Developing Interventions for Children's Exercise (DICE): a pilot evaluation of school-based exercise interventions for primary school children aged 7 to 8 years.

BACKGROUND: Developing Interventions for Children's Exercise (DICE) is an initiative aimed at determining effective school-based exercise programs. To assess feasibility, we conducted a pilot study of exercise sessions which varied in duration and frequency. METHODS: Exercise interventions were delivered to Year 3 pupils (age 7-8 years; n = 73) in primary schools within Yorkshire, UK. Evaluations were conducted using focus group sessions, questionnaires and observations. RESULTS: The study revealed positive aspects of all interventions, including favorable effects on children's concentration during lessons and identified the value of incorporation of the DICE concept into curriculum lessons. Children appeared enthused and reported well-being and enjoyment. Areas requiring attention were the need for appropriate timetabling of sessions and ensuring the availability of space. CONCLUSION: The concept and sessions were well-accepted by teachers who confirmed their full support of any future implementation There appears to be potential for the encouragement and empowerment of teachers to support physical activity and healthy school environments, and to take an interest in the health of their pupils. Ultimately, these findings should assist in the design of successful exercise interventions in the school setting.

The early and mid-term fate of the axillary artery following axillary artery cut-down and cardiac catheterization in infants and young children.

OBJECTIVES: To study the early and mid-term vascular complications of axillary artery catheterization in children <2 years by clinical and ultrasound examination. BACKGROUND: Femoral arterial access for cardiac catheterization in young children is associated with significant morbidity. Early complications of axillary artery catheterization have been reported but no long-term vascular follow-up data are available. METHODS: Prospective case-control study using standard vascular ultrasound techniques to examine the upper limbs in study participants (n = 10). RESULTS: In total, 23% of axillary artery catheterizarions (56 procedures in 54 patients) resulted in acute arterial insufficiency requiring heparin. Of the survivors under follow-up (n = 33), none had symptoms of chronic arterial insufficiency. At a median follow-up of 8 years postprocedure, three out of the ten study participants had a weak brachial pulse in the test arm but no significant difference in arm measurements. Color Doppler revealed occlusion of the axillary artery in the test arm with collateralization in three patients. The brachial peak systolic velocity (V(max)) was significantly lower in the test arm than the control arm of all the patients with a mean difference of 30 cm/sec (P = 0.007). CONCLUSION: Our study is the first to examine the long-term vascular sequelae of axillary artery catheterization using ultrasound examination and highlights the importance of careful surveillance of vascular access sites. Although axillary artery cut-down for cardiac catheterization in infants and young children does not appear to result in clinical signs of chronic arterial insufficiency, we demonstrate clear evidence of flow abnormalities on vascular ultrasound which are of uncertain long-term significance.

Bone cross-sectional geometry in male runners, gymnasts, swimmers and non-athletic controls: a hip-structural analysis study.

Loading of the skeleton is important for the development of a functionally and mechanically appropriate bone structure, and can be achieved through impact exercise. Proximal femur cross-sectional geometry was assessed in the male athletes (n = 55) representing gymnastics, endurance running and swimming, and non-athletic controls (n = 22). Dual energy X-ray absorptiometry (iDXA, GE Healthcare, UK) measurements of the total body (for body composition) and the left proximal femur were obtained. Advanced hip structural analysis (AHA) was utilised to determine the areal bone mineral density (aBMD), hip axis length (HAL), cross-sectional area (CSA), cross-sectional moment of inertia (CSMI) and the femoral strength index (FSI). Gymnasts and runners had greater age, height and weight adjusted aBMD than in swimmers and controls (p < 0.05). Gymnasts and runners had greater resistance to axial loads (CSA) and the runners had increased resistance against bending forces (CSMI) compared to swimmers and controls (p < 0.01). Controls had a lower FSI compared to gymnasts and runners (1.4 vs. 1.8 and 2.1, respectively, p < 0.005). Lean mass correlated with aBMD, CSA and FSI (r = 0.365-0.457, p < 0.01), particularly in controls (r = 0.657-0.759, p < 0.005). Skeletal loading through the gymnastics and running appears to confer a superior bone geometrical advantage in the young adult men. The importance of lean body mass appears to be of particular significance for non-athletes. Further characterisation of the bone structural advantages associated with different sports would be of value to inform the strategies directed at maximising bone strength and thus, preventing fracture.

Five-year follow-up investigation of bone mineral density by age in premenopausal elite-level long-distance runners.

OBJECTIVE: To evaluate bone mineral density (BMD) by age in premenopausal elite long-distance runners at 2 time points, 5.02 ± 0.5 years apart. DESIGN: Follow-up study. SETTING: University Research Institute. PARTICIPANTS: Twenty-three elite-level distance runners (baseline age, 24.9 ± 3.9 years; body mass index, 18.7 ± 1.1; running distance, 89.3 ± 19.4 km/wk) participated in the study. MAIN OUTCOME MEASURES: Dual-energy x-ray absorptiometry (iDXA; GE Healthcare)-derived BMD z-scores for the total body (TB), lumbar spine (LS) (L2-L4), and proximal femur. A z-score of <-1.0 indicated low BMD by age. RESULTS: Lumbar spine BMD z-scores had increased significantly by follow-up for all runners (baseline, -1.1 ± 0.9; follow-up, -0.7 ± 0.7; P = 0.04) and for formerly amenorrheic runners with restored menstruation (n = 10; baseline, -1.5 ± 0.9; follow-up, -0.9 ± 0.6; P = 0.03). Total body, but not proximal femur z-scores, had also increased (P < 0.05). Improvements in z-scores correlated with an increased body fat (LS: R2 = 0.27; TB: R2 = 0.35; P < 0.01) and menstrual history score (LS: R2 = 0.36; TB: R2 = 0.27; P < 0.05). There were no associations with lean mass or running volume at any skeletal site (P = 0.07-0.89). CONCLUSIONS: Low BMD by age in highly-trained female runners may be at least partially reversible before the age of 30 years, even when competitive running is continued. This seems to be related to restored menstruation and an increased body fat. Further larger studies are required to clarify our findings.

In vivo precision of the GE Lunar iDXA densitometer for the measurement of total-body, lumbar spine, and femoral bone mineral density in adults.

Knowledge of precision is integral to the monitoring of bone mineral density (BMD) changes using dual-energy X-ray absorptiometry (DXA). We evaluated the precision for bone measurements acquired using a GE Lunar iDXA (GE Healthcare, Waukesha, WI) in self-selected men and women, with mean age of 34.8 yr (standard deviation [SD]: 8.4; range: 20.1-50.5), heterogeneous in terms of body mass index (mean: 25.8 kg/m(2); SD: 5.1; range: 16.7-42.7 kg/m(2)). Two consecutive iDXA scans (with repositioning) of the total body, lumbar spine, and femur were conducted within 1h, for each subject. The coefficient of variation (CV), the root-mean-square (RMS) averages of SDs of repeated measurements, and the corresponding 95% least significant change were calculated. Linear regression analyses were also undertaken. We found a high level of precision for BMD measurements, particularly for scans of the total body, lumbar spine, and total hip (RMS: 0.007, 0.004, and 0.007 g/cm(2); CV: 0.63%, 0.41%, and 0.53%, respectively). Precision error for the femoral neck was higher but still represented good reproducibility (RMS: 0.014 g/cm(2); CV: 1.36%). There were associations between body size and total-body BMD and total-hip BMD SD precisions (r=0.534-0.806, p<0.05) in male subjects. Regression parameters showed good association between consecutive measurements for all body sites (r(2)=0.98-0.99). The Lunar iDXA provided excellent precision for BMD measurements of the total body, lumbar spine, femoral neck, and total hip.

Modelling the propagation of ultrasound in the joint space of a human knee.

There is strong evidence to support the clinical use of low-intensity pulsed ultrasound (LIPUS) to augment fracture healing. A previous experimental study showed that ultrasound can propagate in the joint space of a single human cadaveric knee. A full experimental investigation of this propagation is not possible due to poor reproducibility, the scarcity of human cadaveric tissues and the practical difficulties in making ultrasound measurements in the knee. The aim of the present work is to investigate whether a computer simulation (Wave2000 Pro®; Cyberlogic Inc., New York, NY, USA) can give a good representation of the experimental model. The simulations provided a good agreement with the experimental data, giving some confidence in the application of this computer simulation method as a means of determining whether ultrasound can propagate through different anatomical regions where bone is present.

A pilot investigation of load-carrying on the head and bone mineral density in premenopausal, black African women.

Although the influence of weight-bearing activity on bone mass has been widely investigated in white women, few studies have been conducted in black, African populations. We investigated bone mineral density (BMD) in black South African women, with and without a history of load-carrying on the head. We also investigated whether load carrying may offer protection against low BMD in users of injectable progestin contraception (IPC). Participants were 32 black, South African women (22.4 +/- 3.2 years). Load carrying history was determined by questionnaire and interview; participants were grouped as load carriers (LC; n = 18) or non-load carriers (NLC; n = 14). Ten women were using IPC and 6 were load-carriers. Total body (TB), lumbar spine (LS) and total hip (H) BMD were measured by dual energy X-ray absorptiometry. There were no differences in BMD between LC and NLC, and after controlling for age and BMI using two-tailed partial correlations. IPC users had lower BMD at all sites compared to non-IPC users (p < 0.05) and there were no associations between load carrying and BMD in this group. When IPC users were excluded from analysis, LC had higher LS BMD than NLC (p < 0.005). Correlations were found between the weight of load carried and LS BMD (r = 0.743, p < 0.005), and between years of load carrying and LS and TB BMD (r = 0.563, r = 0.538, respectively; both p < 0.05). Load carrying on the head may offer osteogenic benefits to the spine but these benefits did not appear in women using IPC.

A cross-sectional study of bone mineral density in children and adolescents attending a Cystic Fibrosis Centre.

BACKGROUND: Low bone mineral density is common in adults with cystic fibrosis. Children with good lung function compared to controls matched for body size have normal bone mineralisation. There are few data in large unselected populations of children. METHODS: All children between five and 16 years were invited to take part. Disease severity was assessed. Bone mineral measurements using a GE-Lunar Prodigy densitometer were expressed as age and gender matched Z-scores. Bone mineral apparent density for L2-L4 was estimated and data from UK Caucasian children used to create age and gender specific reference ranges for predicted values. Z-scores were calculated. Total body analysis utilised the Molgaard method. Blood was sampled for measurement of 25-hydroxyvitamin D, and parathyroid hormone levels. RESULTS: 107 children entered the study. 18 and 10 children had low areal and apparent bone mineral density respectively. Short, narrow bones were common. Fifteen children reported 22 fractures, 20 with associated trauma. The best predictors of bone status were ZBMI and percent predicted FEV(1). CONCLUSIONS: Bone mineral density corrected for body size was normal in over 90% of children. These results are similar to previously reported results in small studies of children with well preserved respiratory function.

Female athlete triad in monozygotic twins.

UNLABELLED: Female monozygotic twins, both international endurance athletes aged 18 years, presented for a dual energy x-ray absorptiometry (DXA) scan as part of a university clinical trial. Twin 1 had only menstruated twice since menarche; Twin 2 had not yet started menstruating. Both twins acknowledged suffering from disordered eating for approximately 3 years. Both twins presented with low lumbar spine bone mineral density (BMD) and normal total body, total hip, and femoral neck BMD. DIAGNOSIS: Female athlete triad comprising disordered eating with insufficient energy availability, amenorrhea, and low age-related BMD. MANAGEMENT: Despite some weight gain and reduction of athletic training and competition over a 5-year period, lumbar BMD remained low in both twins and was complicated by a rapid decline in BMD at the hips. Twin 2 remained amenorrheic. The oral contraceptive pill was not effective in maintaining BMD in the other twin. Contraindicated treatment with bisphosphonates was not tolerated and promptly ceased. This case seminar emphasizes the absence of a clear physician-coordinated multi-disciplinary treatment approach and the complexity in treating all the components of the triad in young athletes. KEYWORDS: female athlete triad; monozygotic; amenorrhea; bone mineral density.

The temperature dependence of the speed of sound in bovine bone marrow at 750 kHz.

We present values for the speed of sound (SOS) in bovine bone marrow as a function of temperature between 17 degrees C and 44 degrees C. The measurements were made using a time-of-flight approach on a volume of roughly 10 mL, at 750 kHz. The equipment was validated using both distilled water and castor oil. The results show a linear response with SOS changing from 1456.23 ms(-1) at 17 degrees C to 1342.40 ms(-1) at 44 degrees C. The mean value at 37 degrees C was (1371.91 ms(-1)). The temperature coefficient of the SOS was found to be -4.21 +/- 0.19 ms(-1) degrees C(-1). This was well fitted to a least squares model with R2 = 0.88.

The effect of normalization of ECW volume as a marker of hydration in peritoneal dialysis patients and controls.

OBJECTIVES: We measured extraceLlular water (ECW) and intracellular water (ICW) volumes in peritoneal dialysis (PD) patients and controls to determine the effect of ICW variation on ECW/ICW ratio and to compare alternative ratios of ECW to height, height2, weight, and body surface area (BSA). PATIENTS AND METHODS: We measured body water compartments by deuterium oxide and bromide dilution in 29 PD patients (14 M, 15 F) and 31 controls (15 M, 16 F). RESULTS: ECW was similar in PD patients (17.58 +/- 3.58 L) and controls (17.20 +/- 2.97 L), p = NS. ICW was nonsignificantly lowerin PD patients (17.58 +/- 4.88 L) than in controls (19.71 +/- 5.08 L), p = NS. ECW/ICW was greaterin PD patients (1.06 +/- 0.32) than in controls (0.92 +/- 0.25), p = 0.057, and was inversely correlated with ICW in PD patients (r = -0.733, p < 0.0001) and controls (r = -0.721, p < 0.0001). In contrast, ECW/height, ECW/height2, ECW/weight, and ECW/BSA were similar for the two groups. CONCLUSIONS: ECW/ICW is affected by changes in ICW as well as by ECW varying with hydration. ECW/ICW ratio leads to the spurious impression of overhydration in subjects with smaller ICW volumes. ECW/ICW does not reflect hydration alone and other methods of expressing ECW as a measure of hydration need further evaluation.

Vitamin K status among children with cystic fibrosis and its relationship to bone mineral density and bone turnover.

OBJECTIVE: The aim of this study was to assess vitamin K status in an unselected population of children with cystic fibrosis (CF) and to investigate any vitamin K effect on bone turnover and bone mineral status. METHODS: Children > or =5 years of age who were attending the CF unit were invited to enter the study. Fasting blood samples were analyzed for levels of vitamin K1 and prothrombin produced in vitamin K absence; total, undercarboxylated, and carboxylated osteocalcin (OC); and bone-specific alkaline phosphatase and procollagen I carboxy-terminal propeptide (bone formation markers). Levels of N-telopeptide and free pyridinoline and deoxypyridinoline (bone breakdown products) were measured in urine samples. Bone mineral density and bone mineral content were measured at the lumbar spine and for the total body with a GE Lunar Prodigy densitometer. Statistical analyses were performed with Minitab version 9.1. RESULTS: One hundred six children entered the study. Sixty-five of 93 children (70%) from whom blood samples were obtained showed suboptimal vitamin K status, on the basis of low serum vitamin K1 levels, increased prothrombin produced in vitamin K absence levels, or both abnormalities. Vitamin K1 levels showed a significant negative correlation with undercarboxylated OC levels but showed no significant correlation with any marker of bone turnover or measurement of bone mineral status. Undercarboxylated OC levels were correlated significantly with bone turnover markers, which themselves showed a significant negative correlation with measurements of bone mineral density and content. There were no significant correlations between carboxylated or undercarboxylated OC levels and bone density measurements. CONCLUSIONS: Vitamin K1 deficiency is common among children with CF, and routine supplements should be considered. Through its role in the carboxylation of OC, vitamin K deficiency may be associated with an uncoupling of the balance between bone resorption and bone formation. A cause-effect relationship between vitamin K deficiency and low bone mass has not been proved.

Percentage fat in overweight and obese children: comparison of DXA and air displacement plethysmography.

OBJECTIVE: To compare percentage body fat (percentage fat) estimates from DXA and air displacement plethysmography (ADP) in overweight and obese children. RESEARCH METHODS AND PROCEDURES: Sixty-nine children (49 boys and 20 girls) 14.0+/-1.65 years of age, with a BMI of 31.3+/-5.6 kg/m2 and a percentage fat (DXA) of 42.5+/-8.4%, participated in the study. ADP body fat content was estimated from body density (Db) using equations devised by Siri (ADP(Siri)) and Lohman (ADP(Loh)). RESULTS: ADP estimates of percentage fat were highly correlated with those of DXA in both male and female subjects (r=0.90 to 0.93, all p<0.001; standard error of estimate=2.50% to 3.39%). Compared with DXA estimates, ADP(Siri) and ADP(Loh) produced significantly (p<0.01) lower estimates of mean body fat content in boys (-2.85% and -4.64%, respectively) and girls (-2.95% and -5.15%, respectively). Agreement between ADP and DXA methods was further examined using the total error and methods of Bland and Altman. Total error ranged from 4.46% to 6.38% in both male and female subjects. The 95% limits of agreement were relatively similar for all percentage fat estimates, ranging from +/-6.73% to +/-7.94%. DISCUSSION: In this study, conversion of Db using the Siri equation led to mean percentage fat estimates that agreed better with those determined by DXA compared with the Lohman equations. However, relatively high limits of agreement using either equation resulted in percentage fat estimates that were not interchangeable with percentage fat determined by DXA.

Abnormalities of body composition in peritoneal dialysis patients.

OBJECTIVES: Body composition changes occur in peritoneal dialysis (PD) due to abnormalities in nutrition and hydration. We investigated abnormalities of nutrition and hydration in PD patients compared with healthy controls by measurement of total body potassium (TBK) and body water compartments. DESIGN: Cross-sectional comparison study. METHODS: We measured TBK--an indicator of body cell mass--by whole body counting, total body water (TBW) by deuterium oxide dilution, and extracellular water (ECW) by bromide dilution in 29 PD patients and 32 controls. RESULTS: The absolute mean value of TBK for PD patients was not significantly lower than in controls. The ratios of observed TBK to predicted TBK from prediction formulas were compared. Equations used were those of Boddy, Bruce, Burkinshaw, and Ellis and our own equation derived from a local control database (Leeds). Observed/predicted ratios of TBK were significantly less in PD than in control subjects for all equations. Water volumes did not differ between PD and control groups. Observed/predicted ratios for TBK in PD patients correlated with serum potassium (Boddy r = 0.355, p = 0.06; Bruce r = 0.411, p < 0.05; Burkinshaw r = 0.457, p < 0.01; Leeds r = 0.412, p < or = 0.05; Ellis r = 0.356, p = 0.06) and tended to correlate with serum albumin (Bruce r = 0.343, p = 0.07; Burkinshaw r = 0.421, p < 0.05; Leeds r = 0.357, p = 0.06; Ellis r = 0.310, p = NS). There was no relationship with serum potassium in controls. Serum albumin in PD correlated with TBK (r = 0.445, p < 0.02), TBK/height (r = 0.419, p < 0.05), TBK/weight (r = 0.554, p = 0.002), and TBK/TBW (r = 0.586, p = 0.0001). Extracellular water/intracellular water (ECW/ICW) was inversely related to TBK (r = -0.455, p < 0.02 in PD; r = -0.387, p < 0.05 in controls) and to TBK/height (r = -0.446, p < 0.02 in PD; r = -0.411, p = 0.02 in controls). TBK/weight reduced with age in PD (r = -0.445, p < 0.02), as did TBK/TBW in PD (r = -0.463, p < 0.02). ECW/ICW tended to increase with age in PD (r = 0.351, p = 0.06). CONCLUSIONS: Observed/predicted ratio of TBK is reduced in PD patients relative to healthy controls, indicating reduced body cell mass. Serum albumin and potassium reflect TBK indices in PD. Body water volumes did not differ between PD and controls, implying no overall abnormality in hydration in the PD group. However, ECW is relatively increased compared to ICW with decreasing TBK indices, suggesting relative ECW expansion with reduction in body cell mass.

Annual changes of bone density over 12 years in an amenorrheic athlete.

PURPOSE: To link annual changes of bone mineral density (BMD) over 12 consecutive years to pharmacological intervention and to fluctuations of body mass and body composition in an amenorrheic athlete. METHODS: BMD of the lumbar spine (LS) and total proximal femur (PF) were measured using dual energy x-ray absorptiometry (DXA), every 11-13 months between ages 24.8 and 36.9 yr. Body composition was assessed every 3-4 yr from a whole body DXA scan. Body mass was recorded every 3 months. For the first 5 yr of study, the subject used oral contraceptives (OC). For the subsequent 7 yr, she used estradiol skin patches (EP) with oral norethisterone. RESULTS: The first DXA scan (age 24.8 yr) revealed a low BMD at both LS and PF, with T-scores of -1.4 and -2.8, respectively. During the next 5 yr, while adhering to OC, the BMD of her LS and PF declined by 9.8% and 12.1%, respectively. Concomitantly, her body mass fell from 45.1 to 41.4 kg, her body mass index (BMI) from 16.4 to 15.0 kg.m-2, and her percent body fat from 8.3 to <4.0%. While treated with EP and norethisterone (age 29.8-33.5 yr), her LS BMD gradually increased by 9.4%, despite a further 0.8 kg decline of body mass. From age 33.8 to 36.9 yr, voluntary weight gain (2-3 kg.yr-1; total: 8.1 kg) was accompanied by an increase of her PF BMD (16.9%), with no further increase at the LS. CONCLUSION: Changes of BMD at the total proximal femur reflected changes of body mass in this subject. At the lumbar spine, BMD declined with weight loss but increased in association with transdermal estradiol treatment in the absence of weight gain.

Comparison of anthropometric equations for estimation of total body water in peritoneal dialysis patients.

BACKGROUND: Several formulae exist for estimating total body water (TBW). We aimed to assess their validity in peritoneal dialysis patients by comparison with TBW estimated by deuterium oxide dilution (TBW(D)). METHODS: We compared the equations of Chertow (TBW(Cher)), Chumlea (TBW(Chum)), Hume and Weyers (TBW(HW)), Johansson (TBW(J)), Lee (TBW(L)), Watson (TBW(W)) and TBW as 58% of body weight (TBW(0.58Wt)) with TBW(D) in 31 peritoneal dialysis (PD) patients and 32 controls. Estimates were compared with TBW(D) using Bland and Altman comparison. Extracellular water (ECW) was also estimated by sodium bromide dilution. RESULTS: In PD patients, mean TBW(D) was 35.04 (SD 7.84) l. Estimates were greater for TBW(Cher), TBW(Chum), TBW(HW), TBW(J) and TBW(0.58Wt). Mean TBW(L) and TBW(W) did not differ from TBW(D). Ninety-five percent limits of agreement (LOA) compared with TBW(D) (as a percentage of the mean) were similar for all of the different equations in PD patients (between +/-15.4 and +/-17.3%) except TBW(0.58Wt), which was far greater (+/-26.4%). In controls, mean TBW(D) was 37.03 (SD 6.63) l. Estimates were greater for TBW(Cher), TBW(Chum), TBW(HW), TBW(J) and TBW(0.58Wt). Mean TBW(L) and TBW(W) did not differ from TBW(D). Ninety-five percent LOA compared with TBW(D) (as a percentage of the mean) were similar for all equations in the controls, and closer than in PD patients (between +/-9.1 and +/-11.5%) except TBW(0.58Wt), which was again far greater than the other equations (+/-28.1%). TBW(HW) - TBW(D) correlated with mean TBW (r=-0.412, P<0.05 in PD and r=-0.383, P<0.05 in controls). TBW(W) - TBW(D) (r=-0.539, P<0.005) correlated with mean TBW in PD. TBW(0.58Wt) - TBW(D) correlated with body mass index (BMI) (r=0.624, P<0.0001 in PD and r=0.829, P<0.0001 in controls) and ECW/TBW (r=0.406, P<0.05 in PD and r=0.411, P<0.02 in controls). CONCLUSIONS: Predictive equations were less accurate in PD than controls. TBW(0.58Wt) was most inaccurate, with systematic overestimation of TBW with increasing BMI and ECW/TBW. There were no differences in LOA with TBW(D) for the other equations within each group.