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目的研究维生素D受体基因多态性与0～6岁汉族儿童骨密度(BMD)的关系,为临床儿童低BMD的早期预防提供理论依据。方法上海新华医院上海市儿科医学研究所2002年7月至2004年3月收集排除影响骨代谢疾病的上海地区0～6岁汉族儿童204例,进行问卷调查、体格测量;用原子吸收分光光度计测血清锌;用放射免疫法测血清25(OH)D3;用超声BMD仪测定胫骨中段骨密度;用聚合酶链反应限制性片段长度多态性方法,分析4个限制性酶切位点(ApaI、TaqI、BsmI、FokI)的多态分布。用多因素协变量方差分析维生素D受体(VDR)基因多态性与BMD的关系。结果多因素协方差分析消除血清25(OH)D3水平、血清锌水平、户外体育活动等因素对BMD的影响后,发现VDR基因BsmI酶切位点等位基因型和FokI酶切位点等位基因型与BMD相关,Bb基因型的BMD百分位数明显低于bb基因型,分别为22.00%和43.14%,差异有显著性(F=5.04,P<0.05);ff基因型骨密度低于Ff与FF基因型,分别为26.97%、37.95%、53.52%,差异有极显著性(F=8.11,P<0.001)。而在ApaI、TaqI酶切位点,不同等位基因型与BMD无关(F=1.08、1.27,P>0.05)。结论VDR基因在BsmI、FokI酶切位点的多态性与0～6岁汉族儿童BMD相关。     

Vitamin D receptor alleles predict growth and bone density in girls

OBJECTIVES—Polymorphism of the vitamin D receptor (VDR), collagen α I type I (Col I αI), and oestrogen receptor (ER) genes have been shown to account for some of the heritability of bone mineral density (BMD) in adults. This study examined this relation in prepubertal children.METHODS AND SUBJECTS—The relation between genotypes of VDR gene (Taq I, Bsm I, Fok I), Col I αI gene (Msc I), and ER gene (Pvu II) with areal BMD, volumetric BMD, and growth were examined in 114 (68 girls) healthy 7 year old, white children.RESULTS—The genotype of the VDR gene (Taq I) correlated with lumbar spine (L1-4) volumetric BMD in girls only, but at no other bone sites. In girls, VDR genotype affected areal BMD at all sites. After adjusting for height and weight, however, this effect was explained completely by the independent effect of the VDR genotype on growth. Girls with genotype TT, were 3.9 kg heavier and 4.1 cm taller than those with tt, but this relation was not present at birth. No relation was found between genotypes of the VDR gene (Fok I), Col I αI gene (Msc I), or ER gene (Pvu II) and BMD or growth variables.CONCLUSIONS—In prepubertal girls, VDR alleles contribute to lumbar spine volumetric BMD variance, but the areal BMD effect reflects the relation between areal BMD and growth. VDR alleles might affect postnatal growth regulation.     

DNA测序研究维生素D受体基因多态性与儿童克罗恩病相关性

目的：初步探讨维生素D受体基因多态性TaqI、BsmI、ApaI位点在儿童克罗恩病（CD）发病中的作用。方法：选取19例CD患儿为病例组,122例正常健康体检儿童为对照组。ELISA方法检测血清25羟维生素D3 [25(OH)D3]水平;基因测序方法检测两组维生素D受体基因多态性TaqI、BsmI、ApaI位点,比较两组之间基因型和等位基因分布频率。结果：病例组血清25(OH)D3水平（17.3±2.4 ng/mL）较对照组（26.9±2.1 ng/mL）明显降低,差异有统计学意义（P0.05）。结论：CD患儿存在低25(OH)D3水平;维生素D受体基因多态性TaqI、BsmI、ApaI位点与CD的发生无关。     

Known VDR polymorphisms are not associated with bone mineral density measures in pediatric Cushing disease

Decreased bone mineral density (BMD) has been documented in adults with Cushing disease (CD), and allelic variants of the vitamin D receptor (VDR) gene have been associated with osteopenia. Genetic factors play an important role in bone accrual and its response to various diseases; among them, the most studied are the allelic variants of the VDR gene. There is debate as to whether described variants in the VDR gene have an effect on BMD. In the current study, we sought to analyze whether BMD differences in patients with CD were associated with the Taq1 and Apal VDR allelotypes. The data showed lack of association between BMD and these widely studied VDR polymorphisms, suggesting that the effect of endogenous hypercortisolism on bone in the context of CD does not depend on VDR genotypes.     

Bone mineral status in ambulatory pediatric patients on long-term anti-epileptic drug therapy

BACKGROUND: For ambulatory pediatric outpatients,reports of abnormalities of bone metabolism associated with anti-epileptic drugs are inconsistent and may be difficult to interpret. METHODS: The effects of long-term anti-epileptic therapy (mainly valproic acid and/or carbamazepine) on bone mineral status were evaluated in ambulatory epileptic patients(seven males and 11 females) aged 5.5-15.9 years.Bone mineral density (BMD) at the lumbar spine was measured by dual-energy X-ray absorptiometry and markers of bone and mineral metabolism were determined. RESULTS: The mean BMD was decreased by 9% in our patients relative to the control, and five patients (all males)showed osteopenia, defined as BMD SD scores less than - 1.5.Serum levels of minerals, intact parathyroid hormone and 1alpha,25(OH)2 vitamin D were within the normal ranges. In most patients, serum levels of intact osteocalcin, carboxyterminal propeptide of type I procollagen and pyridinoline cross-linked telopeptide of type I collagen were reduced relative to the corresponding mean control values. The BB genotype by BsmI restriction fragment length polymorphism, associated with low BMD, was not found in our patients. The dietary calcium intake in the osteopenic patients was significantly lower than that of the non-osteopenic patients. CONCLUSIONS: Our results indicate that long-term anti-epileptic treatment induces a state of decreased bone turnover in children, resulting in osteopenia preferentially in males. The alterations may be due, at least in part, to direct effects of the drugs on bone cells; and that low calcium intake could be an aggravating factor for anti-epileptic-associated osteopenia.     

Bone mineral density and metabolism in children with congenital hypothyroidism after prolonged l-thyroxine therapy

Abstract The effect of long-term l -thyroxine (LT4) replacement therapy on bone mineral density and on biochemical markers of bone turnover were studied in children with congenital hypothyroidism (CH). Forty-four children and adolescents (mean age 8.5 ± 3.5 years) with primary CH who began LT4 replacement therapy within the first month of life were studied. Bone mineral density (BMD) of the lumbar vertebrae and the upper femoral bone was measured by dual energy X-ray absorptiometry. Serum osteocalcin (OC) and bone alkaline phosphatase were measured as markers of bone formation and urinary deoxypyridinoline was taken as a marker of bone resorption. Bone mineral densities of CH children were not different from those in age-matched controls. The biochemical markers of bone turnover were normal except for the serum OC levels which were found to be higher than in controls and positively correlated with the free thyroid hormone levels (for FT4 r = 0.42, p = 0.02). Eight CH children demonstrated low BMD values (below -1 SDS) at - 2 ± 0.7 SDS for the lumbar spine and - 1.6 ± 0.5 SDS for the femoral site. These eight children showed lower mean weight ( p < 0.05) and their dietary calcium intake tended to be less ( p < 0.06) than that seen in the normal BMD group. In conclusion, our results show that LT4 replacement therapy for 8 years is not detrimental to the skeletal mineralization of CH children. As in a healthy population, weight and current intake of calcium seem to be major determinants of bone density. Dietary recommendations, especially when calcium intake is below the recommended dietary allowance, may have to be reconsidered.     

Influence of genetic polymorphisms on bone disease of preterm infants

Bone disease is an important complication among very low birth weight (VLBW, <1500 g) infants. In adults, osteoporosis is associated with polymorphisms of vitamin D receptor (VDR), estrogen receptor (ER), and collagen Ialpha1 (COLIA1) genes. However, limited information is available regarding the role of these polymorphisms in bone disease in premature infants. We have investigated the possible association between bone disease and the allelic polymorphisms of these three genes in 65 VLBW infants. Twenty infants (30.8%) were diagnosed with bone disease based on high activity of bone formation (serum alkaline phosphatase and osteocalcin), bone resorption (urinary excretion of calcium and pyridinium crosslink) markers, and positive radiologic signs. Statistically significant correlation between thymine-adenine repeat [(TA)(n)] allelic variant of ER gene and bone disease was observed. Infants without bone disorder more often carried a high number of repeats [(TA)(n) >18] [odds ratio (OR): 0.17, 95% confidence interval (CI): 0.05-0.55]. A low number of repeats [(TA)(n) <19] was found more frequently in infants suffering from bone disease (OR: 6.00, 95% CI: 1.77-20.31). Significant interaction (p = 0.009) between VDR and COLIA1 genotypes was observed. In a logistic regression model, bone disorder of preterms significantly correlated with male gender (p = 0.002), lower gestational age (p = 0.015), homozygous allelic variants of high number of (TA)(n) repeats (p = 0.006), and interaction between VDR and COLIA1 genotype (p = 0.009).     

Analysis of polymorphisms of the vitamin D receptor, estrogen receptor, and collagen Ialpha1 genes and their relationship with height in children with bone cancer

PURPOSE: The authors' objectives were to compare height at diagnosis of children with bone tumors with that of Spanish reference children; to analyze the frequency of the genotypes for the polymorphisms of the vitamin D receptor (VDR), estrogen receptor (ER), and collagen Ialpha1 (COLIalpha1) genes in patients and in healthy controls; and to test the relationship between the genetic markers and height. PATIENTS AND METHODS: Height and weight at diagnosis were measured in 58 osteosarcoma and 36 Ewing sarcoma patients and compared with standards published for Spanish reference children according to sex and age. For the molecular analysis, genetic polymorphisms of the VDR (Fok I, Apa I, and TaqI), ER (Pvu II and XbaI), and COLIalpha1 (Msc I) genes were characterized in 72 osteosarcoma and 53 Ewing sarcomas and in a group of 143 healthy matched children. RESULTS: Osteosarcoma and Ewing sarcoma patients were significantly taller than Spanish reference children. Osteosarcoma patients showed a significantly higher frequency of the Ff genotype for the Fok I polymorphism (VDR gene) than the control group. The odds ratio for this genotype was 1.78, with an increased relative risk of 78% for heterozygous Ff carriers. Among Ewing sarcoma patients, this same genotype was significantly associated with lower height than homozygotes (FF or ff). CONCLUSIONS: Children with bone cancer are significantly taller than the reference population, which may be influenced by the genotype for the Fok I polymorphism of the VDR gene.     

维生素D受体基因多态性与维生素D缺乏性佝偻病易感性的研究

目的 通过研究维生素D受体(VDR)基因多态性与维生素D缺乏性佝偻病易感性的相关性,探讨维生素D缺乏性佝偻病的遗传易感因素。方法 利用限制性内切酶FokI,应用聚合酶链反应-限制性片段长度多态性(PCR—RFLP)分析、基因测序等技术测定48例维生素D缺乏性佝偻病患儿(病例组)和92名正常儿童(对照组)的VDR基因多态性,比较两组VDR基因型和等位基因的分布频率,并计算基因型优势比(OR)。结果 在48例佝偻病患儿中FF、Ff和ff基因型分布频率分别为46％、33％和21％;而在92名正常儿童中FF、Ff和ff基因型分布频率分别为22％、52％和26％。两组VDR基因型的分布频率差异有显著性(x^2=8．912,P=0．012),病例组中FF基因型占明显优势(OR=3．046)。两组VDR基因等位基因的分布频率差异也有显著性(x^2=5．451,P=0．020),病例组中F等位基因分布频率高于对照组。结论 VDR基因多态性与维生素D缺乏性佝偻病有相关性,提示VDR基因多态性可能在决定个体维生素D缺乏性佝偻病遗传易感性方面有重要作用。     

维生素D受体基因多态性与儿童铅易感性的关系

目的　了解某铅污染较重矿区汉族儿童维生素D受体 (VDR)基因多态性的分布状况 ,探讨维生素D受体基因多态性与儿童铅易感性间的关系。方法　整群抽取矿区幼儿园 5～ 6岁汉族儿童 12 0名。研究VDR等位基因 (VDRB和VDRb)的出现频率并测定血铅水平 ,同时问卷调查每位研究对象血铅水平的相关因素。结果　 ( 1)所研究儿童VDRBB型 2例 ,占 1 7% ;VDRBb型 11例 ,占9 2 % ;VDRbb型 10 7例 ,占 89 2 % ;( 2 )携有VDRB等位基因的儿童血铅平均值 [( 0 910 8± 0 2 650 )μmol/L]明显高于VDR基因型为bb者 [( 0 740 1± 0 2 70 1) μmol/L] (t =2 155,P <0 0 5)。 ( 3 )儿童血铅水平相关因素分析发现 :VDR基因型 ,燃料类型及母亲文化程度等 7个因素与血铅显著相关 ,采用多元逐步回归分析后 ,发现VDR基因型对血铅水平的影响在排除协变量影响后仍有显著的统计学意义。结论　本组儿童VDR基因存在遗传多态性 ;携有VDRB等位基因的儿童对铅易感性较高 ,可能成为铅毒性作用的高危人群     

卡马西平和丙戊酸钠对癫癎患儿骨代谢的影响

目的探讨长期服用卡马西平（CBZ）或丙戊酸钠（VPA）对癫痫患儿骨代谢的影响。方法对92名单独服用CBZ或VPA2年以上的癫痫患儿及35名年龄匹配的健康儿童的骨密度进行测量,测定骨代谢特异性生化指标,血清骨钙素（OC,骨形成指标）和尿脱氧吡啶酚（DPD,骨吸收指标）,并调查每日钙摄入量。结果癫痫患儿骨密度明显低于对照组（P〈0．05）,服用抗癫痫药物（AEDs）的时间与骨密度呈负相关（rs=-0．21～-0．31,P〈0．05）。癫痫患儿中低骨密度患儿32人,占35％,明显高于对照组14％（P〈0．05）。低骨密度的癫痫患儿多体重指数较高（P〈0．05）,每日钙摄入量较少（P〈0．01）,服用AEDs的时间相对较长（P〈0．01）。癫痫患儿血清OC浓度明显低于对照组（P〈0．01）;而尿DPD浓度与对照组基本一致（P〉0．05）。结论长期服用CBZ或VPA会导致骨代谢异常,骨密度下降、骨转换降低（以骨形成减少为主）;而钙摄入量不足及体重指数偏高是加剧骨骼异常的诱发因素。     

兰州地区回族与汉族儿童维生素D受体基因多态性分布

目的：了解兰州地区回族与汉族儿童维生素D受体(VDR)基因多态性分布,探讨不同种族之间VDR基因型频率的分布。方法：利用限制性内切酶Bsm Ⅰ,采用聚合酶链反应限制性片段长度多态性技术(PCR-RFLP),对兰州地区回族健康儿童81例和汉族健康儿童169例VDR基因多态性进行检测。结果：发现在回族81例中,bb型57例(70.4％),Bb型22例(27.2％),BB型2例(2.5％);在汉族169例中,bb型154例(91.1％),Bb型12例(7.1％),BB型3例(1.8％)。结论：兰州地区回族VDR基因多态性分布与汉族相比存在显著性差异。     

Reduced bone mineral density at diagnosis and bone mineral recovery during treatment in children with Graves' disease

OBJECTIVES: In children with Graves' disease, the prevalence of osteopenia is unknown, and the possible restoration of bone mass by antithyroid treatment has not been evaluated. The aim of this study was to prospectively evaluate the bone mineral density (BMD) and bone metabolism at diagnosis and after 1 and 2 years of medical treatment. Twenty-six children (19 girls and 7 boys) aged 11 +/- 3.4 years (range 3.4 to 15.3 years) were studied. STUDY DESIGN: BMD of the lumbar spine and proximal femur were measured by dual-energy x-ray absorptiometry. Values were compared with those of healthy children of similar age, sex, and pubertal stage. RESULTS: At diagnosis the mean BMD (standard deviation score [SDS]) was significantly reduced in both sites (P <.001) with a preferential loss of cortical bone (femoral BMD = -1.7 +/- 1.0 SDS) rather than trabecular bone (lumbar spine BMD = -0.8 +/- 1.1 SDS) (P =.003). Severe osteopenia (below -2 SDS) was found in 11 (42%) of 26 patients. Osteocalcin was significantly higher than in the control group (P <.0001), but other bone metabolism markers were normal. During treatment (n = 19) a significant gain in femoral (F = 14.7; P =.001) and lumbar spine (F = 5; P =.02) BMD (SDS) was observed, and none of the patients showed osteopenia. The annual percent change in the BMD values at the femoral (+23% +/- 11% and +6% +/- 4%, respectively, during the first and second years) and lumbar spine (+19% +/- 9% and +6% +/- 5%, respectively, during the first and second years) sites was greater during the first year than during the second year of treatment (P <.02 for femoral, P <.04 for lumbar spine). No significant age difference in BMD SD score or in BMD percent change values was observed. Osteocalcin returned rapidly to normal values, and all other bone metabolism markers remained in the normal range. CONCLUSIONS: In conclusion, severe osteopenia was observed at diagnosis in children with Graves' disease but was rapidly corrected after 1 and 2 years of treatment. Initial reduced bone mass with high bone turnover caused by hyperthyroidism was corrected after 1 year of euthyroid conditions.     

The effects of antiepileptic drugs on the relationships between leptin levels and bone turnover in prepubertal children with epilepsy

Antiepileptic drugs (AED) had an effect on bone metabolism in children. This study was conducted in order to determine the relationships between serum leptin levels, bone mineral density (BMD) and bone turnover markers in epileptic children. Fifty-three patients were treated with valproic acid (VPA) and 23 with carbamazepine (CBZ) monotherapy; 50 healthy children were included in the study as controls. Serum alkaline phosphatase (ALP) and cross-linked C-telopeptide (CTx) levels were statistically significantly higher in the CBZ group than in the VPA group and the control group (p < 0.0001, p < 0.010, respectively). Serum osteocalcin and ALP levels were significantly lower in the VPA group than in the control group (P < 0.012, P < 0.030, respectively). Although we found slightly higher serum leptin levels in both the CBZ and VPA groups, they were not significantly different from the control group (P > 0.05). We demonstrated that the markers of bone formation and resorption increased with CBZ and decreased with VPA treatment without affecting BMD and vitamin D levels in prepubertal epileptic children.     

中国急性白血病儿童的细胞色素P450-3A4基因型多态性分析

目的阐明中国急性白血病(AL)和健康儿童中细胞色素P450-3A4(CYP3A4)的基因型分布特点,探讨CYP3A4基因型多态性与儿童白血病的易感性及化疗效应之间可能的相关性。方法应用PCR-RFLP及DNA测序法检测120例AL和85例健康儿童的CYP3A4基因型,分析两组CYP3A4基因型差异。结果85例健康儿童中仅1例为CYP3A4*1B的杂合子基因型,均为野生型,杂合子型的突变频率为1.2%;120例AL儿童中5例(4例ALL和1例AML)表现为杂合子基因型,1例ALL为纯合子基因型,其杂合子基因型突变率为4.2%,纯合子基因型突变率为0.8%。经PCR-RFLP检测并经DNA测序验证,所有受检者的CYP3A4*3基因型均为野生型。结论虽然AL患儿的CYP3A4*1B基因突变率高于健康儿童,但差异无显著性,因此尚不能推论CYP3A4*1B基因型与中国儿童AL发病相关。CYP3A4*3基因在中国健康和AL儿童中是一种罕见的等位基因,其对于CYP3A4酶活性的影响及其在白血病发生中的作用有待进一步探讨。     

维生素D受体基因多态性与新疆南部地区维吾尔族儿童尿路结石相关性研究

目的：探讨维生素D受体（VDR）基因多态性与新疆南部地区维吾尔族儿童尿路结石相关性,阐明分子遗传学规律。方法：维吾尔族尿路结石患儿（病例组）74例和维吾尔族正常儿童（对照组）103例纳入此研究,应用聚合酶链反应-限制性片段长度多态性分析研究VDR基因FokI和ApaI位点多态性与新疆南部地区维吾尔族儿童尿路结石相关性。结果：VDR基因FokI位点FF、Ff、ff 3种基因型在病例组及对照组之间分布差异有统计学意义（χ2=7.818, P＜0.05）,基因型Ff在病例组占58%,明显高于对照组,差异有统计学意义（P＜0.05）。VDR基因ApaI位点AA、Aa、aa 3种基因型在病例组和对照组的分布差异无统计学差意义（P>0.05）。结论：VDR基因FokI位点多态性将来可作为维吾尔族儿童泌尿系结石的候选基因。     

GHR and VDR genes do not contribute to the growth hormone (GH) response in GH deficient and Turner syndrome patients

We have prospectively assessed the influence of GHR and VDR gene polymorphisms on the response to rhGH therapy in Venezuelan children with growth hormone deficiency (GHD, n=28) and Turner syndrome (TS, n=25). Clinical data during rhGH treatment were compared in GH and TS patients with different genotypes. PCR amplifications were performed to obtain the genotype frequencies of the polymorphisms. Clinical data at the start of treatment and rhGH doses were indistinguishable among patients with GHD or TS with different GHR or VDR genotypes. After the first two years of rhGH treatment, clinical data in both GHD and TS patients were not different according GHR or VDR genotypes. In addition, there was no significant difference among the subjects when both these genotypes were combined. Gene polymorphisms in low penetrance genes do not contribute to the rhGH therapy response in patients with GHD and TS.     

Children with chronic kidney disease: a 3-year prospective study of growth, bone mass and bone turnover

Aim: Children with chronic kidney disease (CKD) are at risk of developing skeletal problems. This 3-year prospective study investigated the development of bone mass and bone turnover in children with CKD.
Methods: Fifteen patients, 4–15 years, were included with a median glomerular filtration rate of 48 (range 8–94) mL/min/1.73 m². Bone mineral density (BMD) and markers of bone and mineral metabolism were investigated over a 3-year period.
Results: Growth was satisfactory but a delayed bone age was observed. Total body bone mineral density (TBBMD) Z-scores were below zero in five patients at start and after 3 years, but none had a Z-score below −2.5. Lumbar spine BMD Z-scores were below zero in three patients at start and in five patients after 3 years. The median TBBMD and lumbar spine Z-scores did not change during the study period. Eleven CKD patients had increased PTH levels at baseline and 13 patients after 3 years. Most children had normal levels of leptin and vitamin D. Almost 50% of the patients had increased osteoprotegerin levels after 3 years.
Conclusion: A normal BMD does not exclude mineral bone disorder in patients with CKD, yet the BMD Z-scores were well preserved and most markers of bone turnover were within the reference intervals.     

维生素D缺乏性佝偻病遗传易感性的研究

目的：遗传因素是否参与维生素D缺乏性佝偻病目前尚未明了。拟通过研究维生素D受体基因多态性与维生素D缺乏性佝偻病易感性的相关性,探讨维生素D缺乏性佝偻病的遗传易感性。方法：应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)分析技术检测159例维生素D缺乏性佝偻病儿童和78例正常儿童(对照组)维生素D受体(VDR)基因FokI位点的多态性,比较两组之间VDR基因型和等位基因的频率。结果：维生素D缺乏性佝偻病患儿和对照组儿童的VDR基因FokI位点基因型分布频率分别为:FF(37%),Ff(51%),ff(12%)和FF(18%),Ff(55%),ff(27%),两组之间的差异有显著性(χ20.01(2)=9.210,χ2=13.3880,P<0.01);佝偻病患儿和对照组儿童的VDR基因FokI位点等位基因分布频率分别为:F(63%),f(37%)和F(46%),f(54%),两组之间的差异有显著性(χ2=6.18,P<0.05)。佝偻病患儿F等位基因分布频率明显高于对照组人群(63%vs46%)两组之间的差异有显著性;而佝偻病患儿f等位基因频率显著低于对照组(37%vs 54%)。结论：VDR基因FokI酶切位点的多态性可能与维生素D缺乏性佝偻病的遗传易感性有关。     

Decreased lumbar spine bone mass and low bone turnover in children and adolescents with insulin dependent diabetes mellitus followed longitudinally

The effects of insulin dependent diabetes mellitus (IDDM) on bone metabolism are still not well defined. We evaluated total bone mineral content (TBMC) and bone mineral density (BMD) at the lumbar spine and femoral neck using dual X-ray absorptiometry in 26 IDDM children (15 M, 11 F) with a mean chronological age of 12.1+/-3.1 yr (range 7.1-14.2 yr). Duration of diabetes was 4.3+/-2.9 yr, with a mean glycosylated hemoglobin of 9.2+/-0.4%. BMD and TBMC standard deviation scores (Z-scores) were determined by comparing our results to controls matched for age, sex and pubertal status. BMD and bone formation and resorption markers were determined at the beginning of the study and after one year of follow up. Mean lumbar spine Z-score was -1.06+/-0.2, with negative values in 24 of 26 children (92.6%); 14/26 patients (53.8%) had a lumbar spine Z-score >1.0 SD below the mean. Mean lumbar spine Z-score remained unchanged after one year of follow up (-1.02+/-0.3). No significant differences were obtained in femoral neck BMD or TBMC between groups. No correlation was observed between lumbar spine BMD Z-scores and duration of IDDM or degree of diabetes control, as assessed by the mean glycosylated hemoglobin. Daily urinary calcium excretion was elevated in our patients initially and after one year of follow up; however, no correlation was obtained between lumbar spine BMD and 24 h urinary calcium excretion. Carboxy-terminal propeptide of type 1 collagen values and levels of urinary cross-linked N-telopeptides of type 1 collagen in the diabetic children were significantly lower than those of the matched controls. Osteoblastic activity as assessed by serum osteocalcin and by the carboxy-terminal propeptide of type I collagen and bone resorption as measured by cross-linked N-telopeptides of type 1 collagen did not correlate with the lumbar spine Z-scores. When IDDM patients were subdivided into males and females and into children with more than or less than 2 yr duration of diabetes since diagnosis, no differences between groups were found. These results suggest that insulin dependent diabetes in children is associated with low bone turnover resulting in a deficit in bone mass which may be manifested as osteopenia in the growing bone. This defect is already present in trabecular bone early on in the disease and seems not to be related to glycemic control.