Bone mass in young adults with Down syndrome

Background Down syndrome (DS) is a frequent cause of intellectual disability. With the increasing life expectancy of these patients, concerns have been raised about the risk of osteoporosis. In fact, several investigators have reported a reduced bone mass in DS. However, the results may be confounded by comorbid diseases, and differences in lifestyle habits and body size. Therefore, we planned to determine anthropometric and lifestyle factors influencing bone mineral density (BMD) in young adults with DS. Methods Thirty‐nine patients with DS (mean age 26 years) and 78 controls were studied. Areal BMD was measured by dual x‐ray decsitometry (DXA); volumetric BMD at the lumbar spine and femoral neck was estimated with published formulae. Results DS patients had lower areal BMD than controls at all regions (spine, hip and total body). Height and projected bone area were also lower. There were no differences between both groups regarding estimated volumetric BMD at the femoral neck. However, spine volumetric BMD was also lower in DS than controls. In multivariate analysis, DS, male sex, little physical activity and low sunlight exposure were associated with lower spine volumetric BMD; on the other hand, fat mass and sunlight exposure were associated with femoral neck volumetric BMD. Conclusion This study shows that patients with DS had a reduced areal BMD, but it is in part a consequence of the reduced body size, particularly at the femoral neck. Physical activity and sunlight exposure are associated to volumetric BMD and should be stimulated in order to maintain an adequate bone mass in these patients.     

Effects of physical training and calcium intake on bone mineral density of students with mental retardation

The purpose of this study was to investigate the effects of physical training and calcium intake on bone mineral density (BMD) of students with mental retardation. Forty mentally retarded boys (age 7–10 years old) were randomly assigned to four groups (no differences in age, BMD, calcium intake and physical activity): training groups with or without calcium supplementation (Tr+Ca+ and Tr+Ca?) and nontraining groups with or without calcium supplementation (Tr?Ca+ and Tr?Ca?). The intervention involved 45 min of physical training performed 3 sessions a week and/or the addition of dietary calcium-rich food using enriched cow milk with vitamin D containing 230 mg calcium per serving, over 6 months. Paired-samples t-test and ANOVA analysis was used to determine the main and combined effects of training and calcium on BMD. All groups showed greater femoral neck BMD after 6 months. The increase in femoral neck BMD in the Tr+Ca+ group was 10% greater than increase in the Tr+Ca? group (not significant). Apparently, the effect of training was greater than calcium intake because the Tr+Ca? group achieved 4% greater BMD than Tr?Ca+ group (not significant). In this study, both training groups had greater BMD than the control group (Tr?Ca?) (P < 0.05).In these participants with inadequate calcium intakes, additional exercise and calcium supplementation resulted in a 6–20% greater increase in BMD than controls at the loaded site (femoral neck). These results help to provide more evidence for public health organizations to deal with both exercise and nutrition issues in children for the achievement of peak BMD.     

Reduced bone mineral density in patients with haemophilia A and B in Northern Greece

Haemophilia A and B has been associated with increased prevalence of low bone mass (67-86%). The aim of this study was to estimate the prevalence of bone disease in haemophiliacs and its association with potential risk factors. Adult patients with haemophilia A and B followed-up in the Haemophilia Centre of Northern Greece were included. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA) in lumbar spine (LS), femoral neck (FN), total hip (TH) and great trochanter (GT). One-hundred four male patients (aged 45.8 ± 15.1 years) and 50 controls (aged 44.9 ± 12.8 years) were screened. Low BMD was diagnosed in 28 patients (26.9%) and 10 controls (20%) (p=0.0001). Patients had lower BMD in TH (p=0.007), FN (p=0.029) and GT (p=0.008) than controls, without differences in LS. BMD was positively associated with the severity of haemophilia, history of herpes virus C or human immunodeficiency virus and level of physical activity, and negatively with the level of arthropathy. In multiple-regression analysis, only the level of physical activity and 25-hydroxyvitamin D [25(OH)D] significantly predicted BMD. Half of the patients had vitamin D deficiency. In conclusion, our study showed increased prevalence of low BMD in haemophiliacs. The levels of physical activity and 25(OH)D independently predicted low BMD.     

Bone status in multiple sclerosis: beyond corticosteroids

The aim of this study was to determine the possible factors affecting bone mineral density (BMD) in multiple sclerosis (MS). In this cross-sectional study, 65 clinically definite MS patients and 72 comparable controls were prospectively evaluated. To assess bone mineral metabolism in MS, the BMD of the lumbar spine and hip (femoral neck, trochanter and total) was measured by dual-energy X-ray absorptiometry, and serum vitamin D and parathyroid hormone levels and biochemical markers of bone turnover were also evaluated. MS patients had significantly lower BMD values than the control group at all measurement sites. There was a significant correlation between the disease duration and BMD values at the trochanter in women with MS. A correlation between femoral BMD values and functional status in women was also detected. There was no relationship between bone biochemical markers and BMD, except a negative correlation between bone alkaline phosphatase and trochanter BMD. Both disability and disease duration have an influence on BMD of the MS patients, whereas no significant correlation between glucocorticoid use and BMD was observed.     

Antiepileptic drug-induced bone loss in young male patients who have seizures

BACKGROUND: Long-term antiepileptic drug (AED) therapy is a known risk factor for bone loss and fractures. Vitamin D deficiency is frequently cited as a cause for bone loss in patients who have seizures. OBJECTIVE: To determine whether men who have seizures, but who are otherwise healthy, suffer substantial bone loss in the hip while taking AEDs. PATIENTS AND METHODS: We prospectively examined femoral neck bone mineral density (BMD) by dual-energy x-ray absorptiometry in 81 consecutive men, aged between 25 and 54 years old (mean age, 45 years), who were attending an outpatient seizure clinic. Low BMD values were analyzed for known risk factors for bone loss. Dual-energy x-ray absorptiometry scans were repeated in 54 patients, 12 to 29 months later (mean, 19 months), to assess the rate of change in BMD over time. RESULTS: Multivariate linear regression analysis revealed that age (P<.001) and time receiving AEDs (P<.003) were the 2 important risk factors associated with low femoral neck BMD. Neither vitamin D deficiency, hypogonadism, cigarette smoking, nor excess alcohol intake were associated with low BMD after correcting for age and time on AEDs. Longitudinal analysis of femoral neck BMD revealed that only those in the youngest age group (25-44 years) showed significant declines in femoral neck BMD (1.8% annualized loss; 95% confidence interval, -3.1 to -0.9; P<.003) while receiving AED therapy. There was no evidence that a specific type of AED was more causally related to bone loss in this group although most patients were taking phenytoin sodium or carbamazepine during the longitudinal assessment. CONCLUSIONS: Long-term AED therapy in young male patients who have seizures causes significant bone loss at the hip in the absence of vitamin D deficiency. Dual-energy x-ray absorptiometry scanning of the hip is useful in identifying patients who are particularly susceptible to rapid bone loss while taking AEDs.     

A case control study on bone mineral density in Chinese patients with Parkinson’s disease

Although previous studies showed that patients with Parkinson’s disease (PD) have low bone mineral density (BMD), there is little data on factors predisposing PD patients to low BMD. We compared the BMD of 108 PD patients (58 females) with an average age of 68 (range 42–83) years with that of 216 sex- and age-matched controls, adjusting for other covariate factors (exercise levels, estrogen status, dietary calcium intake, smoking, drinking, body mass index, and percentage of body fat). The mean BMD in the hip and lumbar spine of male PD patients did not differ significantly from those of male controls. On the other hand, the mean BMD in femoral neck was significantly lower in female PD patients than in controls (0.53 ± 0.11 g/cm² versus 0.58 ± 0.10 g/cm², P = 0.005). Compared with controls, female PD patients experienced menopause much earlier (47 years versus 50 years, P = 0.028). The percentage of body fat was also lower in female PD patients (33% versus 36%, P = 0.02). A lower BMD in the hip in female PD patients was associated with an increased number of months after menopause (P = 0.004) and lower percentage of body fat (P = 0.025). We concluded that female patients with PD have lower hip BMD, but this association appears largely attributable to differences in percentage body fat and years since menopause. After multivariate adjustment, PD no longer remained independently associated with reduced BMD in female patients.     

Intramuscular blood flow in Duchenne and Becker Muscular Dystrophy: Quantitative power Doppler sonography relates to disease severity

ObjectiveAbsent or truncated dystrophin in Duchenne (DMD) and Becker (BMD) muscular dystrophies results in impaired vasodilatory pathways and exercise induced muscle ischemia. Here, we used power Doppler sonography to quantify changes in intramuscular blood flow immediately following exercise in boys with D/BMD.MethodWe quantified changes in intramuscular blood flow following exercise using power Doppler sonography in 14 boys with D/BMD and compared changes in muscle blood flow to disease severity and to historic controls.ResultPost exercise blood flow change in the anterior forearm muscles is lower in (1) DMD (median 0.25%; range −0.47 to 2.19%) than BMD (2.46%; 2.02–3.38%, p < 0.05) and historical controls (6.59%; 2.16–12.40%, p < 0.01); (2) in non-ambulatory (0.04%; −0.47 to 0.10%) than ambulatory DMD boys (0.71%; 0.07–2.19%, p < 0.05); and (3) in muscle with higher echointensity (r_s = −0.7253, p = 0.005). The tibialis anterior showed similar findings. We estimate that a single sample clinical trial would require 19 subjects to detect a doubling of blood flow to the anterior forearm after the intervention.ConclusionPost-exercise blood flow is reduced in D/BMD and relates to disease severity.SignificanceOur protocol for quantifying post-exercise intramuscular blood flow is feasible for clinical trials in D/BMD.     

Bone mineral density accrual in students with autism spectrum disorders: Effects of calcium intake and physical training

The purpose of this study was to investigate the effects of weight bearing exercise and calcium intake on bone mineral density (BMD) of students with autism spectrum disorders. For this reason 60 boy students with autism disorder (age 8-10 years old) were assigned to four groups with no differences in age, BMD, calcium intake, and physical activity: exercise groups with or without calcium supplementation (Ex+Ca+ and Ex+Ca−) and non-exercise groups with or without calcium supplementation (Ex−Ca+ and Ex−Ca−). The intervention involved 50 min of weight bearing exercise performed 3 sessions a week and/or the addition of dietary calcium rich food using enriched cow milk with vitamin D containing 250 mg calcium per serving, over 6 months. Paired-samples t test, one way ANOVA analysis, and Tukey tests were used to determine the main and combined effects of training and calcium on BMD. All groups showed greater femoral neck BMD after 6 months. The increase in femoral neck BMD in the Ex+Ca+ group was 14.04% greater than increase in the Ex+Ca− group (P < 0.05). Apparently, the effect of training was greater than calcium intake because the Ex+Ca− group achieved 4.71% greater BMD than Ex−Ca+ group (P < 0.05). In this study, all experimental groups had greater BMD than the control group (Ex−Ca−) (P < 0.05).In these participants, additional weight bearing exercise and calcium supplementation resulted in a greater increase in BMD than controls at the loaded site (femoral neck). These results help to provide more evidence for public health organizations to deal with both exercise and nutrition issues in children with autism disorder for the achievement and of peak BMD.     

Long-term effects of intravenous high dose methylprednisolone pulses on bone mineral density in patients with multiple sclerosis

To determine the effects of high dose methylprednisolone (HDMP) pulses on bone mineral density (BMD) in patients with multiple sclerosis (MS), we studied 25 MS patients who received regular pulses of HDMP as well as pulses of HDMP for relapses, 18 MS patients who received HDMP at the same dose schedule only for relapses, and 61 healthy controls. We measured BMDs at lumbar spine and femoral neck and we assessed biochemical markers of bone metabolism and turnover. The average lifetime dosage of MP was 75.4 (SD 11.9) g in the pulsed HDMP group and 28.6 (SD 18.3) g in the HDMP for relapses group (P < 0.0001). Two MS patients (4.7%) and four controls (6.6%) had osteoporosis (P = NS), whereas 25 patients with MS (58.1%) and 21 controls (34.4%) had osteopenia (P = 0.016). BMDs measured at lumbar spine and femoral neck and biochemical indices of bone metabolism did not differ in MS patients and controls. BMD measures were not associated with lifetime methylprednisolone dosage. In partial correlation analysis, controlling for age, gender and menopausal status there was a significant inverse correlation between BMD at femoral neck and Expanded Disability Status Scale (EDSS) score (r = -0.31, P = 0.05). In conclusion, treatment with repeated HDMP pulses was not associated with osteoporosis in patients with MS who participated in a trial of methylprednisolone. However, osteopenia was observed more frequently in MS patients than healthy controls. Our data are reassuring, as them suggest that repeated pulses of methylprednisolone do not result in substantially increased risk of osteoporosis in MS patients. Moreover, osteopenia was found only in patients treated for relapses, who had a significantly higher EDSS score than patients in the HDMP group, suggesting that decreased mobility may contribute to bone loss more than corticosteroid use. BMD should be monitored in patients with MS, regardless of the use of methylprednisolone.     

Bone mineral density changes after physical training and calcium intake in students with attention deficit and hyper activity disorders

In this study we investigate the effects of weight bearing exercise and calcium intake on bone mineral density (BMD) of students with attention deficit and hyper activity (ADHD) disorder. For this reason 54 male students with ADHD (age 8-12 years old) were assigned to four groups with no differences in age, BMD, calcium intake, and physical activity: exercise groups with or without calcium supplementation (Ex+Ca+ and Ex+Ca−) and non-exercise groups with or without calcium supplementation (Ex−Ca+ and Ex−Ca−). The intervention involved 50 min of weight bearing exercise performed 3 sessions a week and/or the addition of dietary calcium rich food using enriched cow milk with vitamin D containing 250 mg calcium per serving, over 9 months. Paired-samples t-test, one way ANOVA analysis, and Tukey tests were used to determine the main and combined effects of training and calcium on BMD. All groups showed greater femoral neck BMD after 9 months. The increase in femoral neck BMD was significantly different between all groups (p < 0.05). Ex+Ca+ group has greater increase in BMD than other groups. Apparently, the effect of training was greater than calcium intake (p < 0.05). These results help to provide more evidence for public health organizations to deal with both exercise and nutrition issues in children with ADHD disorder for the achievement of peak BMD.     

Bone density and antiepileptic drugs: a case-controlled study.

This case-controlled study explored the relationship between bone mineral density (BMD) and long-term treatment with antiepileptic drugs (AEDs) in older adults with epilepsy. Seventy-eight patients (47 post-menopausal females, 31 males, aged 47-76 years) with epilepsy participated in the study. Each had only ever received treatment with either enzyme-inducing (n = 52) or non-inducing (n = 26) AEDs. Individuals were matched for age, sex, height and weight with a drug-naive control. All patients underwent bone densitometry at the lumbar spine and femoral neck and had blood sampling and urine collected for a range of bone markers. Male patients had lower BMD than controls at the lumbar spine (P < 0.01) and neck of the femur (P < 0.005). Female patients had significantly reduced bone density at the femoral neck (P < 0.05) only. AED usage was independently associated with an overall reduction in bone density at femoral sites and contributed to just over 5% of the variance at the femoral neck. Duration of treatment and type of AED were not independent factors for reduction in BMD. This case-controlled study supports the hypothesis that long-term AED therapy is an independent risk factor for reduced BMD in epileptic patients. Adults receiving treatment for epilepsy are at higher risk of osteoporosis and should be offered bone densitometry.     

Body composition in nutritionally adequate ambulatory and non-ambulatory children with cerebral palsy and a healthy reference group

Bone-mineral content (BMC; g) and density (BMD; g/cm2) were measured by dual energy X-ray absorptiometry in the proximal femur, femoral neck, and total body of nutritionally adequate children (n=17; 11 girls, six boys; aged 7.6 to 13.8 years) with spastic cerebral palsy (CP). Bone-mineral-free lean tissue (BMFL; g) and fat mass (FM; g) were obtained from total body scans. Chronological and developmental age-based z scores for the children with CP were derived from a pediatric database (n=894). Children with CP had BMC z scores from -1.8 (total body) to -3.2 (femoral neck) SDs below the normative sample. Non-independent ambulators had lower z scores for total body BMD, femoral neck BMD, and BMC than independent ambulators. The BMFL z score of individuals with CP was 2 SDs below that of the reference group and higher in the independent ambulators than in the non-independent ambulators, whereas FM deviated little. These findings suggest that non-nutritional factors, such as ambulation, account for the low BMC, BMD, and BMFL tissue observed in this population.     

Investigation of the relationship between vitamin D and bone mineral density in newly diagnosed multiple sclerosis

The aim of this study was to investigate the relationship between vitamin D and bone mineral density in newly diagnosed multiple sclerosis (MS) and to compare results with data from healthy controls. A total of 60 subjects, including 30 patients with MS, newly diagnosed and untreated (18 females, 12 males, at 18–40 years of age) and 30 healthy controls (20 female, 10 male) were enrolled in this study. Bone mineral density (BMD) of the lumbar spine and left femoral neck region were measured by dual-energy X-ray absorptiometry (DEXA). Serum levels of 25-hydroxyvitamin D (25OHD) were measured by chemiluminescence microparticle immunoassay (CMIA) on the Architect-i2000^® (Abbott) system. 25OHD levels of MS patients were significantly lower than in controls. 25OHD levels were 27.2 ± 14.1 ng/ml in MS patients and 42.6 ± 8.8 ng/ml in controls (p = 0.001). Twenty-six (86.6 %) of our patients had a reduced BMD in lumbar spine or femoral neck region; of these 24 patients (80 %) had osteopenia and 2 patients (6.6 %) had osteoporosis. Interestingly, there was no significant correlation between 25OHD and BMD in lumbar spine and femoral neck region (r = 0.454, p = 0,074; r = 0.636, p = 0.082). Interestingly, a significant reduction of bone density in female MS patients was observed. In our study, 25OHD deficiency and lower BMD appeared in newly diagnosed multiple sclerosis. This is compatible with shared etiologic or pathogenic factors in MS and osteopenia/osteoporosis, and calls for an active approach to optimize bone health in early stages of MS.     

A 2-year prospective study of bone metabolism and bone mineral density in adolescents with anorexia nervosa

Summary Osteopenia and osteoporosis are complications of adolescent anorexia nervosa (AN) and may result in a permanent deficit of bone mass in adulthood. It is still unclear if a complete catch-up in bone mineral density (BMD) is possible after weight rehabilitation in AN. Methods. We investigated bone formation (bAP, PICP), bone resorption (CTX) and BMD (lumbar spine, femoral neck) along with endocrinological parameters in 19 girls with AN (14.4 ± 1.6 years) and in 19 healthy controls for 2 years after inpatient re-feeding. Results. Re-feeding normalised bone formation activity in patients. The pattern of bone turnover in patients after 2 years was similar to the pattern healthy controls had shown 2 years before. BMD of patients was significantly lower than in controls and did not change throughout the entire study. Conclusions. Weight rehabilitation leads to prolonged normalization of bone turnover in adolescent AN. Since we could not observe a “catch up” effect in BMD of girls with AN in a 2-year follow-up, BMD of these patients needs to be carefully monitored until adulthood to detect early osteoporosis. The first two authors contributed equally     

Derangements in bone mineral parameters and bone mineral density in south Indian subjects on antiepileptic medications

Background:

Although there are reports describing the association of alternations of bone and mineral metabolism in epileptic patients with long-term anticonvulsant therapy, there are only limited Indian studies which have looked at this aspect.

Objectives:

This study was done to compare the prevalence of changes in bone mineral parameters and bone mineral density (BMD) in ambulant individuals on long-term anticonvulsant therapy with age- and body mass index (BMI)-matched healthy controls.

Materials and Methods:

There were 55 men (on medications for more than 6 months) and age- and BMI-matched 53 controls. Drug history, dietary calcium intake (DCI), and duration of sunlight exposure were recorded. Bone mineral parameters and BMD were measured.

Results:

The control group had a significantly higher daily DCI with mean ± SD of 396 ± 91 mg versus 326 ± 101 mg (P = 0.007) and more sunlight exposure of 234 ± 81 vs 167 ± 69 min (P = 0.05). BMD at the femoral neck was significantly lower in cases (0.783 ± 0.105 g/cm²) when compared to controls (0.819 ± 0.114 g/cm²). Majority of the patients (61%) had low femoral neck BMD (P = 0.04). There was no significant difference in the proportion of subjects with vitamin D deficiency (<20 ng/mL) between cases (n = 32) and controls (n = 37) (P = 0.234).

Conclusions:

Vitamin D deficiency was seen in both the groups in equal proportions, highlighting the existence of a high prevalence of this problem in India. Low femoral neck BMD found in cases may stress the need for supplementing calcium and treating vitamin D deficiency in this specific group. However, the benefit of such intervention has to be studied in a larger proportion of epileptic patients.     

Negative impact of high cumulative glucocorticoid dose on bone metabolism of patients with myasthenia gravis

This current study aimed to evaluate the frequency of low bone mass, osteopenia, and osteoporosis in patients with myasthenia gravis (MG) and to investigate the possible association between bone mineral density (BMD) and plasma levels of bone metabolism markers. Eighty patients with MG and 62 controls BMD were measured in the right femoral neck and lumbar spine by dual-energy X-ray absorptiometry. Plasma concentrations of osteocalcin, osteopontin, osteoprotegerin, tumor necrosis factor (TNF-α), interleukin (IL)-1β, IL-6, dickkopf (DKK-1), sclerostin, insulin, leptin, adrenocorticotropic hormone, parathyroid hormone, and fibroblast growth factor (FGF-23) were analyzed by Luminex®. The mean age of patients was 41.9 years, with 13.5 years of length of illness, and a mean cumulative dose of glucocorticoids 38,123 mg. Patients had significant reduction in BMD of the lumbar, the femoral neck, and in the whole body when compared with controls. Fourteen percent MG patients had osteoporosis at the lumbar spine and 2.5% at the femoral neck. In comparison with controls, patients with MG presented lower levels of osteocalcin, adrenocorticotropic hormone, parathyroid hormone, sclerostin, TNF-α, and DKK-1 and higher levels of FGF-23, leptin, and IL-6. There was a significant negative correlation between cumulative glucocorticoid dose and serum calcium, lumbar spine T-score, femoral neck BMD, T-score, and Z-score. After multivariate analysis, higher TNF-α levels increased the likelihood of presenting low bone mass by 2.62. MG patients under corticotherapy presented low BMD and altered levels of bone markers.     

Atypical sensory processing in adolescents with an autism spectrum disorder and their non-affected siblings

Atypical sensory processing is common in autism spectrum disorders (ASD). Specific profiles have been proposed in different age groups, but no study has focused specifically on adolescents. Identifying traits of ASD that are shared by individuals with ASD and their non-affected family members can shed light on the genetic underpinnings of ASD. Eighty adolescents with ASD (64 boys, 16 girls), 56 non-affected adolescent siblings (21 boys, 35 girls) and 33 adolescent controls (18 boys, 15 girls) filled out the Adolescent/Adult Sensory Profile, a self-report questionnaire resulting in four sensory quadrants according to Dunn's model of sensory processing. Adolescents with ASD differed significantly from controls on the quadrants Sensation Seeking and Sensation Avoidance. On quadrant 2 (Sensation Seeking) siblings scored significantly lower than controls and significantly higher than ASD. These results confirm the presence of atypical sensory processing in adolescents with ASD. We argue that reduced Sensation Seeking might be a candidate for an intermediate phenotype.     

中国老年人骨量丢失与维生素D受体基因启动子中Cdx-2结合位点的多态性

背景：骨质疏松症是一种与基因有关的骨脆性疾病，维生素D受体基因是主要候选基因之一。 目的：前瞻性调查老年人维生素D受体基因启动子中Cdx-2结合位点多态性与骨密度、骨量丢失的关系。 设计、时间及地点：前瞻性横断面调查，于2000-03/2005-03在沈阳医学院营养与食品卫生学教研室完成。 对象：选取沈阳市某社区无血缘关系、60岁以上的100名汉族健康老年人作为调查对象，性别不限，未服用过维生素D和钙补充剂，均自愿参与调查。 方法：用聚合酶链反应限制性片段长度多态性方法检测维生素D受体基因启动子中Cdx-2结合位点的多态性，应用DPX-L双能X射线吸收仪分别在调查初始和5年后两次测量调查对象的髋部骨密度。 主要观察指标：检测维生素D受体基因启动子中Cdx-2结合位点基因型分布，以协方差分析法分析维生素D受体基因启动子中Cdx-2结合位点多态性与髋部骨密度的关系。 结果：调查人群维生素D受体基因启动子中Cdx-2结合位点基因型频率分布为AA型17%，AG型57%，GG型26%；男女间等位基因型分布差异无显著性意义（P > 0.05）；该人群中等位基因频率分布符合Hardy-Weinberg 定律。无论男女各基因型间年龄、身高和体质量差异均无显著性意义（P > 0.05）。经身高、体质量和年龄校正后，调查初始不同基因型调查对象间股骨颈和大转子的骨密度差异无显著性意义（P > 0.05）；不同基因型调查对象间各部位年骨量丢失率差异也无显著性意义（P > 0.05）。 结论：调查人群维生素D受体基因启动子中Cdx-2结合位点基因型与髋部骨密度及骨量丢失无明显相关性。     

Effortful control in typically developing boys and in boys with ADHD or autism spectrum disorder

Despite increased interest in the role of effortful control (EC) in developmental disorders, few studies have focused on EC in autism spectrum disorders (ASD) and no study so far has directly compared children with ASD and children with ADHD. A first aim of this study was to investigate whether typically developing (TD) boys, boys with ADHD and boys with ASD can be differentiated based on EC levels. A second aim was to evaluate the relationship between EC and symptoms of ADHD and ASD. We assessed EC in 27 TD boys, 27 boys with ADHD and 27 boys with ASD (age 10-15) using different EC questionnaires. Clinical groups scored lower than the TD group on all EC total scales, but could only be differentiated from each other by means of self-reported persistence, impulsivity and activation control. Our data suggest that although EC is useful in differentiating TD boys from clinical groups, it is less efficient in distinguishing ADHD from ASD. Also, results suggest that EC plays a role in the manifestation of symptoms of both ADHD and ASD and that high levels of EC enable children to function more adequate in daily situations.     

Bone metabolism markers and bone mineral density in children with neurofibromatosis type-1

Some experimental studies suggested that there may be a bone formation defect rather than a disorder in bone resorption in patients NF1. The aim of this study was to determine bone mineral density (BMD) with dual-energy X-ray absorptiometry (DEXA) and investigate specific bone formation and bone resorption and bone turnover markers in children with NF1. Thirty-two children and adolescents (16 boys, 16 girls; 16 prepubertal, 16 pubertal) with NF1 were recruited. Their age ranged from 3 to 17 years. They were compared with matched healthy children. Dual-energy X-ray absorptiometry were applied to 26 patients and 27 controls. Nine of 32 subjects with NF1 had a skeletal abnormality. BMD of the lumbar spine, and femoral neck in NF1 patients significantly decreased compared to that of healthy subjects. They were also significantly decreased in pubertal patients when compared to pubertal controls and in prepubertal patients when compared to prepubertal controls. Patients with skeletal abnormalities were found to have significantly lower level of osteocalcin when compared to patients without skeletal abnormality. Other biochemical markers did not exhibit any difference between the groups. In conclusion, our findings suggest that bone formation markers rather than DEXA could be good predictors of skeletal abnormalities among NF1 patients. However, in our study the number of the NF1 patients with skeletal abnormality and the number of bone formation markers studied were all limited. It is appropriate to perform larger studies with other bone formation markers beside osteocalcin.