Effect of Whole-body Vibration frequency on muscle tensile state during graded plantar flexor isometric contractions

Background

Acute physiological and biomechanical alterations have been reported following whole-body vibration (WBV). Stiffening of muscles has only been anecdotally reported in response to WBV. Accordingly, this study investigated active plantar flexor muscle stiffness in response to a single WBV bout at four mechanical vibration frequencies.

Methods

Thirteen healthy adults (37.1 ± 14.4 years old) randomly received WBV in 4 different frequencies (6, 12, 24, and 0 Hz control) for 5 min. Shear wave speed (SWS) in longitudinal and transverse projections, architecture, and electric muscle activity were recorded in the medial gastrocnemius (MG) and soleus (SOL) muscle during graded plantar flexor contraction. Subjective rating of perceived muscle stiffness was assessed via Likert-scale.

Results

SWS of the MG at rest was enhanced in response to 5 min of 24 Hz WBV (p = 0.025), while a small reduction in SOL SWS was found during contraction (p = 0.005) in the longitudinal view. Subjective stiffness rating was increased following 12 Hz intervention. After 24 Hz WBV, pennation angle for MG was decreased (p = 0.011) during contraction. As a secondary finding, plantar flexor strength was significantly increased with each visit, which, however, did not affect the study's main outcome because of balanced sequence allocation.

Conclusion

SWS effects were solely limited to 24 Hz mechanical vibration and in the longitudinal projection. The observed effects are compatible with an interpretation by post-activation potentiation, warm-up, and force-distribution within the triceps surae muscles following 5 min WBV. The outcome may suggest SWS as a useful tool for assessing acute changes in muscle stiffness.

Jumping Mechanography: Reference Centiles in Childhood and Introduction of the Nerve-Muscle Index to Quantify Motor Efficiency

Jumping mechanography provides robust motor function indicators among children. The study aim was to develop centiles for the single 2-leg jump (S2LJ) in German children and adolescents and to identify differences in children with obesity. Data were collected in 2004-2021 through the German DOrtmund Nutritional and Anthropometric Longitudinally Designed (DONALD) study. All participants (6-18 years, mean age 11.4) performed annually an S2LJ aiming for maximum height on a Ground Reaction Force Platform. LMS (lambda-mu-sigma), including resampling, was used to develop centiles for velocity (vmax), jump height (hmax), relative force (Fmax/BW), relative power (Pmax/mass), impulse asymmetry and a new parameter to describe jump efficiency, the Nerve-Muscle Index (NMI), defined as vmax/(Fmax/BW). Data from 882 children and adolescents were analyzed (3062 measurements, median 3 per individual). In females, Fmax/BW values were higher in younger age but remained constant in adolescence. vmax, hmax and Pmax/mass increased in childhood, reaching a plateau in adolescence. In males, vmax, hmax and Pmax/mass showed a constant increase and the Fmax/BW remained lower. Children with obesity showed lower Fmax/BW, hmax, vmax and the NMI, hence, lower velocity per relative force unit and less efficient jump. The centiles should be used to monitor motor development in childhood. The NMI is a surrogate for motor efficiency.

Impaired Physical Performance in X-linked Hypophosphatemia Is not Caused by Depleted Muscular Phosphate Stores

CONTEXT

X-linked hypophosphatemia (XLH) is a rare genetic disease, characterized by renal phosphate wasting and complex musculoskeletal manifestations including decreased physical performance.

OBJECTIVE

To characterize muscular deficits in patients with XLH and investigate phosphate stores in muscles.

METHODS

Case-control study (Muscle fatigability in X-linked Hypophosphatemia [MuXLiH]) with a 1-time assessment at the German Aerospace Center (DLR), Cologne, from May to December 2019, including patients with XLH cared for at the Osteology Department, University of Wuerzburg. Thirteen patients with XLH and 13 age/sex/body weight-matched controls aged 18-65 years were included. The main outcome measure was 31P-magnetic resonance spectroscopy (31P-MRS)-based assessment of phosphate metabolites in the soleus muscle at rest. Further analyses included magnetic resonance imaging-based muscle volume measurement, laboratory testing, isokinetic maximum voluntary contraction (MVC), fatigue testing, and jumping mechanography.

RESULTS

By means of 31P-MRS, no significant differences were observed between XLH and controls regarding phosphate metabolites except for a slightly increased phosphocreatine to inorganic phosphate (PCr/Pi) ratio (XLH: 13.44 ± 3.22, control: 11.01 ± 2.62, P = .023). Quadriceps muscle volume was reduced in XLH (XLH: 812.1 ± 309.0 mL, control: 1391.1 ± 306.2 mv, P < .001). No significant differences were observed regarding isokinetic maximum torque (MVC) adjusted to quadriceps muscle volume. Jumping peak power and jump height were significantly reduced in XLH vs controls (both P < .001).

CONCLUSION

The content of phosphoric compounds within the musculature of patients with XLH was not observed to be different from controls. Volume-adjusted muscle strength and fatiguability were not different either. Reduced physical performance in patients with XLH may result from long-term adaptation to reduced physical activity due to skeletal impairment.

Curvature of gastrocnemius muscle fascicles as function of muscle-tendon complex length and contraction in humans

It has been shown that muscle fascicle curvature increases with increasing contraction level and decreasing muscle-tendon complex length. The analyses were done with limited examination windows concerning contraction level, muscle-tendon complex length, and/or intramuscular position of ultrasound imaging. With this study we aimed to investigate the correlation between fascicle arching and contraction, muscle-tendon complex length and their associated architectural parameters in gastrocnemius muscles to develop hypotheses concerning the fundamental mechanism of fascicle curving. Twelve participants were tested in five different positions (90°/105°*, 90°/90°*, 135°/90°*, 170°/90°*, and 170°/75°*; *knee/ankle angle). They performed isometric contractions at four different contraction levels (5%, 25%, 50%, and 75% of maximum voluntary contraction) in each position. Panoramic ultrasound images of gastrocnemius muscles were collected at rest and during constant contraction. Aponeuroses and fascicles were tracked in all ultrasound images and the parameters fascicle curvature, muscle-tendon complex strain, contraction level, pennation angle, fascicle length, fascicle strain, intramuscular position, sex and age group were analyzed by linear mixed effect models. Mean fascicle curvature of the medial gastrocnemius increased with contraction level (+5 m^-1 from 0% to 100%; p = 0.006). Muscle-tendon complex length had no significant impact on mean fascicle curvature. Mean pennation angle (2.2 m^-1 per 10°; p < 0.001), inverse mean fascicle length (20 m^-1 per cm^-1 ; p = 0.003), and mean fascicle strain (-0.07 m^-1 per +10%; p = 0.004) correlated with mean fascicle curvature. Evidence has also been found for intermuscular, intramuscular, and sex-specific intramuscular differences of fascicle curving. Pennation angle and the inverse fascicle length show the highest predictive capacities for fascicle curving. Due to the strong correlations between pennation angle and fascicle curvature and the intramuscular pattern of curving we suggest for future studies to examine correlations between fascicle curvature and intramuscular fluid pressure.

Changes in cardiovascular risk factors among children and young adults with type 1 diabetes during the COVID-19 pandemic compared to previous years-Results from the German DPV registry

BACKGROUND

The diverse stages of the COVID-19 pandemic led to several social circumstances that influenced daily life and health behavior.

PURPOSE

To evaluate changes in cardiovascular risk factors and physical activity among children and young adults with type 1 diabetes (T1D) during the COVID-19 pandemic in Germany compared to previous years.

METHODS

A total of 32 785 individuals aged 6-21 years at baseline with T1D from the German diabetes patient follow-up (DPV) registry contributed data on 101 484 person-years between 2016 and 2021. The first treatment year of each individual within this period was considered as baseline. Based on trends from 2016 to 2019, we estimated differences in body mass index-SD score (BMI-SDS), blood pressure (BP-SDS), and lipid levels (non-high-density lipoprotein [non-HDL]) between observed and predicted estimates for the years 2020 and 2021 using linear regression analysis standardized for age, diabetes duration, sex, and migratory background. The proportion doing organized sports and smoking cigarettes was analyzed using multivariable logistic regression models.

RESULTS

BMI-SDS increased constantly from 2016 to 2021 without a significant increase above expected values for 2020/2021. Systolic BP-SDS (difference observed vs. expected with 95% confidence interval, 2020: 0.10 [0.07-0.14], 2021: 0.17 [0.14-0.20]) and non-HDL (2020: 2.7 [1.3-4.1] mg/dl, 2021: 4.1 [2.7-5.5] mg/dl) were significantly increased (all p < .001) in both pandemic years. The proportion of subjects participating in organized sports was reduced from over 70% in prepandemic years to 35%-65% in diverse stages/waves of the COVID-19 pandemic. The percentage smoking cigarettes did not change.

CONCLUSIONS

We describe an increase in BP and atherogenic lipid levels coinciding with a reduction in physical activity but no acceleration of the prepandemic increases in BMI-SDS among young people with T1D during the COVID-19 pandemic.

Lower limb bone geometry in adult individuals with X-linked hypophosphatemia: an observational study

We assessed lower-limb geometry in adults with X-linked hypophosphatemia (XLH) and controls. We found large differences in multiple measures including femoral and tibial torsion, bowing and cross-sectional area and acetabular version and coverage which may contribute to clinical problems such as osteoarthritis, fractures and altered gait common in XLH.

PURPOSE

Individuals with X-linked hypophosphatemia (XLH) are at risk of lower-limb deformities and early onset of osteoarthritis. These two factors may be linked, as altered biomechanics is a risk factor for osteoarthritis. This exploratory evaluation aims at providing clues and concepts for this association to facilitate future larger-scale and longitudinal studies on that aspect.

METHODS

For this observational study, 13 patients with XLH, aged 18-65 years (6 female), were compared with sex-, age- and weight-matched healthy individuals at a single German research centre. Femoral and hip joint geometry, including femoral and tibial torsion and femoral and tibial shaft bowing, bone cross-sectional area (CSA) and acetabular version and coverage were measured from magnetic resonance imaging (MRI) scans.

RESULTS

Total femoral torsion was 29° lower in individuals with XLH than in controls (p < 0.001), mainly resulting from lower intertrochanteric torsion (ITT) (p < 0.001). Femoral lateral and frontal bowing, tibial frontal bowing, mechanical axis, femoral mechanical-anatomical angle, acetabular version and acetabular coverage were all greater and tibial torsion lower in individuals with XLH as compared to controls (all p < 0.05). Greater femoral total and marrow cavity CSA, greater tibial marrow cavity CSA and lower cortical CSA were observed in XLH (all p < 0.05).

DISCUSSION

We observed large differences in clinically relevant measures of tibia and particularly femur bone geometry in individuals with XLH compared to controls. These differences may plausibly contribute to clinical manifestations of XLH such as early-onset osteoarthritis, pseudofractures and altered gait and therefore should be considered when planning corrective surgeries.

Twenty years of newborn screening for congenital adrenal hyperplasia and congenital primary hypothyroidism – experiences from the DGKED/AQUAPE study group for quality improvement in Germany

Congenital primary hypothyroidism (CH) and congenital adrenal hyperplasia (CAH) are targeted by the German and Austrian newborn screening. For both diseases, there are registries for quality improvement, based on standardized observational data from long-term patient follow-up, under the auspices of the DGKED study group. By September 2021, the CH registry HypoDOK includes datasets from 23,348 visits of 1,840 patients, and the CAH registry contains datasets from 36,237 visits of 1,976 patients. Here, we report on the recruitment process, patient characteristics, and research contributions from the registries, and underline that the registries are an important tool to improve patient care and outcomes. Registries for rare conditions should thus be considered as an important public health measure and they should be adequately institutionalized and funded.

Longitudinal relationship of particulate matter and metabolic control and severe hypoglycaemia in children and adolescents with type 1 diabetes

BACKGROUND

Evidence for the metabolic impact of long-term exposure to air pollution on diabetes is lacking. We investigated the association of particulate matter <10 μm (PM₁₀) and <2.5 μm (PM_2.5) with yearly averages of HbA1c, daily insulin dose (IU/kg) and rates of severe hypoglycaemia in type 1 diabetes (T1D).

METHODS

We studied data of 44,383 individuals with T1D < 21 years which were documented in 377 German centres within the diabetes prospective follow-up registry (DPV) between 2009 and 2018. Outcomes were aggregated by year and by patient. PM₁₀-and PM_2.5-yearly averages prior to the respective treatment year were linked to individuals via the five-digit postcode areas of residency. Repeated measures linear and negative binomial regression were used to study the association between PM-quartiles (Q1 lowest, Q4 highest concentration) and yearly averages of HbA1c, daily insulin dose and rates of severe hypoglycaemia (confounders: sex, time-dependent age, age at diabetes onset, time-dependent type of treatment, migratory background, degree of urbanisation and socioeconomic index of deprivation).

RESULTS

Adjusted mean HbA1c increased with PM₁₀ (Q1: 7.96% [95%-CI: 7.95-7.98], Q4: 8.03% [8.02-8.05], p-value<0.001) and with PM_2.5 (Q1: 7.97% [7.95-7.99], Q4: 8.02% [8.01-8.04], p < 0.001). Changes in daily insulin dose were inversely related to PM (PM₁₀ and PM_2.5: Q1 0.85 IU/kg [0.84-0.85], Q4: 0.83 IU/kg [0.82-0.83], p < 0.001). Adjusted rates of severe hypoglycaemia increased with PM-quartile groups (PM₁₀ Q1:11.2 events/100 PY [10.9-11.5], PM₁₀ Q4: 15.3 [14.9-15.7], p < 0.001; PM_2.5 Q1: 9.9 events/100 PY [9.6-10.2], PM_2.5 Q4: 14.2 [13.9-14.6], p < 0.001).

DISCUSSION

Air pollution was associated with higher HbA1c levels and increased risk of severe hypoglycaemia in people with T1D, consequently indicating a higher risk of diabetes complications. Further studies are needed to explore causal pathways of the observed associations.

Influence of motivational placebo-related factors on the effects of exercise treatment in depressive adolescents

Recent meta-analyses reveal a moderate effect of physical activity (PA) in the treatment of adolescent depression. However, not only the underlying neurobiological mechanisms, also the influences of placebo-related motivational factors (beliefs and expectancies in sporting, enjoyment and prior sports experiences), are still unclear. Based on the data of our prior study "Mood Vibes", we hypothesized that placebo-inherent factors like positive prior sports experiences and motivational factors, (positive beliefs, expectancies, and enjoyment related to PA), would increase the effects of an add-on exercise-therapy in juvenile depression. From 64 included depressed adolescents, 41 underwent an intensive add-on PA-therapy. Motivational factors were assessed using sport-specific scales. The changes in depression scores under treatment were rated by self-rating scale (German "Childhood Depression Inventory", (DIKJ)). A mixed model for repeated measures (MMRM) was used to analyze the effects of the different motivational variates on DIKJ. While prior sports experiences had no impact, motivational factors showed a significant effect on PA-induced changes in DIKJ scores (p = 0.002). The demotivated participants improved less, whereas it was sufficient to be neutral towards sporting to benefit significantly more. Motivational placebo-related factors (beliefs, expectancies and enjoyment regarding PA) affected the outcomes of an exercise treatment in depressed adolescents. Yet, a neutral mindset was sufficient to profit more from PA. Prior sporting in the sense of positive conditioning and as a protective factor did not play a role. Knowledge about these influences could in a second step help to develop tailored therapies.

Effects of long-term immobilisation on endomysium of the soleus muscle in humans

NEW FINDINGS

What is the central question of this study? While muscle fibre atrophy in response to immobilisation has been extensively examined, intramuscular connective tissue, particularly endomysium, has been largely neglected: does endomysium content of the soleus muscle increase during bed rest? What is the main finding and its importance? Absolute endomysium content did not change, and previous studies reporting an increase are explicable by muscle fibre atrophy. It must be expected that even a relative connective tissue accumulation will lead to an increase in muscle stiffness.

ABSTRACT

Muscle fibres atrophy during conditions of disuse. Whilst animal data suggest an increase in endomysium content with disuse, that information is not available for humans. We hypothesised that endomysium content increases during immobilisation. To test this hypothesis, biopsy samples of the soleus muscle obtained from 21 volunteers who underwent 60 days of bed rest were analysed using immunofluorescence-labelled laminin γ-1 to delineate individual muscle fibres as well as the endomysium space. The endomysium-to-fibre-area ratio (EFAr, as a percentage) was assessed as a measure related to stiffness, and the endomysium-to-fibre-number ratio (EFNr) was calculated to determine whether any increase in EFAr was absolute, or could be attributed to muscle fibre shrinkage. As expected, we found muscle fibre atrophy (P = 0.0031) that amounted to shrinkage by 16.6% (SD 28.2%) on day 55 of bed rest. ENAr increased on day 55 of bed rest (P < 0.001). However, when analysing EFNr, no effect of bed rest was found (P = 0.62). These results demonstrate that an increase in EFAr is likely to be a direct effect of muscle fibre atrophy. Based on the assumption that the total number of muscle fibres remains unchanged during 55 days of bed rest, this implies that the absolute amount of connective tissue in the soleus muscle remained unchanged. The increased relative endomysium content, however, could be functionally related to an increase in muscle stiffness.

Immunological Effects of an Add-On Physical Exercise Therapy in Depressed Adolescents and Its Interplay with Depression Severity

BACKGROUND

Pro-inflammatory cytokines (PICs) have gained attention in the pathophysiology and treatment of depressive disorders. At the same time, the therapeutic effect of physical activity seems to work via immunomodulatory pathways. The interventional study "Mood Vibes" analyzed the influence of exercise on depression severity (primary endpoint) in depressive adolescents; the influence of PICs on the clinical outcome was analyzed as a secondary endpoint.

METHODS

Clinically diagnosed depressed adolescents (N = 64; 28.1% male; mean age = 15.9; mean BMI = 24.6) were included and participated either in Whole Body Vibration (WBV) (n = 21) or bicycle ergometer training (n = 20) in addition to treatment-as-usual (TAU). Patients in the control treatment group received TAU only (n = 23). The PICs (interleukin-6-IL-6 and tumor necrosis factor-α-TNF-α) were analyzed before intervention, after 6 weeks of training (t1), and 8 weeks post-intervention (t2). The effects of the treatment on depression severity were rated by self-rating "Depression Inventory for Children and Adolescents" (DIKJ).

RESULTS

Basal IL-6 decreased in all groups from t0 to t1, but it increased again in WBV and controls at t2. TNF-α diminished in ergometer and controls from baseline to t1. PIC levels showed no correlation with depression severity at baseline. The influence on DIKJ scores over time was significant for IL-6 in the WBV group (p = 0.008). Sex had an impact on TNF-α (p < 0.001), with higher concentrations in male patients. Higher body mass index was associated with higher IL-6 concentrations over all measurement points (p < 0.001).

CONCLUSIONS

The positive effects of an intensive add-on exercise therapy on adolescent depression seem to be partly influenced by immunomodulation. A small sample size and non-randomized controls are limitations of this study.

Effects of Lee Silverman Voice Treatment BIG and conventional physiotherapy on non-motor and motor symptoms in Parkinson's disease: a randomized controlled study comparing three exercise models

Background:

Parkinson’s disease (PD) patients experience disabling motor dysfunctions as well as non-motor symptoms (NMSs) that can highly impact their perceived quality of life. Besides pharmacological treatment options, active intervention programs have set some attention in managing these symptoms. However, previous studies mainly assessed the effectiveness of active intervention programs on functional mobility and motor symptoms.

Objective:

This study aimed to investigate the effect of Lee Silverman Voice Treatment (LSVT) BIG, an intensified and personalized physiotherapy (INTENSIVE), and a conventional physiotherapy (NORMAL) on NMSs in PD.

Method:

Forty-four patients with mild to moderate PD were randomly assigned to one of the three treatment groups. LSVT BIG and INTENSIVE were delivered one-on-one in 16 1-hour sessions within 4 weeks (4×/week). Patients assigned to NORMAL received 16 individual 1-hour sessions within 8 weeks (2×/week). The primary outcome measure was the difference in change from baseline in the non-motor symptom assessment scale for Parkinson’s disease (NMSS) between treatment groups to follow up at week 8. Patients were blinded for the NMSS being the primary outcome, but not the different treatment groups.

Results:

ANCOVA (Analysis of Covariance) showed reduced NMSS scores for all groups, with INTENSIVE being superior to NORMAL (p = 0.033). For secondary outcome measures (stride length, gait velocity and chair rising test) LSVT BIG and INTENSIVE were both superior to NORMAL.

Conclusions:

The study provides evidence that all three exercise programs are effective techniques to improve NMSs as well as motor function in PD.

DRKS registration number:

DRKS00008732

[Perioperative enhanced recovery after surgery program for Ivor Lewis esophagectomy : First experiences of a high-volume center]

BACKGROUND AND OBJECTIVE

Transthoracic esophagectomy is generally accepted as the standard of surgical care for patients with esophageal cancer. Despite improvements in the perioperative management this surgical procedure is associated with a clinically relevant morbidity. Fast-track protocols (synonym: enhanced recovery after surgery, ERAS) are conceived to perioperatively maintain the physiological homoeostasis and thereby to accelerate postoperative rehabilitation and reduce morbidity. In this prospective observational study the initial experiences of a high-volume center with the implementation of an ERAS protocol after transthoracic esophagectomy were analyzed.

MATERIAL AND METHODS

A total of 26 patients with esophageal cancer and a low index of comorbidities prior to hybrid Ivor Lewis esophagectomy were included in this study. According to an ERAS protocol all patients underwent a standardized perioperative treatment pathway aiming to discharge the patients from the inpatient treatment on postoperative day 10. The primary outcome parameter was the rate of major complications (Clavien-Dindo IIIb/IV), which was compared to a cohort of 52 non-ERAS patients.

RESULTS AND CONCLUSION

The ERAS programs with the various core elements can be implemented in patients scheduled for transthoracic esophagectomy, although the organizational and personnel expenditure of this fast-track protocol is high. The length of hospital stay appears to be reduced without compromising patient safety. The limiting variable of the ERAS protocol remains the early and adequate enteral feeding load of the gastric conduit before discharge on postoperative day 10.

Reference Centiles for the Evaluation of Nutritional Status in Children using Body Fat Percentage, Fat Mass and Lean Body Mass Index

BACKGROUND

Body fat percentage (BF%), fat mass index (FMI), and lean body mass index (LBMI) are often used to evaluate the nutritional status of children. Until now, no pediatric FMI reference centiles are applicable for GE Healthcare Lunar DXA systems. The aim of the study was to generate age-specific BF%, FMI, and LBMI references centiles for GE Healthcare Lunar DXA systems.

METHODOLOGY

Published values from the National Health and Nutrition Examination Survey 1999-2004 (age 8-20 years) were used to generate the reference centiles for the non-Hispanic black, non-Hispanic white, and Mexican American NHANES population. The LMS and LMSP methods were used to generate the reference centiles.

RESULTS

Data of 2433 non-Hispanic black children (972 females), 2026 non-Hispanic white children (873 females), and 2547 Mexican American children (1010 females) were eligible.

CONCLUSIONS

We presented age-specific reference centiles for BF%, FMI, and LBMI for children and adolescents which were ethnicity specific (non-Hispanic black, non-Hispanic white, and Mexican American) and directly applicable to Prodigy and iDXA GE Healthcare Lunar systems with software version 14.0. We proposed the use of BF%, FMI, and LBMI together to evaluate nutritional status in children.

Pharmacotherapy in Rare Skeletal Diseases

New therapeutic approaches have been established in the field of rare skeletal diseases (e.g., for osteogenesis imperfecta, achondroplasia, hypophosphatemic rickets, hypophosphatasia, and fibrodysplasia ossificans progressiva). After elucidation of the underlying genotypes and pathophysiologic alterations of these diseases, new treatment options have been designed. Most drugs are based on an interaction with the disease-specific cascade of enzymes and proteins involved in the disease. Thereby an approved treatment is available for children with severe forms of hypophosphatasia and hypophosphatemic rickets (asfotase alfa, burosumab). Additionally, there are different phase 3 trials ongoing assessing the efficacy and safety of drugs for osteogenesis imperfecta, achondroplasia, and fibrodysplasia ossificans progressiva (denosumab, vosoritide, palovarotene).Because all these diseases are rare, the number of investigated patients in the trials is small, and the knowledge about rare side effects and long-term outcome is limited. Therefore it is recommended to treat the patients in specialized centers where the effects of the drugs can be evaluated and data about safety, side effects, and efficacy can be collected.Based on the fact that most drugs for rare diseases are highly expensive clear indications for start of a treatment, evaluation of the therapy and recommendations how long a treatment has to be administrated are urgently needed.

Motor Function Improvement in Children with Ataxia Receiving Interval Rehabilitation, Including Vibration-Assisted Hometraining: A Retrospective Study

BACKGROUND

Physiotherapy, including vibration-assisted therapy, has been proven to be effective for patients with ataxic cerebral palsy. Herewith, we studied the effect of a functional, goal-oriented interval rehabilitation program, including vibration-assisted home-training on the motor function of children with congenital ataxias.

PATIENTS

45 children (mean age 7.7 years, SD 4.70) with ataxia, having received a 6-month home-based side-alternating vibration-assisted therapy combined with intensive, goal-oriented, functional rehabilitation intervals, were included in the study, classified according to the progressive or non-progressive ataxia character.

METHOD

Retrospective analysis of the prospectively collected data of the registry of the Cologne rehabilitation program "Auf die Beine". Motor abilities have been assessed prior to the intervention (M0), after 6 months of home-training (M6) as well as in a follow-up 6 months later (M12). We performed a gait analysis, a 1-minute walking test (1-MWT), and the Gross Motor Function Measure (GMFM-66).

RESULTS

The GMFM-66 improvement (M6-M0 vs. M12-M6) was statistically significant with median improvement of 2.4 points (non-progressive) and 2.9 points (progressive) respectively, and clinically relevant. The 1-MWT improvement was statistically significant and clinically relevant for non-progressive ataxia.

CONCLUSION

The intensive training, including vibration-assisted therapy significantly improved the motor function of children with ataxia. Six months later the skills were preserved in children with progressive ataxia and could be further developed in non-progressive forms.

Glucocorticoids and Body Fat Inversely Associate With Bone Marrow Density of the Distal Radius in Healthy Youths

CONTEXT

Elevated bone marrow adipose tissue (BMAT) is associated with lower bone quality, higher fracture rates, and an unfavorable overall metabolic profile. Apart from age, particularly glucocorticoids (GC), body fat, and diet are discussed to influence BMAT. We hypothesized that already in healthy youths, higher fat intake, higher fat mass index (FMI), and higher GC secretion, still within the normal range, may associate with increased BMAT.

DESIGN

In a subsample of healthy 6- to 18-year-old participants of the Dortmund Nutritional and Anthropometric Longitudinally Designed Study, peripheral quantitative CT of the nondominant proximal forearm was used to determine bone marrow density of the distal radius as an inverse surrogate parameter for BMAT. In those participants (n = 172) who had collected two, 24-hour urines within around one year before bone measurement, major urinary GC metabolites were measured by gas chromatography-mass spectrometry and summed up to assess daily adrenal GC secretion (ΣC21). Dietary intake was assessed by 3-day weighed dietary records. FMI was anthropometrically calculated. Separate multiple linear regression models were used to analyze the relationships of ΣC21, FMI, and fat intake with BMAT.

RESULTS

After controlling for confounders, such as age, energy intake, and forearm muscle area, ΣC21 (β = -0.042) and FMI (β = -0.002) showed inverse relationships with bone marrow density (P < 0.05), whereas fat intake did not associate significantly.

CONCLUSION

Our results indicate that already a moderately elevated GC secretion and higher body fatness during adolescence may adversely impact BMAT, an indicator for long-term bone health.

Growth Hormone Treatment for Short Stature in the USA, Germany and France: 15 Years of Surveillance in the Genetics and Neuroendocrinology of Short-Stature International Study (GeNeSIS)

BACKGROUND/AIMS

To describe characteristics, auxological outcomes and safety in paediatric patients with growth disorders treated with growth hormone (GH), for cohorts from the USA, Germany and France enrolled in GeNeSIS, a post-authorisation surveillance programme.

METHODS

Diagnosis and biochemical measurement data were based on reporting from, and GH treatment was initiated at the discretion of, treating physicians. Auxological outcomes during the first 4 years of GH treatment and at near-adult height (NAH) were analysed. Serious and treatment-emergent adverse events were described.

RESULTS

Children in the USA (n = 9,810), Germany (n = 2,682) and France (n = 1,667) received GH (dose varied between countries), most commonly for GH deficiency. Across diagnostic groups and countries, mean height velocity standard deviation score (SDS) was > 0 and height SDS increased from baseline during the first 4 years of treatment, with greatest improvements during year 1. Most children achieved NAH within the normal range (height SDS >-2). No new or unexpected safety concerns were noted.

CONCLUSION

GH treatment improved growth indices to a similar extent for patients in all three countries despite variations in GH doses. Data from these three countries, which together contributed > 60% of patients to GeNeSIS, indicated no new safety signals and the benefit-risk profile of GH remains unchanged.

Genotype/phenotype correlations in 538 congenital adrenal hyperplasia patients from Germany and Austria: discordances in milder genotypes and in screened versus prescreening patients

Congenital adrenal hyperplasia (CAH) due to CYP21A2 gene mutations is associated with a variety of clinical phenotypes (salt wasting, SW; simple virilizing, SV; nonclassical, NC) depending on residual 21-hydroxylase activity. Phenotypes and genotypes correlate well in 80-90% of cases. We set out to test the predictive value of CAH phenotype assignment based on genotype classification in a large multicenter cohort. A retrospective evaluation of genetic data from 538 CAH patients (195 screened) collected from 28 tertiary centers as part of a German quality control program was performed. Genotypes were classified according to residual 21-hydroxylase activity (null, A, B, C) and assigned clinical phenotypes correlated with predicted phenotypes, including analysis of Prader stages. Ultimately, concordance of genotypes with clinical phenotypes was compared in patients diagnosed before or after the introduction of nationwide CAH-newborn screening. Severe genotypes (null and A) correlated well with the expected phenotype (SW in 97 and 91%, respectively), whereas less severe genotypes (B and C) correlated poorly (SV in 45% and NC in 57%, respectively). This was underlined by a high degree of virilization in girls with C genotypes (Prader stage >1 in 28%). SW was diagnosed in 90% of screening-positive babies with classical CAH compared with 74% of prescreening patients. In our CAH series, assigned phenotypes were more severe than expected in milder genotypes and in screened vs prescreening patients. Diagnostic discrimination between phenotypes based on genotypes may prove overcome due to the overlap in their clinical presentations.

Quality of Life of Short-Statured Children Born Small for Gestational Age or Idiopathic Growth Hormone Deficiency Within 1 Year of Growth Hormone Treatment

Aside from clinical endpoints like height gain, health-related quality of life has also become an important outcome indicator in the medical field. However, the data on short stature and health-related quality of life is inconsistent. Therefore, we examined changes in health-related quality of life in German children with idiopathic growth hormone deficiency or children born small for gestational age before and after 12 months of human growth hormone treatment. Children with idiopathic short stature without treatment served as a comparison group. At baseline, health-related quality of life data of 154 patients with idiopathic growth hormone deficiency (n = 65), born small for gestational age (n = 58), and idiopathic short stature (n = 31) and one parent each was collected. Of these, 130 completed health-related quality of life assessments after 1-year of human growth hormone treatment. Outcome measures included the Quality of Life in Short Stature Youth questionnaire, as well as clinical and sociodemographic data. Our results showed that the physical, social, and emotional health-related quality of life of children treated with human growth hormone significantly increased, while untreated patients with idiopathic short stature reported a decrease in these domains. Along with this, a statistically significant increase in height in the treated group can be observed, while the slight increase in the untreated group was not significant. In conclusion, the results showed that human growth hormone treatment may have a positive effect not only on height but also in improving patient-reported health-related quality of life of children with idiopathic growth hormone deficiency and children born small for gestational age.

Sodium Chloride Supplementation Is Not Routinely Performed in the Majority of German and Austrian Infants with Classic Salt-Wasting Congenital Adrenal Hyperplasia and Has No Effect on Linear Growth and Hydrocortisone or Fludrocortisone Dose

INTRODUCTION

Sodium chloride supplementation in salt-wasting congenital adrenal hyperplasia (CAH) is generally recommended in infants, but its implementation in routine care is very heterogeneous.

OBJECTIVE

To evaluate oral sodium chloride supplementation, growth, and hydrocortisone and fludrocortisone dose in infants with salt-wasting CAH due to 21-hydroxylase in 311 infants from the AQUAPE CAH database.

RESULTS

Of 358 patients with classic CAH born between 1999 and 2015, 311 patients had salt-wasting CAH (133 females, 178 males). Of these, 86 patients (27.7%) received oral sodium chloride supplementation in a mean dose of 0.9 ± 1.4 mmol/kg/day (excluding nutritional sodium content) during the first year of life. 225 patients (72.3%) were not treated with sodium chloride. The percentage of sodium chloride-supplemented patients rose from 15.2% in children born 1999-2004 to 37.5% in children born 2011-2015. Sodium chloride-supplemented and -unsupplemented infants did not significantly differ in hydrocortisone and fludrocortisone dose, target height-corrected height-SDS, and BMI-SDS during the first 2 years of life.

CONCLUSION

In the AQUAPE CAH database, approximately one-third of infants with salt-wasting CAH receive sodium chloride supplementation. Sodium chloride supplementation is performed more frequently in recent years. However, salt supplementation had no influence on growth, daily fludrocortisone and hydrocortisone dose, and frequency of adrenal crisis.

A 6-Year Follow-Up of Fracture Incidence and Volumetric Bone Mineral Density Development in Girls With Turner Syndrome

CONTEXT

Patients with Turner syndrome (TS) are at risk for osteoporotic fractures.

OBJECTIVE

The aims of this study were to assess the incidence of clinically important fractures in girls with TS and prospectively describe the development of volumetric bone mineral density (BMD).

DESIGN

Peripheral quantitative computerized tomography (pQCT) of the radius every other year over the 6 years of observation.

SETTING

Government-funded university referral center.

PARTICIPANTS

Thirty-two girls with TS, aged 6 to 16 years, were included in the analyses. Fracture incidence was compared with the data in the general population. Bone density and strength were compared with data from 185 healthy girls.

OUTCOMES

The main clinical outcome was the fracture occurrence. The secondary outcomes were the changes in Z-scores of the bone parameters.

RESULTS

Three girls with TS sustained four fractures during 6 years of observation. The fracture rate in TS was not substantially higher than the downward-biased fracture-rate estimate from age-matched, healthy controls (P = 0.48). Whereas the trabecular BMD Z-score decreased with age (β estimate -0.21 ± 0.04, P < 0.001), total bone cross-sectional area correspondingly increased (+0.16 ± 0.04, P < 0.001), which led to normal bone strength. A positive history of incident fractures was not significantly associated with any of the pQCT-derived bone parameters.

CONCLUSIONS

Current pediatric TS patients that are treated with growth hormone and estrogens are not at risk for osteoporotic fractures. Low BMD in TS may be counterweighted by enlarged bone radius, which leads to normal bone strength at the appendicular skeleton.

Alleviation of Motor Impairments in Patients with Cerebral Palsy: Acute Effects of Whole-body Vibration on Stretch Reflex Response, Voluntary Muscle Activation and Mobility

INTRODUCTION

Individuals suffering from cerebral palsy (CP) often have involuntary, reflex-evoked muscle activity resulting in spastic hyperreflexia. Whole-body vibration (WBV) has been demonstrated to reduce reflex activity in healthy subjects, but evidence in CP patients is still limited. Therefore, this study aimed to establish the acute neuromuscular and kinematic effects of WBV in subjects with spastic CP.

METHODS

44 children with spastic CP were tested on neuromuscular activation and kinematics before and immediately after a 1-min bout of WBV (16-25 Hz, 1.5-3 mm). Assessment included (1) recordings of stretch reflex (SR) activity of the triceps surae, (2) electromyography (EMG) measurements of maximal voluntary muscle activation of lower limb muscles, and (3) neuromuscular activation during active range of motion (aROM). We recorded EMG of m. soleus (SOL), m. gastrocnemius medialis (GM), m. tibialis anterior, m. vastus medialis, m. rectus femoris, and m. biceps femoris. Angular excursion was recorded by goniometry of the ankle and knee joint.

RESULTS

After WBV, (1) SOL SRs were decreased (p < 0.01) while (2) maximal voluntary activation (p < 0.05) and (3) angular excursion in the knee joint (p < 0.01) were significantly increased. No changes could be observed for GM SR amplitudes or ankle joint excursion. Neuromuscular coordination expressed by greater agonist-antagonist ratios during aROM was significantly enhanced (p < 0.05).

DISCUSSION

The findings point toward acute neuromuscular and kinematic effects following one bout of WBV. Protocols demonstrate that pathological reflex responses are reduced (spinal level), while the execution of voluntary movement (supraspinal level) is improved in regards to kinematic and neuromuscular control. This facilitation of muscle and joint control is probably due to a reduction of spasticity-associated spinal excitability in favor of giving access for greater supraspinal input during voluntary motor control.

Analysis of the functional muscle-bone unit of the forearm in patients with phenylketonuria by peripheral quantitative computed tomography

Bone disease in patients with phenylketonuria (PKU) is incompletely characterized. We therefore analyzed, in a cross-sectional study radius macroscopic bone architecture and forearm muscle size by peripheral quantitative computed tomography (pQCT) and muscle strength by hand dynamometry in a large cohort (n = 56) of adolescent and adult patients with PKU aged 26.0 ± 8.9 (range, 11.8-41.5) years. Data were compared with a reference population (n = 700) from the DONALD study using identical methodology. We observed a significant reduction of cortical thickness (z-score -1.01 ± 0.79), Strength-Strain Index (SSI) (z-score -0.81 ± 1.03), and total bone mineral density (BMD) of the distal radius (z-score -1.05 ± 1.00). Mean muscle cross-sectional area (z-score -0.98 ± 1.19) and muscle grip force (z-score -0.64 ± 1.26) were also significantly reduced, indicating an impaired muscular system as part of the clinical phenotype of PKU. SSI positively correlated (r = 0.53, P < 0.001) with the corresponding muscle cross-sectional area in the reference population; however, the regression line slope in PKU patients was less steep (P < 0.001), indicating that bone strength is not adequately adapted to muscle force. In conclusion, the radial bone in PKU patients is characterized by reduced bone strength in relation to muscular force, decreased cortical thickness, and impaired total BMD at the metaphyseal site. These alterations indicate a mixed bone defect in PKU, both of which are due to primary alterations of bone metabolism and to secondary alterations in response to neuromuscular abnormalities.

Oscillatory whole-body vibration improves exercise capacity and physical performance in pulmonary arterial hypertension: a randomised clinical study

Objective

In patients with pulmonary arterial hypertension (PAH), supportive therapies may be beneficial in addition to targeted medical treatment. Here, we evaluated the effectiveness and safety of oscillatory whole-body vibration (WBV) in patients on stable PAH therapy.

Methods

Twenty-two patients with PAH (mean PAP≥25 mm Hg and pulmonary arterial wedge pressure (PAWP)≤15 mm Hg) who were in world health organization (WHO)-Functional Class II or III and on stable PAH therapy for≥3 months, were randomised to receive WBV (16 sessions of 1-hour duration within 4 weeks) or to a control group, that subsequently received WBV. Follow-up measures included the 6-min walking distance (6MWD), cardiopulmonary exercise testing (CPET), echocardiography, muscle-power, and health-related quality of life (HRQoL; SF-36 and LPH questionnaires).

Results

When compared to the control group, patients receiving WBV exhibited a significant improvement in the primary endpoint, the 6MWD (+35.4±10.9 vs −4.4±7.6 m), resulting in a net benefit of 39.7±7.8 m (p=0.004). WBV was also associated with substantial improvements in CPET variables, muscle power, and HRQoL. The combined analysis of all patients (n=22) indicated significant net improvements versus baseline in the 6MWD (+38.6 m), peakVO2 (+65.7 mL/min), anaerobic threshold (+40.9 mL VO₂/min), muscle power (+4.4%), and HRQoL (SF-36 +9.7, LPH −11.5 points) (all p<0.05). WBV was well tolerated in all patients, and no procedure-related severe adverse events (SAEs) occurred.

Conclusions

WBV substantially improves exercise capacity, physical performance, and HRQoL in patients with PAH who are on stable targeted therapy. This methodology may be utilised in structured training programmes, and may be feasible for continuous long-term physical exercise in these patients.

Trial registration number

NCT01763112; Results.

Urinary Citrate, an Index of Acid-Base Status, Predicts Bone Strength in Youths and Fracture Risk in Adult Females

CONTEXT

Diet can impact on bone strength via metabolic shifts in acid-base status. In contrast to the strongly diet-dependent biomarker urinary potential renal acid load (uPRAL), the amount of renally excreted citrate integrates nutritional and systemic influences on acid-base homeostasis with high citrate indicating prevailing alkalization.

OBJECTIVE

To examine the association between urinary citrate excretion and bone strength as well as long-term fracture risk.

DESIGN AND PARTICIPANTS

Prospective cross-sectional analysis; 231 healthy children (6-18 y) of the Dortmund Nutritional and Anthropometric Longitudinally Designed Study were included, with at least 2 urine collections available during the 4 years preceding peripheral quantitative computed tomography (pQCT) of the nondominant proximal forearm. uPRAL, urinary citrate, and urinary nitrogen excretion were quantified in 857 24-hour urine samples. Data on overall fracture incidence were collected within a 15-year follow-up after pQCT measurement.

MAIN OUTCOME MEASURES

Parameters of bone quality and geometry (pQCT) as well as long-term fracture incidence.

RESULTS

After controlling for confounders, especially forearm length, muscle area, and urinary nitrogen (biomarker of protein intake), urinary citrate excretion was positively associated with various parameters of bone quality and geometry (P < .05). Fracture risk in adult females, but not in males, was inversely associated with urinary citrate and positively with uPRAL (P < .05).

CONCLUSIONS

Although urinary citrate has to be confirmed as an integrated noninvasive biomarker of systemic acid-base status in further studies, our results substantiate dietary and metabolic acidity as potentially adverse for bone health in the long run from childhood onward.

Blood Pressure in a Large Cohort of Children and Adolescents With Classic Adrenal Hyperplasia (CAH) Due to 21-Hydroxylase Deficiency

BACKGROUND

Data on blood pressure (BP) in children and adolescents with classic congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency are conflicting in the literature.

PATIENTS AND METHODS

BP data of n = 716 children and adolescents (aged 3-18 years) from a national CAH database were analyzed. BP data were adjusted for height and compared to contemporary national reference data. A systolic and diastolic BP above the 95th centile was defined as hypertensive.

RESULTS

Overall prevalence of hypertension was 12.5%. Prevalence of hypertension was higher in younger children than in adolescents (18.5% vs. 4.9%). Until 8 years of age, fludrocortisone dose/m(2)/day correlated significantly with BP in regression analysis (P < 0.0001). BP correlated significantly with body mass index standard deviation score (BMI-SDS) (P < 0.0001), but not with hydrocortisone dose. In patients with salt-wasting CAH, BMI-SDS and BP were significantly higher compared to patients with simple virilising CAH, P < 0.01.

CONCLUSION

Especially young CAH children seem to be at risk for-most likely transient-hypertension, since the prevalence of hypertension decreases with age. In children up to 8 years of age, the used fludrocortisone dose is a significant risk factor for hypertension. Therefore we recommend accurate measurement of BP and careful fludrocortisone dosing in children with CAH.

Long-term Surveillance of Children with Congenital Hypothyroidism: Data from the German Registry for Congenital Hypothyroidism (AQUAPE "Hypo Dok")

BACKGROUND

The German study group for quality assurance in pediatric endocrinology and the University of Ulm have established a software ("Hypo Dok") for the documentation of longitudinal data of patients with congenital primary hypothyroidism (CH). Aim of this study was to analyse the long-term follow-up of patients with CH and to compare treatment with current guidelines.

METHODS/PATIENTS

Anonymised data of 1,080 patients from 46 centres were statistically analysed.

RESULTS

Newborn screening result was available at a mean age of 7.3 days. Confirmation of the diagnosis was established at 8.4 days and therapy was started at 11 days. The average screening TSH was 180.0 mIU/L. During the first 3 months mean levothyroxine (LT4) dose was 10.7 µg/kg/day or 186.0 µg/m²/day. Weight-, BMI- and height-SDS did not differ significantly from the normal population. Only 25% of the patients (n=262) underwent formal EQ/IQ-testing. Their average IQ was 98.8 ± 13.2 points.

DISCUSSION

In Germany screening, confirmation and start of treatment of CH are within the recommended time frame of 14 days. Initial LT4-doses are adequate. The auxological longterm outcome of young CH patients is normal. The implementation of standardized IQ testing has to be improved in routine patient care.

CONCLUSION

Longitudinal data of patients with CH was analysed and compared to current guidelines. Confirmation and start of treatment are according to the recommendations. However standardised IQ testing requires improvement.

Artificially low cortical bone mineral density in Turner syndrome is due to the partial volume effect

We aimed to show that the decrease in the cortical bone mineral density (BMD) in the radius in Turner syndrome (TS) is artificially caused by the partial volume effect. We confirmed that the partial volume effect-corrected cortical BMD is not decreased in TS compared to in the healthy controls. Other factors are responsible for the increased fracture rate in TS.

INTRODUCTION

Decreased cortical bone mineral density (BMD) has been reported in Turner syndrome (TS), using peripheral quantitative computerised tomography, and it is perceived as one of the major factors leading to increased fracture risk. We tested the hypothesis that low cortical BMD in the radius is caused artificially by the partial volume effect.

METHODS

A cross-sectional study was conducted at the university hospital referral centre between March and October 2013. Thirty-two participants with TS who consented to the study were included (mean age 15.3 ± 3.2 years). We assessed the cortical BMD in the radius as well as the tibia, where the cortex is thicker compared with the radius.

RESULTS

Whereas the cortical BMD was decreased in the radius (mean ± SD Z-score -0.6 ± 1.5, p = 0.037), it was increased in the tibia (mean Z-score 0.83 ± 1.0, p < 0.001). After correcting the cortical BMD for the partial volume effect, the mean Z-score was normal in the radius in TS (0.4 ± 1.3, p = 0.064). The corrected cortical BMD values were similar in the radius and tibia (1108 ± 52 vs. 1104 ± 48, group difference p = 0.75).

CONCLUSIONS

The cortical BMD is not decreased in TS. The partial volume effect is responsible for previous findings of decreased cortical BMD in the radius. Altered bone geometry or other factors rather than low cortical BMD likely play a role in the increased fracture risk in TS.

Higher glucocorticoid secretion in the physiological range is associated with lower bone strength at the proximal radius in healthy children: importance of protein intake adjustment

Whether higher production of glucocorticoids (GCs) within the physiological range may already be affecting bone status in healthy children is unknown. Because dietary protein intake affects both bone and GCs, we examined the association of urinary measures of glucocorticoid status and cortical bone in healthy non-obese children, after particularly controlling for protein intake. Proximal forearm bone parameters were measured by peripheral quantitative computed tomography (pQCT). Subjects studied (n = 175, 87 males, aged 6 to 18 years) had two 24-hour urine samples collected: the first sample at 1 year before bone measurement, and the second sample at the time of bone measurement. Major urinary GC metabolites were measured by mass spectrometry and summed to assess daily adrenal GC secretion (∑C21). Urinary free cortisol (UFF) and cortisone (UFE) were summed to assess potentially bioactive free GCs (UFF + UFE). After controlling for several covariates and especially urinary nitrogen (the biomarker of protein intake) cortisol secretion ∑C21 was inversely associated with all analyzed pQCT measures of bone quality. ∑C21 also predicted a higher endosteal and lower periosteal circumference, explaining both a smaller cortical area and (together with lower BMD) a lower strength-strain-index (SSI). UFF + UFE, UFE itself, and a urinary metabolite-estimate of 11beta-hydroxysteroid dehydrogenase type1 (11beta-HSD1) activity showed corresponding reciprocal associations (p < 0.05) with BMD and bone mineral content, but not with SSI and bone geometry variables. In conclusion, higher GC levels, even within the physiological range, appear to exert negative influences on bone modeling and remodeling already during growth. Our physiological data also suggest a relevant role of cortisone as the direct source for intracrine-generated cortisol by bone cell 11beta-HSD1.

Time since onset of walking predicts tibial bone strength in early childhood

Bone strength in adulthood is known to be affected by health at birth and early childhood. Habitual bone loading is a primary determinant of bone strength in later childhood and adulthood. However, the effects of physical activity in early childhood (e.g. crawling, standing and walking) on bone strength are unknown. Fifty-three children (twenty-seven males) were included in a longitudinal study in their early infancy. Shortly after birth (0.3±0.3months), details of mass and height were obtained along with a pQCT scan at 20% distal-proximal tibia length. At 14.8±0.5months of age the same data were collected, along with details of age at onset of standing, crawling, supported and unsupported walking. Time since onset of walking unsupported was associated with greater bone mass, cortical bone area, pericortical circumference and polar moment of inertia of both total and cortical bone (all P<0.05). There were no significant associations between other physical activity timepoints and bone measures. Age at onset of walking was not significantly related to mass, length or bone measures at birth. The results suggest that time since attainment of independent walking - representing exposure of the tibia to the large reaction and muscular forces associated with locomotion - is a primary determinant of bone strength in early childhood. This finding raises the possible opportunity of physical activity interventions at young age in paediatric populations associated with low childhood bone strength and late walking (e.g. low birth weight, cerebral palsy and Down's Syndrome, etc.).

Effect of whole-body vibration and insulin-like growth factor-I on muscle paralysis-induced bone degeneration after botulinum toxin injection in mice

Botulinum toxin A (BTX)-induced muscle paralysis results in pronounced bone degradation with substantial bone loss. We hypothesized that whole-body vibration (WBV) and insulin-like growth factor-I (IGF-I) treatment can counteract paralysis-induced bone degradation following BTX injections by activation of the protein kinase B (Akt) signaling pathway. Female C57BL/6 mice (n = 60, 16 weeks) were assigned into six groups (n = 10 each): SHAM, BTX, BTX+WBV, BTX+IGF-I, BTX+WBV+IGF-I, and a baseline group, which was killed at the beginning of the study. Mice received a BTX (1.0 U/0.1 mL) or saline (SHAM) injection in the right hind limb. The BTX+IGF-I and BTX+WBV+IGF-I groups obtained daily subcutaneous injections of human IGF-I (1 μg/day). The BTX+WBV and BTX+WBV+IGF-I groups underwent WBV (25 Hz, 2.1 g, 0.83 mm) for 30 min/day, 5 days/week for 4 weeks. Femora were scanned by pQCT, and mechanical properties were determined. On tibial sections TRAP staining, static histomorphometry, and immunohistochemical staining against Akt, phospho-Akt, IGF-IR (IGF-I receptor), and phospho-IGF-IR were conducted. BTX injection decreased trabecular and cortical bone mineral density. The WBV and WBV+IGF-I groups showed no difference in trabecular bone mineral density compared to the SHAM group. The phospho-IGF-IR and phospho-Akt stainings were not differentially altered in the injected hind limbs between groups. We found that high-frequency, low-magnitude WBV can counteract paralysis-induced bone loss following BTX injections, while we could not detect any effect of treatment with IGF-I.

Growth hormone treatment adherence in prepubertal and pubertal children with different growth disorders

BACKGROUND/AIMS

Treatment of children with growth disorders with recombinant human growth hormone is necessary for improved outcomes, including final height.

METHODS

Adherence data from the Observational Study Saizen®-online, recorded with the easypod™ device collected between October 2009 and May 2011, were analyzed in pediatric patients receiving recombinant human growth hormone treatment for a variety of growth disorders.

RESULTS

Data from 75 children (46 boys, 29 girls) with different growth disorders were analyzed over a period of 343 ± 201 (SD) days. Boys and girls showed similar mean ± SD adherence rates of 90.5 ± 3.1% and 92.2 ± 10.7%, respectively. Pubertal children (n = 41) had a significantly lower adherence rate (89.1 ± 13.7%) than prepubertal children (n = 29) (96.5 ± 3.9%; p < 0.005). There were nonsignificant differences in adherence rates according to diagnosis: growth hormone deficiency (n = 48) 91.4 ± 11.0%, small for gestational age (n = 18) 91.1 ± 15.3%, Turner syndrome (n = 6) 86.0 ± 14.5%, and chronic renal failure (n = 3) 99.3 ± 1.0%, although the latter two groups were small.

CONCLUSION

Our data indicate that only a small number of pediatric patients using the easypod device had poor adherence to treatment. Further reliable adherence data are required to identify factors affecting long-term adherence in this population.

Whole-body vibration training in children with Duchenne muscular dystrophy and spinal muscular atrophy

INTRODUCTION

Whole-body-vibration training is used to improve muscle strength and function and might therefore constitute a potential supportive therapy for neuromuscular diseases.

OBJECTIVE

To evaluate safety of whole-body vibration training in ambulatory children with Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA).

METHODS

14 children with DMD and 8 with SMA underwent an 8-week vibration training programme on a Galileo MedM at home (3 × 3 min twice a day, 5 days a week). Primary outcome was safety of the training, assessed clinically and by measuring serum creatine kinase levels. Secondary outcome was efficacy as measured by changes in time function tests, muscle strength and angular degree of dorsiflexion of the ankles.

RESULTS

All children showed good clinical tolerance. In boys with DMD, creatine kinase increased by 56% after the first day of training and returned to baseline after 8 weeks of continuous whole-body vibration training. No changes in laboratory parameters were observed in children with SMA. Secondary outcomes showed mild, but not significant, improvements with the exception of the distance walked in the 6-min walking test in children with SMA, which rose from 371.3 m to 402.8 m (p < 0.01).

INTERPRETATION

Whole-body vibration training is clinically well tolerated in children with DMD and SMA. The relevance of the temporary increase in creatine kinase in DMD during the first days of training is unclear, but it is not related to clinical symptoms or deterioration.

Muscle area estimation from cortical bone

This article investigates the relationship between the cortical bone of the radius and the muscle area of the forearm. The aim of this study was to develop a method for muscle area estimation from cortical bone area at 65% of radius length where the muscle area at the forearm is largest. Muscle area and cortical area were measured directly in vivo by peripheral Quantitative Computed Tomography (pQCT). We found significant correlations between muscle area and cortical area (r = 0.881) in the forearm that are in line with previous studies. We have set up a regression model by testing relevant parameters such as age, sex, forearm length, and stature that were all highly correlated to muscle area. The influence of age and sex on the proportion of muscle area to cortical area is strong and potentially related to the effects of testosterone and estrogen on the muscle-bone-unit. Muscle area estimation from cortical bone is possible with a Percent Standard Error of Estimate (%SEE) ranging from 12.03% to 14.83%, depending on the parameters available and the age and sex of the individual. Muscle area estimation from cortical bone can provide new information for the study of skeletal and/or fossil human remains.

Mutations in WNT1 cause different forms of bone fragility

We report that hypofunctional alleles of WNT1 cause autosomal-recessive osteogenesis imperfecta, a congenital disorder characterized by reduced bone mass and recurrent fractures. In consanguineous families, we identified five homozygous mutations in WNT1: one frameshift mutation, two missense mutations, one splice-site mutation, and one nonsense mutation. In addition, in a family affected by dominantly inherited early-onset osteoporosis, a heterozygous WNT1 missense mutation was identified in affected individuals. Initial functional analysis revealed that altered WNT1 proteins fail to activate canonical LRP5-mediated WNT-regulated β-catenin signaling. Furthermore, osteoblasts cultured in vitro showed enhanced Wnt1 expression with advancing differentiation, indicating a role of WNT1 in osteoblast function and bone development. Our finding that homozygous and heterozygous variants in WNT1 predispose to low-bone-mass phenotypes might advance the development of more effective therapeutic strategies for congenital forms of bone fragility, as well as for common forms of age-related osteoporosis.

Measuring procedures to determine the Cobb angle in idiopathic scoliosis: a systematic review

BACKGROUND

Scoliosis of the vertebral column can be assessed with the Cobb angle (Cobb 1948). This examination is performed manually by measuring the angle on radiographs and is considered the gold standard. However, studies evaluating the reproducibility of this procedure have shown high variability in intra- and inter-observer agreement. Because of technical advancements, interests in new procedures to determine the Cobb angle has been renewed. This review aims to systematically investigate the reproducibility of various new techniques to determine the Cobb angle in idiopathic scoliosis and to assess whether new technical procedures are reasonable alternatives when compared to manual measurement of the Cobb angle.

METHOD

Systematic review. Studies examining procedures used to determine the Cobb angle were selected. Two review authors independently selected studies for inclusion, extracted data and assessed risk of bias. Statistical results of reliability and agreement were summarised and described.

RESULTS

Eleven studies of new measuring procedures were included, all reporting the reproducibility. The new procedures can be divided into computer-assisted procedures, automatic procedures and smartphone apps.

CONCLUSIONS

All investigated measuring procedures showed high degrees of reliability. In general, digital procedures tend to be slightly better than manual ones. For all other measurement procedures (automatic or smartphone), results varied. Studies implementing vertebral pre-selection and observer training achieved better agreement.

Vascular adaptations induced by 6 weeks WBV resistance exercise training

BACKGROUND

The impact of whole-body vibration (WBV) upon the cardiovascular system is receiving increasing attention. Despite numerous studies addressing the acute cardiovascular effects of WBV training, very little is known regarding long-term adaptations in healthy humans.

METHODS

A 6-week training study, with a 70 days follow-up was designed to compare resistive exercise with or without super-imposed whole-body vibrations. Arterial diameter, intima media thickness and flow-mediated dilation (FMD) were assessed by ultrasonography in the superficial femoral artery (SFA), the brachial (BA) and the carotid arteries (CA).

RESULTS

SFA resting diameter was increased from 6·22 mm (SD = 0·69 mm) at baseline to 6·52 mm (SD = 0·74 mm) at the end of the training period (P = 0·03) with no difference between groups (P = 0·48). Arterial wall thickness was significantly reduced by 4·3% (SD = 11%) in the CA only (P = 0·04). FMD was not affected by any of the interventions and in any of the investigated arteries.

CONCLUSION

To the best of our knowledge, this has been the first study to show that the superposition of vibration upon conventional resistance exercise does not have a specific effect upon long-term vascular adaptation in asymptomatic humans. Our findings seem to be at variance with the findings observed in a bed-rest setting. One possible explanation could be that the independently saturable effects of flow-mediated versus acceleration-related endothelial shear stresses on arterial structure and function differ between ambulatory and bed-rest conditions.

Is breastfeeding related to bone properties? A longitudinal analysis of associations between breastfeeding duration and pQCT parameters in children and adolescents

Nutritive and bioactive components of human milk could be involved in programming metabolic systems that affect bone growth throughout the life course. Bone properties in childhood and adolescence might differ, depending on breastfeeding duration. Thus, breastfeeding could be a relevant factor in the context of primary osteoporosis prevention. The prospective association between breastfeeding duration and bone properties was investigated using the data of 284 participants of the Dortmund Nutritional and Anthropometric Longitudinally Designed Study. Breastfeeding duration was assessed during infancy. Bone properties were measured by peripheral quantitative computed tomography (pQCT) at ages 5-23 years. Cortical volumetric bone mineral density, cortical bone mineral content, strength strain index, total cross-sectional area of the bone and cross-sectional area of the cortical bone were determined at the 65% site of the radius. Linear regression analyses were performed to check for differences in pQCT parameters of subjects who had not or shortly been breastfed (0-16 weeks) and subjects who had been breastfed for a long duration (≥17 weeks). Multivariable models adjusted for age, gender, forearm length, muscle cross-sectional area, body mass index standard deviation score (SDS), height SDS and socio-economic status did not yield associations between breastfeeding duration and pQCT parameters. These findings suggest neither protective nor adverse effects of prolonged breastfeeding on bone health in childhood and adolescence. Influences of early nutrition on bone growth might be overridden by current effects of mechanical loads on bone physiology.