15% (p < 0.05), respectively, while ICTP did not change significantly. In the FP group, OC and ICTP decreased during the first 2 mo by a mean of 19% (p < 0.01) and 21% (p < 0.01), respectively, returning to the pretreatment level at 4 mo, while PICP tended to increase during the 4 mo (14%, p = 0.12). In the steroid treated children whose height SD score decreased during the first 12 mo of therapy, both OC and PICP decreased during the first 4 mo by a mean of 20% (p < 0.01) and 21% (p < 0.001), respectively. In those children who had no growth suppression, the changes were not significant: -4% in OC and +13% in PICP. Furthermore, in children who developed evidence of adrenocortical suppression (on the basis of a low-dose ACTH test), OC decreased more (23%, p < 0.01) than in those with normal adrenocortical function (10%, p = 0.06). In conclusion, both inhaled BUD and FP caused dose-dependent effects on biochemical markers of bone metabolism. The children who developed growth or adrenocortical suppression were likely to have changes also in bone metabolism.     

Biochemical markers of bone turnover in the diagnosis of renal osteodystrophy in dialyzed children

In this study we investigated the value of biochemical markers of bone turnover in the diagnosis of renal osteodystrophy in dialysis patients. The study was carried out in 22 chronic renal failure patients (mean age: 16.1 +/- 4.5) being treated with chronic dialysis. There were three groups according to intact parathormone (iPTH) levels: Group I (n: 6): iPTH levels were less than 200 pg/ml; Group II (n: 9): iPTH levels were between 201 and 500 pg/ml; and Group III (n: 7). iPTH levels were higher than 501 pg/ml. We investigated iPTH, bone alkaline phosphatase, total serum alkaline phosphatase, osteocalcin, serum type 1 procollagen peptide (PICP) and insulin-like growth factor-1 (IGF-1) levels in all patients. In group III mean bone alkaline phosphatase level (126.0 +/- 10.95) was significantly higher than in both group I and group II (52.16 +/- 22.8, 57.35 +/- 16.21) (p < 0.001). Mean osteocalcin level (35.13 +/- 2.93) in group I was significantly lower than in group III (40.52 +/- 2.83) (p < 0.05). Serum alkaline phosphatase, PICP and IGF-1 levels were not different between the groups (p > 0.05). There was a significant positive correlation between bone alkaline phosphatase and iPTH (r = 0.80, p < 0.0001). Serum osteocalcin correlated with both bone alkaline phosphatase and iPTH (correlation) coefficients were r = 0.44 and r = 0.51 respectively, p < 0.05). It is concluded that bone alkaline phosphatase and osteoocalcin combined with iPTH level seem to be useful noninvasive markers of bone metabolism in dialysis patients.     

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目的探讨不同海拔地区女性青少年血清骨碱性磷酸酶(BAP)、Ⅰ型前胶原羧基端前肽(PICP)和骨钙素(OC)的特点及其差异,为临床运用提供基础数据。方法 2003年6月至2005年10月采用分层整群抽样方法,从西藏拉萨(海拔3500m)、西藏那曲(海拔4500m)和辽宁锦州(海拔28m)的大、中、小学随机抽取12～<19岁健康女性青少年共1093名,进行身高及血清BAP、PICP和OC测定。结果拉萨组和那曲组血清BAP、PICP和OC总体水平均高于锦州组,组间差异有统计学意义(P<0.01);拉萨组3个生化标志物显著高于那曲组(P<0.01或P<0.05)。3组血清BAP、PICP和OC均在12～<13岁时出现高峰,且随年龄增长迅速下降,但锦州组3个生化标志物随年龄变化趋势较拉萨组和那曲组平缓。血清BAP、PICP和OC水平均与身高密切相关(r=0.56、0.48、0.43,P<0.01)。结论不同海拔女性青少年血清BAP、PICP和OC随年龄变化特点基本一致,但高原藏族青少年血清BAP、PICP和OC高于平原汉族青少年。应建立针对高原藏族青少年的骨形成标志物的正常参考值。     

Evaluation of serum osteocalcin as an index of altered bone metabolism

Recent evidence suggests that the protein osteocalcin is like the bone alkaline phosphatase produced by osteoblasts and circulates in human blood. With the introduction of a radioimmunoassay for serum osteocalcin it was hoped that this test would provide a useful index of altered bone metabolism. Therefore serum osteocalcin was measured in 88 controls and 112 patients with disorders of calcium and phosphate metabolism, isolated elevation of alkaline serum phosphatase in the absence of disease (isolated hyperphosphatasaemia) and children prone to osteopenia.In the controls serum osteocalcin was higher in children<15 years (median and range: 11.9, 7.7–15.3 ng/ml) than in adults (3.7, 2.6–5.2 ng/ml) and was highly correlated to alkaline serum phosphatase activity (r=0.87, n=88, P<0.01). Osteocalcin was elevated in primary hypoparathyroidism, low in untreated hypoparathyroidism but normal in hypoparathyroidism (including pseudohypoparathyroidism) during vitamin D treatment. The bone protein was low-normal and increased to high-normal levels during vitamin D therapy in vitamin D deficiency rickets and familial hypophosphataemic rickets, but remained low in patients with end organ resistance to 1,25-dihydroxyvitamin D. Osteocalcin (and urinary hydroxyproline) were not elevated in isolated hyperphosphatasaemia, indicating that mechanisms other than increased bone turnover may account for the markedly elevated serum alkaline phosphatase activity in these subjects. Osteocalcin was decreased in children with diabetes mellitus type I and in patients on glucocorticoid treatment, indicating decreased bone formation. It is concluded that the measurement of serum osteocalcin seems to be a reliable index of bone formation provided that the vitamin D status and renal function are normal. Although serum osteocalcin and alkaline phosphatase were generally correlated there were examples of dissociation between both indices. In some circumstances (e.g. rickets) serum osteocalcin may severe as a useful index of an effective therapy.Abbreviations AP alkaline phosphatase activity - Gla gammacarboxy-glutamic acid - 1,25 (OH)₂D₃ 1,25-dihydroxyvitamin - D₃ calcitriol - PTH parathyroid hormone - HP hypoparathyroidism - PHP pseudohypoparathyroidism - I^oHPT primary hyperparathyroidism - VDR vitamin D deficiency rickets - VDDR II vitamin D dependency rickets type II - FHL familial hypophosphataemic rickets - IH isolated hyperphosphatasaemia in the absence of disease     

Plasma levels of carboxy terminal propeptide of type I procollagen and pyridinoline cross-linked telopeptide of type I collagen in healthy school children

The aim of this study was to reveal the relationship of the plasma levels of the carboxy terminal propeptide of type I procollagen (PICP) and the pyridinoline cross-linked carboxyterminal telopeptide domains of type I collagen (ICTP) to age and height velocity (HV), and to compare PICP and ICTP levels in those who have not reached their final height with those who have. PICP and ICTP levels were measured by RIA in 271 healthy children (161M, 110F) aged from 10 to 15 y. The HV was calculated from their health check-up cards. The subjects were divided into two groups in this study: the final height (FH) group whose HV was < 1.0 cm/y, and the non-final height (NFH) group whose HV in the last year was ≥ 1.0 cm/y. PICP and ICTP levels almost paralleled the values of age-related changes of HV. Furthermore PICP and ICTP levels significantly correlated with HV. PICP and ICTP levels of the FH group were higher than those of adults previously reported. The values will be useful as reference for healthy children and growth disorder. Before reaching final height, PICP and ICTP can be useful makers of not only bone turnover but also of linear growth. Bone turnover rate is still increasingly active just after linear growth has been completed, and then it become similar to the levels of adults.     

Collagen-derived markers of bone metabolism in osteogenesis imperfecta

Markers of bone formation [C-terminal and N-terminal propeptides of procollagen I (PICP, PINP), osteocalcin and alkaline phosphatase] and bone resorption [C-terminal cross-linked telopeptide of collagen I (ICTP) and hydroxypyridinium cross-links, pyridinoline (Pyr) and deoxypyridinoline (Dpyr)] were measured in 78 osteogenesis imperfecta (OI) patients to investigate bone metabolism in vivo and relate marker concentrations to phenotype and in vitro collagen I defects, as shown by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). PICP and PINP were generally low, and the serum levels were lower in all children and adults with mild OI and a quantitative collagen defect than in patients with severe OI and a qualitative collagen I defect. ICTP, Pyr and Dpyr were generally normal or reduced, but elevated in severely affected adults with a qualitative collagen I defect. The in vivo findings correlated with in vitro results of collagen I SDS-PAGE. Bone turnover is reduced in OI children and mildly affected OI adults, whereas bone resorption is elevated in severely affected adults. These findings may prove helpful for diagnosis and decision-making regarding therapy in OI.     

长期应用糖皮质激素对慢性血小板减少性紫癜患儿骨代谢的影响

目的探讨长期应用糖皮质激素对慢性血小板减少性紫癜患儿骨代谢的影响以及钙剂和维生素D的干预作用。方法将36例慢性血小板减少性紫癜患儿随机分为干预组(A)和未干预组(B),给予口服泼尼松1.5mg/(kg·d),4～6周后逐渐减量。疗程超过6月。干预组同时给维生素D330万IU1次口服,口服牡蛎碳酸钙75mg,Bid(牡蛎碳酸钙:每片150mg,东盛科技启东盖天力股份有限公司)。每周3天,共6月。治疗前及应用激素4周后采集患儿静脉血,分别测定I型前胶原羧基末端前肽(PICP),尿脱氧吡啶啉(DPD)和DPD排泄率。结果两组患儿糖皮质激素治疗前血清中PICP的浓度、尿中DPD的排泄率无显著性差异(P>0.05);干预组糖皮质激素治疗后血清中PICP的浓度、尿中DPD的排泄率与治疗前相比差异无统计学意义(P>0.05);未干预组糖皮质激素治疗后血清中PICP的浓度较治疗前明显降低、尿中DPD的排泄率较治疗前明显增高,差异均具有统计学意义(P<0.05)。结论长期应用糖皮质激素对慢性血小板减少性紫癜患儿骨骼代谢有潜在的影响,早期干预可以改善。     

Disturbance in bone turnover in children with a malignancy at completion of chemotherapy.

BACKGROUND: Osteoporosis and pathological fractures have been observed in children with a malignancy. The mechanisms of osteopenia in childhood malignancies have not been well established. The purpose of the present study was to evaluate changes in bone turnover and in bone hormonal metabolism in children with a malignancy at completion of their chemotherapy. PROCEDURE: Serum levels of human intact osteocalcin, type I collagen carboxyterminal propeptide (PICP), type I collagen carboxyterminal telopeptide (ICTP), 25-hydroxyvitamin D [25-(OH)-D], 1,25-dihydroxyvitamin D [1, 25-(OH)(2)-D], intact parathyroid hormone, insulin-like growth factor I (IGF-I), IGF binding protein 3 (IGFBP-3), alkaline phosphatase, calcium, and phosphate were analyzed in 22 children with acute lymphoblastic leukemia and in 26 children with other malignancies. Results were expressed as Z-scores [mean (95% confidence intervals)] relative to healthy Caucasian-children. RESULTS: The marker of collagen degradation (ICTP) was significantly increased [1.43 (1.10-1.76), P < 0.0001] compared to reference values, whereas the markers of bone formation (PICP, osteocalcin) were not changed [0.07 (-0.55 to 0.49), 0.35 (-0.05 to 0.74), respectively, NS]. Serum 25-(OH)-D, 1,25-(OH)(2)-D, and calcium were significantly reduced [-0.65 (-0.87 to -0.42), -0.68 (-0.92 to -0. 42), -1.42 (-1.80 to -1.04), P < 0.0001, respectively]. CONCLUSIONS: Disturbance in bone turnover with low serum 25-(OH)-D, 1, 25-(OH)(2)-D, and calcium was observed in children with a malignancy at completion of their chemotherapy. A controlled study determining the possible benefits of vitamin D and calcium supplementation on bone turnover could be considered in these patients.     

Bone mineral density in patients with classic galactosaemia.

BACKGROUND: Diminished bone mineral density (BMD) is a well known complication in women with classic galactosaemia caused by premature ovarian failure. Diminished BMD in prepubertal patients of either sex has, however, only been reported once. Aim: To assess BMD in children with classic galactosaemia. METHODS: Eleven treated patients (five males, six females, aged 2-18 years) had BMD determined by dual energy x ray absorptiometry. Two measurements were performed, an areal measurement of the total body and a volumetric measurement of the femoral neck. Results were expressed as Z scores. Dietary calcium intake, blood calcium, phosphate, vitamin D, parathormone, and markers of bone formation (bone alkaline phosphatase, osteocalcin) and bone resorption (NTX) were determined. RESULTS: All patients had a significantly diminished BMD. Mean Z score of the volumetric BMD was -1.76 (range -0.7 to -3.3), and of the areal BMD -0.99 (range -0.5 to -1.4). Dietary calcium intake and calcium, phosphate, parathormone, bone alkaline phosphatase, vitamin D metabolites, and osteocalcin (free and carboxylated) were normal in all patients. NTX levels in blood were significantly lower (p < 0.001) than in control subjects. CONCLUSION: BMD in this group of children of both sexes with classic galactosaemia under dietary treatment was decreased. Lower NTX levels in galactosaemics point to an apparent decreased bone resorption.     

Varying role of vitamin D deficiency in the etiology of rickets in young children vs. adolescents in northern India

The relative importance of calcium vs. vitamin D deficiency in the etiology of nutritional rickets in the tropics may be different in children compared with adolescents. We studied calcium intake, sun exposure, serum alkaline phosphatase, and 25 hydroxyvitamin D in 24 children and 16 adolescents with rickets/osteomalacia. The values were compared with those obtained in control subjects (34 children and 19 adolescents). We found that young children with rickets had lower calcium intake compared with controls (285 +/- 113 vs. 404 +/- 149 mg/day, p < 0.01), but similar sun exposure (55 +/- 28 vs. 56 +/- 23 min x m2/day) and 25 hydroxyvitamin D (49 +/- 38 vs. 61 +/- 36 nmol/l). Sixteen of 24 children with rickets had 25 hydroxyvitamin D above the rachitic range (> 25 nmol/l), in contrast to one of 16 adolescents. Adolescent patients had low calcium intake vs. controls (305 +/- 196 vs. 762 +/- 183 mg, p < 0.001), and lower sunshine exposure (16 +/- 15 vs. 27 +/- 17 min x m2/day, p < 0.01) and serum 25 hydroxyvitamin D (12.6 +/- 7.1 vs. 46 +/- 45.4 nmol/l, p < 0.001). The odds ratio for developing rickets with a daily calcium intake below 300 mg was 4.8 (95 per cent CI, 1.9 - 12.4, p = 0.001). Subjects with rickets were randomized to receive 1 g calcium daily, with or without vitamin D. Children showed complete healing in 3 months, whether they received calcium alone or with vitamin D. Adolescents showed no response to calcium alone, but had complete healing with calcium and vitamin D in 3-9 months (mean 5.3 months). Thus deficient calcium intake is universal among children and adolescents with rickets/osteomalacia. Inadequate sun exposure and vitamin D deficiency are important in the etiology of adolescent osteomalacia.     

Circulating leptin levels and bone mineral density in children with biliary atresia

AIM: To investigate circulating leptin levels in biliary atresia (BA) patients and the association of leptin with bone mineral density (BMD) and the severity of BA. METHODS: We have examined 50 patients with BA and 15 matched healthy controls. Serum leptin, osteocalcin and C-terminal telopeptide of type I collagen (CTX) levels were measured by sandwich enzyme-linked immunosorbent assay (ELISA). BMD of the lumbar spine was measured by dual energy X-ray absorptiometry. RESULTS: Serum leptin levels of BA patients were lower than those of healthy controls (2.7 +/- 0.3 vs. 7.1 +/- 1.7 ng/mL, p = 0.0001). Among the BA patients, serum leptin levels were significantly lower in patients with jaundice than patients without jaundice (1.7 +/- 0.2 vs. 3.4 +/- 0.4 ng/mL, p = 0.001). BMD of BA patients was correlated (p < 0.001) with leptin levels, age and BMI (r = 0.55, r = 0.75 and r = 0.58, respectively). The serum CTX levels were significantly higher in jaundice patients compared with jaundice-free patients and the healthy controls (0.6 +/- 0.2 vs. 0.2 +/- 0.1 ng/mL, p = 0.01), whereas the serum osteocalcin levels in BA patients were not different from those in the controls. CONCLUSION: Circulating leptin levels are correlated with BMD and the presence of jaundice in BA, suggesting that the leptin may play a physiological role in maintaining bone mass of BA patients with jaundice.     

Measurements of bone turnover markers in premature infants

We determined the levels of circulating bone turnover markers in preterm infants during the first weeks of life. Twenty premature infants (mean gestational age 27+/-2.2 weeks, mean birth weight 894+/-231 g) hospitalized in the neonatal intensive care unit (NICU) at the Meir General Hospital, Israel, participated in the study. Measurements of bone turnover markers were performed at birth, and every week thereafter for an average follow-up of 11.2+/-0.7 weeks. Bone osteoblastic activity was assessed by measurements of circulating osteocalcin, bone-specific alkaline phosphatase (BSAP) and the C-terminal procollagen peptide (PICP) levels. Bone resorption was assessed by measurements of serum levels of the carboxy-terminal cross-links telopeptide of type I collagen (ICTP). All three markers of osteoblastic activity increased markedly and significantly during the first three weeks of life, and then continued to increase gradually until week 10 (p<0.01). Circulating ICTP levels increased in the first week of life and then decreased gradually throughout the follow-up (p<0.01). The study participants were divided into premature infants born at extremely low birth weight (ELBW: <1000 g, n=12) and very low birth weight (VLBW: 1000-1250 g, n=8). Osteocalcin (in weeks 2-5 of life), PICP (weeks 3-5), and ICTP levels (weeks 2-3) were significantly higher in VLBW preterms. These results suggest increased bone formation in premature infants in the first three months of life. The increased bone turnover in VLBW compared to ELBW premature infants may be the result of a generally higher morbidity in ELBW preterm infants in early stages of life.     

The relationship between osteocalcin levels and sexual stages of puberty in male children

Osteocalcin is a specific and reliable marker which increases with rapid bone turnover and gives data about bone metabolism. The pubertal growth spurt is also known as a good example of rapid bone turnover. The aim of this study was to determine whether osteocalcin is a useful marker for the pubertal growth spurt period. In this study, osteocalcin levels in male adolescents were examined in relation to their sexual maturation stage and age. The osteocalcin levels and alkaline phosphatase levels were compared during the pubertal growth spurt. Serum osteocalcin and alkaline phosphatase levels were evaluated in 100 eligible healthy male children and adolescents (aged 10 to 17 years). Five groups (n: 20 each) of children and adolescents were formed according to their sexual maturation stages. Finally, the subjects were divided into three main groups in relation to the pubertal growth spurt and sexual maturation stages. Data were evaluated and compared among these three groups: First group = Stage 1 (prepuberty) + Stage 2 (early puberty) consisted of 40 (20 + 20) children and adolescents. Their mean osteocalcin value was 17.2 +/- 6.3 ng/ml and alkaline phosphatase 573.8 +/- 143.9 IU/L. Second group: Stage 3 + Stage 4 consisted of 40 (20 + 20) children and adolescents. These groups were known as the pubertal growth spurt groups. Their mean osteocalcin value was 29.4 +/- 10.6 ng/ml and alkaline phosphatase 728.4 +/- 233.9 IU/L. Third group: In this group, there were 20 children and adolescents who reached Stage 5 of sexual maturation and whose pubertal growth spurt was slowing. Their mean osteocalcin value was 15.3 +/- 5.8 ng/ml and alkaline phosphatase 435.8 +/- 184.8 IU/L. During the pubertal growth spurt, there is a relationship between bone remodelling and increasing osteocalcin and alkaline phosphatase levels. When sexual maturation reaches Stage 4 at 14 years old, osteocalcin and alkaline phosphatase levels make a peak, associated with the rapid growth in height. As sexual maturation reaches Stage 5, osteocalcin and alkaline phosphatase levels gradually decrease with growth maturation and their levels decline to the level of adults at the completion of this period. Our study showed that osteocalcin and alkaline phosphatase levels can be used as markers for evaluation of the growth spurt period.     

Reduced bone mineral density and increased bone turnover in Prader-Willi syndrome compared with controls matched for sex and body mass index--a cross-sectional study

OBJECTIVES: To study bone mineral status, body composition, and biochemical markers of bone turnover in Prader-Willi syndrome (PWS). STUDY DESIGN: Eight subjects with PWS (three males, five females; mean age, 24 years [range 16-41]) were included. Each subject was compared with an age-, sex- and body mass index-matched control randomly drawn from the background population. Bone mineral density (BMD), lean body mass, and fat mass were measured. Plasma PINP, PIIINP, osteocalcin, total alkaline phosphatase, bone-specific alkaline phosphatase, C-terminal telopeptide of type I collagen, and urine cross-linked N-terminal telopeptide of type I collagen were measured as biochemical markers of bone and collagen turnover. RESULTS: The PWS patients had significantly lower whole-body BMD (mean +/- SD, 1.020 +/- 0.041 vs 1.237 +/- 0.118 g/cm(2); 2p <.01) than controls due to lower bone mineral content (BMC: 2291 +/- 607 vs 2825 +/- 409 g; 2p=.02). Resorptive and formative bone markers were significantly elevated in patients compared with controls. Plasma testosterone was low in male patients (3.50 +/- 4.97 vs 19.2 +/- 8.78 nmol/L, 2p=.05), whereas no difference in plasma estradiol was present. CONCLUSIONS: The patients had a low BMD due to a high bone turnover. This high turnover was probably linked to sex steroid deficiency.     

Nutritional and metabolic rickets

Nutritional rickets is casued by vitamin D deficiency due to lack of exposure to sunlight. Neonatal rickets occurs only in infants born to mothers with very severe osteomalacia. Calcium deficiency alone does not cause mineralisation defects. It only causes osteoporosis and secondary hyperparathyroidism with raised plasma, 1,25 (OH)₂D and osteocalcin. Low 25-OHD, increased IPTH, increased alkaline phosphatase in plasma and decreased calcium and increased hydroxyproline in urine are diagnostic of rickets. Low or undetectable plasma levels of 25-OHD, in presence of high plasma 1,25(OH)₂D and IPTH are often observed during treatment with vitamin D. Even the marginal intakes of fluoride (> 2.5 mg/day) cause rickets in calcium deficient children. Indian children often need high dose of vitamin D due to severely depleted D stores, high IPTH and severe bone disease (radiologic and histomorphometric) for treatment.     

Effects of dexamethasone treatment on bone and collagen turnover in preterm infants with chronic lung disease

Dexamethasone is used commonly in the treatment of chronic lung disease of prematurity, but there are concerns about possible deleterious effects on growth and bone. Our aim in this study was to examine the effects of dexamethasone treatment on bone and collagen turnover in preterm infants. Bone-specific alkaline phosphatase, the C-terminal propeptide of type I collagen (PICP, reflecting whole-body type I collagen synthesis), and the N-terminal propeptide of type III procollagen (P3NP, reflecting soft tissue collagen turnover), together with the C-terminal telopeptide of type I collagen (ICTP), urinary pyridinoline (Pyd), and deoxypyridinoline (all markers of collagen breakdown) were measured at weekly intervals over the first 12 wk of life in 14 preterm infants with chronic lung disease treated with dexamethasone. Results were expressed as SD scores relative to preterm control infants not treated with dexamethasone. PICP, P3NP, ICTP, and Pyd all showed marked decreases (-2.1 to -3.7 SD scores) during the first week of treatment (p < 0.001), returning to pretreatment levels after stopping dexamethasone. In the group as a whole, these collagen markers were negatively correlated with dexamethasone dose (p < 0.0001); negative correlations were also seen in most individual babies, although the slopes of individual regression lines varied by a factor of 2. Weight gain at 12 wk was correlated with PICP, expressed as the mean SD score over 12 wk for each baby, (r = 0.69, p < 0.01) but not with other markers or cumulative dose of dexamethasone. We conclude that dexamethasone markedly suppressed collagen turnover in preterm infants in a dose-dependent fashion, although some babies were more affected than others. The degree of suppression of type I collagen synthesis was a strong independent predictor of overall weight gain over the first 12 wk of life.     

The effect of neonatal sepsis on bone turnover in very-low birth weight premature infants

Neonatal sepsis is very common in preterm infants, and severe morbidity during the neonatal period is a major cause of osteopenia of prematurity. We examined the effect of neonatal sepsis on bone turnover markers in premature infants. Twenty-four premature infants participated in the study. Ten of the premature infants developed sepsis during their hospitalization in the neonatal intensive care unit (mean gestational age [GA] 27.3 +/- 0.4 weeks; mean birth weight [BW] 898 +/- 82 g). Fourteen infants who did not develop sepsis served as controls (GA: 26.8 +/- 0.8 weeks, BW: 892 +/- 66 g). Blood samples for bone turnover markers were collected during the initial sepsis workup, and at the end of the first week of treatment, and were compared to the corresponding weekly changes in bone markers in the controls. In addition, samples were collected at the end of the 10th week of life to determine long-term effects of sepsis on bone turnover. Bone osteoblastic activity was assessed by measurements of circulating osteocalcin, bone-specific alkaline phosphatase (BSAP) and the C-terminal procollagen peptide (PICP) levels. Bone resorption was assessed by measurements of circulating carboxy terminal cross-links telopeptide of type I collagen (ICTP). There were no significant differences in the weekly changes of all bone turnover markers in premature infants who developed or did not develop sepsis. No significant differences were found in bone turnover markers at the age of 10 weeks between the groups. Neonatal sepsis in premature infants was not associated with biochemical evidence of reduced bone turnover.     

Effect of zinc supplementation on growth hormone secretion, IGF-I, IGFBP-3, somatomedin generation, alkaline phosphatase, osteocalcin and growth in prepubertal children with idiopathic short stature

Controversy exists about the effect of zinc on growth and the GH-IGF system. Zinc supplementation has been shown to stimulate linear growth in zinc-deficient children. However the mechanism of this effect has not been well characterized. Furthermore, the effect of zinc supplementation on non-zinc-deficient short children is unknown. We investigated the effect of zinc supplementation on endogenous GH secretion, serum IGF-I and IGFBP-3 concentrations, IGF-I and IGFBP-3 generation in response to exogenous GH, bone formation markers, and linear growth of non-zinc-deficient children with idiopathic short stature. We analyzed prospectively serum zinc, IGF-I, IGFBP-3, alkaline phosphatase, osteocalcin, and GH response to clonidine test, and performed a somatomedin generation test before and 6 weeks after zinc supplementation in 22 (16 M, 6 F) prepubertal children with idiopathic short stature. Serum IGF-I increased from 67.4+/-70.6 to 98.2+/-77.3 ng/ml (p <0.001), IGFBP-3 from 2326+/-770 to 2758+/-826 ng/ml (p <0.001), alkaline phosphatase from 525+/-136 to 666+/-197 U/l (p <0.0001), and osteocalcin from 16.8+/-10.6 to 25.8+/-12.8 ng/ml (p <0.05) after zinc supplementation despite there being no difference in GH response to clonidine after zinc supplementation (peak GH 11.6+/-6.9 vs 13.4+/-7.8 ng/ml, GH area under the curve during clonidine test 689+/-395 vs 761+/-468, NS). Percent change in IGF-I and IGFBP-3 during the somatomedin generation test was not significantly affected by zinc supplementation (118% vs 136% and 57% vs 44%, respectively). There was no significant correlation between percentage increase in zinc levels and percentage increase in parameters tested. Height SDS or weight SDS did not improve significantly in 17 patients who continued on zinc supplementation for at least 6 months (6-12 months) (-2.59 vs -2.53 SDS and -1.80 vs -1.67 SDS, respectively). Zinc supplementation increased basal IGF-I, IGFBP-3, alkaline phosphatase and osteocalcin without changing GH response to clonidine. Zinc supplementation did not affect sensitivity to exogenous GH as tested by IGF-I and IGFBP-3 generation test. These results suggest a direct stimulatory effect of zinc on serum IGF-IGFBP-3, alkaline phosphatase and osteocalcin. Despite improvements in the above parameters, zinc supplementation to children with idiopathic short stature with normal serum zinc levels did not significantly change height or weight SDS during 6-12 months follow-up.     

Vitamin E treatment of nonalcoholic steatohepatitis in children: a pilot study

AIM: To determine whether supplemental oral vitamin E is effective in lowering serum aminotransferase and alkaline phosphatase levels in children with nonalcoholic steatohepatitis (NASH) associated with obesity. STUDY DESIGN: Open-label pilot study enrolling all children <16 years old with chronically elevated serum aminotransferase (alanine aminotransferase and aspartate aminotransferase) levels for greater than 3 months, who demonstrated a diffusely echogenic liver on ultrasonography, had no demonstrable reason for abnormal serum chemistry values other than obesity, and therefore were diagnosed to have NASH. Patients were prescribed oral vitamin E between 400 and 1200 IU per day. Serum chemistry values were monitored monthly during treatment. RESULTS: Eleven subjects with a mean age of 12.4 years were enrolled; treated patients were followed up for 4 to 10 months. The body mass index did not change significantly before and after treatment (32.8 +/- 3.8 kg/m(2) vs 32.5 +/- 4.4 kg/m(2), respectively). Serum alanine aminotransferase decreased from 175 +/- 106 IU/L to 40 +/- 26 IU/L (P <.001, paired Student t test), serum aspartate aminotransferase decreased from 104 +/- 61 IU/L to 33 +/- 11 IU/L (P <.002), and alkaline phosphatase decreased from 279 +/- 42 IU/L to 202 +/- 66 IU/L (P <.003) during treatment. Serum aminotransferase levels remained normal during treatment but returned to abnormal in those electing to stop treatment. Serum alpha-tocopherol levels were within the normal range before the commencement of therapy and increased significantly with supplementation. The liver remained diffusely echogenic during therapy, at the time serum aminotransferase levels were reduced. CONCLUSIONS: Daily oral vitamin E administration normalized serum aminotransferase and alkaline phosphatase levels in children with NASH. Obese children with NASH should be encouraged to lose weight as part of a comprehensive weight reduction program and to consider taking supplemental alpha-tocopherol.