Inge Roggen

Bone size and bone strength are increased in obese male adolescents.

CONTEXT Controversy exists on the effect of obesity on bone development during puberty. OBJECTIVE Our objective was to determine differences in volumetric bone mineral density (vBMD) and bone geometry in male obese adolescents (ObAs) in overlap with changes in bone maturation, muscle mass and force development, and circulating sex steroids and IGF-I. We hypothesized that changes in bone parameters are more evident at the weight-bearing site and that changes in serum estradiol are most prominent. DESIGN, SETTING, AND PARTICIPANTS We recruited 51 male ObAs (10-19 years) at the entry of a residential weight-loss program and 51 healthy age-matched and 51 bone-age-matched controls. MAIN OUTCOME MEASURES vBMD and geometric bone parameters, as well as muscle and fat area were studied at the forearm and lower leg by peripheral quantitative computed tomography. Muscle force was studied by jumping mechanography. RESULTS In addition to an advanced bone maturation, differences in trabecular bone parameters (higher vBMD and larger trabecular area) and cortical bone geometry (larger cortical area and periosteal and endosteal circumference) were observed in ObAs both at the radius and tibia at different pubertal stages. After matching for bone age, all differences at the tibia, but only the difference in trabecular vBMD at the radius, remained significant. Larger muscle area and higher maximal force were found in ObAs compared with controls, as well as higher circulating free estrogen, but similar free testosterone and IGF-I levels. CONCLUSIONS ObAs have larger and stronger bones at both the forearm and lower leg. The observed differences in bone parameters can be explained by a combination of advanced bone maturation, higher estrogen exposure, and greater mechanical loading resulting from a higher muscle mass and strength.

Trabecular Bone Mineral Density and Bone Geometry of the Distal Radius at Completion of Pubertal Growth in Childhood Type 1 Diabetes

Aim: To identify disease-related risk factors for an altered bone mineral density (BMD) and geometry at young adulthood in patients with diabetes mellitus type 1 (DM1). Methods: Fifty-six DM1 patients (23 females, 33 males) with prepubertal onset of diabetes were studied after completion of skeletal growth. Bone parameters at the distal radius were investigated by peripheral quantitative computed tomography. Disease-related parameters, in particular average HbA1c during the 2 years around peak height velocity, were analyzed. Forty-seven healthy controls (32 females, 15 males) were studied. Results: Trabecular BMD was similar between DM1 patients and controls. The mean (±SD) cross-sectional bone area (CSA) was smaller in DM1 patients compared to controls (282.5 ± 45.4 vs. 326.7 ± 52.2 mm2, p = 0.002 and males 391.0 ± 61.3 vs. 423.4 ± 81.9 mm2, p = 0.1). In female DM1 patients, the CSA z-score correlated negatively with the body mass index z-score (r = -0.52, p = 0.01) and positively with the height z-score (r = 0.49, p = 0.02). Conclusions: DM1 patients are at risk for smaller bone sizes at the distal radius at the end of pubertal growth, especially females with increased adiposity. Diabetes-specific parameters seem to have a low impact on forearm volumetric apparent mineral density.

Sex Steroids in Relation to Sexual and Skeletal Maturation in Obese Male Adolescents

BACKGROUND Childhood obesity is associated with an accelerated skeletal maturation. However, data concerning pubertal development and sex steroid levels in obese adolescents are scarce and contrasting. OBJECTIVES To study sex steroids in relation to sexual and skeletal maturation and to serum prostate specific antigen (PSA), as a marker of androgen activity, in obese boys from early to late adolescence. METHODS Ninety obese boys (aged 10-19 y) at the start of a residential obesity treatment program and 90 age-matched controls were studied cross-sectionally. Pubertal status was assessed according to the Tanner method. Skeletal age was determined by an x-ray of the left hand. Morning concentrations of total testosterone (TT) and estradiol (E2) were measured by liquid chromatography-tandem mass spectrometry, free T (FT) was measured by equilibrium dialysis, and LH, FSH, SHBG, and PSA were measured by immunoassays. RESULTS Genital staging was comparable between the obese and nonobese groups, whereas skeletal bone advancement (mean, 1 y) was present in early and midadolescence in the obese males. Although both median SHBG and TT concentrations were significantly (P < .001) lower in obese subjects during mid and late puberty, median FT, LH, FSH, and PSA levels were comparable to those of controls. In contrast, serum E2 concentrations were significantly (P < .001) higher in the obese group at all pubertal stages. CONCLUSION Obese boys have lower circulating SHBG and TT, but similar FT concentrations during mid and late puberty in parallel with a normal pubertal progression and serum PSA levels. Our data indicate that in obese boys, serum FT concentration is a better marker of androgen activity than TT. On the other hand, skeletal maturation and E2 were increased from the beginning of puberty, suggesting a significant contribution of hyperestrogenemia in the advancement of skeletal maturation in obese boys.

Associations of Sex Steroids With Bone Maturation, Bone Mineral Density, Bone Geometry, and Body Composition: A Cross-Sectional Study in Healthy Male Adolescents

BACKGROUND Although both testosterone (T) and estradiol (E2) are considered essential in the regulation of the male skeleton, there are few data concerning the relative contribution of T and E2 on bone mineral density (BMD), bone geometry, and bone maturation in healthy boys. OBJECTIVE The objective of the study was to analyze the relationship between T and E2 and BMD, bone geometry, skeletal maturation, and body composition. METHODS This is a cross-sectional study in 199 healthy boys (aged 6-19 y). T and E2 were determined by liquid chromatography tandem mass spectrometry. Whole-body and lumbar areal bone mineral density (aBMD) and bone area, lean mass, and fat mass were determined by dual-energy X-ray absorptiometry. Trabecular (distal site) and cortical (proximal site) volumetric BMD (vBMD) and bone geometry were assessed at the nondominant forearm and leg using peripheral quantitative computed tomography. Skeletal age was determined by an X-ray of the left hand. RESULTS T was positively associated with lean mass (P < .001), lumbar and whole-body bone area (P < .001), trabecular and cortical area (P < .01), and periosteal circumference (P < .01) at the radius. E2 was positively associated with lumbar and whole-body aBMD (P < .001), trabecular vBMD at the radius and tibia (P < .01), and cortical thickness at the radius (P < .05). E2 was an independent negative predictor of the endosteal circumference (P < .01). Moreover, E2 was positively associated with bone age advancement (P < .001). CONCLUSION Circulating E2 is positively associated with bone maturation and aBMD and vBMD and negatively with endosteal circumference in healthy boys, whereas T is a determinant of lean mass and bone size. These findings underscore the important role of E2 in skeletal development in boys.

Comparative bone status assessment by dual energy X-ray absorptiometry, peripheral quantitative computed tomography and quantitative ultrasound in adolescents and young adults with cystic fibrosis

PURPOSE Quantitative ultrasound bone sonometry (QUS) might be a promising screening method for cystic fibrosis (CF)-related bone disease, given its absence of radiation exposure, portability of the equipment and low cost.The value of axial transmission forearm QUS in detecting osteopenia in CF was therefore studied. METHODS We investigated the application of QUS in the evaluation of bone status in a group of 64 adolescents (>12 years) and young adults (<40 years) with CF in a comparison with a dual X-ray absorptiometry (DXA) of the whole body and peripheral quantitative computed tomography (pQCT) of the radius at 4% and 66% sites. RESULTS Mean (SD) Z-scores of speed of sound (SOS), whole body bone mineral content (BMC), radial trabecular bone mineral density (BMD), and radial cortical BMD were respectively -0.31 (0.78), -0.09 (1.28), 0.10 (1.16) and -0.62 (2.88). The pQCT determined bone geometry values (cortical bone area and cortical thickness) were more depressed than the BMD data. QUS had a sensitivity and specificity of respectively 0% and 96% for diagnosing osteopenia (based on a whole body BMC Z-score<-2). CONCLUSIONS QUS cannot replace DXA, but can screen out patients with normal bone mass. Further and larger studies are needed to examine if QUS may reflect other aspects than bone mass, or if it is possible to improve its sensitivity by supplementing the SOS results with clinical risk factors.

The influence of dairy consumption, sedentary behaviour and physical activity on bone mass in Flemish children: a cross-sectional study

BackgroundThis cross-sectional study aimed to look for an association in young children between whole body bone mineral content (BMC) and areal bone mineral density (aBMD) and dairy consumption as well as sedentary behaviour (SB) and physical activity (PA). Moreover, we investigated whether there was an interaction effect between dairy consumption and SB or PA on BMC and aBMD.MethodsHealthy children (6-12 years) were recruited from primary schools. Body composition and whole body bone mass were measured with dual-energy X-ray absorptiometry (DXA), dairy consumption was assessed with a food frequency questionnaire (FFQ) and PA and SB with an accelerometer. In total, 272 children underwent a DXA scan. Complete FFQ data were available for 264 children and 210 children had matching data from accelerometry recordings. Regression analyses were used to study the associations between (1) BMC and aBMD and (2) dairy consumption, SB and PA, adjusting for age, gender, pubertal stage, height and body composition.ResultsDairy consumption was positively associated with whole body BMC and aBMD (absolute value as well as z-score), after correction for relevant confounders. SB was negatively associated with aBMD z-score and light PA was positively associated with both BMC and aBMD z-score. No gender differences were found. Moreover, an interaction effect between vigorous PA (VPA) and dairy consumption on aBMD (z-score) and BMC z-score was found, indicating that children with both high VPA and high dairy consumption had higher values for BMC and aBMD of the whole body minus the head.ConclusionAlready at young age, PA and dairy consumption positively influence whole body bone mass assessed by DXA. Moreover, this study indicates clearly that SB is negatively associated with whole body bone density. Promoting regular PA and sufficient dairy consumption in young children and limiting SB can be expected to positively influence their bone mass accumulation, which can help in the prevention of osteoporosis later in life.

Centor criteria in children in a paediatric emergency department: for what it is worth

Introduction Centor criteria (fever >38.5°C, swollen, tender anterior cervical lymph nodes, tonsillar exudate and absence of cough) are an algorithm to assess the probability of group A β haemolytic Streptococcus (GABHS) as the origin of sore throat, developed for adults. We wanted to evaluate the correlation between Centor criteria and presence of GABHS in children with sore throat admitted to our paediatric emergency department (PED). Design Retrospective cohort study. Setting The emergency department of a large tertiary university hospital in Brussels, with over 20 000 yearly visits for children below age 16. Participants All medical records (from 2008 to 2010) of children between ages 2 and 16, who were diagnosed with pharyngitis, tonsillitis or sore throat and having a throat swab culture for GABHS. Children with underlying chronic respiratory, cardiac, haematological or immunological diseases and children who had already received antibiotics (AB) prior to the PED consult were excluded. Only records with a full disease history were selected. Out of a total 2118 visits for sore throats, 441 met our criteria. The children were divided into two age groups, 2–5 and 5–16 years. Results The prevalence of GABHS was higher in the older children compared to the preschoolers (38.7 vs 27.6; p=0.01), and the overall prevalence was 32%. There was no significant difference in the prevalence of GABHS for all different Centor scores within an age group. Likelihood ratios (LR) demonstrate that none of the individual symptoms or a Centor score of ≥3 seems to be effective in ruling in or ruling out GABHS. Pooled LR (CI) for Centor ≥3 was 0.67 (CI 0.50 to 0.90) for the preschoolers and 1.37 (CI 1.04 to 1.79) for the older children. Conclusions Our results confirm the ineffectiveness of Centor criteria as a predicting factor for finding GABHS in a throat swab culture in children.

The relationship between paediatric calcaneal quantitative ultrasound measurements and dual energy X-ray absorptiometry (DXA) and DXA with laser (DXL) as well as body composition.

Background:Quantitative ultrasound (QUS) is a quick, non-invasive and inexpensive method to measure bone strength. Moreover, the device is portable, which makes it easy to be used in the field. In contrast to other bone measuring techniques, QUS does not use any ionised radiation. However, the validity of QUS in the measurement of bone health and the relationship between QUS output and body composition have not been assessed in very young children.Objective:To investigate the relationship between paediatric calcaneal QUS and both dual-energy X-ray absorptiometry (DXA) and calcaneal DXA with laser (DXL) and body composition parameters.Subjects:A total of 37 Belgian children (10 boys and 27 girls; 4 to 8 years old) underwent a calcaneal QUS as well as a DXA scan. A total of 24 Swedish children (15 boys and 9 girls; 3 to 5 years old) underwent a calcaneal QUS as well as a heel DXL scan. The height and weight of all children were measured.Results:The QUS stiffness index (SI) was significantly negatively correlated with bone mineral density (BMD) of the total body (r=−0.370, P=0.02). No significant correlations were found between the SI and DXL results. In the total sample, the SI showed a significant positive correlation with body mass index (BMI) (r=0.298, P=0.02), even after correction for age, gender and centre. In the Belgian sample, the SI was also significantly positively correlated with total body fat mass content (r=0.416, P=0.01) and body fat percentage (r=0.566, P<0.01) obtained by whole-body DXA.Conclusion:The SI measured by QUS does not correlate significantly with BMD values measured by DXA or DXL in 3- to 8-year-old children. However, there is a significant positive correlation between SI and BMI and body fat %.

Pediatric Reference Values for Tibial Trabecular Bone Mineral Density and Bone Geometry Parameters Using Peripheral Quantitative Computed Tomography

The purpose of this study was to establish reference data, in relation to age and body height, for tibial trabecular and cortical volumetric bone mineral density, bone mineral content, and cross-sectional bone geometry in healthy children and adolescents using peripheral quantitative computed tomography (pQCT). Over a 2-year period, 432 (207 male and 225 female) healthy children, with an age range of 5 to 19 years, from 6 different geographic areas in Belgium were recruited. Multislice pQCT scanning (XCT2000®, Stratec Medizintechnik, Pforzheim, Germany) was performed at the distal metaphysis (at the 4 % site) and the distal diaphysis (14 and 38 % sites) of the tibia of the dominant leg. Gender-specific centile curves in relation to age and body height were generated with the LMS method for total and trabecular volumetric bone mineral density (at 4 % site), bone mineral content, total bone cross-sectional area, periosteal circumference (all at 4, 14, and 38 % site), cortical volumetric bone mineral density, endosteal circumference, and cortical thickness (at the 14 and the 38 % site). These centile curves can be used for the interpretation of pQCT results at the 4, 14, and 38 % site of the tibia in European children and adolescents, at least when a similar methodology is used.

Forearm bone mineralization in recently diagnosed female adolescents with a premenarchal onset of anorexia nervosa

OBJECTIVE Data available on bone mineralization by peripheral quantitative computed tomography (pQCT) in adolescents with an early onset anorexia nervosa (AN) is limited. We investigated whether a disturbed bone mineralization can be observed at the distal radius in recently diagnosed female adolescents with AN and a premenarchal onset of this disease. METHOD Twenty-four premenarchal patients with AN and 22 healthy females which were age and height matched, were selected from our reference database; both groups underwent a pQCT bone assessment at the distal radius of the nondominant arm. RESULTS The patients age ranged between 13.3 and 18.4 years. Their percent weight loss ranged between 5 and 36% (median 23%) and occurred within the preceding 3 to 44 months. Trabecular volumetric bone mineral density of the patient group was significantly lower than the comparison group (185.6 ± 30.2 vs.209.3 ± 34.0 mm(2) ; p = 0.02). Bone cross-sectional area, bone mineral content, total volumetric bone mineral density and periosteal circumference were also lower, albeit not significantly. The bone parameters were unrelated to the under nutrition severity and duration. DISCUSSION In premenarchal patients with AN the trabecular bone mineralization of the forearm is significantly reduced, this might be an early indicator of altered bone mineral accrual.